About This Board Review Set
This is Part 132 of the comprehensive OITE and AAOS Orthopedic Surgery Board Review series authored by Dr. Mohammed Hutaif, Consultant Orthopedic & Spine Surgeon.
This set has been strictly audited and contains 100 100% verified, high-yield multiple-choice questions (MCQs) modelled on the exact format of the Orthopaedic In-Training Examination (OITE) and the American Academy of Orthopaedic Surgeons (AAOS) board examinations.
How to Use the Interactive Quiz
Two distinct learning modes are available:
- Study Mode — After selecting an answer, you immediately see whether you are correct or incorrect, together with a full clinical explanation and literature references.
- Exam Mode — All feedback is hidden until you click Submit & See Results. A live timer tracks elapsed time. A percentage score and detailed breakdown are displayed upon submission.
Pro Tip: Use keyboard shortcuts A–E to select options, F to flag a question for review, and Enter to jump to the next unanswered question.
Topics Covered in Part 132
This module focuses heavily on: Dislocation, Foot, Fracture, Knee, Trauma.
Sample Questions from This Set
Sample Question 1: Figures 16a and 16b are the radiograph and MR image of a 15-year-old dance athlete with 2 weeks of pain at the left distal femur, a limp, and an inability to dance. Knee motion is 0 to 135 degrees with minimal pain and there is no effusion....
Sample Question 2: A 37-year-old woman has had intermittent paresthesias and numbness in the plantar foot for the past 6 months. She reports that the symptoms are worse with activity, and the paresthesias are beginning to awaken her at night. MRI scans are sh...
Sample Question 3: A previously healthy 29-year-old man reports a 2-day history of severe atraumatic lower back pain. He denies any bowel or bladder difficulties and no constitutional signs. Examination is consistent with mechanical back pain. No focal neurol...
Sample Question 4: A 36-year-old woman sustained a tarsometatarsal joint fracture-dislocation in a motor vehicle accident. The patient is treated with open reduction and internal fixation. What is the most common complication?...
Sample Question 5: Figure 19 shows an arthroscopic view from the anterior lateral portal of the knee looking into the suprapatella pouch. The use of an electrothermal device during this procedure most commonly causes significant postoperative complications by...
Why Active MCQ Practice Works
Evidence consistently demonstrates that active recall through spaced MCQ practice yields substantially greater long-term retention than passive reading alone (Roediger & Karpicke, 2006). All questions in this specific module have been algorithmically verified for clinical integrity and complete explanations.
Comprehensive 100-Question Exam
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Question 1
Figures 16a and 16b are the radiograph and MR image of a 15-year-old dance athlete with 2 weeks of pain at the left distal femur, a limp, and an inability to dance. Knee motion is 0 to 135 degrees with minimal pain and there is no effusion. Her temperature is 37.0°C, WBC is 12000 /µL (rr, 4500-11000 /µL), CRP is 0.8 mg/L (rr, 0.08-3.1 mg/L), and ESR is 21 mm/h (rr, 0-20 mm/h).
Explanation
DISCUSSION
Figures 14a through 14e show a 13-year-old boy with osteomyelitis of the distal tibia and a large subperiosteal abscess. The patient has failed treatment with IV ceftriaxone, and methicillin-resistant Staphylococcus aureus infection is likely. Aspiration, cultures, irrigation and debridement, IV vancomycin, an infectious disease consult, and an evaluation for possible deep vein thrombosis is prudent initial treatment. Figure 15a through 15c show a 7-year-old girl who sustained a deer tick bite while vacationing in Connecticut. She has Lyme arthritis and a Lyme “bulls-eye” rash on the same leg. Aspiration, cultures, Lyme serology, and oral amoxicillin for 30 days is prudent initial treatment. Figures 16a and 16b are the radiograph and MR image of a 15-year-old dance athlete with a probable minor fracture via a benign cyst of the distal femur. The geographic cyst may be a nonossifying fibroma, eosinophilic granuloma, Brodie abscess, or simple bone cyst. Biopsy, culture, curettage and bone graft, and possible internal fixation is reasonable initial treatment.
Figures 14a through 14e show a 13-year-old boy with osteomyelitis of the distal tibia and a large subperiosteal abscess. The patient has failed treatment with IV ceftriaxone, and methicillin-resistant Staphylococcus aureus infection is likely. Aspiration, cultures, irrigation and debridement, IV vancomycin, an infectious disease consult, and an evaluation for possible deep vein thrombosis is prudent initial treatment. Figure 15a through 15c show a 7-year-old girl who sustained a deer tick bite while vacationing in Connecticut. She has Lyme arthritis and a Lyme “bulls-eye” rash on the same leg. Aspiration, cultures, Lyme serology, and oral amoxicillin for 30 days is prudent initial treatment. Figures 16a and 16b are the radiograph and MR image of a 15-year-old dance athlete with a probable minor fracture via a benign cyst of the distal femur. The geographic cyst may be a nonossifying fibroma, eosinophilic granuloma, Brodie abscess, or simple bone cyst. Biopsy, culture, curettage and bone graft, and possible internal fixation is reasonable initial treatment.
Question 2
A 37-year-old woman has had intermittent paresthesias and numbness in the plantar foot for the past 6 months. She reports that the symptoms are worse with activity, and the paresthesias are beginning to awaken her at night. MRI scans are shown in Figures 6a and 6b. What is the most likely diagnosis?
Explanation
DISCUSSION: The symptoms are consistent with tarsal tunnel syndrome. Ganglion cysts are a well-known cause of tarsal tunnel syndrome. The MRI scans show a high intensity, well-circumscribed mass in the tarsal tunnel that is consistent with a fluid-filled cyst. Patients usually respond well to excision of the ganglion and resolution of the tarsal tunnel symptoms. The surrounding fat is a different signal intensity on the MRI scans, which rules out a lipoma. Synovial cell sarcoma has a heterogeneous appearance on an MRI scan. Metastatic tumors are most commonly found in the osseous structures of the foot, not the soft tissues.
REFERENCES: Rozbruch SR, Chang V, Bohne WH, et al: Ganglion cysts of the lower extremity: An analysis of 54 cases and review of the literature. Orthopedics 1998;21:141-148.
Llauger J, Palmer J, Monill JM, et al: MR imaging of benign soft-tissue masses of the foot and ankle. Radiographics 1998;18:1481-1498.
Takakura Y, Kitada C, Sugimoto K, et al: Tarsal tunnel syndrome: Causes and results of operative treatment. J Bone Joint Surg Br 1991;73:125-128.
REFERENCES: Rozbruch SR, Chang V, Bohne WH, et al: Ganglion cysts of the lower extremity: An analysis of 54 cases and review of the literature. Orthopedics 1998;21:141-148.
Llauger J, Palmer J, Monill JM, et al: MR imaging of benign soft-tissue masses of the foot and ankle. Radiographics 1998;18:1481-1498.
Takakura Y, Kitada C, Sugimoto K, et al: Tarsal tunnel syndrome: Causes and results of operative treatment. J Bone Joint Surg Br 1991;73:125-128.
Question 3
A previously healthy 29-year-old man reports a 2-day history of severe atraumatic lower back pain. He denies any bowel or bladder difficulties and no constitutional signs. Examination is consistent with mechanical back pain. No focal neurologic deficits or pathologic reflexes are noted. What is the most appropriate management?
Explanation
DISCUSSION: In general, a previously healthy patient with an acute onset of nontraumatic lower back pain does not need diagnostic imaging before proceeding with therapeutic treatment. In the absence of any “red flags” during the history and physical examination, such as trauma or constitutional symptoms (ie, fevers, chills, weight loss), the appropriate treatment for acute onset lower back pain is purely symptomatic treatment including limited analgesics and early range of motion. Diagnostic imaging is not necessary unless the initial treatment is unsuccessful and symptoms are prolonged. Miller and associates suggested that the use of radiographs can lead to better patient satisfaction but not necessarily better outcomes.
REFERENCES: Miller P, Kendrick D, Bentley E, et al: Cost effectiveness of lumbar spine radiographs in primary care patients with low back pain. Spine 2002;27:2291-2297.
Wong DA, Transfeldt E: Macnab’s Backache, ed 4. Philadelphia, PA, Lippincott Williams and Wilkins 2007, pp 298-338.
REFERENCES: Miller P, Kendrick D, Bentley E, et al: Cost effectiveness of lumbar spine radiographs in primary care patients with low back pain. Spine 2002;27:2291-2297.
Wong DA, Transfeldt E: Macnab’s Backache, ed 4. Philadelphia, PA, Lippincott Williams and Wilkins 2007, pp 298-338.
Question 4
A 36-year-old woman sustained a tarsometatarsal joint fracture-dislocation in a motor vehicle accident. The patient is treated with open reduction and internal fixation. What is the most common complication?
Explanation
DISCUSSION: The most common complication associated with tarsometatarsal joint injury is posttraumatic arthritis. In one series, symptomatic arthritis developed in 25% of the patients and half of those went on to fusion. In another series, 26% had painful arthritis. Initial treatment should consist of shoe modification, inserts, and anti-inflammatory drugs. Fusion is reserved for failure of nonsurgical management. Hardware failure may occur, but it is clinically unimportant.
REFERENCES: Kuo RS, Tejwani NC, DiGiovanni CW, et al: Outcome after open reduction and internal fixation of Lisfranc joint injuries. J Bone Joint Surg Am 2000;82:1609-1618.
Arntz CT, Veith RG, Hansen ST Jr: Fractures and fracture-dislocations of the tarsometatarsal joint. J Bone Joint Surg Am 1988;70:173-181.
Thompson MC, Mormino MA: Injury to the tarsometatarsal joint complex. J Am Acad Orthop Surg 2003;11:260-267.
REFERENCES: Kuo RS, Tejwani NC, DiGiovanni CW, et al: Outcome after open reduction and internal fixation of Lisfranc joint injuries. J Bone Joint Surg Am 2000;82:1609-1618.
Arntz CT, Veith RG, Hansen ST Jr: Fractures and fracture-dislocations of the tarsometatarsal joint. J Bone Joint Surg Am 1988;70:173-181.
Thompson MC, Mormino MA: Injury to the tarsometatarsal joint complex. J Am Acad Orthop Surg 2003;11:260-267.
Question 5
Figure 19 shows an arthroscopic view from the anterior lateral portal of the knee looking into the suprapatella pouch. The use of an electrothermal device during this procedure most commonly causes significant postoperative complications by damaging which of the following structures?
Explanation
DISCUSSION: While it is possible to damage any of these structures, unrecognized intraoperative laceration without adequate coagulation of the superior lateral geniculate artery is common. This can result in significant postoperative hemarthrosis and a return to surgery when bleeding cannot be controlled.
REFERENCES: Cash JD, Hughston JC: Treatment of acute patella dislocation. Am J Sports Med 1988;16:244-249.
Henry R, Goletz B, Williamson C: Lateral release in patello-femoral subluxation. Am J Sports Med 1986;14:121.
REFERENCES: Cash JD, Hughston JC: Treatment of acute patella dislocation. Am J Sports Med 1988;16:244-249.
Henry R, Goletz B, Williamson C: Lateral release in patello-femoral subluxation. Am J Sports Med 1986;14:121.
Question 6
Compared with retention of the native patella in primary total knee arthroplasty, routine patellar resurfacing is associated with
Explanation
DISCUSSION:
Despite concerns regarding fracture, osteonecrosis, and patellar clunk, the routine retention of the native patella during primary total knee replacement is associated with a 20% to 30% increased revision risk in
large joint registries. In addition, the retention of the native patella results in a 5.7% revision surgery rate
in patients with anterior knee pain.
Despite concerns regarding fracture, osteonecrosis, and patellar clunk, the routine retention of the native patella during primary total knee replacement is associated with a 20% to 30% increased revision risk in
large joint registries. In addition, the retention of the native patella results in a 5.7% revision surgery rate
in patients with anterior knee pain.
Question 7
A coach of three football teams—the B team, junior varsity team, and varsity team—wants to study the average times in the 40-yard dash for his players. Which test would help him determine if the mean 40-yard dash times for the athletes on one team are different from those on the other teams?
Explanation
Data collected in research studies fall into one of two categories—continuous or discrete. Continuous data can be displayed on a curve. Examples include height, weight, and time recorded in a 40-yard dash. Discrete data represent data that fall into specific categories such as gender or the presence or absence of a risk factor. ANOVA is used to determine statistical significance in mean values of continuous data when there are more than two independent samples. The 2-sample t test compares mean values of continuous data between two independent groups. The Chi-square test and Fisher's exact tests are tests used to analyze discrete data.
Question 8
-Postsurgically, the patient recovers well and is fully rehabilitated. He demonstrates full motion with no instability or pain and is cleared to return to play 12 months after the surgery. He asks for your advice regarding use of a functional brace for playing basketball following his reconstruction. What is the most appropriate recommendation?
Explanation
DISCUSSION FOR QUESTIONS 89 THROUGH 95
The athlete most likely suffered an acute ACL rupture however the presence of a lipohemarthrosis is concerning for the possibility of an intraarticular fracture. Because of this, the patient should not be allowed full weight bearing until a fracture is ruled out with radiographs. Given the athlete’s inability to perform a straight leg raise, the extensor mechanism is not functioning and a telescoping knee brace locked in extension should be utilized. A neoprene knee sleeve does not have a role in the
treatment of this acute injury.The radiographs reveal a lateral avulsion fracture off of the proximal tibial epiphysis which is known as a Segond fracture. It is indicative of an ACL injury and the fracture fragment seen is the consequence of the lateral capsule injury sustained during the pivot-shift mechanism. There is no radiographic evidence of a medial tibial plateau fracture. A radiographic sign of a chronic MCL injury is known as a Pellegrini-Stieda lesion and this is seen as calcification of the femoral origin of the MCL. A radiographic sign of an acute LCL rupture would be an avulsion fracture of the tip of the fibula.The MRI shows kissing contusions of the posterolateral tibial plateau and the midpoint of the lateral femoral condyle. These “kissing lesions” are seen as a result of a pivot shift mechanism of injury and are diagnostic for an ACL rupture. The most common associated injury in an acute ACL rupture is a lateral meniscus tear. Medial meniscus tears are more common in chronic ACL injuries. PCL rupture and PLC injury are all associated injuries seen in acute ACL rupture; however, these are much less common than meniscal tears. The team physician has a role in encouraging, but
not demanding, the athlete to report the injury andtreatment to the scholarship school’s coaching staff. What the athlete decides to do is his decision; the physician would be violating the athlete’s HIPAA rights as well as their confidence by reporting it directly to the scholarship school. Clearly the physician should not discourage the athlete from reporting the injury. The athlete is 18 years old and, as such, the physician would need the athlete’s permission to discuss any medical issues with the family in keeping with HIPAA.
The athlete’s exam demonstrates incompetence of both bundles of the ACL as demonstrated by the loss of stability with anterior translation of the tibia (Lachman test) as well as with rotation (pivot shift). The external rotation stress with the knee in 30 degrees of flexion tests the competence of the posterolateral corner while rotation at 90 degrees of flexion tests the PCL. Since the athlete’s knee is stable to posterior drawer testing demonstrating an intact PCL and the external rotation at 30 degrees is equivalent to that at 90 degrees, the posterolateral corner in intact.
The ACL has two separate and distinct bundles, the AM and PL. Each bundle takes on tension at varying degrees of knee flexion and therefore each bundle is thought to have a varying contribution to the stability of the knee. The AM bundle takes on tension with the knee in flexion and the PL bundle is tight in extension. Neither bundle is isometric during knee range of motion. Both bundles have contributions to rotational stability of the knee throughout the range of motion.
The success of traditional trans-tibial single-bundle ACL reconstruction has recently been called into question given the demonstration of persistent rotational instability following reconstruction. The persistence of rotational instability in trans-tibial single bundle ACL reconstruction has been attributed to the location of the graft in a vertically malpositioned femoral tunnel. The goal of double-bundle ACL reconstruction is to more accurately reproduce the native ACL and provide grafts that contribute to anteroposterior stability as well as rotational stability by placing the grafts in more anatomic locations not central in the knee axis. There is an increased cost and surgical time associated with double-bundle reconstruction.
The use of functional braces following ACL reconstruction is a surgeon’s preference because there is no difference in retear rate with or without a brace. Some authors recommend brace use for one to two years following ACL reconstruction for all athletic activities, but this is not supported by the literature. No literature exists showing a higher rate of reinjury with a functional brace and off-the shelf and custom braces have been found to be equivalent leading those who advocate for braces to recommend off-theshelf braces given their significantly lower cost.
The athlete most likely suffered an acute ACL rupture however the presence of a lipohemarthrosis is concerning for the possibility of an intraarticular fracture. Because of this, the patient should not be allowed full weight bearing until a fracture is ruled out with radiographs. Given the athlete’s inability to perform a straight leg raise, the extensor mechanism is not functioning and a telescoping knee brace locked in extension should be utilized. A neoprene knee sleeve does not have a role in the
treatment of this acute injury.The radiographs reveal a lateral avulsion fracture off of the proximal tibial epiphysis which is known as a Segond fracture. It is indicative of an ACL injury and the fracture fragment seen is the consequence of the lateral capsule injury sustained during the pivot-shift mechanism. There is no radiographic evidence of a medial tibial plateau fracture. A radiographic sign of a chronic MCL injury is known as a Pellegrini-Stieda lesion and this is seen as calcification of the femoral origin of the MCL. A radiographic sign of an acute LCL rupture would be an avulsion fracture of the tip of the fibula.The MRI shows kissing contusions of the posterolateral tibial plateau and the midpoint of the lateral femoral condyle. These “kissing lesions” are seen as a result of a pivot shift mechanism of injury and are diagnostic for an ACL rupture. The most common associated injury in an acute ACL rupture is a lateral meniscus tear. Medial meniscus tears are more common in chronic ACL injuries. PCL rupture and PLC injury are all associated injuries seen in acute ACL rupture; however, these are much less common than meniscal tears. The team physician has a role in encouraging, but
not demanding, the athlete to report the injury andtreatment to the scholarship school’s coaching staff. What the athlete decides to do is his decision; the physician would be violating the athlete’s HIPAA rights as well as their confidence by reporting it directly to the scholarship school. Clearly the physician should not discourage the athlete from reporting the injury. The athlete is 18 years old and, as such, the physician would need the athlete’s permission to discuss any medical issues with the family in keeping with HIPAA.
The athlete’s exam demonstrates incompetence of both bundles of the ACL as demonstrated by the loss of stability with anterior translation of the tibia (Lachman test) as well as with rotation (pivot shift). The external rotation stress with the knee in 30 degrees of flexion tests the competence of the posterolateral corner while rotation at 90 degrees of flexion tests the PCL. Since the athlete’s knee is stable to posterior drawer testing demonstrating an intact PCL and the external rotation at 30 degrees is equivalent to that at 90 degrees, the posterolateral corner in intact.
The ACL has two separate and distinct bundles, the AM and PL. Each bundle takes on tension at varying degrees of knee flexion and therefore each bundle is thought to have a varying contribution to the stability of the knee. The AM bundle takes on tension with the knee in flexion and the PL bundle is tight in extension. Neither bundle is isometric during knee range of motion. Both bundles have contributions to rotational stability of the knee throughout the range of motion.
The success of traditional trans-tibial single-bundle ACL reconstruction has recently been called into question given the demonstration of persistent rotational instability following reconstruction. The persistence of rotational instability in trans-tibial single bundle ACL reconstruction has been attributed to the location of the graft in a vertically malpositioned femoral tunnel. The goal of double-bundle ACL reconstruction is to more accurately reproduce the native ACL and provide grafts that contribute to anteroposterior stability as well as rotational stability by placing the grafts in more anatomic locations not central in the knee axis. There is an increased cost and surgical time associated with double-bundle reconstruction.
The use of functional braces following ACL reconstruction is a surgeon’s preference because there is no difference in retear rate with or without a brace. Some authors recommend brace use for one to two years following ACL reconstruction for all athletic activities, but this is not supported by the literature. No literature exists showing a higher rate of reinjury with a functional brace and off-the shelf and custom braces have been found to be equivalent leading those who advocate for braces to recommend off-theshelf braces given their significantly lower cost.
Question 9
A 6-year-old Little League pitcher has had pain in the right elbow for the past 2 weeks. Examination reveals mild lateral elbow joint tenderness with full range of motion and no effusion or collateral laxity. A radiograph is shown in Figure 38. Initial management should consist of
Explanation
DISCUSSION: The radiograph shows osteochondritis dissecans (OCD) of the capitellum, one manifestation of “pitcher’s elbow.” The lesion is nondisplaced, and healing is possible if the inciting throwing activities are curtailed. Long arm cast treatment may be reasonable for the noncompliant patient but should not exceed 6 weeks duration. Surgical treatment is indicated for loose bodies or cartilage flaps. Elbow OCD lesions are now being seen in younger children as more participate in organized sports, especially baseball and gymnastics.
REFERENCES: Bauer M, Jonsson K, Josefsson PO, et al: Osteochondritis dissecans of the elbow: A long-term follow-up study. Clin Orthop 1992;284:156-160.
Takahara M, Ogino T, Sasaki I, et al: Long term outcome of osteochondritis dissecans of the humeral capitellum. Clin Orthop 1999;363:108-115.
Byrd JW, Jones KS: Arthroscopic surgery for isolated capitellar osteochondritis dissecans in adolescent baseball players: Minimum three-year follow-up. Am J Sports Med
2002;30:474-478.
REFERENCES: Bauer M, Jonsson K, Josefsson PO, et al: Osteochondritis dissecans of the elbow: A long-term follow-up study. Clin Orthop 1992;284:156-160.
Takahara M, Ogino T, Sasaki I, et al: Long term outcome of osteochondritis dissecans of the humeral capitellum. Clin Orthop 1999;363:108-115.
Byrd JW, Jones KS: Arthroscopic surgery for isolated capitellar osteochondritis dissecans in adolescent baseball players: Minimum three-year follow-up. Am J Sports Med
2002;30:474-478.
Question 10
Giant cell tumors of bone can occur in many different areas throughout the body. All of the following are common locations for giant cell tumors of bone EXCEPT?
Explanation
Giant cell tumors are common around the knee, distal radius, sacrum and hands. They are not typically found in the diaphysis of bone.
Giant cell tumors are one of the more common tumors in young adults 22-40 years of age. There is much argument as to whether giant cell tumors arise in the metaphysis or the epiphysis, but most authors agree that giant cell tumors are very uncommon in the diaphysis. The most common sites of giant cell tumors in bone, which are the distal radius, sacrum, distal femur, proximal tibia and proximal humerus. Treatment typically involves intralesional curettage with adjuvant treatment (e.g., phenol, hydrogen peroxide, argon beam, etc).
Williams et al undertook a prospective study to evaulate the recurrence rate of giant cell tumors of the hand and they found that soft tissue extension of the tumor significantly increased the rate of local recurrence. This finding is significant because multiple previous studies have demonstrated similar higher recurrence rates for giant cell tumors with soft tissue extension in other areas like around the knee and the distal radius.
Illustration A are radiographs classic for a giant cell tumor showing a large lytic metaphseal-epiphyseal lesion in the distal femur. Illustration B is an axial CT of the distal femur showing the lytic giant cell tumor, abutting and fracturing the subchondral bone. Illustration C is histology classic for a giant cell tumor where the nuclei of the multi-nucleated giant cells look identical to the nuclei of the stromal cells.
Incorrect Answers:
What is the most appropriate treatment for a 65-year-old female with a 100-pack-year tobacco history who presents with a new painful lytic lesion in her femoral diaphysis?
Antegrade femoral nailing with reamings sent to pathology for analysis
Antegrade femoral nailing with adjuvant radiotherapy to the lesion 3
. Minimally invasive plating of the femur for stabilization and open cementation of the lesion
Referral to medical oncology for chemo-radiotherapy
Lesion biopsy with further treatment based on the results of the biopsy
New lesions which are not diagnosed by imaging and require surgical intervention need to have an appropriate biopsy with treatment dictated by the results of the biopsy. While this patient has a significant tobacco history, incorrect treatment of this lytic bone lesion could affect both her overall morbidity and mortality. As an example, a lytic high-grade chondrosarcoma may look exactly like a metastatic lesion but requires wide surgical excision, not just stabilization of an impending pathological fracture. Intramedullary nailing of a chondrosarcoma would spread the tumor the entire length of the bone and likely require a major amputation, not a limb salvage operation.
A 14-year-old child is referred to your office for evaluation of a tibia lesion found incidentally after a minor ankle injury. A radiograph of the child's ankle is shown in Figure A. What treatment do you suggest?
Endocrine consultation secondary to associated endocrine abnormalities
Surgical consultation secondary to associated gastrointestional cancers
Short leg cast and non-weight bearing for a minimum of 6 weeks
Open biopsy and tumor staging
Routine followup of tibial lesion
The radiograph is classic for a non-ossifying fibroma given the classic eccentric position, sclerotic margin, and benign appearance. Other than routine followup for the tibial lesion, this child requires no subsequent treatment. Marks and Bauer review the diagnosis, imaging, and treatment of many different fibrous tumors of bone and review the diagnostic imaging criteria specific to each subclass of bony fibrous tumors.
The chromosomal translocation t(X;18)is found in which of the following conditions?
Myxoid liposarcoma
Synovial Sarcoma
Osteosarcoma
Ewing's Sarcoma
Clear cell sarcoma
Synovial sarcoma is a rare soft tissue sarcoma with biphasic features of both spindle cell and epithelial differentiation. Synovial sarcoma is a rare high-grade tumor that spreads along fascial planes and, thus, can be much more widespread than apparent on initial evaluation. Males are more commonly affected than females with a ratio of 1.1:1. Synovial sarcoma is characterized by a specific chromosomal translocation t(X;18)(p11;q11) that is observed in more than 90% of cases. The t(X;18)(p11;q11) translocation fuses the SYT gene from chromosome 18 to either of 2 homologous genes at Xp11, either SSX1 or SSX2. The fusion proteins SYT-SSX1 and SYT-SSX2 function as aberrant transcriptional regulators, resulting in either activation of protooncogenes or inhibition of tumor suppressor genes.
Kawai et al found that SYT-SSX fusion transcripts are a defining diagnostic marker of synovial sarcomas. These fusion transcripts may yield important independent prognostic information and provide important information for different types of treatment.
Incorrect Answers
Giant cell tumors are one of the more common tumors in young adults 22-40 years of age. There is much argument as to whether giant cell tumors arise in the metaphysis or the epiphysis, but most authors agree that giant cell tumors are very uncommon in the diaphysis. The most common sites of giant cell tumors in bone, which are the distal radius, sacrum, distal femur, proximal tibia and proximal humerus. Treatment typically involves intralesional curettage with adjuvant treatment (e.g., phenol, hydrogen peroxide, argon beam, etc).
Williams et al undertook a prospective study to evaulate the recurrence rate of giant cell tumors of the hand and they found that soft tissue extension of the tumor significantly increased the rate of local recurrence. This finding is significant because multiple previous studies have demonstrated similar higher recurrence rates for giant cell tumors with soft tissue extension in other areas like around the knee and the distal radius.
Illustration A are radiographs classic for a giant cell tumor showing a large lytic metaphseal-epiphyseal lesion in the distal femur. Illustration B is an axial CT of the distal femur showing the lytic giant cell tumor, abutting and fracturing the subchondral bone. Illustration C is histology classic for a giant cell tumor where the nuclei of the multi-nucleated giant cells look identical to the nuclei of the stromal cells.
Incorrect Answers:
What is the most appropriate treatment for a 65-year-old female with a 100-pack-year tobacco history who presents with a new painful lytic lesion in her femoral diaphysis?
Antegrade femoral nailing with reamings sent to pathology for analysis
Antegrade femoral nailing with adjuvant radiotherapy to the lesion 3
. Minimally invasive plating of the femur for stabilization and open cementation of the lesion
Referral to medical oncology for chemo-radiotherapy
Lesion biopsy with further treatment based on the results of the biopsy
New lesions which are not diagnosed by imaging and require surgical intervention need to have an appropriate biopsy with treatment dictated by the results of the biopsy. While this patient has a significant tobacco history, incorrect treatment of this lytic bone lesion could affect both her overall morbidity and mortality. As an example, a lytic high-grade chondrosarcoma may look exactly like a metastatic lesion but requires wide surgical excision, not just stabilization of an impending pathological fracture. Intramedullary nailing of a chondrosarcoma would spread the tumor the entire length of the bone and likely require a major amputation, not a limb salvage operation.
A 14-year-old child is referred to your office for evaluation of a tibia lesion found incidentally after a minor ankle injury. A radiograph of the child's ankle is shown in Figure A. What treatment do you suggest?
Endocrine consultation secondary to associated endocrine abnormalities
Surgical consultation secondary to associated gastrointestional cancers
Short leg cast and non-weight bearing for a minimum of 6 weeks
Open biopsy and tumor staging
Routine followup of tibial lesion
The radiograph is classic for a non-ossifying fibroma given the classic eccentric position, sclerotic margin, and benign appearance. Other than routine followup for the tibial lesion, this child requires no subsequent treatment. Marks and Bauer review the diagnosis, imaging, and treatment of many different fibrous tumors of bone and review the diagnostic imaging criteria specific to each subclass of bony fibrous tumors.
The chromosomal translocation t(X;18)is found in which of the following conditions?
Myxoid liposarcoma
Synovial Sarcoma
Osteosarcoma
Ewing's Sarcoma
Clear cell sarcoma
Synovial sarcoma is a rare soft tissue sarcoma with biphasic features of both spindle cell and epithelial differentiation. Synovial sarcoma is a rare high-grade tumor that spreads along fascial planes and, thus, can be much more widespread than apparent on initial evaluation. Males are more commonly affected than females with a ratio of 1.1:1. Synovial sarcoma is characterized by a specific chromosomal translocation t(X;18)(p11;q11) that is observed in more than 90% of cases. The t(X;18)(p11;q11) translocation fuses the SYT gene from chromosome 18 to either of 2 homologous genes at Xp11, either SSX1 or SSX2. The fusion proteins SYT-SSX1 and SYT-SSX2 function as aberrant transcriptional regulators, resulting in either activation of protooncogenes or inhibition of tumor suppressor genes.
Kawai et al found that SYT-SSX fusion transcripts are a defining diagnostic marker of synovial sarcomas. These fusion transcripts may yield important independent prognostic information and provide important information for different types of treatment.
Incorrect Answers
Question 11
A 75-year-old woman reports foot pain and states that her foot has become progressively “flatter” in the past 3 years. Custom inserts and physical therapy have failed to provide relief. Examination reveals a flexible hindfoot and mild heel cord contracture. The patient is able to perform a single limb heel rise. Weight-bearing radiographs are shown in Figures 21a through 21d. What is the most appropriate surgical management?
Explanation
DISCUSSION: The patient has end-stage midfoot arthritis, with a secondary flatfoot deformity through the midfoot. The ability to perform a single limb heel rise indicates that the posterior tibial tendon is functioning, and the weight-bearing radiographs show normal calcaneal pitch and talar head coverage, thus confirming that the flatfoot deformity is isolated to the midfoot. Therefore, the most appropriate treatment is medial column arthrodesis and heel cord lengthening. The other listed procedures are not indicated because they are used in the management of adult flatfoot from posterior tibial tendon insufficiency.
REFERENCES: Toolan BC: Midfoot arthrodesis: Challenges and treatment alternatives. Foot Ankle Clin 2002;7:75-93.
Horton GA, Olney BW: Deformity correction and arthrodesis of the midfoot with a medial plate. Foot Ankle 1993;14:493-499.
REFERENCES: Toolan BC: Midfoot arthrodesis: Challenges and treatment alternatives. Foot Ankle Clin 2002;7:75-93.
Horton GA, Olney BW: Deformity correction and arthrodesis of the midfoot with a medial plate. Foot Ankle 1993;14:493-499.
Question 12
If the quality of the tendon is poor at the lateral attachment of a partial articular side rotator cuff tear (more than 6 mm of footprint exposure or greater than 50% thickness), what should the surgeon do? Review Topic
Explanation
Generally, partial articular side rotator cuff tears are treated by either debridement or repair. The decision to repair depends on the "thickness" of the tear and the retraction of the undersurface of the rotator cuff as well as the quality of the remaining tissue. More than 6 mm of footprint exposure suggests a 50% thicknes tear. If it is poor quality as in this case, the surgeon should complete the tear and repair the tendon as in a small full-thickness tear. Intrasubstance tears with an intact footprint can be treated with trans-tendon repair.
Question 13
A 32-year-old amateur bowler has progressive pain in the lateral aspect of the proximal forearm and elbow. Nonsurgical management consisting of a tennis elbow brace, nonsteroidal anti-inflammatory drugs, and activity modification has failed to provide relief. Examination reveals tenderness in the lateral aspect of the proximal forearm and exacerbation of symptoms with resisted finger extension. Radiographs of the elbow reveal no abnormalities. Which of the following studies will aid in diagnosis?
Explanation
DISCUSSION: It is often difficult to accurately discern between lateral epicondylitis and radial tunnel syndrome. Neither MRI nor a bone scan is likely to reveal abnormalities. Electrodiagnostic studies are often inconclusive, and radial tunnel syndrome often presents without motor weakness. The symptoms of radial tunnel syndrome are expected to improve with an injection of lidocaine into the radial tunnel; therefore, this is the test of choice in this clinical scenario. Radiographs of the wrist will not assist in making the diagnosis.
REFERENCES: Eversmann WW Jr: Entrapment and compression neuropathies, in Green DP (ed): Operative Hand Surgery, ed 3. New York, NY, Churchill Livingston, 1993, pp 1341-1385.
Sarhadi NS, Korday SN, Bainbridge LC: Radial tunnel syndrome: Diagnosis and management. J Hand Surg Br 1998;23:617-619.
REFERENCES: Eversmann WW Jr: Entrapment and compression neuropathies, in Green DP (ed): Operative Hand Surgery, ed 3. New York, NY, Churchill Livingston, 1993, pp 1341-1385.
Sarhadi NS, Korday SN, Bainbridge LC: Radial tunnel syndrome: Diagnosis and management. J Hand Surg Br 1998;23:617-619.
Question 14
An MRI arthrogram of the elbow is shown in Figure 6. Based on these findings, what is the most likely diagnosis?
Explanation
DISCUSSION: MRI arthrography is the imaging study of choice for evaluation of medial collateral ligament injuries.
REFERENCES: Carrino JA, Morrison WB, Zou KH, et al: Noncontrast MR imaging and MR arthrography of the ulnar collateral ligament of the elbow: Prospective evaluation of two-dimensional pulse sequences for detection of complete tears. Skeletal Radiol 2001;30:625-632.
Munshi M, Pretterklieber ML, Chung CB, et al: Anterior bundle of ulnar collateral ligament: Evaluation of anatomic relationships by using MR imaging, MR arthrography, and gross anatomic and histologic analysis. Radiology 2004;231:797-803.
REFERENCES: Carrino JA, Morrison WB, Zou KH, et al: Noncontrast MR imaging and MR arthrography of the ulnar collateral ligament of the elbow: Prospective evaluation of two-dimensional pulse sequences for detection of complete tears. Skeletal Radiol 2001;30:625-632.
Munshi M, Pretterklieber ML, Chung CB, et al: Anterior bundle of ulnar collateral ligament: Evaluation of anatomic relationships by using MR imaging, MR arthrography, and gross anatomic and histologic analysis. Radiology 2004;231:797-803.
Question 15
A 2-year-old child has refused to bear weight on his leg for the past 2 days. His parents report that he will crawl, has no fever, and has painless full range of motion of his hip and knee. Examination reveals no deformity or bruising, but there is mild swelling and tenderness over the anterior tibia. C-reactive protein, WBC count, and erythrocyte sedimentation rate studies are normal. Radiographs are negative. What is the best course of action?
Explanation
DISCUSSION: Despite the negative radiographic findings, the child’s age and presentation are most consistent with a toddler’s fracture. There is often not a witnessed injury. The differential diagnosis of infection is unlikely given that the child is afebrile and shows no signs of illness. Immobilization will make the child more comfortable and will often allow weight bearing. Repeat radiographs at the end of treatment will show a healing fracture and confirm the diagnosis. Aspiration of the tibial metaphysis would be indicated to obtain material for culture. The bone scan and MRI would show abnormalities, but these studies are nonspecific, costly, and time-consuming. Occasionally, oblique radiographs will show the fracture.
REFERENCES: Halsey MF, Finzel KC, Carrion WV, Haralabatos SS, et al: Toddler’s fracture: Presumptive diagnosis and treatment. J Pediatr Orthop 2001;21:152-156.
Oudjihane K, Newman B, Oh KS, et al: Occult fractures in preschool children. Trauma 1988;28:858-860.
REFERENCES: Halsey MF, Finzel KC, Carrion WV, Haralabatos SS, et al: Toddler’s fracture: Presumptive diagnosis and treatment. J Pediatr Orthop 2001;21:152-156.
Oudjihane K, Newman B, Oh KS, et al: Occult fractures in preschool children. Trauma 1988;28:858-860.
Question 16
Figures 30a through 30c show the CT scans and standing lateral radiograph of a 30-year-old woman who was injured in a fall while snowboarding. She is neurologically intact in the lower extremities and has normal rectal tone and sensation. She has tenderness at the thoracolumbar junction but no ecchymosis or palpable defect. Mobilization in a thoracolumbosacral orthosis for this patient has been proven to result in which of the following clinical outcomes? Review Topic
Explanation
Surgical and nonsurgical treatment have been shown to be equivalent in terms of clinical outcome in a prospective randomized trial of stable burst fractures. There is relatively limited risk of neurologic injury with careful mobilization in appropriate bracing of patients with this injury pattern. There is only infrequent symptomatic late stenosis, with many patients experiencing resorption of the intra-canal fragments. The status of the adjacent disks has not been shown to be a prognostically important factor. The complication rates of surgical and nonsurgical treatments appear to be similar if not less for nonsurgical treatment.
Question 17
An 18-year-old collegiate football player injures his right shoulder during a tackle. He reports pain and numbness in the shoulder and numbness radiating to his fingers. His symptoms improve within 15 minutes and he has no residual symptoms. This condition is best known as Review Topic
Explanation
The condition described in this case is known as a stinger or burner. It is caused by stretching the upper trunk of the brachial plexus in the C5 and C6 nerve roots. The symptoms are temporary and last 15 to 20 minutes. There are no residual deficits, unless the patient has had multiple repetitive injuries. Once motor and sensory examination findings and reflexes have normalized, the athlete can return to play. Acute spinal cord injury may cause temporary complete paralysis in the upper and lower extremities with resolution of symptoms within 24 hours. Central cord syndrome affects the upper more than lower extermities and affects mostly elderly patients. Nerve root avulsions lead to permanent deficits and have a poor prognosis for return of function. Guillain-Barre syndrome is an autoimmune disease that presents as an ascending paralysis with weakness in the legs that spreads to the upper limbs and the face along with complete loss of deep tendon reflexes.
Question 18
Which nerve is most commonly injured after total knee arthroplasty?
Explanation
DISCUSSION
The tibial or peroneal nerves usually are not injured during total knee arthroplasty. Incidence of peroneal nerve damage is highest in knees with a valgus deformity and an associated flexion contracture attributable to nerve stretch. This nerve injury occurs in as many as 9% of patients undergoing knee arthroplasty. Tibial nerve injury is a rare occurrence and usually an iatrogenic transection injury. The infrapatellar branch of the saphenous nerve and its nerve plexus is commonly injured after the medial parapatellar approach, and altered sensation attributable to injury is reported in up to 70% of cases. Injury typically manifests as numbness inferior to the patella. The sartorial branch of the saphenous nerve provides sensation distal to the knee and is uncommonly injured with a medial parapatellar approach. These concepts are illustrated in video 57, “Selective Exposures in Orthopaedic Surgery: The Knee, 2nd Edition.”
RECOMMENDED READINGS
Clarke HD, Bush-Joseph CA, Wolf BR. Selective Exposures in Orthopaedic Surgery: The Knee, 2nd Edition [DVD]. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2012.
Hunter LY, Louis DS, Ricciardi JR, O'Connor GA. The saphenous nerve: its course and importance in medial arthrotomy. Am J Sports Med. 1979 Jul-Aug;7(4):227-30. PubMed PMID: 474860.View Abstract at PubMed
Mistry D, O'Meeghan C. Fate of the infrapatellar branch of the saphenous nerve post total knee arthroplasty. ANZ J Surg. 2005 Sep;75(9):822-4. PubMed PMID: 16174002.View Abstract at PubMed
Schinsky MF, Macaulay W, Parks ML, Kiernan H, Nercessian OA. Nerve injury after primary total knee arthroplasty. J Arthroplasty. 2001 Dec;16(8):1048-54. PubMed PMID: 11740762.View Abstract at PubMed
The tibial or peroneal nerves usually are not injured during total knee arthroplasty. Incidence of peroneal nerve damage is highest in knees with a valgus deformity and an associated flexion contracture attributable to nerve stretch. This nerve injury occurs in as many as 9% of patients undergoing knee arthroplasty. Tibial nerve injury is a rare occurrence and usually an iatrogenic transection injury. The infrapatellar branch of the saphenous nerve and its nerve plexus is commonly injured after the medial parapatellar approach, and altered sensation attributable to injury is reported in up to 70% of cases. Injury typically manifests as numbness inferior to the patella. The sartorial branch of the saphenous nerve provides sensation distal to the knee and is uncommonly injured with a medial parapatellar approach. These concepts are illustrated in video 57, “Selective Exposures in Orthopaedic Surgery: The Knee, 2nd Edition.”
RECOMMENDED READINGS
Clarke HD, Bush-Joseph CA, Wolf BR. Selective Exposures in Orthopaedic Surgery: The Knee, 2nd Edition [DVD]. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2012.
Hunter LY, Louis DS, Ricciardi JR, O'Connor GA. The saphenous nerve: its course and importance in medial arthrotomy. Am J Sports Med. 1979 Jul-Aug;7(4):227-30. PubMed PMID: 474860.View Abstract at PubMed
Mistry D, O'Meeghan C. Fate of the infrapatellar branch of the saphenous nerve post total knee arthroplasty. ANZ J Surg. 2005 Sep;75(9):822-4. PubMed PMID: 16174002.View Abstract at PubMed
Schinsky MF, Macaulay W, Parks ML, Kiernan H, Nercessian OA. Nerve injury after primary total knee arthroplasty. J Arthroplasty. 2001 Dec;16(8):1048-54. PubMed PMID: 11740762.View Abstract at PubMed
Question 19
A 26-year-old weightlifter has increasing pain in his left shoulder for 4 months. Nonsurgical treatment consisting of anti-inflammatory medication, corticosteroid injections, and rest fails to alleviate his symptoms. He undergoes an arthroscopic distal clavicle resection with excision of the distal 8 mm of clavicle (Mumford procedure). Three months after surgery, he reports mild pain and popping by his clavicle. His clavicle demonstrates mild posterior instability on examination without any obvious deformity on his radiographs. What structures were compromised during his excision?
Explanation
The posterior and superior acromioclavicular ligaments provide the most restraint to posterior translation of the acromioclavicular joint and must be preserved during a Mumford procedure. Anterior and superior acromioclavicular joint ligaments are the opposite of the preferred response and prevent anterior translation of the clavicle. Injuries to the conoid and trapezoid ligaments are more pronounced with grade III or higher acromioclavicular separations, with superior migration of the clavicle relative to the acromion.
Question 20
A 22-year-old woman has had progressive upper extremity weakness for the past several years. History reveals no pain in her neck or shoulders. Examination reveals scapular winging of both shoulders and weakness in external rotation. She can abduct to only 120 degrees bilaterally, and there is mild supraspinatus weakness. She is otherwise neurologically intact with normal sensation and reflexes; however, she has difficulty whistling. A clinical photograph is shown in Figure 14. What is the most likely diagnosis?
Explanation
DISCUSSION: Progressive weakness is a common sign with a large differential diagnosis. Nerve, muscle, and joint problems should be excluded when a patient has diffuse weakness and atrophy. Fascioscapulohumeral dystrophy is a rare disease characterized by facial muscle weakness and proximal shoulder muscle weakness. The weakness is usually bilateral, and scapular winging is common. If the scapular winging becomes pronounced, elevation of the shoulder can be affected. In severe cases, scapulothoracic fusion or pectoralis muscle transfer to the scapula may be indicated. Duchenne muscular dystrophy is typically severe and progressive. The other diagnoses are not compatible with the history or the physical findings.
REFERENCES: Shapiro F, Specht L: The diagnosis and orthopaedic treatment of inherited muscular diseases of childhood. J Bone Joint Surg Am 1993;75:439-454.
Bunch WH, Siegel IM: Scapulothoracic arthrodesis in fascioscapulohumeral muscular dystrophy: Review of seventeen procedures with three to twenty-one-year follow-up. J Bone Joint Surg Am 1993;75:372-376.
REFERENCES: Shapiro F, Specht L: The diagnosis and orthopaedic treatment of inherited muscular diseases of childhood. J Bone Joint Surg Am 1993;75:439-454.
Bunch WH, Siegel IM: Scapulothoracic arthrodesis in fascioscapulohumeral muscular dystrophy: Review of seventeen procedures with three to twenty-one-year follow-up. J Bone Joint Surg Am 1993;75:372-376.
Question 21
What is the standard interval for placement of an anterolateral portal in ankle arthroscopy?
Explanation
As with arthroscopy of the knee, the anterolateral (AL) portal is the primary diagnostic portal used for initial placement of the arthroscope. The AL portal is made 5 mm below the joint line just lateral to the extensor tendons. The lateral cutaneous branch of the superficial peroneal nerve lies near this portal region. From this approach, one can visualize the anteromedial (AM), anterocentral (AC), and most of the AL areas of the tibiotalar joint. With the addition of laterally based external distraction instrumentation, the surgeon can usually advance the arthroscope posterocentrally and posterolaterally to visualize most of the articulation and the structures in the central and posterior compartments: the intraarticular aspects and synovium of the distal tibiofibular syndesmosis, the posterior tibiofibular ligament, the transverse ligament, and the synovial plicae that overlie the transverse ligament.
Question 22
A 12-year-old girl sustains an acute injury to the right elbow in a fall. An AP radiograph is shown in Figure 5. Nonsurgical management will most likely result in
Explanation
DISCUSSION: The patient has a significantly displaced medial epicondyle fracture. The only absolute indication for surgical treatment is irreducible incarceration in the joint. Nonsurgical management usually results in a painless nonunion with good elbow function and little elbow instability. Prolonged immobilization should be avoided to prevent stiffness. Tardy ulnar nerve palsy and cubitus varus are not complications of medial epicondyle fractures.
REFERENCES: Chamber HG, Wilkins KE: Part IV: Apophyseal injuries of the distal humerus, in Rockwood CA Jr, Wilkins KE, Beaty JH (eds): Fractures in Children, ed 4. Philadelphia, PA, Lippincott-Raven, 1996, vol 3, pp 801-812.
Farsetti P, Potenza V, Caterini R, Ippolito E: Long-term results of treatment of fractures of the medial humeral epicondyle in children. J Bone Joint Surg Am 2001;83:1299-1305.
REFERENCES: Chamber HG, Wilkins KE: Part IV: Apophyseal injuries of the distal humerus, in Rockwood CA Jr, Wilkins KE, Beaty JH (eds): Fractures in Children, ed 4. Philadelphia, PA, Lippincott-Raven, 1996, vol 3, pp 801-812.
Farsetti P, Potenza V, Caterini R, Ippolito E: Long-term results of treatment of fractures of the medial humeral epicondyle in children. J Bone Joint Surg Am 2001;83:1299-1305.
Question 23
A 70-year-old healthy man had total knee arthroplasty 18 years ago, and it now is painful. Radiographs reveal aseptic loosening and the range of motion before surgery is 15 to 85 degrees. The strongest indication for performing a tibial tubercle osteotomy to aid in exposure in his knee would be
Explanation
Question 24
A 45-year-old IV drug abuser has sternoclavicular (SC) joint pain for the past 2 weeks. He is afebrile and physical exam findings include point tenderness and swelling. He most likely has septic arthritis of the sternoclavicular joint. If so, what is the most likely infecting organism?
Explanation
DISCUSSION: Risk factors for sternoclavicular septic arthritis include IV drug abuse, diabetes, and HIV.
According to the reference by Ross et al, Staphylococcus aureus accounts for 49% of infections. SC joint arthritis accounts for 1% of septic arthritis in the general population but 17% in the IV drug abuse population. Symptoms include spontaneous swelling with the appearance of joint subluxation and localized pain. These patients are not uncommonly afebrile.
According to the reference by Ross et al, Staphylococcus aureus accounts for 49% of infections. SC joint arthritis accounts for 1% of septic arthritis in the general population but 17% in the IV drug abuse population. Symptoms include spontaneous swelling with the appearance of joint subluxation and localized pain. These patients are not uncommonly afebrile.
Question 25
Which structure is shown in Video 27? 27
Explanation
DISCUSSION
Video 27 shows the medial patellofemoral ligament running from the medial epicondyle of the femur to the medial portion of the patella. The posterior oblique ligament and the superficial medial collateral ligament run from medial epicondyle to the tibia.
RECOMMENDED READINGS
Babb JR, Detterline AJ, Noyes FR. AAOS Orthopaedic Video Theater. The Key to the Knee: A Layer-by-Layer Video Demonstration of Medial and Anterior Aatomy. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2009.
Hoppenfeld S, deBoer P. Surgical Exposures in Orthopedics. 3rd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2003:493-568.
Video 27 shows the medial patellofemoral ligament running from the medial epicondyle of the femur to the medial portion of the patella. The posterior oblique ligament and the superficial medial collateral ligament run from medial epicondyle to the tibia.
RECOMMENDED READINGS
Babb JR, Detterline AJ, Noyes FR. AAOS Orthopaedic Video Theater. The Key to the Knee: A Layer-by-Layer Video Demonstration of Medial and Anterior Aatomy. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2009.
Hoppenfeld S, deBoer P. Surgical Exposures in Orthopedics. 3rd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2003:493-568.
Question 26
Which of the following studies is considered most sensitive in monitoring a therapeutic response in acute hematogenous osteomyelitis?
Explanation
DISCUSSION: C-reactive protein declines rapidly as the clinical picture improves. Failure of the C-reactive protein to decline after 48 to 72 hours of treatment should indicate that treatment may need to be altered. Blood culture is positive only 50% of the time and will be negative soon after antibiotics are administered, even if treatment is not progressing satisfactorily. WBC count is highly variable and poorly correlated with treatment. The ESR rises rapidly but declines too slowly to guide treatment. Radiographic findings may not change but can take up to 2 weeks to show changes.
REFERENCE: Unidia-Kallio L, et al: Serum c-reactive protein, ESR and WBC in acute hematogenous osteomyelitis in children. Pediatrics 1994;93:59-62.
REFERENCE: Unidia-Kallio L, et al: Serum c-reactive protein, ESR and WBC in acute hematogenous osteomyelitis in children. Pediatrics 1994;93:59-62.
Question 27
A 25-year-old woman sustains a fall on an outstretched hand. She complains of elbow pain. Examination reveals tenderness over the lateral elbow and pain on elbow motion. Injury radiographs and CT scans are shown in Figures A and B, respectively. What is the next best step?
Explanation
This patient has Mason II radial head fracture. ORIF will give the best results.
Non-/minimally displaced radial head fractures without a block to rotation can be managed nonoperatively. Complete articular fractures with >=3 fragments do better with radial head replacement. Indications for ORIF include large articular surface fragments, > 2 mm of displacement, mechanical block to forearm rotation, or associated fractures or ligament injuries requiring surgery.
Pike et al. retrospectively compared patients undergoing ORIF for isolated radial head fractures with radial fractures associated with other fractures/dislocations. They found no differences in pain/disability and complications or secondary capsular release between groups.
Yoon et al. retrospectively compared isolated partial articular displaced (2-5mm) radial head fractures treated nonoperatively vs ORIF. They found no clinical benefit with ORIF compared to non-operative management. The ORIF group had more complications. Younger patient age and larger fracture displacement favored operative intervention. Younger patients fared worse.
Figures A and B are radiographs and 3D reformatted CT images showing a displaced partial articular radial head fracture.
Incorrect Answers:
>= 3 fragments.
Non-/minimally displaced radial head fractures without a block to rotation can be managed nonoperatively. Complete articular fractures with >=3 fragments do better with radial head replacement. Indications for ORIF include large articular surface fragments, > 2 mm of displacement, mechanical block to forearm rotation, or associated fractures or ligament injuries requiring surgery.
Pike et al. retrospectively compared patients undergoing ORIF for isolated radial head fractures with radial fractures associated with other fractures/dislocations. They found no differences in pain/disability and complications or secondary capsular release between groups.
Yoon et al. retrospectively compared isolated partial articular displaced (2-5mm) radial head fractures treated nonoperatively vs ORIF. They found no clinical benefit with ORIF compared to non-operative management. The ORIF group had more complications. Younger patient age and larger fracture displacement favored operative intervention. Younger patients fared worse.
Figures A and B are radiographs and 3D reformatted CT images showing a displaced partial articular radial head fracture.
Incorrect Answers:
>= 3 fragments.
Question 28
Which of the following statements is correct regarding Vitamin D?
Explanation
24,25-dihydroxycholecalciferol in an inactive form of Vitamin D. High levels of 1,25-dihydroxyvitamin D stimulate the enzymatic production of 24,25-dihydroxyvitamin D, the inactive form of vitamin D, thereby self-regulating the action of 1,25-dihydroxyvitamin D.
Vitamin D is paramount to proper calcium homeostasis and has important clinical implications in the orthopaedic patient. Vitamin D3 is synthesized in the skin and is converted to 25-hydroxycholecalciferol in the liver. 25-hydroxycholecalciferol is then converted in the kidney into 1,25-dihydroxycholecalciferol, the active form of vitamin
D. The best test to determine Vitamin D deficiency is the measurement of 25-hydroxycholecalciferol, as it has a longer half-life and circulating levels are 1,000x more than 1,25-dihydrocholecalciferol.
Patton et al. review the importance of Vitamin D in the orthopaedic patient. They discuss the implications of Vitamin D deficiency, and urge orthopaedic surgeons to be proficient in both the diagnosis and treatment of the condition.
Bogunovic et al. measured the levels of 25-hydroxycholecalciferol in 723 patients who were to undergo orthopaedic surgery. 40% of these patients were noted to be deficient in Vitamin D, with the highest rates in patients scheduled to undergo trauma and sports surgery.
Illustration A reviews Vitamin D metabolism. 24,25-dihydroxycholecalciferol is referred to as pre-Vitamin D.
Incorrect Answers:
Vitamin D is paramount to proper calcium homeostasis and has important clinical implications in the orthopaedic patient. Vitamin D3 is synthesized in the skin and is converted to 25-hydroxycholecalciferol in the liver. 25-hydroxycholecalciferol is then converted in the kidney into 1,25-dihydroxycholecalciferol, the active form of vitamin
D. The best test to determine Vitamin D deficiency is the measurement of 25-hydroxycholecalciferol, as it has a longer half-life and circulating levels are 1,000x more than 1,25-dihydrocholecalciferol.
Patton et al. review the importance of Vitamin D in the orthopaedic patient. They discuss the implications of Vitamin D deficiency, and urge orthopaedic surgeons to be proficient in both the diagnosis and treatment of the condition.
Bogunovic et al. measured the levels of 25-hydroxycholecalciferol in 723 patients who were to undergo orthopaedic surgery. 40% of these patients were noted to be deficient in Vitamin D, with the highest rates in patients scheduled to undergo trauma and sports surgery.
Illustration A reviews Vitamin D metabolism. 24,25-dihydroxycholecalciferol is referred to as pre-Vitamin D.
Incorrect Answers:
Question 29
Figures below depict the radiographs obtained from a 76-year-old woman with a painful total knee arthroplasty. She describes an uneventful recovery with no wound-healing issues and was pain free for the first 10 years. Although reporting no trauma or inciting event, she now describes pain in the entire knee that is most severe with her first few steps. She has begun to notice night pain and, more recently, constant swelling. What is the most appropriate work-up at this time?
Explanation
DISCUSSION:
An evaluation of the painful total knee must be supported by an understanding of the potential etiologies of pain. They may include, aseptic loosening, infection, osteolysis, gap imbalance, referred pain, stiffness, and complex regional pain syndrome. In this case, the patient demonstrates start-up pain and had no prior history of infections. Her radiographs show subsidence of the tibia, indicating a loose prosthesis. Knowing that the prosthesis is already loose precludes the need for a bone scan. It is, however, important to rule out infection in this case; therefore, CRP and ESR testing is essential. Aspiration is also recommended when going into knee arthroplasty, and infection is a concern.
An evaluation of the painful total knee must be supported by an understanding of the potential etiologies of pain. They may include, aseptic loosening, infection, osteolysis, gap imbalance, referred pain, stiffness, and complex regional pain syndrome. In this case, the patient demonstrates start-up pain and had no prior history of infections. Her radiographs show subsidence of the tibia, indicating a loose prosthesis. Knowing that the prosthesis is already loose precludes the need for a bone scan. It is, however, important to rule out infection in this case; therefore, CRP and ESR testing is essential. Aspiration is also recommended when going into knee arthroplasty, and infection is a concern.
Question 30
Posterior sternoclavicular dislocations are most commonly associated with which of the following complications?
Explanation
DISCUSSION: Posterior sternoclavicular dislocations are commonly associated with tracheal compression, which can be a life-threatening condition requiring immediate reduction. The other listed complications are less common.
REFERENCES: Brooks AL, Henning GD: Injury to the proximal clavicular epiphysis, abstracted. J Bone Joint Surg Am 1972;54:1347-1348.
Beaty JH (ed): Orthopaedic Knowledge Update 6. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 255-260.
REFERENCES: Brooks AL, Henning GD: Injury to the proximal clavicular epiphysis, abstracted. J Bone Joint Surg Am 1972;54:1347-1348.
Beaty JH (ed): Orthopaedic Knowledge Update 6. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 255-260.
Question 31
Figure 99 is the radiograph of an 18-year-old National Collegiate Athletic Association Division I basketball player who jumped for a basket. After landing, he was unable to put weight on his left great toe. He developed pain, swelling, and ecchymosis maximally around the sesamoids. When assessing stability of the first metatarsophalangeal joint, he appears to have more laxity on the left. What is the best next step?
Explanation
DISCUSSION
This patient jumped on his forefoot and landed with pain in his great toe. His radiograph shows possible increased space between the sesamoids and the base of the phalanx. A comparison radiograph on the other side will reveal if this position is normal for this patient. If findings are asymmetric, turf toe injury is a possibility based on this patient's symptoms and mechanism of injury.
RECOMMENDED READINGS
Waldrop NE 3rd, Zirker CA, Wijdicks CA, Laprade RF, Clanton TO. Radiographic evaluation of plantar plate injury: an in vitro biomechanical study. Foot Ankle Int. 2013 Mar;34(3):403-8. doi: 10.1177/1071100712464953. Epub 2013 Jan 14. PubMed PMID: 23520299. View
Abstract at PubMed
McCormick JJ, Anderson RB. The great toe: failed turf toe, chronic turf toe, and complicated sesamoid injuries. Foot Ankle Clin. 2009 Jun;14(2):135-50. doi: 10.1016/j.fcl.2009.01.001. Review. PubMed PMID: 19501799. View Abstract at PubMed
This patient jumped on his forefoot and landed with pain in his great toe. His radiograph shows possible increased space between the sesamoids and the base of the phalanx. A comparison radiograph on the other side will reveal if this position is normal for this patient. If findings are asymmetric, turf toe injury is a possibility based on this patient's symptoms and mechanism of injury.
RECOMMENDED READINGS
Waldrop NE 3rd, Zirker CA, Wijdicks CA, Laprade RF, Clanton TO. Radiographic evaluation of plantar plate injury: an in vitro biomechanical study. Foot Ankle Int. 2013 Mar;34(3):403-8. doi: 10.1177/1071100712464953. Epub 2013 Jan 14. PubMed PMID: 23520299. View
Abstract at PubMed
McCormick JJ, Anderson RB. The great toe: failed turf toe, chronic turf toe, and complicated sesamoid injuries. Foot Ankle Clin. 2009 Jun;14(2):135-50. doi: 10.1016/j.fcl.2009.01.001. Review. PubMed PMID: 19501799. View Abstract at PubMed
Question 32
repair of the rotator cuff
Explanation
Humeral arthroplasty is indicated when there is a defect equivalent to more than 45 percent of the articular surface of the humeral head or dislocation that had been present for more than six months. Posterior dislocations is often missed during initial management. Twenty-five of forty-one dislocations were diagnosed in less than six months.( Hawkins RJ,JBJS 87)
Question 33
What is the most common fracture associated with a lateral subtalar dislocation?
Explanation
DISCUSSION: The most common tarsal fracture associated with lateral dislocations is the cuboid, although the anterior process of the calcaneus and the lateral process of the talus can also be affected. In medial dislocations, the dorsomedial talar head, the posterior tubercles of the talus, and the lateral navicular are most often fractured.
Post-reduction x-rays need to be scrutinized carefully for fractures of the tarsal bones as this is the most common injury associated with subtalar dislocations. Occult fractures of the lateral process of the talus are also associated with these injuries.
The referenced study by Wagner et al noted radiographic subtalar DJD in 2/3 of their patients, but noted no correlation between radiographic and clinical outcomes. The referenced study by Bibbo et al noted an 88% incidence of other concurrent injuries and an 89% rate of radiographic DJD at 5 year follow-up. The referenced article by Saltzman et al is a review of hindfoot dislocations.
Post-reduction x-rays need to be scrutinized carefully for fractures of the tarsal bones as this is the most common injury associated with subtalar dislocations. Occult fractures of the lateral process of the talus are also associated with these injuries.
The referenced study by Wagner et al noted radiographic subtalar DJD in 2/3 of their patients, but noted no correlation between radiographic and clinical outcomes. The referenced study by Bibbo et al noted an 88% incidence of other concurrent injuries and an 89% rate of radiographic DJD at 5 year follow-up. The referenced article by Saltzman et al is a review of hindfoot dislocations.
Question 34
Figure A is a pelvic radiograph of a healthy 20-month old girl with a limb leg discrepancy. A hip arthrogram under general anesthesia reveals concentric reduction of the left hip ONLY when the hip is positioned in 70 to 80 degrees of abduction. The next best step in treatment would be: Review Topic
Explanation
Figure A shows left hip subluxation consistent with late presenting developmental hip dysplasia (DDH). The most appropriate treatment at this stage would be open hip
capsulorrhaphy, +/- femoral osteotomy +/- pelvic osteotomy
In children older than 18 months, open reduction is the preferred treatment for hip dysplasia. Open reduction is also considered when concentric closed reduction cannot be achieved or when excessive abduction (>60 degrees) is required to maintain reduction (due to increasing risk of avascular necrosis). The goal of open reduction is to remove the blocks to reduction and to increase stability by preforming soft-tissue or bone procedures.
Wenger et al. reviewed the surgical treatment of DDH. They say that the impediment to congruent reduction are the iliopsoas muscle, joint capsule, ligamentum teres, pulvinar, labrum, and transverse acetabular ligament. The most commonly used approaches are anterior and medial/anteromedial to the hip.
Gholve et al. reviewed DDH and the factors that contribute to secondary procedures. In their study, neither age nor unilateral vs bilateral dislocation had a direct influence on the outcome or the need for secondary procedures. The variable that significantly influenced the need for a secondary procedure was the concomitant use of a femoral osteotomy during initial surgical treatment. Of the 27 patients who did not have concurrent femoral osteotomy at index surgery, 19/27 (73%) required a secondary procedure (P<0.001).
Figure A shows an AP pelvic radiograph of an infant. Focusing on the left hip, there is lateral and superior subluxation of the femoral head, with the femoral head lateral to Perkin's line. The medial joint space is increased. The acetabular index is increased
>30 degrees. Shenton's line is disrupted. These are all features of DDH.
Incorrect Answers:
capsulorrhaphy, +/- femoral osteotomy +/- pelvic osteotomy
In children older than 18 months, open reduction is the preferred treatment for hip dysplasia. Open reduction is also considered when concentric closed reduction cannot be achieved or when excessive abduction (>60 degrees) is required to maintain reduction (due to increasing risk of avascular necrosis). The goal of open reduction is to remove the blocks to reduction and to increase stability by preforming soft-tissue or bone procedures.
Wenger et al. reviewed the surgical treatment of DDH. They say that the impediment to congruent reduction are the iliopsoas muscle, joint capsule, ligamentum teres, pulvinar, labrum, and transverse acetabular ligament. The most commonly used approaches are anterior and medial/anteromedial to the hip.
Gholve et al. reviewed DDH and the factors that contribute to secondary procedures. In their study, neither age nor unilateral vs bilateral dislocation had a direct influence on the outcome or the need for secondary procedures. The variable that significantly influenced the need for a secondary procedure was the concomitant use of a femoral osteotomy during initial surgical treatment. Of the 27 patients who did not have concurrent femoral osteotomy at index surgery, 19/27 (73%) required a secondary procedure (P<0.001).
Figure A shows an AP pelvic radiograph of an infant. Focusing on the left hip, there is lateral and superior subluxation of the femoral head, with the femoral head lateral to Perkin's line. The medial joint space is increased. The acetabular index is increased
>30 degrees. Shenton's line is disrupted. These are all features of DDH.
Incorrect Answers:
Question 35
Figures 71a and 71b/ are the MR images of a 65-year-old man who dislocated his shoulder. What is his most likely chief symptom?
Explanation
DISCUSSION
This patient has a massive rotator cuff tear resulting in disruption of the transverse force couple between the subscapularis anteriorly and the infraspinatus and teres minor posteriorly. These muscles provide dynamic shoulder stability throughout active elevation. Loss of the force couple produces a pathologic increase in translation of the humeral head and decreased active abduction and external rotation, which results in difficulty raising an arm. The most common neurologic deficit after shoulder dislocation is isolated injury to the axillary nerve that supplies sensation to the lateral aspect of the shoulder, not the anterior aspect. Recurrent instability is uncommon unless there is a labral tear or massive subscapularis tear. The biceps muscle is not viewed in the MR images, and a complete proximal biceps tendon rupture would be uncommon in the setting of an anterior shoulder dislocation.
CLINICAL SITUATION FOR QUESTIONS 72 THROUGH 75
Figures 72a through 72e are the MR images of a 12-year-old boy with left lateral-sided knee pain following a football injury. He has a several-year history of recurrent knee pain that improves with rest. An examination reveals a moderate effusion. Range of motion is 0 degrees
to 90 degrees and is limited by pain in deep flexion. He has tenderness to palpation along the lateral joint line, and no instability is noted.
This patient has a massive rotator cuff tear resulting in disruption of the transverse force couple between the subscapularis anteriorly and the infraspinatus and teres minor posteriorly. These muscles provide dynamic shoulder stability throughout active elevation. Loss of the force couple produces a pathologic increase in translation of the humeral head and decreased active abduction and external rotation, which results in difficulty raising an arm. The most common neurologic deficit after shoulder dislocation is isolated injury to the axillary nerve that supplies sensation to the lateral aspect of the shoulder, not the anterior aspect. Recurrent instability is uncommon unless there is a labral tear or massive subscapularis tear. The biceps muscle is not viewed in the MR images, and a complete proximal biceps tendon rupture would be uncommon in the setting of an anterior shoulder dislocation.
CLINICAL SITUATION FOR QUESTIONS 72 THROUGH 75
Figures 72a through 72e are the MR images of a 12-year-old boy with left lateral-sided knee pain following a football injury. He has a several-year history of recurrent knee pain that improves with rest. An examination reveals a moderate effusion. Range of motion is 0 degrees
to 90 degrees and is limited by pain in deep flexion. He has tenderness to palpation along the lateral joint line, and no instability is noted.
Question 36
Figures below show the radiographs, and the MRIs obtained from a 32-year-old man with worsening left knee pain. A 3-foot hip-to-ankle radiograph shows a 13-degree varus knee deformity. The patient sustained a major left knee injury 5 years ago and a confirmed complete anterior cruciate ligament (ACL) tear. He managed this injury nonsurgically with a functional brace but experienced worsening pain. He was seen by an orthopaedic surgeon 18 months ago, and a medial meniscus tear was diagnosed; the tear was treated with an arthroscopic partial medial meniscectomy. Since then, his knee has been giving way more often, and he no longer feels safe working on a pitched roof. The patient received 6 months of formal physical therapy and was fitted for a new functional ACL brace, but he still has pain and instability. He believes he has exhausted his nonsurgical options and would like to undergo surgery. What is the most appropriate treatment at this time?
Explanation
DISCUSSION:
Proximal tibial osteotomy is the most appropriate intervention to correct varus malalignment and to reduce stress on the ACL. In some cases, proximal tibial osteotomy alone may address both pain and instability, but if instability persists, particularly in the setting in which instability can be dangerous, subsequent ACL reconstruction can further stabilize the knee with less stress on the graft after the correction of malalignment. Varus alignment places increased stress on the native or reconstructed ACL. ACL reconstruction should be performed only at the same time as or following proximal tibial osteotomy to correct alignment in the setting of varus malalignment. It is not appropriate to perform ACL reconstruction prior to proximal tibial osteotomy in this setting. Distal femoral osteotomy is not indicated to correct varus malalignment. Varus alignment places increased stress on the native or reconstructed ACL, and ACL reconstruction alone is not indicated for this patient.
Proximal tibial osteotomy is the most appropriate intervention to correct varus malalignment and to reduce stress on the ACL. In some cases, proximal tibial osteotomy alone may address both pain and instability, but if instability persists, particularly in the setting in which instability can be dangerous, subsequent ACL reconstruction can further stabilize the knee with less stress on the graft after the correction of malalignment. Varus alignment places increased stress on the native or reconstructed ACL. ACL reconstruction should be performed only at the same time as or following proximal tibial osteotomy to correct alignment in the setting of varus malalignment. It is not appropriate to perform ACL reconstruction prior to proximal tibial osteotomy in this setting. Distal femoral osteotomy is not indicated to correct varus malalignment. Varus alignment places increased stress on the native or reconstructed ACL, and ACL reconstruction alone is not indicated for this patient.
Question 37
What is the most common complication following surgical treatment of a displaced talar neck fracture?
Explanation
The most frequent complication is posttraumatic arthritis. With talar neck fractures, osteonecrosis is relatively common, occurring in up to 50% of patients. Fracture nonunion occurs in 10% to 12% of patients. Varus malunion can occur with medial comminution. Wound dehiscence and deep infection are much less frequently encountered.
(SBQ12TR.14) Elevated interleukin 6 (IL-6) is most closely associated to which of the following clinical outcomes in orthopedic trauma patients?
Decreased mortality rates
Increased mortality rates
Decreased osteomyelitis infection rates
Increased rhabdomyolysis rates
Increased compartmental syndrome rates
Elevated levels of Interleukin 6 (IL-6) is most closely associated with higher injury severity scores and increased mortality rates in polytrauma orthopaedic patients.
Hyperstimulation of the inflammatory system by major trauma is considered to be the key element in the pathogenesis of severe inflammatory response syndrome and multi-organ dysfunction syndrome. IL-6 is a complex acute-reactant cytokinase that is expressed by cells in response to tissue injury. IL-6 levels are associated with injury severity, complications, and mortality. Patients with the most severe injuries have the highest IL-6 serum levels.
Sears et al. reviewed the markers of inflammation in major trauma. They suggest that interleukin-6 and human leukocyte antigen-DR class II molecules appear to have the greatest potential for use in predicting the clinical course and outcome in trauma patients. Early identification of traumatic patients, based on inflammatory markers and genomic predisposition, could help to guide intervention and treatment.
Pape et al measured the perioperative concentrations of interleukin-6 in sixty-eight blunt trauma patients with non-life threatening pelvic fractures. Release of proinflammatory cytokines were higher in patients undergoing surgical procedures that cause increased blood loss. The release of markers seems to be related to the type and magnitude of surgery, rather than to the duration of the procedure.
Illustration A shows a diagram of the acute inflammatory response after major trauma Incorrect Answers:
(SBQ12TR.14) Elevated interleukin 6 (IL-6) is most closely associated to which of the following clinical outcomes in orthopedic trauma patients?
Decreased mortality rates
Increased mortality rates
Decreased osteomyelitis infection rates
Increased rhabdomyolysis rates
Increased compartmental syndrome rates
Elevated levels of Interleukin 6 (IL-6) is most closely associated with higher injury severity scores and increased mortality rates in polytrauma orthopaedic patients.
Hyperstimulation of the inflammatory system by major trauma is considered to be the key element in the pathogenesis of severe inflammatory response syndrome and multi-organ dysfunction syndrome. IL-6 is a complex acute-reactant cytokinase that is expressed by cells in response to tissue injury. IL-6 levels are associated with injury severity, complications, and mortality. Patients with the most severe injuries have the highest IL-6 serum levels.
Sears et al. reviewed the markers of inflammation in major trauma. They suggest that interleukin-6 and human leukocyte antigen-DR class II molecules appear to have the greatest potential for use in predicting the clinical course and outcome in trauma patients. Early identification of traumatic patients, based on inflammatory markers and genomic predisposition, could help to guide intervention and treatment.
Pape et al measured the perioperative concentrations of interleukin-6 in sixty-eight blunt trauma patients with non-life threatening pelvic fractures. Release of proinflammatory cytokines were higher in patients undergoing surgical procedures that cause increased blood loss. The release of markers seems to be related to the type and magnitude of surgery, rather than to the duration of the procedure.
Illustration A shows a diagram of the acute inflammatory response after major trauma Incorrect Answers:
Question 38
What is the most common benign bone tumor in childhood?
Explanation
DISCUSSION: The most common benign bone tumor in childhood is a nonossifying fibroma. It is estimated that 30% of children have a nonossifying fibroma. In most patients, the lesion is not identified until a radiograph is obtained for unrelated reasons. Similarly, most identified cases of fibrous cortical defect are not biopsied because the radiographic and clinical presentations are diagnostic.
REFERENCES: Aboulafia AJ, Kennon RE, Jelinek JS: Benign bone tumors of childhood. J Am Acad Orthop Surg 1999;7:377-388.
Biermann JS: Common benign lesions of bone in children and adolescents. J Pediatr Orthop 2002;22:268-273.
REFERENCES: Aboulafia AJ, Kennon RE, Jelinek JS: Benign bone tumors of childhood. J Am Acad Orthop Surg 1999;7:377-388.
Biermann JS: Common benign lesions of bone in children and adolescents. J Pediatr Orthop 2002;22:268-273.
Question 39
A 21-year-old man sustains multiple gunshot wounds to his right upper extremity. He can not extend his digits or his thumb but can extend and radially deviate his wrist. An injury to the radial nerve or one of its branches has most likely occurred at which of the following locations?
Explanation
DISCUSSION: In this patient, the radial nerve is most likely injured at the level of the radial neck. The radial nerve emerges from the posterior cord of the brachial plexus and travels along the spiral groove of the humerus. At the level of the lateral humeral condyle, the radial nerve branches into the posterior interosseous nerve after giving off two cutaneous branches, the superficial radial and the posterior cutaneous. The posterior interosseous nerve travels through the supinator muscle and winds around the radial neck. At this level, the posterior interosseous nerve is vulnerable to injury, particularly following fracture or penetrating trauma.
REFERENCES: Netter F: The Ciba Collection of Medical Illustrations: The Musculoskeletal System, Part 1: Anatomy, Physiology and Metabolic Disorders. West Caldwell, NJ, Ciba-Geigy Corporation, 1987, vol 8, p 53.
Hollinshead W: Anatomy for Surgeons: The Back and Limbs, ed 3. Philadelphia, PA, Harper and Row, 1982, vol 3, pp 428-429.
REFERENCES: Netter F: The Ciba Collection of Medical Illustrations: The Musculoskeletal System, Part 1: Anatomy, Physiology and Metabolic Disorders. West Caldwell, NJ, Ciba-Geigy Corporation, 1987, vol 8, p 53.
Hollinshead W: Anatomy for Surgeons: The Back and Limbs, ed 3. Philadelphia, PA, Harper and Row, 1982, vol 3, pp 428-429.
Question 40
An otherwise healthy 30-year-old man undergoes right shoulder arthroscopic Bankart repair under regional anesthesia using an interscalene brachial plexus block. In the recovery room, he reports mild difficulty breathing and his chest radiograph shows a high riding diaphragm on the right side. His peripheral oxygenation is 97% on 2 liters of oxygen by nasal cannula. What is the most appropriate management?
Explanation
Because the phrenic nerve lies in close proximity to the site of anesthetic injection, temporary hemidiaphragmatic paresis is a very common side effect of interscalene brachial plexus block. Pulmonary function and chest wall mechanics may be slightly compromised, but can easily be compensated in a healthy patient. Therefore, with sufficient oxygenation, aggressive assessments or treatments such as arterial blood gas measurements, emergent spiral CT scans, chest tube insertions, or endotracheal intubation are not warranted. For this stable patient, continued monitoring with gradual withdrawal of oxygen is the most appropriate treatment.
Question 41
In the spine, osteoblastomas usually originate in the
Explanation
DISCUSSION: Osteoblastomas are benign lesions that represent less than 5% of benign bone tumors. Most lesions are located in the spine, followed by the femur, tibia, and skull. Patients with spinal lesions usually have pain that may be associated with scoliosis. The most common location in the spine is within the posterior elements.
REFERENCE: Frassica FJ, Waltrip RL, Sponseller PD, Ma LD, McCarthy EF Jr: Clinicopathologic features and treatment of osteoid osteoma and osteoblastoma in children and adolescents. Orthop Clin North Am 1996;27:559-574.
REFERENCE: Frassica FJ, Waltrip RL, Sponseller PD, Ma LD, McCarthy EF Jr: Clinicopathologic features and treatment of osteoid osteoma and osteoblastoma in children and adolescents. Orthop Clin North Am 1996;27:559-574.
Question 42
Figures 31a and 31b are the radiographs of a 5-year-old boy with an elbow injury.
Explanation
DISCUSSION
Figure 26 shows lucent areas of both femoral condyles. This may represent a variation of ossification, in which case this boy’s knee pain is coincidental. Another possibility is atypical osteochondritis dissecans. An MRI will distinguish between the 2 entities and will guide treatment.
Figures 27a and 27b show healing rib and distal tibia fractures. These fractures likely are attributable to child abuse. A plain radiographic skeletal survey is sufficient for orthopaedic needs.
A triplane fracture of the distal tibia is revealed in Figure 28. A CT scan will quantify displacement and identify fracture fragments for planning of screw trajectories if open reduction and internal fixation is indicated (displacement > 2 mm).
In Figure 29, the linear lucency of the capitellum indicates an early osteochondritis dissecans. An MRI will allow staging of the lesion.
Figure 30 shows that the left radius and ulna do not align with the humerus; this is the likely result of a transphyseal fracture of the distal humerus. An arthrogram will outline the unossified distal humerus and allow for reduction. For an unstable neonate, this likely can be performed in the NICU.
Figures 31a and 31b reveal a widely displaced lateral condyle fracture for which open reduction and internal fixation is required. No advanced imaging is necessary.
Figure 26 shows lucent areas of both femoral condyles. This may represent a variation of ossification, in which case this boy’s knee pain is coincidental. Another possibility is atypical osteochondritis dissecans. An MRI will distinguish between the 2 entities and will guide treatment.
Figures 27a and 27b show healing rib and distal tibia fractures. These fractures likely are attributable to child abuse. A plain radiographic skeletal survey is sufficient for orthopaedic needs.
A triplane fracture of the distal tibia is revealed in Figure 28. A CT scan will quantify displacement and identify fracture fragments for planning of screw trajectories if open reduction and internal fixation is indicated (displacement > 2 mm).
In Figure 29, the linear lucency of the capitellum indicates an early osteochondritis dissecans. An MRI will allow staging of the lesion.
Figure 30 shows that the left radius and ulna do not align with the humerus; this is the likely result of a transphyseal fracture of the distal humerus. An arthrogram will outline the unossified distal humerus and allow for reduction. For an unstable neonate, this likely can be performed in the NICU.
Figures 31a and 31b reveal a widely displaced lateral condyle fracture for which open reduction and internal fixation is required. No advanced imaging is necessary.
Question 43
A 73-year-old man has stiffness after undergoing primary posterior cruciate ligament-retaining total knee arthroplasty 18 months ago. Extensive physiotherapy, dynamic splinting, and manipulations under anesthesia have failed to result in improvement. Examination reveals range of motion from 30 degrees to 60 degrees of flexion. The components are well fixed, and the evaluation for infection is negative. In discussing the possibility of revision arthroplasty, the patient should be advised that
Explanation
DISCUSSION: Stiffness following primary total knee arthroplasty remains a vexing problem. Treatment options have included extensive physical therapy, dynamic splinting, manipulation under anesthesia, arthroscopic arthrolysis, open arthrolysis with polyethylene exchange, and ultimately revision arthroplasty. Results are not as gratifying as would be expected. Babis and associates performed an open arthrolysis and polyethylene exchange on seven patients who were followed for a mean of 4.2 months. The results were poor. The mean improvement in arc of motion was only 20 degrees. Nicholls and Dorr treated 13 patients for stiffness. Only 40% of those patients obtained good to excellent results. Four patients (30%) required manipulation because of recurrent stiffness postoperatively. They noted they could not predictably improve the arc of motion with a revision operation. Haidukewych and associates reported on 15 patients who underwent revision of well-fixed components after total knee arthroplasty for stiffness. Of the 15 patients, 10 (66%) were satisfied with the outcome revision. Interestingly, they noted that in patients for whom the total arc of motion did not improve but who regained near full extension, there was a greater amount of satisfaction with the procedure than for those who did not regain full extension.
REFERENCES: Babis GC, Trousdale RT, Pagnano MW, et al: Poor outcomes of isolated tibial insert exchange and arthrolysis for the management of stiffness following total knee arthroplasty. J Bone Joint Surg Am 2001;83:1534-1536.
Nicholls DW, Dorr LD: Revision surgery for stiff total knee arthroplasty. J Arthroplasty 1990;5:S73-S77.
Haidukewych GJ, Jacofsky DJ, Pagnano MW, et al: Functional results after revision of well-fixed components for stiffness after primary total knee arthroplasty. J Arthroplasty 2005;20:133-138.
REFERENCES: Babis GC, Trousdale RT, Pagnano MW, et al: Poor outcomes of isolated tibial insert exchange and arthrolysis for the management of stiffness following total knee arthroplasty. J Bone Joint Surg Am 2001;83:1534-1536.
Nicholls DW, Dorr LD: Revision surgery for stiff total knee arthroplasty. J Arthroplasty 1990;5:S73-S77.
Haidukewych GJ, Jacofsky DJ, Pagnano MW, et al: Functional results after revision of well-fixed components for stiffness after primary total knee arthroplasty. J Arthroplasty 2005;20:133-138.
Question 44
A type 2A hangman’s fracture, which has the potential to overdistract with traction, has which of the following hallmark findings?
Explanation
DISCUSSION: Type 2A hangman’s fractures are thought to have a flexion mechanism rather than extension and axial loading. This allows them to rotate around the anterior longitudinal ligament into flexion. Anterior translation of greater than 3 mm and angulation distinguish type 2 fractures from type 1 fractures. Although there is an association between C1 ring fractures and C2 fractures, this does not factor into the classification. If a C2-3 facet dislocation exists in combination with a C2 pars fracture, it is considered a type 3 fracture.
REFERENCES: Garfin SR, Vaccaro AR (eds): Orthopaedic Knowledge Update: Spine. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, pp 197-217.
Levine AM, Edwards CC: The management of traumatic spondylolisthesis of the axis. J Bone Joint Surg Am 1985;67:217-226.
REFERENCES: Garfin SR, Vaccaro AR (eds): Orthopaedic Knowledge Update: Spine. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, pp 197-217.
Levine AM, Edwards CC: The management of traumatic spondylolisthesis of the axis. J Bone Joint Surg Am 1985;67:217-226.
Question 45
Figure 29 shows the radiograph of a 25-year-old woman who has had a 3-month history of ankle pain after sustaining an inversion injury to the ankle. She reports occasional catching, but no sense of instability. Examination reveals ligament stability. Management should consist of
Explanation
DISCUSSION: Osteochondral lesions of the talar dome can have a traumatic or nontraumatic etiology. Most authors site a probable traumatic etiology for lateral lesions. Stage I and II lesions, which are composed of compressed subchondral bone or a partial detached osteochondral fragment, can be treated initially in a non-weight-bearing short leg cast for 6 weeks. Stage III medial lesions can also be treated in the same manner. If symptoms persist, the treament of choice is debridement of the fracture, curettage of the lesion, and drilling of the subchondral bone. This treatment also applies to lateral stage III and all stage IV lesions. If the fragment is at least one third of the size of the talar dome, management should consist of open reduction and internal fixation. In patients with more chronic lesions (4 to 6 months of persistent pain), the threshold to proceed with surgery is lower, even in a stage II lesion.
REFERENCES: Lutter LD, Mizel MS, Pfeffer GB (eds): Orthopaedic Knowledge Update: Foot and Ankle. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1994, pp 205-226.
Pettine KA, Morrey BF: Osteochondral fractures of the talus: A long-term follow-up. J Bone Joint Surg Br 1987;69:89-92.
REFERENCES: Lutter LD, Mizel MS, Pfeffer GB (eds): Orthopaedic Knowledge Update: Foot and Ankle. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1994, pp 205-226.
Pettine KA, Morrey BF: Osteochondral fractures of the talus: A long-term follow-up. J Bone Joint Surg Br 1987;69:89-92.
Question 46
Which of the following is considered the most accurate test to determine the amount of limb-length discrepancy in a patient with a knee flexion contracture of 35°?
Explanation
DISCUSSION: Flexion contractures and angular deformities of a limb cause inaccurate limb-length measurement results with most clinical methods. A CT scanogram is more accurate than standard scanograms for determining limb length in patients with knee flexion contractures of 30° or more. The cost and time necessary to complete the examinations are comparable, but the CT scanogram delivers only 20% of the radiation needed for standard scanograms.
REFERENCES: Aaron A, Weinstein D, Thickman D, Eilert R: Comparison of orthoroentgenography and computed tomography in the measurement of limb-length discrepancy. J Bone Joint Surg Am 1992;74:897-902.
Tachdjian MO: Pediatric Orthopedics. Philadelphia, Pa, WB Saunders, 1990, pp 2867-2870.
REFERENCES: Aaron A, Weinstein D, Thickman D, Eilert R: Comparison of orthoroentgenography and computed tomography in the measurement of limb-length discrepancy. J Bone Joint Surg Am 1992;74:897-902.
Tachdjian MO: Pediatric Orthopedics. Philadelphia, Pa, WB Saunders, 1990, pp 2867-2870.
Question 47
Which of the following fluoroscopic views is used to assess intra-articular screw penetration during volar fixation of a distal radius fracture?
Explanation
Due to radial inclination, a true lateral view of the wrist will not show whether screws from a volar plate are intra-articular; a 23° elevated lateral view is needed to adequately assess this.
The amount of elevation will depend on the degree to which the surgeon restores radial inclination; for example, if the surgeon only restores 15° of radial inclination, then the surgeon would only have to elevate the wrist 15° from a true lateral in order to have the radiographic beam point down the joint line. Failure to diagnose intra-articular screws intraoperatively can lead to degenerative changes.
Tweet et al. performed a survey of orthopedic surgeons regarding their preferred method of visualizing screw placement during wrist fixation. The majority of surgeons reported that they obtain multiple views, including AP/PA wrist views, a 23° lateral inclination view, and a true lateral view. They also performed a cadaveric study looking at different x-ray views and screw penetration. They reported that live rotational fluoroscopy provided the highest sensitivity (93%) and specificity (96%) for the detection of intra-articular screw penetration.
Patel et al. evaluated the ability of surgeons at different levels to critically assess distal radius fixation and screw placement. They found that supplementation with a 23° lateral view increased accuracy and confidence in all position, specialty, and experience groups. Confidence scores were significantly higher following the evaluation of three views versus two views. Residents exhibited the greatest improvements in accuracy and confidence. For first-phase (standard view) assessments, accuracy scores were significantly better for attendings with less than 10 years of post-fellowship experience than those with more.
Illustration A is a non-elevated lateral of the wrist, while illustration B is a 23° elevated lateral radiograph. Illustration C is an example of a skyline view, which assesses for screws penetrating the dorsal cortex.
Incorrect Answers:
check for long distal screws.
OrthoCash 2020
The amount of elevation will depend on the degree to which the surgeon restores radial inclination; for example, if the surgeon only restores 15° of radial inclination, then the surgeon would only have to elevate the wrist 15° from a true lateral in order to have the radiographic beam point down the joint line. Failure to diagnose intra-articular screws intraoperatively can lead to degenerative changes.
Tweet et al. performed a survey of orthopedic surgeons regarding their preferred method of visualizing screw placement during wrist fixation. The majority of surgeons reported that they obtain multiple views, including AP/PA wrist views, a 23° lateral inclination view, and a true lateral view. They also performed a cadaveric study looking at different x-ray views and screw penetration. They reported that live rotational fluoroscopy provided the highest sensitivity (93%) and specificity (96%) for the detection of intra-articular screw penetration.
Patel et al. evaluated the ability of surgeons at different levels to critically assess distal radius fixation and screw placement. They found that supplementation with a 23° lateral view increased accuracy and confidence in all position, specialty, and experience groups. Confidence scores were significantly higher following the evaluation of three views versus two views. Residents exhibited the greatest improvements in accuracy and confidence. For first-phase (standard view) assessments, accuracy scores were significantly better for attendings with less than 10 years of post-fellowship experience than those with more.
Illustration A is a non-elevated lateral of the wrist, while illustration B is a 23° elevated lateral radiograph. Illustration C is an example of a skyline view, which assesses for screws penetrating the dorsal cortex.
Incorrect Answers:
check for long distal screws.
OrthoCash 2020
Question 48
Figures 14a and 14b show the initial radiographs of an 18-year-old man who fell while snowboarding. Figures 14c and 14d show the radiographs obtained following closed reduction. Examination reveals that the elbow is stable with range of motion. Management should now consist of
Explanation
DISCUSSION: The initial radiographs reveal a simple elbow dislocation without associated fractures. After successful closed reduction, the range of stability should be assessed. If the elbow is stable, nonsurgical management should consist of a short period of immobilization followed by range-of-motion exercises. Immobilization for more than 3 weeks results in significant elbow stiffness. Surgical repair is indicated for dislocations that are irreducible, have associated fractures, or where stability cannot be maintained with closed treatment.
REFERENCES: Cohen MS, Hastings H II: Acute elbow dislocations: Evaluation and management. J Am Acad Orthop Surg 1998;6:15-23.
O’Driscoll SW: Elbow dislocations, in Morrey BF (ed): The Elbow and Its Disorders, ed 3. Philadelphia, PA, WB Saunders, 2000, pp 409-420.
REFERENCES: Cohen MS, Hastings H II: Acute elbow dislocations: Evaluation and management. J Am Acad Orthop Surg 1998;6:15-23.
O’Driscoll SW: Elbow dislocations, in Morrey BF (ed): The Elbow and Its Disorders, ed 3. Philadelphia, PA, WB Saunders, 2000, pp 409-420.
Question 49
A patient undergoes a proximal tibial resection that is reconstructed with a fresh frozen osteoarticular allograft. Eleven months later, the graft is retrieved. Histologically, the articular cartilage and subchondral bone retrieved would be expected to show evidence of
Explanation
DISCUSSION: Osteoarticular allografts are devoid of host chondrocytes but do contain “mummified” cellular debris left over from donor processing. The cartilage architecture is preserved in the first 2 to 3 years after transplantation. The articular surface is covered with a pannus of fibrocartilage maintaining the joint space radiographically; this pannus later contains islands of fibrocartilage containing host mesenchymal stem cells. Degenerative changes to the joint surface occur earlier and are more severe in joints that are unstable. Only with degenerative changes at the surface is there histologic evidence of subchondral revascularization. Often degenerative changes involving the articular cartilage reach the tidemark, but the tidemark itself remains structurally intact.
REFERENCES: Enneking WF, Campanacci DA: Retrieved human allografts:
A clinicopathological study. J Bone Joint Surg Am 2001;83:971-986.
Enneking WF, Mindell ER: Observations on massive retrieved human allografts.
J Bone Joint Surg Am 1991;73:1123-1142.
REFERENCES: Enneking WF, Campanacci DA: Retrieved human allografts:
A clinicopathological study. J Bone Joint Surg Am 2001;83:971-986.
Enneking WF, Mindell ER: Observations on massive retrieved human allografts.
J Bone Joint Surg Am 1991;73:1123-1142.
Question 50
What is an example of cognitive rest after concussion? Review Topic
Explanation
Physical and cognitive rest are recommended as treatment for sports-related concussion. Cognitive rest involves minimizing activities that require concentration and attention such as reading, schoolwork, video games, text messaging, working online, and playing games that require concentration such as chess. Limiting or eliminating video games after concussion is a form of cognitive rest.
Question 51
Figures 1 and 2 are the radiographs of a 20-year-old college multisport athlete who has had longstanding pain in his left hip. He denies any specific event that initiated his pain, but he notes that he had hip problems when he was an infant. He denies pain with activities of daily living, but he believes his pain is increasingly limiting his ability to exercise. He localizes the pain to his groin. He denies low-back or buttock pain or pain that radiates down his leg. What examination findings are most consistent with the pathology seen in the radiographs?
Explanation
This patient has cam-type femoroacetabular impingement. Decreased internal rotation and a positive impingement test (forced flexion, adduction, and internal rotation) are classic findings. The lack of pain with resisted hip flexion makes hip flexor strain unlikely, and the lack of tenderness at the greater
trochanter renders trochanteric bursitis unlikely. Although athletic pubalgia can be a source of longstanding groin pain, he lacks the pain with a resisted sit-up and tenderness along the pubic ramus that is frequently noted in patients with pubalgia. His radiographs reveal a focal femoral neck prominence consistent with cam impingement, although pistol grip deformities and flattening of the lateral femoral head are often present as well. His MRI scan shows a labral tear, which is common in cam impingement. Surgical treatment for cam impingement can be effective for symptomatic patients. Even among high-level athletes, open surgical dislocation of the hip has been shown to have good results. Most patients with cam impingement can be treated with arthroscopic osteoplasty and achieve results comparable with those realized with open surgical dislocation. The literature describes success in terms of athletes returning to sports (even professional athletes) to be approximately 90% after arthroscopic treatment. Byrd and Jones described five patients who developed transient neurapraxias that resolved uneventfully. The patients in his series who had concomitant microfracture had a 92% return to sports within the follow-up period. Cam impingement has long been thought to be associated with a history of a slipped capital femoral epiphysis. The capitis in these patients is displaced posteriorly, resulting in a prominent anterior femoral neck and decreased hip internal rotation. Pincer impingement is associated with a deep acetabulum, such as protrusion acetabula and acetabular retroversion. A patient who underwent a periacetabular osteotomy can develop a more retroverted acetabulum as well.
trochanter renders trochanteric bursitis unlikely. Although athletic pubalgia can be a source of longstanding groin pain, he lacks the pain with a resisted sit-up and tenderness along the pubic ramus that is frequently noted in patients with pubalgia. His radiographs reveal a focal femoral neck prominence consistent with cam impingement, although pistol grip deformities and flattening of the lateral femoral head are often present as well. His MRI scan shows a labral tear, which is common in cam impingement. Surgical treatment for cam impingement can be effective for symptomatic patients. Even among high-level athletes, open surgical dislocation of the hip has been shown to have good results. Most patients with cam impingement can be treated with arthroscopic osteoplasty and achieve results comparable with those realized with open surgical dislocation. The literature describes success in terms of athletes returning to sports (even professional athletes) to be approximately 90% after arthroscopic treatment. Byrd and Jones described five patients who developed transient neurapraxias that resolved uneventfully. The patients in his series who had concomitant microfracture had a 92% return to sports within the follow-up period. Cam impingement has long been thought to be associated with a history of a slipped capital femoral epiphysis. The capitis in these patients is displaced posteriorly, resulting in a prominent anterior femoral neck and decreased hip internal rotation. Pincer impingement is associated with a deep acetabulum, such as protrusion acetabula and acetabular retroversion. A patient who underwent a periacetabular osteotomy can develop a more retroverted acetabulum as well.
Question 52
Figures below demonstrate the radiographs obtained from a 56-year-old man with a 3-year history of right groin pain. A comprehensive nonsurgical program has failed, and the patient would like to proceed with total hip arthroplasty. He is seen by a pain management specialist and is currently taking 40 mg of sustained-release morphine twice daily with oxycodone 10 mg 2 to 3 times a day for severe pain. What is the recommended course of action regarding his chronic narcotic use?
Explanation
DISCUSSION:
Chronic opioid consumption prior to total joint arthroplasty has been associated with increased pain after surgery, increased opioid requirements, a slower recovery and longer hospital stay, and higher 90-day postoperative complications compared with patients not on chronic opioids preoperatively. Based on this information, Nguyen and associates performed a study in three patient groups that included 1) chronic opioid users who underwent no preoperative intervention, 2) chronic opioid users who were weaned down to 50% of their prior opioid regimen, and 3) patients who were not chronic opioid users. The authors found that the reduction of preoperative opioid use improved postoperative function, pain, and recovery and that the weaned group performed more like the opioid naive group than the chronic opioid user
group. Increasing opioid use prior to surgery in this patient would make it more difficult to control pain after surgery. Stopping all of his opioids just prior to surgery would place the patient at substantial risk for opioid withdrawal and is not recommended. Avoiding the use of all narcotics and using only acetaminophen postoperatively is very unlikely to provide appropriate pain relief in a chronic opioid user. The recommendation based on the provided literature is to decrease the patient's narcotic use prior to
surgery.
Chronic opioid consumption prior to total joint arthroplasty has been associated with increased pain after surgery, increased opioid requirements, a slower recovery and longer hospital stay, and higher 90-day postoperative complications compared with patients not on chronic opioids preoperatively. Based on this information, Nguyen and associates performed a study in three patient groups that included 1) chronic opioid users who underwent no preoperative intervention, 2) chronic opioid users who were weaned down to 50% of their prior opioid regimen, and 3) patients who were not chronic opioid users. The authors found that the reduction of preoperative opioid use improved postoperative function, pain, and recovery and that the weaned group performed more like the opioid naive group than the chronic opioid user
group. Increasing opioid use prior to surgery in this patient would make it more difficult to control pain after surgery. Stopping all of his opioids just prior to surgery would place the patient at substantial risk for opioid withdrawal and is not recommended. Avoiding the use of all narcotics and using only acetaminophen postoperatively is very unlikely to provide appropriate pain relief in a chronic opioid user. The recommendation based on the provided literature is to decrease the patient's narcotic use prior to
surgery.
Question 53
-An absolute contraindication for closed management of a humeral shaft fracture in a fracture brace is
Explanation
Question 54
A 4-year-old boy sustained a nondisplaced, but complete, fracture of the left proximal tibial metaphysis 1 year ago. The fracture healed uneventfully in an anatomic position. Examination of the injured extremity now reveals 18° of valgus compared with 3° of valgus on the opposite side. Management should now include
Explanation
DISCUSSION: The development of a valgus deformity after this type of fracture is a well-known occurrence, and the patient’s parents should be informed about this risk. In a patient who is age 4 years, the natural history is one of gradual correction by the development of a physiologic varus deformity at the distal tibial physis; therefore, no active intervention is needed at this time. Bracing has no effect on the deformity, and the child is too young for any procedure on the growth plate. Proximal tibial osteotomy is reserved until the patient nears skeletal maturity because of the risk of recurrence of the deformity. Lateral stapling can be done near skeletal maturity if the deformity persists, but this is unlikely to be necessary.
REFERENCES: Zionts LE, MacEwen GD: Spontaneous improvement of posttraumatic tibia valga. J Bone Joint Surg Am 1986;68:680-687.
Beaty JH, Kumar A: Fractures about the knee in children. J Bone Joint Surg Am 1994;76:1870-1880.
REFERENCES: Zionts LE, MacEwen GD: Spontaneous improvement of posttraumatic tibia valga. J Bone Joint Surg Am 1986;68:680-687.
Beaty JH, Kumar A: Fractures about the knee in children. J Bone Joint Surg Am 1994;76:1870-1880.
Question 55
The spinal cord terminates as the conus medullaris at what vertebral level in adults? Review Topic 1 T12
Explanation
The spinal cord anatomy changes at the thoracolumbar junction. The spinal cord terminates as the conus medullaris at the lower portion of L1 in women and the pedicle of L1 in men.
Question 56
What nerve is at the highest risk for injury with a percutaneous repair of an Achilles tendon injury?
Explanation
DISCUSSION: Cadaver and clinical studies have shown that the sural nerve is at the highest risk for injury with a percutaneous repair of the Achilles tendon.
REFERENCE: Hockenbury RT, Johns JC: A biomechanical in vitro comparison of open versus percutaneous repair of tendon Achilles. Foot Ankle 1990;11:67-72.
REFERENCE: Hockenbury RT, Johns JC: A biomechanical in vitro comparison of open versus percutaneous repair of tendon Achilles. Foot Ankle 1990;11:67-72.
Question 57
A 77-year-old man with diabetes mellitus has had a nonhealing Wagner grade I ulcer under the medial sesamoid for the past 3 months. He smokes tobacco regularly. He has undergone several debridements and total contact casting. Examination reveals no palpable pulses. He has no erythema or purulence, and he is afebrile. Radiographs reveal no abnormalities. What is the best initial diagnostic test to help determine why the ulcer has failed to heal?
Explanation
DISCUSSION: The best initial test for this patient is to assess the vascular supply to the foot. An elderly smoker with diabetes mellitus has a high risk of peripheral vascular disease. Decreased weight bearing has not been successful. Although a bone scan might be helpful, it would take secondary consideration to the patient’s vascular supply, especially in the absence of any acute infection. Monofilament testing would help diagnosis neuropathy, which is a root cause behind the ulcer forming, but does not prevent it from healing. The Thompson’s test is used to diagnosis an Achilles tendon rupture.
REFERENCE: Brodsky JW: Evaluation of the diabetic foot. Instr Course Lect 1999;48:289-303.
REFERENCE: Brodsky JW: Evaluation of the diabetic foot. Instr Course Lect 1999;48:289-303.
Question 58
An 80-year-old patient presents 8 months postoperatively with right groin pain. Examination reveals a leg length discrepancy of 1.5cm. Recent radiographs are seen in Figures A and B. What is the most appropriate treatment plan?
Explanation
This patient has atrophic non-union (NU) and varus collapse following cephalomedullary nailing of a subtrochanteric fracture. The ideal treatment involves nail removal, correction of alignment, fracture fixation, and bone grafting. Fixation can be achieved with a nail or plate.
Subtrochanteric fractures can be treated with cephalomedullary nailing or fixed angle plates. Nailing of these fractures is technically challenging because the fracture must be reduced prior to nail passage. Failure to do so leads to varus and procurvatum malreduction.
Bellabarba et al. reviewed plating of femoral nonunions after intramedullary nailing. Of 23 nonunions, 21 healed at an average of 12 weeks. The remaining 2 cases required repeat plating (at 2 and 8 weeks) for hardware breakage because of noncompliance with weightbearing restrictions. They advocate plating because it allows for correction of malalignment and provides a biomechanically superior tension band construct.
Incorrect Answers:
(SBQ12TR.48) A 28-year-old male college student sustains a severe foot injury from gunshot-related violence, and subsequently undergoes a lower-extremity amputation
as shown in Figure A. At long-term follow-up, which of the following is the strongest predictor of patient satisfaction as related to his injury?
Age less than 30
Marijuana use
Use of negative pressure wound therapy
Male gender
Ability to return to work
The strongest factor to predict patient-reported outcomes after trauma-related lower extremity amputations is the patient's ability to return to work. This is likely due to the effect of the return to work on the physical, emotional, and financial aspects of the patient's life.
The LEAP study is a multicenter, prospective study evaluating multiple aspects of reconstruction versus amputation in the treatment of mangled extremity injuries. With regard to patient satisfaction, treatment variables such as decision for reconstruction versus amputation, or initial presence or absence of plantar sensation have little impact. In addition, demographic factors such as age, gender, socioeconomic status, and education level do not predict patient satisfaction. Instead, the most important predictors of patient satisfaction at 2 years after injury include the ability to return to work, absence of depression, faster walking speed, and decreased pain.
O'Toole et al reviewed 463 patients treated for limb-threatening lower-extremity injuries and identified factors associated with patient reported outcomes two years after surgery. They found that return to work was the most associated with outcomes, but that physical functioning, walking speed, pain levels, and presence of depression were also associated to a lesser extent with outcomes.
Bosse et al performed a multicenter, prospective study to assess outcomes of 569 patients with severe lower extremity limb injuries that resulted in either amputation or
limb salvage procedures. They found that at two years postoperatively, no significant differences were seen between groups in patient-reported outcome. Worse outcomes were associated with rehospitalization for a major complication, a low educational level, nonwhite race, poverty, lack of private health insurance, poor social-support network, low self-efficacy (the patient's confidence in being able to resume life activities), and involvement in disability-compensation litigation.
Figure A shows a clinical photograph of a Pirigoff amputation at early follow-up. This amputation is an end-bearing amputation that utilizes the plantar heel pad for weightbearing, and relies on a tibiocalcaneal arthrodesis.
Incorrect Answers:
1-4: These options are not as strong of a factor of patient satisfaction in long-term follow up after trauma-induced lower extremity amputation.
Subtrochanteric fractures can be treated with cephalomedullary nailing or fixed angle plates. Nailing of these fractures is technically challenging because the fracture must be reduced prior to nail passage. Failure to do so leads to varus and procurvatum malreduction.
Bellabarba et al. reviewed plating of femoral nonunions after intramedullary nailing. Of 23 nonunions, 21 healed at an average of 12 weeks. The remaining 2 cases required repeat plating (at 2 and 8 weeks) for hardware breakage because of noncompliance with weightbearing restrictions. They advocate plating because it allows for correction of malalignment and provides a biomechanically superior tension band construct.
Incorrect Answers:
(SBQ12TR.48) A 28-year-old male college student sustains a severe foot injury from gunshot-related violence, and subsequently undergoes a lower-extremity amputation
as shown in Figure A. At long-term follow-up, which of the following is the strongest predictor of patient satisfaction as related to his injury?
Age less than 30
Marijuana use
Use of negative pressure wound therapy
Male gender
Ability to return to work
The strongest factor to predict patient-reported outcomes after trauma-related lower extremity amputations is the patient's ability to return to work. This is likely due to the effect of the return to work on the physical, emotional, and financial aspects of the patient's life.
The LEAP study is a multicenter, prospective study evaluating multiple aspects of reconstruction versus amputation in the treatment of mangled extremity injuries. With regard to patient satisfaction, treatment variables such as decision for reconstruction versus amputation, or initial presence or absence of plantar sensation have little impact. In addition, demographic factors such as age, gender, socioeconomic status, and education level do not predict patient satisfaction. Instead, the most important predictors of patient satisfaction at 2 years after injury include the ability to return to work, absence of depression, faster walking speed, and decreased pain.
O'Toole et al reviewed 463 patients treated for limb-threatening lower-extremity injuries and identified factors associated with patient reported outcomes two years after surgery. They found that return to work was the most associated with outcomes, but that physical functioning, walking speed, pain levels, and presence of depression were also associated to a lesser extent with outcomes.
Bosse et al performed a multicenter, prospective study to assess outcomes of 569 patients with severe lower extremity limb injuries that resulted in either amputation or
limb salvage procedures. They found that at two years postoperatively, no significant differences were seen between groups in patient-reported outcome. Worse outcomes were associated with rehospitalization for a major complication, a low educational level, nonwhite race, poverty, lack of private health insurance, poor social-support network, low self-efficacy (the patient's confidence in being able to resume life activities), and involvement in disability-compensation litigation.
Figure A shows a clinical photograph of a Pirigoff amputation at early follow-up. This amputation is an end-bearing amputation that utilizes the plantar heel pad for weightbearing, and relies on a tibiocalcaneal arthrodesis.
Incorrect Answers:
1-4: These options are not as strong of a factor of patient satisfaction in long-term follow up after trauma-induced lower extremity amputation.
Question 59
A 33-year-old female with generalized ligamentous laxity is diagnosed with spontaneous atraumatic subluxation of the sternoclavicular joint. She notes mild, intermittent pain and a small amount of prominence to that area. What is the most appropriate treatment at this time?
Explanation
DISCUSSION: Spontaneous atraumatic subluxaton of the sternoclavicular joint is a rare condition and is generally associated with ligamentous laxity. Higginbotham et al reported that spontaneous atraumatic anterior subluxation of the sternoclavicular joint may occur during overhead elevation of the arm. The majority of cases are not painful, and the subluxation usually reduces with lowering the arm. Surgery is rarely indicated. Nonsurgical management, including patient education of the benign nature of the condition, is recommended. Rockwood et al reviewed a series of 37 patients with this condition and noted that at an average follow-up of eight years, the twenty-nine patients who were treated non-operatively had excellent results, with no limitations of activity or changes in lifestyle. The eight patients who were treated operatively (group II) had numerous problems, including noticeable scars, persistent instability, pain, or limitation of activity that resulted in an alteration in lifestyle. The referenced article by Higginbotham is a review of atraumatic disorders of the sternoclavicular joint.
Question 60
A 66-year-old woman with known poorly controlled rheumatoid arthritis reports that for the past 4 weeks she has been unable to extend the metacarpophalangeal (MCP) joints of her right hand index, middle, ring and little fingers. She cannot hyperextend the thumb interphalangeal joint. Active wrist extension is possible, but shows radial deviation. Examination reveals mild synovitis at the wrist and MCP joints of the affected hand. There is no ulnar deviation at the MCP joints with normal alignment. When the MCP joints are passively extended, the patient is unable to maintain them in this position. There is no piano key sign at the distal ulna. Passive wrist motion shows a normal tenodesis effect. Which of the following would most likely confirm your diagnosis? Review Topic
Explanation
There are many causes of inability to extend the MCP joints in a patient with rheumatoid arthritis. The most common cause is rupture of the extensor tendons. An intact tenodesis test suggests that the extensor tendons are intact, thus surgical exploration is not indicated and would not confirm the diagnosis. The patient has normal alignment of the fingers without ulnar deviation, suggesting that there are no MCP dislocations to account for the inability to extend the MCP joints; therefore, radiographs would not confirm the diagnosis. The most likely cause of inability to extend the fingers in this patient is posterior interosseous nerve (PIN) palsy. Electrodiagnostic studies would confirm the presence of PIN palsy. An MRI of the elbow may show synovitis at the radiocapitellar joint, which can cause the PIN palsy. This finding however, is nonspecific and many patients without PIN palsy would also demonstrate synovitis at the radiocapitellar joint. Therefore, although an MRI would be helpful in localizing a potential cause of PIN compression, it would not in itself confirm the diagnosis.
Question 61
A 75-year-old woman has a 1-year history of right hip pain and a right total hip arthroplasty (THA) performed in 1999. Her left THA, performed in 2002, is asymptomatic. Plain radiographs show that all of the components appear well fixed and in good position. There is evidence of eccentric polyethylene wear of the right hip with focal osteolysis of the calcar and great trochanter (with none of these findings on the left hip). What is the most likely explanation for her right hip pain?
Explanation
DISCUSSION
This patient likely has 1 conventional polyethylene hip (1999) and 1 hip with highly cross-linked polyethylene (HXLPE) (2002); most centers transitioned to HXLPE around 2001 to 2002. This explains the clear difference in the clinical and radiographic performance of the 2 hips during the second decade. There is clear evidence of decreased wear and osteolysis and clinical benefits (ie, decreased revision rate) during the second decade following the introduction of HXLPE for THA. Acute infection is unlikely considering the chronicity of symptoms. The radiographs show no obvious evidence of cup loosening. A pseudotumor attributable to trunnionosis, while reported, remains an infrequent clinical issue.
This patient likely has 1 conventional polyethylene hip (1999) and 1 hip with highly cross-linked polyethylene (HXLPE) (2002); most centers transitioned to HXLPE around 2001 to 2002. This explains the clear difference in the clinical and radiographic performance of the 2 hips during the second decade. There is clear evidence of decreased wear and osteolysis and clinical benefits (ie, decreased revision rate) during the second decade following the introduction of HXLPE for THA. Acute infection is unlikely considering the chronicity of symptoms. The radiographs show no obvious evidence of cup loosening. A pseudotumor attributable to trunnionosis, while reported, remains an infrequent clinical issue.
Question 62
A 32-year-old volleyball player has dull posterior shoulder pain. An examination reveals moderate external rotation weakness with his arm at his side but normal strength on supraspinatus isolation. Deltoid and supraspinatus bulk appear normal, although there appears to be mild infraspinatus atrophy. Sensation is normal throughout the shoulder and shoulder girdle. What is the most likely diagnosis?
Explanation
This clinical scenario describes a patient with an isolated injury affecting the infraspinatus muscle. The anatomic location of such a lesion would be at the spinoglenoid notch, at which the suprascapular nerve may be compressed distal to its innervation of the supraspinatus but proximal to the infraspinatus innervation. A calcified transverse scapular ligament would also affect the suprascapular nerve but is proximal to the innervation of both muscles. Quadrilateral space syndrome would affect innervation of the deltoid (and teres minor). Parsonage-Turner syndrome is a more diffuse, and often severely painful, brachial plexus neuropathy.
Question 63
A 58-year-old patient who underwent bilateral hip arthroplasty 12 years ago now reports pain in his hips and difficulty with ambulation to the point where he now uses crutches. A radiograph of the hip and pelvis is shown in Figure 26. What is the best treatment option for this patient?
Explanation
DISCUSSION: The radiographs reveal acetabular component failure with bone loss. There
are several treatment options available. The best option for survivorship is a cementless
porous-coated acetabular component. This patient may or may not require structural bone graft, which may need to be determined at the time of surgery. Bipolar implants and cemented acetabular components for revision surgery have not demonstrated long-term success. The use of a protrusio ring is reserved primarily for massive bone loss such as a Paprosky type III bone loss with significant superior migration of the acetabular component. The best clinical results for acetabular component revision have been achieved with cementless porous-coated implants.
REFERENCES: Haddad FS, Masri BA, Garbuz DS, et al: Acetabulum, in Fitzgerald RH, Kaufer H, Malkani AL (eds): Orthopaedics. St Louis, MO, Mosby, 2002, pp 923-936.
D’Antonio JA: Periprosthetic bone loss of the acetabulum: Classification and management. Orthop Clin North Am 1992;23:279-290.
Rubash HE, Sinha RK, Paprosky W, et al: A new classification system for the management of acetabular osteolysis after total hip arthroplasty. Instr Course Lect 1999;48:37-42.
are several treatment options available. The best option for survivorship is a cementless
porous-coated acetabular component. This patient may or may not require structural bone graft, which may need to be determined at the time of surgery. Bipolar implants and cemented acetabular components for revision surgery have not demonstrated long-term success. The use of a protrusio ring is reserved primarily for massive bone loss such as a Paprosky type III bone loss with significant superior migration of the acetabular component. The best clinical results for acetabular component revision have been achieved with cementless porous-coated implants.
REFERENCES: Haddad FS, Masri BA, Garbuz DS, et al: Acetabulum, in Fitzgerald RH, Kaufer H, Malkani AL (eds): Orthopaedics. St Louis, MO, Mosby, 2002, pp 923-936.
D’Antonio JA: Periprosthetic bone loss of the acetabulum: Classification and management. Orthop Clin North Am 1992;23:279-290.
Rubash HE, Sinha RK, Paprosky W, et al: A new classification system for the management of acetabular osteolysis after total hip arthroplasty. Instr Course Lect 1999;48:37-42.
Question 64
A 23-year-old woman with a history of bilateral recurrent ankle sprains, progressive cavovarus feet, and a family history of high arches and foot deformities is seen for evaluation. Management consisting of bracing and physical therapy has been poorly tolerated. Heel varus is partially corrected with a Coleman block. There are thick calluses under the first metatarsal heads. Sensation to touch and
Explanation
The history and presentation are consistent with type I Charcot-Marie-Tooth (CMT), the most common form of hereditary peripheral motor sensory neuropathy. Type I CMT is the most common, occurring in 50% of patients with CMT, and is characterized by marked slowing of motor neuron velocities, and inconsistent slowing of sensory neuron velocities. Peroneus longus to brevis transfer is indicated to release the overpull of the peroneus longus, and restore the eversion and dorsiflexion function of the peroneus brevis. A lateralizing calcaneal osteotomy with proximal translation is indicated to correct heel varus given that the Coleman block only allows for partial correction of heel varus. Proximal translation of the posterior tuber corrects for the increased calcaneal dorsiflexion, improving the lever arm for the triceps surae. A medial column closing wedge osteotomy is often required to correct a rigid, or semirigid plantar flexed first ray to allow for a balanced, plantigrade foot. Triple arthrodesis is indicated for rigid, arthritic hindfoot deformities. Transfer of the posterior tibial tendon to the tibialis anterior is not indicated since it is an out-of-phase transfer. Transfer of the posterior tibial tendon, when performed, should be to the lateral aspect of the foot. A medializing calcaneal osteotomy would accentuate the heel varus. There is no indication for Botox in CMT; Botox injection of the calf would further weaken push-off during gait. Bracing of a progressive semirigid or rigid deformity is not recommended.
Question 65
A 78-year-old man has a history of worsening bilateral calf pain with activity. MRI scans are shown in Figures 31a through 31d. His symptoms are not improved with forward flexion of the lumbar spine. His lower extremity pain is relieved when he sits or ceases activity. Which of the following tests would be most helpful in establishing a diagnosis? Review Topic
Explanation
The differential diagnosis of degenerative lumbar stenosis is extensive. Vascular and neurogenic claudication frequently coexist in the older population. Therefore, it is important to determine the specific etiology of a patient's lower extremity claudication prior to any surgical intervention. Vascular claudication is relieved with cessation of activity, whereas neurogenic claudication requires that the patient sit down or flex the lumbar spine forward to increase the canal diameter. Because this patient does not experience improvement in his symptoms with sitting or forward flexion, it is likely that he is experiencing vascular claudication. The ankle-brachial index (ABI) is the ratio of the blood pressure in the lower legs to the blood pressure in the arms. Compared with the arm, lower blood pressure in the leg is a sign of peripheral vascular disease. The ABI is calculated by dividing the systolic blood pressure in the arteries at the ankle and foot by the higher of the two systolic blood pressures in the arms. An ABI value between 0.40 to 0.80 is moderately decreased and such patients often experience symptoms such as intermittent claudication. Selective nerve root blocks prove to be more useful in identifying specific level(s) of involvement in patients experiencing radicular pain and paresthesias. Their utility is less helpful in lower extremity claudication. Electrophysiologic studies are rarely useful, except in identifying the presence and source of a peripheral neuropathy. About 80% of patients with symptomatic lumbar stenosis will demonstrate electromyographic changes. Osteoarthritis of the hip may be associated with buttock, groin, hip, and thigh pain.
Decreased range of motion and hip joint pain, especially in internal rotation and abduction, are common findings in patients with degenerative arthritis of the hip. While post-myelography CT has been found superior to MRI as a single study for the preoperative planning of decompression for lumbar spinal stenosis, it will not assist in differentiating vascular from neurogenic claudication.
Decreased range of motion and hip joint pain, especially in internal rotation and abduction, are common findings in patients with degenerative arthritis of the hip. While post-myelography CT has been found superior to MRI as a single study for the preoperative planning of decompression for lumbar spinal stenosis, it will not assist in differentiating vascular from neurogenic claudication.
Question 66
Gaucher’s disease is manifested by reticuloendothelial system macrophage accumulation of
Explanation
DISCUSSION: Gaucher’s disease is characterized by macrophage accumulation of glucocerebroside that is caused by a deficiency of lysosomal enzyme glucocerebrosidase. It is an autosomal-recessive trait and is most commonly found in Ashkenazi Jews. Orthopaedic surgeons see patients with Gaucher’s disease usually because of osteonecrosis of the hip. Calcium pyrophosphate is associated with pseudogout. Hydroxyproline is a breakdown product of collagen and is found in high levels in patients with Paget’s disease. Homogentisic acid is associated with ochronosis (alkaptonuria).
REFERENCES: Beatty JH: Orthopaedic Knowledge Update 6. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 247-252.
Goldblatt J, Sacks S, Beighton P: The orthopedic aspects of Gaucher disease. Clin Orthop 1978;137:208-214.
Beutler E: Gaucher’s disease. N Engl J Med 1991;325:1354-1360.
REFERENCES: Beatty JH: Orthopaedic Knowledge Update 6. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 247-252.
Goldblatt J, Sacks S, Beighton P: The orthopedic aspects of Gaucher disease. Clin Orthop 1978;137:208-214.
Beutler E: Gaucher’s disease. N Engl J Med 1991;325:1354-1360.
Question 67
A skeletally mature GMFCS V child with spastic quadriplegic cerebral palsy presents with progressive scoliosis and inability to sit upright in a wheelchair. Radiographs are shown in Figures A and B, depicting a long C-shaped 75 degree curve with pelvic obliquity. Which is the most appropriate treatment option? Review Topic
Explanation
This patient has a large cerebral palsy (CP) scoliotic curve with pelvic obliquity. Posterior instrumentation should be from T2 to the pelvis.
Scoliosis in CP differs from adolescent idiopathic scoliosis. Curves can be classified into double curves (thoracic and lumbar) with minimal pelvic obliquity (Weinstein Group I) and large curves (lumbar/thoracolumbar) with marked pelvic obliquity (Group II). In the presence of pelvic obliquity (>15°), caudal instrumentation should end at the pelvis to reduce the risk of pseudoarthrosis and late loss of correction. Cephalad instrumentation should end high in the thoracic spine (T2) to decrease proximal junctional kyphosis.
Imrie et al. reviewed the management of spinal deformity in CP. They advocate posterior-only pedicle screw fusion for curves <100° that bend down to 50% on traction films, from T2-3 to the pelvis, using iliac screws. They advocate single-stage anterior release and posterior fusion for curves >120° with poor flexibility, or associated severe pelvic obliquity or sagittal deformity.
McCarthy et al. reviewed scoliosis in CP. They advocate proximal fixation to the upper thoracic spine (T1-2), and distal fixation to L4-5 (pelvic obliquity <15°) or to the pelvis (pelvic obliquity >15°). They add anterior release for larger, rigid curves that do not bend out to <60°, and in skeletally immature children.
Figures A and B are PA and lateral scoliosis radiographs demonstrating 75° of thoracolumbar scoliosis and severe pelvic obliquity, and progressive lumbar hyperlordosis. Illustrations A and B are PA and lateral scoliosis radiographs demonstrating correction of curve and pelvic obliquity using the Galveston Technique with segmental fixation utilizing sublaminar wires.
Incorrect Answers:
(SBQ12SP.26) Figure A is a lateral cervical spine radiograph of a 70-year-old female who presents with two months of posterior midline neck pain that is worse with motion. She has no history of trauma. She denies any symptoms of arm pain, gait instability, or dexterity problems with her hands. Physical exam of the lower extremities shows 2+ patellar reflexes and flexion of the great toe with a Babinski test. What should the patient be told regarding these radiographic findings? Review Topic
She requires surgical decompression to prevent progressive neurologic deterioration
85% of individuals over the age of 60 years of age demonstrate these findings
She is indicated for MRI to rule out cervical radiculopathy
She would benefit from modalities such as heat, cold, and transcutaneous electrical stimulation
She has <10% chance of having symptomatic improvement with non-operative treatment
The patient has symptomatic cervical spondylosis. She should be told that 85% of asymptomatic individuals over the age of 60 demonstrate these radiographic findings.
Cervical spondylosis is defined as age-related degenerative changes within the cervical spinal column. It can present as axial neck pain, cervical radiculopathy, cervical myelopathy, or as a combination of each. Radiographs demonstrate loss of disc height, arthrosis of the facet and uncovertebral joints, and endplate sclerosis. Imaging such as cervical spine radiographs and MRI should be interpreted carefully and correlated with clinical symptoms, as radiographic evidence of spondylosis is frequently seen in asymptomatic patients.
Boden et. al. reviewed the cervical MRI of 63 asymptomatic volunteers with no history of cervical spine symptoms. Of those, 19% were interpreted as having an abnormality. These findings included herniated nucleus pulposus, bulging disc, and foraminal stenosis. 60% of patients over 40 years demonstrated disc degeneration or narrowing at one level.
Rao et al. reviewed the presentation, pathogenesis, and management of cervical spondylosis. In this review, they report that 85% of patients older than 60 years demonstrate cervical spondylosis on radiography.
Figure A is a lateral cervical spine radiograph demonstrating spondylosis at multiple levels. There is disc height loss, facet sclerosis, and anterior osteophyte formation.
Incorrect Answers:
Scoliosis in CP differs from adolescent idiopathic scoliosis. Curves can be classified into double curves (thoracic and lumbar) with minimal pelvic obliquity (Weinstein Group I) and large curves (lumbar/thoracolumbar) with marked pelvic obliquity (Group II). In the presence of pelvic obliquity (>15°), caudal instrumentation should end at the pelvis to reduce the risk of pseudoarthrosis and late loss of correction. Cephalad instrumentation should end high in the thoracic spine (T2) to decrease proximal junctional kyphosis.
Imrie et al. reviewed the management of spinal deformity in CP. They advocate posterior-only pedicle screw fusion for curves <100° that bend down to 50% on traction films, from T2-3 to the pelvis, using iliac screws. They advocate single-stage anterior release and posterior fusion for curves >120° with poor flexibility, or associated severe pelvic obliquity or sagittal deformity.
McCarthy et al. reviewed scoliosis in CP. They advocate proximal fixation to the upper thoracic spine (T1-2), and distal fixation to L4-5 (pelvic obliquity <15°) or to the pelvis (pelvic obliquity >15°). They add anterior release for larger, rigid curves that do not bend out to <60°, and in skeletally immature children.
Figures A and B are PA and lateral scoliosis radiographs demonstrating 75° of thoracolumbar scoliosis and severe pelvic obliquity, and progressive lumbar hyperlordosis. Illustrations A and B are PA and lateral scoliosis radiographs demonstrating correction of curve and pelvic obliquity using the Galveston Technique with segmental fixation utilizing sublaminar wires.
Incorrect Answers:
(SBQ12SP.26) Figure A is a lateral cervical spine radiograph of a 70-year-old female who presents with two months of posterior midline neck pain that is worse with motion. She has no history of trauma. She denies any symptoms of arm pain, gait instability, or dexterity problems with her hands. Physical exam of the lower extremities shows 2+ patellar reflexes and flexion of the great toe with a Babinski test. What should the patient be told regarding these radiographic findings? Review Topic
She requires surgical decompression to prevent progressive neurologic deterioration
85% of individuals over the age of 60 years of age demonstrate these findings
She is indicated for MRI to rule out cervical radiculopathy
She would benefit from modalities such as heat, cold, and transcutaneous electrical stimulation
She has <10% chance of having symptomatic improvement with non-operative treatment
The patient has symptomatic cervical spondylosis. She should be told that 85% of asymptomatic individuals over the age of 60 demonstrate these radiographic findings.
Cervical spondylosis is defined as age-related degenerative changes within the cervical spinal column. It can present as axial neck pain, cervical radiculopathy, cervical myelopathy, or as a combination of each. Radiographs demonstrate loss of disc height, arthrosis of the facet and uncovertebral joints, and endplate sclerosis. Imaging such as cervical spine radiographs and MRI should be interpreted carefully and correlated with clinical symptoms, as radiographic evidence of spondylosis is frequently seen in asymptomatic patients.
Boden et. al. reviewed the cervical MRI of 63 asymptomatic volunteers with no history of cervical spine symptoms. Of those, 19% were interpreted as having an abnormality. These findings included herniated nucleus pulposus, bulging disc, and foraminal stenosis. 60% of patients over 40 years demonstrated disc degeneration or narrowing at one level.
Rao et al. reviewed the presentation, pathogenesis, and management of cervical spondylosis. In this review, they report that 85% of patients older than 60 years demonstrate cervical spondylosis on radiography.
Figure A is a lateral cervical spine radiograph demonstrating spondylosis at multiple levels. There is disc height loss, facet sclerosis, and anterior osteophyte formation.
Incorrect Answers:
Question 68
One of the serious potential complications of repair of distal biceps tendon ruptures is limited pronation and supination as a result of synostosis. What surgical approach and technique presents the highest risk for development of this complication?
Explanation
DISCUSSION: The risk of synostosis is imminent with any technique for repairing a distal biceps tendon rupture. However, the risk is quite low for all approaches that avoid exposure of the ulna, including the muscle-splitting two-incision technique.
REFERENCE: Norris TR: Orthopaedic Knowledge Update: Shoulder and Elbow. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, p 342.
REFERENCE: Norris TR: Orthopaedic Knowledge Update: Shoulder and Elbow. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, p 342.
Question 69
After stabilizing a bimalleolar ankle fracture with a plate and lag screws for the fibula and two interfragmental compression screws for the medial malleolus, a syndesmosis screw is indicated in which of the following situations?
Explanation
DISCUSSION: It is imperative to recognize the need for a position screw (syndesmosis screw) to hold the syndesmosis in proper alignment when surgically stabilizing an ankle fracture. Although many different fracture patterns are suspicious for a disrupted syndesmosis, the only sure way to assess the syndesmosis is to stress it with abduction and external rotation of the talus and attempt to displace the fibula from the incisura fibularis. Under fluoroscopy, the talus will move laterally and displace the fibula, show a valgus talar tilt, or show an increase in the medial clear space. If any or all of these signs occur, a syndesmosis screw is inserted after making sure that the fibula is reduced into the incisura fibularis. This screw may traverse three or four cortices but must not act as a lag screw. It usually is inserted with the ankle in maximal dorsiflexion, although this is probably not necessary because it is almost impossible to overcompress the syndesmosis. The diameter of the screw does not make any difference. It may or may not be removed but not before 3 months.
REFERENCES: Tornetta P III, Spoo JE, Reynolds FA, Lee C: Overtightening of the ankle syndesmosis: Is it really possible? J Bone Joint Surg Am 2001;83:489-492.
Stover MD, Kellam JF: Articular fractures: Principles, in Ruedi TP, Murphy WM (eds): AO Principles of Fracture Management. Stuttgart, Thieme, 2000, pp 105-119.
Hahn DM, Colton CL: Malleolar fractures, in Ruedi TP, Murphy WM (eds): AO Principles of Fracture Management. Stuttgart, Thieme, 2000, pp 559-581.
Tile M: Fractures of the ankle, in Schatzker J, Tile M (eds): Rationale of Operative Fracture Care, ed 2. Berlin, Springer-Verlag, 1998, pp 523-561.
REFERENCES: Tornetta P III, Spoo JE, Reynolds FA, Lee C: Overtightening of the ankle syndesmosis: Is it really possible? J Bone Joint Surg Am 2001;83:489-492.
Stover MD, Kellam JF: Articular fractures: Principles, in Ruedi TP, Murphy WM (eds): AO Principles of Fracture Management. Stuttgart, Thieme, 2000, pp 105-119.
Hahn DM, Colton CL: Malleolar fractures, in Ruedi TP, Murphy WM (eds): AO Principles of Fracture Management. Stuttgart, Thieme, 2000, pp 559-581.
Tile M: Fractures of the ankle, in Schatzker J, Tile M (eds): Rationale of Operative Fracture Care, ed 2. Berlin, Springer-Verlag, 1998, pp 523-561.
Question 70
A 34-year-old man presents to clinic with 4 months of right elbow pain. He began going to the gym and playing squash about 3 months ago. On exam, he is tender over the lateral aspect of the elbow and has pain with resisted wrist extension. Which of the following choices lists the correct compartment of the muscle typically involved in this disease and then lists its antagonist muscle? Review Topic
Explanation
The patient presents with lateral epicondylitis, which typically involves the origin of the extensor carpi radialis brevis (ECRB). ECRB is in the mobile wad compartment and its antagonist muscle is flexor carpi ulnaris.
Lateral epicondylitis is an overuse injury, typically secondary to repetitive pronation and supination motion in extension, that leads to inflammation of the ECRB origin at the elbow. Histological analysis typically shows vascular hyperplasia and disorganized collagen. Clinically, patients will have pain over the lateral elbow exacerbated by resisted wrist extension. ECRB, the most commonly involved muscle origin, is innervated by the deep branch of the radial nerve and inserts on the base of the 3rd metacarpal. As it is radial wrist extensor, its antagonist is the ulnar sided wrist flexor.
Brummel et al. reviewed the clinical presentation and management options for lateral epicondylitis. They report acute symptoms in younger patients and chronic symptoms in older patients. NSAIDs, extensor stretching and activity modification are the mainstay of nonsurgical treatment.
Bunata et al. studies 85 cadavar elbows to determine anatomic factors contributing to tennis elbow. They found that the ECRB undersurface rubs against the lateral capitellium in elbow extension leading to tendinosis.
Illustration A is cross-sectional diagram of the forearm with muscle bellies labeled. Notice the location of ECRB in the mobile wad. Illustration B is a coronal T2 MRI showing fluid signal and undersurface tearing near the extensor origin as can be seen in lateral epicondylitis.
Incorrect Answers:
1-4: The ECRB is in the mobile wad and its antagonist is flexor carpi ulnaris. All other answers are incorrect.
Lateral epicondylitis is an overuse injury, typically secondary to repetitive pronation and supination motion in extension, that leads to inflammation of the ECRB origin at the elbow. Histological analysis typically shows vascular hyperplasia and disorganized collagen. Clinically, patients will have pain over the lateral elbow exacerbated by resisted wrist extension. ECRB, the most commonly involved muscle origin, is innervated by the deep branch of the radial nerve and inserts on the base of the 3rd metacarpal. As it is radial wrist extensor, its antagonist is the ulnar sided wrist flexor.
Brummel et al. reviewed the clinical presentation and management options for lateral epicondylitis. They report acute symptoms in younger patients and chronic symptoms in older patients. NSAIDs, extensor stretching and activity modification are the mainstay of nonsurgical treatment.
Bunata et al. studies 85 cadavar elbows to determine anatomic factors contributing to tennis elbow. They found that the ECRB undersurface rubs against the lateral capitellium in elbow extension leading to tendinosis.
Illustration A is cross-sectional diagram of the forearm with muscle bellies labeled. Notice the location of ECRB in the mobile wad. Illustration B is a coronal T2 MRI showing fluid signal and undersurface tearing near the extensor origin as can be seen in lateral epicondylitis.
Incorrect Answers:
1-4: The ECRB is in the mobile wad and its antagonist is flexor carpi ulnaris. All other answers are incorrect.
Question 71
During excision of a Baker cyst, the base or stalk is usually found between the
Explanation
DISCUSSION: Although there are several bursae in the posterior portion of the knee, the most prevalent one with a connection to the knee joint is the one in the interval between the semimembranosus and the medial head of the gastrocnemius muscle. The popliteus muscle and posterior cruciate ligament, the posterior cruciate ligament and lateral gastrocnemius muscle, and the medial gastrocnemius muscle and posterior cruciate ligament are all too lateral and uncommon. The semitendinosus and medial head of the gastrocnemius muscles do not come in contact in the posterior aspect of the knee.
REFERENCES: Resnick D: Diagnosis of Bone and Joint Disorders, ed 3. Philadelphia, PA,
WB Saunders, 1995, p 379.
Justis EJ Jr: Nontraumatic disorders, in Crenshaw AH (ed): Campbell’s Operative Orthopaedics, ed 7. Philadelphia, PA, Lippincott, 1987, vol 3, p 2257.
REFERENCES: Resnick D: Diagnosis of Bone and Joint Disorders, ed 3. Philadelphia, PA,
WB Saunders, 1995, p 379.
Justis EJ Jr: Nontraumatic disorders, in Crenshaw AH (ed): Campbell’s Operative Orthopaedics, ed 7. Philadelphia, PA, Lippincott, 1987, vol 3, p 2257.
Question 72
A 55-year-old man reports increasing weakness in his arms that has progressed to his lower limbs, resulting in frequent tripping and falling. Examination reveals weakness in shoulder abduction and external and internal rotation bilaterally. Fasciculation is noted. He also has weakness in elbow flexion and extension bilaterally, and his grip strength is diminished. An electromyogram and nerve conduction velocity studies show decreased amplitude of compound motor action potential, slightly slowed motor conduction velocity, and denervation signs with decreased recruitment in all extremities. The sensory study is normal. Based on these findings, what is the most likely diagnosis?
Explanation
DISCUSSION: The major determinant of ALS (Lou Gehrig disease) is progressive loss of motor neurons. The loss usually begins in one area, is asymmetrical, and later becomes evident in other areas. The first signs of ALS may include either upper or lower motor neuron loss. Recognition of upper motor neuron involvement depends on clinical signs, but electromyography and nerve conduction velocity studies can help identify lower motor neuron involvement. Electrodiagnostic abnormalities in three or more areas are required to make a definitive diagnosis. The motor unit potentials (MUPs) changes in ALS include impaired MUPs recruitment, unstable MUPs, and abnormal MUPs size and configuration. A number of abnormal spontaneous discharges can occur with ALS, especially fibrillation potentials and fasciculation potentials. In ALS, the motor nerve conduction study will be abnormal, but a co-existing normal sensory study is definitive for this disease.
REFERENCES: de Carvalho M, Johnsen B, Fuglsang-Frederiksen A: Medical technology assessment: Electrodiagnosis in motor neuron diseases and amyotrophic lateral sclerosis. Neurophysiol Clin 2001;31:341-348.
Daube JR: Electrodiagnostic studies in amyotrophic lateral sclerosis and other motor neuron disorders. Muscle Nerve 2000;23:1488-1502.
Troger M, Dengler R: The role of electromyography (EMG) in the diagnosis of ALS. Amyotroph Lateral Scler Other Motor Neuron Disord 2000;1:S33-S40.
REFERENCES: de Carvalho M, Johnsen B, Fuglsang-Frederiksen A: Medical technology assessment: Electrodiagnosis in motor neuron diseases and amyotrophic lateral sclerosis. Neurophysiol Clin 2001;31:341-348.
Daube JR: Electrodiagnostic studies in amyotrophic lateral sclerosis and other motor neuron disorders. Muscle Nerve 2000;23:1488-1502.
Troger M, Dengler R: The role of electromyography (EMG) in the diagnosis of ALS. Amyotroph Lateral Scler Other Motor Neuron Disord 2000;1:S33-S40.
Question 73
Figures 10a through 10c show the radiographs of an 85-year-old man who underwent a revision total knee arthroplasty for loosening of the tibial component 6 months ago. He now reports a mildly uncomfortable mass on the anterior part of the knee joint. Examination reveals 95 degrees of motion and good quadriceps strength, and he can ambulate with minimal pain with a walker. History reveals chronic lymphocytic leukemia for which he is taking antineoplastic medication. Culture of the mass aspirate grew Candida albicans on two separate occasions. The patient and the family strongly prefer nonsurgical management. If long-term suppression is chosen as treatment, what advice should be given to the patient and family?
Explanation
DISCUSSION: In patients with infected implants, treatment usually involves debridement and exchange of the infected components. In rare cases, when there is severe comorbidity and immune system compromise, as there is with this patient, a form of chronic suppression is indicated. This patient’s function is quite satisfactory and, even though there is only a 21% to 38% chance of success (Hirawaka as quoted by Mulvey and Thornhill), an attempt at suppression therapy is indicated. The patient must be followed closely to monitor the potential complications of long-term antifungal therapy and to monitor the integrity of the joint, looking for bone or soft-tissue destruction. Because the patient has satisfactory motion and quadriceps strength, no bracing or other assistive device (except for the walker he is now using) is indicated.
REFERENCE: Mulvey TJ, Thornhill TS: Infected total knee arthroplasty, in Insall JN, Scott WN (eds): Surgery of the Knee, ed 3. Philadelphia, PA, Churchill Livingstone, 2001, vol 2,
pp 1857-1890.
REFERENCE: Mulvey TJ, Thornhill TS: Infected total knee arthroplasty, in Insall JN, Scott WN (eds): Surgery of the Knee, ed 3. Philadelphia, PA, Churchill Livingstone, 2001, vol 2,
pp 1857-1890.
Question 74
Figure 94 is an arthroscopic view of the intercondylar notch of a right knee from an anterolateral portal. After injury to the structure as indicated by the asterisks, which examination test most likely will demonstrate an abnormal finding?
Explanation
DISCUSSION
The structure shown is the PL bundle of the anterior cruciate ligament (ACL), which is tight near terminal knee extension. Biomechanical analysis suggests the PL bundle provides a greater degree of rotational stability than the anteromedial bundle. The pivot-shift test evaluates for rotational instability of the ACL, while the Lachman test assesses anterior-posterior stability. The posterior drawer and PL drawer test findings are positive after a posterior cruciate ligament tear and PL corner injury, respectively.
RESPONSES FOR QUESTIONS 95 THROUGH 98
Axillary nerve injury
Musculocutaneous nerve injury
Radial nerve injury
Glenoid fracture
Loss of reduction
Deltoid detachment
Chondrolysis
Recurrent instability
Propionibacterium acnes (P. acnes) infection
Staphylococcus epidermidis
Staphylococcus aureus
Select the complication listed above that is most commonly associated with the shoulder arthroscopy scenarios described below.
The structure shown is the PL bundle of the anterior cruciate ligament (ACL), which is tight near terminal knee extension. Biomechanical analysis suggests the PL bundle provides a greater degree of rotational stability than the anteromedial bundle. The pivot-shift test evaluates for rotational instability of the ACL, while the Lachman test assesses anterior-posterior stability. The posterior drawer and PL drawer test findings are positive after a posterior cruciate ligament tear and PL corner injury, respectively.
RESPONSES FOR QUESTIONS 95 THROUGH 98
Axillary nerve injury
Musculocutaneous nerve injury
Radial nerve injury
Glenoid fracture
Loss of reduction
Deltoid detachment
Chondrolysis
Recurrent instability
Propionibacterium acnes (P. acnes) infection
Staphylococcus epidermidis
Staphylococcus aureus
Select the complication listed above that is most commonly associated with the shoulder arthroscopy scenarios described below.
Question 75
A 71-year-old man has worsening left hip pain and is indicated for a left total hip arthroplasty (THA). Figure 1 shows a preoperative plan for the patient. The patient is scheduled for a left THA using a direct anterior approach with the pictured implants. If this plan is followed as pictured, what is the likely outcome for this patient? Figure could not be loaded
Explanation
Figure 1 is the radiograph of a 73-year-old woman who had a right hip arthroplasty one year prior. Her BMI is 48. Postoperative radiographs at 6 weeks showed early stem subsidence of 4 mm compared with intraoperative radiographs. The current radiographic findings likely resulted from the
A. spinal fusion.
B. BMI and implant size.
C. mismatch between the metaphysis and diaphysis.
D. modular neck prosthesis.
A. spinal fusion.
B. BMI and implant size.
C. mismatch between the metaphysis and diaphysis.
D. modular neck prosthesis.
Question 76
Figure 20 shows the plain radiograph of a 70-year-old woman who has shoulder pain and is unable to reach above chest level as a result of a fall 3 months ago. An MRI scan of the shoulder shows a large rotator cuff tear. Examination reveals atrophy of the infraspinatus muscle, active forward elevation of 40 degrees, active external rotation of 30 degrees, passive forward elevation of 150 degrees, and passive external rotation of 60 degrees. The patient has no external rotation strength against resistance. Treatment should include
Explanation
This defines a 70y/o lady who 3 months ago sustained a large, to massive rotator cuff tear, not only by MRI, but by physical exam as well. In any age group or duration from injury, massive rotator cuff tears do poorly with surgical intervention. Now add in 3months duration and 70 yr age and boy doesn't rehabilitation sound good.
Question 77
An 18-year-old female Marine Corps recruit enters basic training. Her enlistment history and physical examination showed that she was an elite high school cross country runner. What is her most significant risk factor for a femoral or pelvic stress fracture during basic training?
Explanation
DISCUSSION: Approximately 5% of female recruits incur a stress fracture during the 13 weeks of Marine Corps basic training. Approximately 40% of these were femoral or pelvic stress fractures that were more severe than in civilian athletes or male military recruits. Only women who reported no menses during the previous year had a greater likelihood of femoral or pelvic stress fractures than did women who reported 10 to
12 menses. The referenced study did not find a statistically significant increase in risk of stress fracture in those recruits who had lesser menstrual irregularities in the year prior to recruit training, but there was a trend toward increased risk of stress fracture.
REFERENCES: Shaffer RA, Rauh MJ, Brodine SK, et al: Predictors of stress fracture susceptibility in young female recruits. Am J Sports Med 2006;34:108-115.
Garrick JG (ed): Orthopaedic Knowledge Update: Sports Medicine 3. Rosemont, IL, American Academy of
Orthopaedic Surgeons, 2004, pp 273-283.
12 menses. The referenced study did not find a statistically significant increase in risk of stress fracture in those recruits who had lesser menstrual irregularities in the year prior to recruit training, but there was a trend toward increased risk of stress fracture.
REFERENCES: Shaffer RA, Rauh MJ, Brodine SK, et al: Predictors of stress fracture susceptibility in young female recruits. Am J Sports Med 2006;34:108-115.
Garrick JG (ed): Orthopaedic Knowledge Update: Sports Medicine 3. Rosemont, IL, American Academy of
Orthopaedic Surgeons, 2004, pp 273-283.
Question 78
The acceleration of an object under the influence of a force depends directly on the mass of the object. The angular acceleration of an object under the influence of a moment depends directly on the
Explanation
DISCUSSION: Similar to the action of a force, a moment tends to angularly accelerate an object in a manner proportional to a quantity related to the mass of the object. The concept of a more massive object requiring a larger force to cause the same straight line acceleration is straightforward. The concept for changing angular velocity is similar but not identical. The proportional constant between the moment and the resulting angular acceleration is the mass moment of inertia, which depends not only on the mass of the object, but also its distribution. The unit of mass moment of inertia is obtained by multiplying the mass of the object by the square of the distance between an equivalent location of the center of rotation of the object and an equivalent location of the center of mass. Orthopaedic surgeons can change both the amount of mass carried by a limb and the way that the mass is distributed. For example, in applying a cast to the leg, the physician can affect the mass of the cast by the choice of casting material and by the size of the cast. As the mass moment of inertia of the limb increases (eg, by applying the cast farther down on the leg or using a heavier casting material), the patient will need to exert larger moments to angularly accelerate the leg during gait.
REFERENCES: Andriacchi T, Natarajan RN, Hurwitz DE: Musculoskeletal dynamics, locomotion, and clinical applications, in Mow VC, Hayes WC (eds): Basic Orthopaedic Biomechanics, ed 2. New York, NY, Lippincott-Raven, 1997, pp 43-47.
Burstein AH, Wright TM: Fundamentals of Orthopaedic Biomechanics. Baltimore, MD, Williams and Wilkins, 1994, pp 3-7.
REFERENCES: Andriacchi T, Natarajan RN, Hurwitz DE: Musculoskeletal dynamics, locomotion, and clinical applications, in Mow VC, Hayes WC (eds): Basic Orthopaedic Biomechanics, ed 2. New York, NY, Lippincott-Raven, 1997, pp 43-47.
Burstein AH, Wright TM: Fundamentals of Orthopaedic Biomechanics. Baltimore, MD, Williams and Wilkins, 1994, pp 3-7.
Question 79
Figure 4 shows the MRI scan of a patient who has had bilateral leg pain, weakness, diffuse numbness, and urinary retention for the past week. Examination reveals that motor strength is diffusely decreased, although it may be secondary to pain. The patient is numb throughout both legs, and reflexes in the lower extremities are absent. Rectal examination shows decreased tone, but voluntary tightening is present. Management should consist of
Explanation
DISCUSSION: The patient has a cauda equina syndrome. The fact that he has decreased rectal tone and urinary retention suggests the need for urgent surgery. Patients who are left untreated will have a poor prognosis for return of function. Although most patients who have insidious onset of symptoms with urinary retention will regain normal motor function following decompression, nearly one third will continue to have abnormal voiding patterns or sexual dysfunction of varying degrees.
REFERENCES: Kostuik JP, Harrington I, Alexander D, Rand W, Evans D: Cauda equina syndrome and lumbar disc herniation. J Bone Joint Surg Am 1986;68:386-391.
Wisneski RJ, Garfin SR, Rothman RH, Lutz GE: Lumbar disk disease, in Herkowitz HN, Garfin SR, Balderston RA, et al (eds): The Spine, ed 4. Philadelphia, PA,WB Saunders, 1992, vol 1,
pp 613-679.
REFERENCES: Kostuik JP, Harrington I, Alexander D, Rand W, Evans D: Cauda equina syndrome and lumbar disc herniation. J Bone Joint Surg Am 1986;68:386-391.
Wisneski RJ, Garfin SR, Rothman RH, Lutz GE: Lumbar disk disease, in Herkowitz HN, Garfin SR, Balderston RA, et al (eds): The Spine, ed 4. Philadelphia, PA,WB Saunders, 1992, vol 1,
pp 613-679.
Question 80
At the time of revision total knee arthroplasty, the surgeon is trialing the knee and finds that it extends fully and is stable in flexion with a 23-mm trial spacer; however, the patella is impinging on the polyethylene spacer. No augments were used on the femur or the tibia because the components fit well without them. What is the most appropriate action at this time?
Explanation
DISCUSSION: The surgeon in this case is faced with a common scenario at the time of revision total knee arthroplasty and the tendency is to elevate the joint line. Elevation of the joint line is associated with deleterious effects including anterior knee pain, restricted knee flexion, and instability. The error that has been made is resting the femoral component on the bone that is left behind after removal of the prior component; this typically leads to a femoral component that is too small (leading to an enlarged flexion gap) and proximal to where it should be (enlarging the extension gap). Although the flexion and extension gaps are equivalent, joint line elevation has occurred. To correct this problem, the femoral component size should be increased or offset posteriorly (to decrease the size of the flexion gap) and distal femoral augments should be used to decrease the size of the extension gap and restore the joint line to the appropriate level.
REFERENCES: Laskin RS: Joint line position restoration during revision total knee replacement. Clin Orthop Relat Res 2002;404:169-171.
Yoshii I, Whiteside LA, White SE, et al: Influence of prosthetic joint line position on knee kinematics and patellar position. J Arthroplasty 1991;6:169-177.
Barrack RL, Booth RE Jr, Lonner JH, et al (eds): Orthopaedic Knowledge Update: Hip and Knee Reconstruction
Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, pp 123-145. Question 100
A 68-year-old woman is undergoing a cementless medial/lateral tapered femoral placement during a total hip arthroplasty and the surgeon notices a small crack forming in the anteromedial femoral neck with final implant insertion. The most appropriate management should include which of the following?
Placement of a cerclage cable around the femoral neck above the lesser trochanter
Removal of the implant, placement of a cable around the femoral neck above the lesser trochanter, and reinsertion of the implant
Removal of the press-fit implant and cementing of the same femoral stem
Final seating of the cementless femoral component without additional measures
Removal of the cementless femoral component and placement of a revision modular taper- fluted femoral stem
DISCUSSION: The recognized treatment of the proximal periprosthetic fracture is first to identify its extent and then to optimize the correction. Removing the implant seems logical to accomplish the identification. Several studies indicate that proximal cerclage wiring is adequate to create a “barrel hoop” stability of the proxima l femur. The postoperative management may also include protected weight bearing and periodic radiographs.
REFERENCES: Barrack RL, Booth RE Jr, Lonner JH, et al (eds): Orthopaedic Knowledge Update: Hip and Knee Reconstruction 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, pp 475503.
Warren PJ, Thompson P, Fletcher MD: Transfemoral implantation of the Wagner SL stem: The abolition of
subsidence and enhancement of osteotomy union rate using Dall-Miles cables. Arch Orthop Trauma Surg 2002;122:557-560.
Your Source for Lifelong Orthopaedic Learning
REFERENCES: Laskin RS: Joint line position restoration during revision total knee replacement. Clin Orthop Relat Res 2002;404:169-171.
Yoshii I, Whiteside LA, White SE, et al: Influence of prosthetic joint line position on knee kinematics and patellar position. J Arthroplasty 1991;6:169-177.
Barrack RL, Booth RE Jr, Lonner JH, et al (eds): Orthopaedic Knowledge Update: Hip and Knee Reconstruction
Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, pp 123-145. Question 100
A 68-year-old woman is undergoing a cementless medial/lateral tapered femoral placement during a total hip arthroplasty and the surgeon notices a small crack forming in the anteromedial femoral neck with final implant insertion. The most appropriate management should include which of the following?
Placement of a cerclage cable around the femoral neck above the lesser trochanter
Removal of the implant, placement of a cable around the femoral neck above the lesser trochanter, and reinsertion of the implant
Removal of the press-fit implant and cementing of the same femoral stem
Final seating of the cementless femoral component without additional measures
Removal of the cementless femoral component and placement of a revision modular taper- fluted femoral stem
DISCUSSION: The recognized treatment of the proximal periprosthetic fracture is first to identify its extent and then to optimize the correction. Removing the implant seems logical to accomplish the identification. Several studies indicate that proximal cerclage wiring is adequate to create a “barrel hoop” stability of the proxima l femur. The postoperative management may also include protected weight bearing and periodic radiographs.
REFERENCES: Barrack RL, Booth RE Jr, Lonner JH, et al (eds): Orthopaedic Knowledge Update: Hip and Knee Reconstruction 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, pp 475503.
Warren PJ, Thompson P, Fletcher MD: Transfemoral implantation of the Wagner SL stem: The abolition of
subsidence and enhancement of osteotomy union rate using Dall-Miles cables. Arch Orthop Trauma Surg 2002;122:557-560.
Your Source for Lifelong Orthopaedic Learning
Question 81
use of a true lateral to assess the DRUJ, 4) beginning early range of motion of the wrist after stable fixation and 5) use vitamin C to help mitigate intractable pain.
Explanation
OrthoCash 2020
A 26-year-old male sustains a fall from a ladder onto his outstretched right hand. He is evaluated in the emergency room and is found to have a closed injury to his elbow without evidence of neurovascular compromise. Plain radiographs are obtained and are shown in Figures A and B. During surgery a sequential approach is used to treat each element of this injury. Which part of the procedure is felt to add the most to rotatory stability?
Radial head replacement
Radial head ORIF
Capsular plication
Lateral collateral ligament complex repair or reconstruction
Medial collateral ligament complex reconstruction Corrent answer: 4
The essential lesion that results in the most instability in a terrible triad injury of the elbow is rupture of the lateral collateral ligament. Repair of this lesion
results in the greatest increase in elbow rotatory stability.
The key components of a terrible triad injury are a radial head fracture, coronoid fracture, dislocation of the ulnohumeral joint and disruption of the lateral collateral ligament complex. While restoration of the bony anatomy is important for static stability, the key primary stabilizer that needs to be addressed is the lateral collateral ligament complex. In acute injuries LCL repair may be possible. In chronic injury, LCL reconstruction would need to be considered.
Forthman et al. reviewed 34 patients with an elbow dislocation, 22 of 34 of which were terrible triad injuries. Open reduction internal fixation or radial head replacement (as appropriate) along with LCL repair was completed; the MCL was not surgically addressed. Seventeen of 22 had good or excellent results, indicating that MCL repair is not necessary.
Pugh et al. discuss their surgical protocol for addressing terrible triad injuries with 28/36 of their patients obtaining good or excellent results. Their inside out protocol is described as follows: 1) coronoid fracture ORIF (capsular repair), 2) radial head fracture ORIF or replacement 3) LCL complex repair (isometric point is center of capitellum), 4) reevaluation of stability; MCL repair or hinged fixator application
Jensen et.al in cadaveric studies have demonstrated that radial head replacement alone decreases varus laxity and external rotatory laxity to 14.6 &
A 26-year-old male sustains a fall from a ladder onto his outstretched right hand. He is evaluated in the emergency room and is found to have a closed injury to his elbow without evidence of neurovascular compromise. Plain radiographs are obtained and are shown in Figures A and B. During surgery a sequential approach is used to treat each element of this injury. Which part of the procedure is felt to add the most to rotatory stability?
Radial head replacement
Radial head ORIF
Capsular plication
Lateral collateral ligament complex repair or reconstruction
Medial collateral ligament complex reconstruction Corrent answer: 4
The essential lesion that results in the most instability in a terrible triad injury of the elbow is rupture of the lateral collateral ligament. Repair of this lesion
results in the greatest increase in elbow rotatory stability.
The key components of a terrible triad injury are a radial head fracture, coronoid fracture, dislocation of the ulnohumeral joint and disruption of the lateral collateral ligament complex. While restoration of the bony anatomy is important for static stability, the key primary stabilizer that needs to be addressed is the lateral collateral ligament complex. In acute injuries LCL repair may be possible. In chronic injury, LCL reconstruction would need to be considered.
Forthman et al. reviewed 34 patients with an elbow dislocation, 22 of 34 of which were terrible triad injuries. Open reduction internal fixation or radial head replacement (as appropriate) along with LCL repair was completed; the MCL was not surgically addressed. Seventeen of 22 had good or excellent results, indicating that MCL repair is not necessary.
Pugh et al. discuss their surgical protocol for addressing terrible triad injuries with 28/36 of their patients obtaining good or excellent results. Their inside out protocol is described as follows: 1) coronoid fracture ORIF (capsular repair), 2) radial head fracture ORIF or replacement 3) LCL complex repair (isometric point is center of capitellum), 4) reevaluation of stability; MCL repair or hinged fixator application
Jensen et.al in cadaveric studies have demonstrated that radial head replacement alone decreases varus laxity and external rotatory laxity to 14.6 &
Question 82
A 17-year-old boy has had a mass in his right thigh for the past 6 months. He denies any history of trauma. Examination reveals that the mass is painless and firm. A radiograph and axial MRI scan are shown in Figures 49a and 49b. What is the most likely diagnosis?
Explanation
DISCUSSION: Osteochondroma typically occurs as a bony projection or a sessile growth on the bone, and there can be flaring of the metaphysis. The radiograph shows continuity from the adjacent cancellous bone into the lesion itself. There is no soft-tissue mass or bone destruction to suggest osteosarcoma or Ewing’s sarcoma. Periosteal chondroma has a scalloped out radiographic appearance. Chondroblastoma typically is an epiphyseal-based lesion.
REFERENCE: Wold LA, et al: Osteochondroma: Atlas of Orthopaedic Pathology. Philadelphia, PA, WB Saunders, 1990, p 50.
REFERENCE: Wold LA, et al: Osteochondroma: Atlas of Orthopaedic Pathology. Philadelphia, PA, WB Saunders, 1990, p 50.
Question 83
What is the best way to determine whether a radial head implant is too thick intraoperatively?
Explanation
Widening of the medial ulnohumeral joint on an AP radiograph is only visible after overlengthening of the radial head by 6 mm or more. At least in this cadaver study, the most sensitive method was to visually assess the lateral aspect of the ulnohumeral joint with the radial head resected and then with the trial radial head in place. This method allows detection of any overlengthening.
Question 84
An otherwise healthy 16-year-old boy who has had thoracolumbar pain with an increasingly worse deformity for the past 2 years now reports that the pain is worse at night. He responded well to nonsteroidal anti-inflammatory drugs initially, but they have become less effective. He denies any neurologic or constitutional symptoms. Examination is consistent with a mild thoracolumbar scoliosis and is otherwise normal. Laboratory studies show a normal CBC, erythrocyte sedimentation rate, and C-reactive protein. Standing radiographs show a 20 degrees left thoracolumbar scoliosis, and he has a Risser stage of 4. A bone scan shows increased uptake at L2; a CT scan through this level is shown in Figure 18. Management should now consist of
Explanation
DISCUSSION: The findings and radiographic appearance are most consistent with osteoid osteoma involving the medial pedicle. Scoliosis is commonly seen with this lesion and usually does not need surgical intervention. Excellent results have been reported with surgical excision as well as with percutaneous thermocoagulation. Nonsurgical treatment also has been described in peripheral osteoid osteoma but is not well described for lesions within the spine.
REFERENCES: Cove JA, Taminiau AH, Obermann WR, Vanderschueren GM: Osteoid osteoma of the spine treated with percutaneous computed tomography-guided thermocoagulation. Spine 2000;25:1283-1286.
Kneisl JS, Simon MA: Medical management compared with operative treatment for osteoid-osteoma. J Bone Joint Surg Am 1992;74:179-185.
Pettine KA, Klassen RA: Osteoid-osteoma and osteoblastoma of the spine. J Bone Joint Surg Am 1986;68:354-361.
REFERENCES: Cove JA, Taminiau AH, Obermann WR, Vanderschueren GM: Osteoid osteoma of the spine treated with percutaneous computed tomography-guided thermocoagulation. Spine 2000;25:1283-1286.
Kneisl JS, Simon MA: Medical management compared with operative treatment for osteoid-osteoma. J Bone Joint Surg Am 1992;74:179-185.
Pettine KA, Klassen RA: Osteoid-osteoma and osteoblastoma of the spine. J Bone Joint Surg Am 1986;68:354-361.
Question 85
A 3-year-old girl developed torticollis eight months ago after a severe respiratory tract infection. A initial trial of halter traction was attempted without success. A trial of halo traction was then performed for 3 weeks and then a dynamic computed tomographic (CT) was obtained and shown in Figure A. Panel (a) shows an axial image with maximal rotation to the left. Panel (b) shows an axial image with maximal rotation to the right. What is the most appropriate next step in management? Review Topic
Explanation
The clinical presentation is consistent with chronic torticollis caused by Atlantoaxial rotatory displacement (AARD). Because both halter traction and halo traction were attempted and failed, the next most appropriate next step in management is posterior atlantoaxial fusion.
Common causes of Atlantoaxial rotatory displacement (AARD) include infection, trauma, and recent neck surgery. Diagnosis is challenging and is best confirmed with dynamic CT (CT with the head turned maximally to either side and at neutral). If the symptoms are acute (less than 7 days) then initial treatment with a soft collar and anti-inflammatory medications is indicated. If the condition has been present for more than a week, more aggressive treatment with halter traction (present 1 week to 1 month) or halo traction (present for 1-3 months) is indicated. If nonoperative modalities fail, the condition has been present for > 3 months, or the patient has neurologic deficits, then posterior C1-C2 fusion is indicated.
Copley et al discuss the evaluation and treatment of various congenital and traumatic conditions of the pediatric cervical spine. They report that the underlying mechanism of Atlantoaxial rotatory displacement (AARD) is inflammation and spasm which can be caused by infection, prior surgery, trauma, and rheumatoid arthritis.
Subach et al reviewed at 20 children with atlantoaxial rotatory subluxation. They found that of the 20 patients treated overall, conservative management failed in 6 (30%), and they required posterior fusion because of recurrence of the atlantoaxial rotatory subluxation or unsuccessful reduction. The major factor predicting the failure of conservative management was the duration of subluxation before initial reduction. Patients with long-standing subluxation were more likely to experience recurrence and require surgery.
Figure A shows an asymmetric placed odontoid within the ring of C1. There is an increased distance from the odontoid to the right arch of C1 which is fixed and minimally changes with maximal rotation to the left. This radiographic finding is indicative of fixed subluxation. Illustration A further demonstrates this.
Incorrect
(SBQ12SP.1) A 65-year-old female with a history of breast cancer presents with bilateral buttock and leg pain that is worse with walking and improves with sitting. In addition, she reports that she feels unsteady on her feet and requires holding the railing when going up and down stairs. On physical exam she is unable to complete a tandem gait and has hip flexion weakness, ankle dorsiflexion weakness, and ankle plantar flexion weakness. Her reflex exam shows 3+ bilateral patellar reflexes. Radiographs and an MRI are shown in Figure A and B. What is the next most appropriate step in management. Review Topic
Lumbar epidural injection
Physical therapy with core strengthening and anti-inflammatory medications as needed
Lumbar decompression
Lumbar decompression and fusion
MRI of the cervical and thoracic spine
The clinical scenario is consistent with a patient with symptoms of degenerative spondylolisthesis AND symptoms of myelopathy. Myelopathy must be ruled out by performing an MRI of the cervical and thoracic spine.
Tandem stenosis occurs in approximately 5 to 25% of patients. Because of the stepwise progressive nature of myelopathy, treatment of myelopathy often takes precedence over lumbar spinal stenosis.
Rhee et al. found that the sensitivity and specificity of specific physical exam findings varies. Both the upward babinski reflex and the presence of clonus were found to be very non-sensitive (13%). The most sensitive provacative test was found to be the Hoffman sign (59%).
Salvi et al. reviewed the classic presentations for cervical myelopathy including demographics, history, and physical exam findings (the inability to preform a tandem gait, hyperreflexia, an abnormal babinksi and hoffman reflex, the inability to preform rapid movements and bilateral muscle weakness). Additionally they identify other potential causes for myelopathy, including multiple sclerosis, amyotrophic lateral sclerosis, multifocal motor neuropathy, and Guillain-Barre´syndrome.
Maezawa et al. showed that gait analysis can identify a pattern in patients with myelopathy. Patients with severe myelopathy have a characteristic gait with hyperextension of the knee in the stance phase without plantar flexion of the ankle in the swing phase. They also have decreased walking speed and stride length with a prolonged stance phase.
Figure A and B show a classic degenerative spondylolisthesis.
Incorrect Answers:
Common causes of Atlantoaxial rotatory displacement (AARD) include infection, trauma, and recent neck surgery. Diagnosis is challenging and is best confirmed with dynamic CT (CT with the head turned maximally to either side and at neutral). If the symptoms are acute (less than 7 days) then initial treatment with a soft collar and anti-inflammatory medications is indicated. If the condition has been present for more than a week, more aggressive treatment with halter traction (present 1 week to 1 month) or halo traction (present for 1-3 months) is indicated. If nonoperative modalities fail, the condition has been present for > 3 months, or the patient has neurologic deficits, then posterior C1-C2 fusion is indicated.
Copley et al discuss the evaluation and treatment of various congenital and traumatic conditions of the pediatric cervical spine. They report that the underlying mechanism of Atlantoaxial rotatory displacement (AARD) is inflammation and spasm which can be caused by infection, prior surgery, trauma, and rheumatoid arthritis.
Subach et al reviewed at 20 children with atlantoaxial rotatory subluxation. They found that of the 20 patients treated overall, conservative management failed in 6 (30%), and they required posterior fusion because of recurrence of the atlantoaxial rotatory subluxation or unsuccessful reduction. The major factor predicting the failure of conservative management was the duration of subluxation before initial reduction. Patients with long-standing subluxation were more likely to experience recurrence and require surgery.
Figure A shows an asymmetric placed odontoid within the ring of C1. There is an increased distance from the odontoid to the right arch of C1 which is fixed and minimally changes with maximal rotation to the left. This radiographic finding is indicative of fixed subluxation. Illustration A further demonstrates this.
Incorrect
(SBQ12SP.1) A 65-year-old female with a history of breast cancer presents with bilateral buttock and leg pain that is worse with walking and improves with sitting. In addition, she reports that she feels unsteady on her feet and requires holding the railing when going up and down stairs. On physical exam she is unable to complete a tandem gait and has hip flexion weakness, ankle dorsiflexion weakness, and ankle plantar flexion weakness. Her reflex exam shows 3+ bilateral patellar reflexes. Radiographs and an MRI are shown in Figure A and B. What is the next most appropriate step in management. Review Topic
Lumbar epidural injection
Physical therapy with core strengthening and anti-inflammatory medications as needed
Lumbar decompression
Lumbar decompression and fusion
MRI of the cervical and thoracic spine
The clinical scenario is consistent with a patient with symptoms of degenerative spondylolisthesis AND symptoms of myelopathy. Myelopathy must be ruled out by performing an MRI of the cervical and thoracic spine.
Tandem stenosis occurs in approximately 5 to 25% of patients. Because of the stepwise progressive nature of myelopathy, treatment of myelopathy often takes precedence over lumbar spinal stenosis.
Rhee et al. found that the sensitivity and specificity of specific physical exam findings varies. Both the upward babinski reflex and the presence of clonus were found to be very non-sensitive (13%). The most sensitive provacative test was found to be the Hoffman sign (59%).
Salvi et al. reviewed the classic presentations for cervical myelopathy including demographics, history, and physical exam findings (the inability to preform a tandem gait, hyperreflexia, an abnormal babinksi and hoffman reflex, the inability to preform rapid movements and bilateral muscle weakness). Additionally they identify other potential causes for myelopathy, including multiple sclerosis, amyotrophic lateral sclerosis, multifocal motor neuropathy, and Guillain-Barre´syndrome.
Maezawa et al. showed that gait analysis can identify a pattern in patients with myelopathy. Patients with severe myelopathy have a characteristic gait with hyperextension of the knee in the stance phase without plantar flexion of the ankle in the swing phase. They also have decreased walking speed and stride length with a prolonged stance phase.
Figure A and B show a classic degenerative spondylolisthesis.
Incorrect Answers:
Question 86
A 28-year-old woman who is an avid runner reports pain about the left hip with activities. Nonsurgical management has failed to provide relief. An MRI arthrogram is shown in Figure 47. What is the most likely diagnosis?
Explanation
DISCUSSION: The MRI arthrogram reveals dye extravasation into the labrum, consistent with a labral tear. The MRI findings are not typical of osteonecrosis, stress fracture, or transient osteoporosis. There is no increase in bone marrow edema in the neck or femoral head.
REFERENCES: Guanche CA, Sikka RS: Acetabular labral tears with underlying chondralmalacia: A possible association with high-level running. Arthroscopy 2005;21:580-585.
McCarthy JC: The diagnosis and treatment of labral and chondral injuries. Instr Course Lect 2004;53:573-577.
REFERENCES: Guanche CA, Sikka RS: Acetabular labral tears with underlying chondralmalacia: A possible association with high-level running. Arthroscopy 2005;21:580-585.
McCarthy JC: The diagnosis and treatment of labral and chondral injuries. Instr Course Lect 2004;53:573-577.
Question 87
A 68-year-old male presents with gait instability, clumsiness of the hands, and the MRI images shown in Figure A. You decide to proceed with surgical decompression. When planning your surgical treatment, it is important to note that compared to a posterior approach, the anterior procedure has: Review Topic
Explanation
Surgical decompression of cervical myelopathy via an anterior procedure has lower reported blood loss compared to a posterior procedure.
Cervical myelopathy has a progressive course and therefore if there is evidence of functional impairment surgical decompression is indicated. Either an anterior decompression or posterior decompression can be used depending on a variety of factors including number of levels involved and sagittal alignment of the cervical spine. In general, a posterior approach is used when three or more levels are involved and the spine is in neutral or lordotic alignment.
Fehlings et al. did a prospective study on the risks of complications associated with surgical treatment of cervical myelopathy. They found that combined anterior and posterior procedures had a significantly higher rate of complication than either anterior-only or posterior-only procedures. Posterior procedures had a higher rate of wound infections compared to anterior. They found no statistical difference in the over-all complication rate, incidence of C5 radiculopathy, or dysphagia between an anterior-only or posterior-only procedure.
Fehlings et al. did a prospective study on outcomes following surgical treatment of cervical myelopathy. At one year follow-up they found a significant improvement in mJOA score, Nurick grade, NDI score, and all SF-36v2 dimensions. With the exception of mJOA scores, these improvements were not statistically related to severity of disease.
Liu et al. performed a meta-analysis of outcomes following surgical decompression of cervical myelopathy. They found outcomes following anterior procedures were better than those for posterior procedures when there were less than 3 affected levels. With 3 or greater levels, no statistical difference in outcomes could be found between the two approaches. They note none of their reviewed publications represent high-quality prospective randomized trials.
Figure A is a sagittal MR image of the cervical spine showing multi-level degenerative disease with cord compression consistent with cervical myelopathy.
Incorrect Answers:
Cervical myelopathy has a progressive course and therefore if there is evidence of functional impairment surgical decompression is indicated. Either an anterior decompression or posterior decompression can be used depending on a variety of factors including number of levels involved and sagittal alignment of the cervical spine. In general, a posterior approach is used when three or more levels are involved and the spine is in neutral or lordotic alignment.
Fehlings et al. did a prospective study on the risks of complications associated with surgical treatment of cervical myelopathy. They found that combined anterior and posterior procedures had a significantly higher rate of complication than either anterior-only or posterior-only procedures. Posterior procedures had a higher rate of wound infections compared to anterior. They found no statistical difference in the over-all complication rate, incidence of C5 radiculopathy, or dysphagia between an anterior-only or posterior-only procedure.
Fehlings et al. did a prospective study on outcomes following surgical treatment of cervical myelopathy. At one year follow-up they found a significant improvement in mJOA score, Nurick grade, NDI score, and all SF-36v2 dimensions. With the exception of mJOA scores, these improvements were not statistically related to severity of disease.
Liu et al. performed a meta-analysis of outcomes following surgical decompression of cervical myelopathy. They found outcomes following anterior procedures were better than those for posterior procedures when there were less than 3 affected levels. With 3 or greater levels, no statistical difference in outcomes could be found between the two approaches. They note none of their reviewed publications represent high-quality prospective randomized trials.
Figure A is a sagittal MR image of the cervical spine showing multi-level degenerative disease with cord compression consistent with cervical myelopathy.
Incorrect Answers:
Question 88
Figure 42 shows the radiograph of a 12-year-old boy who has a limp and pain in the left hip with athletic activity. Examination reveals decreased abduction and internal rotation of the left hip, with pain at the extremes of motion and a 1-cm limb-length discrepancy. Management should consist of
Explanation
DISCUSSION: The radiograph shows changes that are most consistent with Legg-Calve´ Perthes disease. Valgus extension osteotomy is the salvage procedure of choice in patients with late symptomatic Perthes disease with severe joint incongruity. Prerequisites for valgus extension osteotomy include an adequate range of hip adduction and proof of improved congruity in the new position. Total hip arthroplasty is not a good alternative in the young patient. Varus osteotomy would further shorten the extremity and place a flattened portion of the femoral head in the acetabulum. A prerequisite of the innominate osteotomy is a congruent reduction.
REFERENCES: Skaggs DL, Tolo VT: Legg-Calve-Perthes disease. J Am Acad Orthop Surg 1996;4:9-16.
Quain S, Catterall A: Hinge abduction of the hip: Diagnosis and treatment. J Bone Joint Surg Br 1986;68:61-64.
REFERENCES: Skaggs DL, Tolo VT: Legg-Calve-Perthes disease. J Am Acad Orthop Surg 1996;4:9-16.
Quain S, Catterall A: Hinge abduction of the hip: Diagnosis and treatment. J Bone Joint Surg Br 1986;68:61-64.
Question 89
A 21-year-old professional ballet dancer reports a painful popping sensation over her right hip joint. Examination reveals that symptoms are reproduced with hip flexion and external rotation. Which of the following studies will best confirm the diagnosis? Review Topic
Explanation
The patient has snapping hip syndrome of the internal type, which is more common in ballet dancers. It is caused by the iliopsoas tendon gliding over the iliopectineal line or the femoral head. The diagnosis usually can be made by the history and physical examination. Snapping is reproduced by hip flexion and extension or flexion with external rotation and abduction. Conventional and dynamic ultrasonography will confirm the snapping structure. Radiographs occasionally show calcifications near the lesser trochanter. MRI can be used to rule out other diagnoses that can simulate snapping hip.
Question 90
positive skin-test response to CSD skin-test antigen; 3) characteristic lymph node lesions; and 4) negative laboratory investigation for unexplained lymphadenopathy. Treatment consists of azithromycin, ciprofloxacin, doxycycline, or multiple other antibiotics, all of which have been used successfully. Radiation therapy and chemotherapy would be reserved for malignant diseases and would not be appropriate in this setting. Treatment is necessary for this infectious entity; therefore, observation or physical therapy is not indicated.
Explanation
The clinical and pathologic description is typical of a giant cell tumor of tendon sheath. Epithelioid sarcoma is the most common soft-tissue sarcoma in the hand and is composed of a nodular arrangement of tumor cells with epithelioid appearance and eosinophilia with a tendency to undergo central degeneration and ulceration. Gouty tophi have a characteristic white, chalky gross appearance and will demonstrate negatively birefringent crystals on polarized light microscopy. Hemangiomas are composed of a variable amount of fat and vessels. Epithelial inclusion cysts are filled with keratin from desquamation of the hyperkeratotic, stratified squamous epithelial cells that line the cysts.
A 56-year-old right hand dominant male presents to your office complaining of right thumb pain worsened with pincer grip and using his mobile phone. He is a writer, and is having difficulty holding his pen. Radiographs from this visit are shown in Figure A. Compared with trapeziectomy alone, which of the following treatment options is likely to result in superior pain relief and improvement of key-pinch strength?
Trapeziometacarpal corticosteroid injection followed by aggressive occupational therapy
Trapeziectomy with interpositional palmaris longus arthroplasty
Trapeziectomy, interpositional arthroplasty, and palmar oblique ligament reconstruction using flexor carpi radialis autograft
Partial trapeziectomy with capsular interpositional arthroplasty
None of the above CORRECT ANSWER: 5
This patient has symptomatic basal joint arthritis with radiographic evidence of pantrapezial arthritis. Simple trapeziectomy has been shown to provide pain relief and improvement of key-pinch strength that is comparable to trapeziectomy plus interpositional arthroplasty.
Definitive surgical management of basal joint arthritis commonly involves excision of the diseased trapezium with concomitant interpositional arthroplasty at the carpometacarpal joint in an effort to mantain the height of the metacarpal. This is commonly done with flexor carpi radialis (FCR) or palmaris longus (PL) autograft. Recent studies have called into question the need for interpositional arthroplasty, suggesting that excision of the trapezium alone can provide non-inferior results.
Davis et. al. randomized 183 symptomatic trapeziometacarpal joints to one of three procedures: trapeziectomy alone, trapeziectomy with palmaris longus interpositional arthroplasty, or trapeziectomy with FCR interpositional arthroplasty and reconstruction of the palmar oblique ligament. For all patients, the thumb metacarpal was percutaneously pinned to the distal pole of the scaphoid to maintain the height of the digit. Patients were evaluated at three and 12 months post-operatively. At both time-points, they found no difference between groups with respect to subjective accounts of pain, function, stiffness, and weakness. Objective measures of thumb key-pinch strength were no different at either time point. The authors concluded that there may be no benefit to ligament reconstruction or tendon interposition in
the short term.
Li et. al. performed a systematic review of four randomized controlled trials and two systematic reviews to evaluate outcomes of trapeziectomy with and without LRTI for treatment of basal joint osteoarthritis. In their review, there were no statistically significant differences in post-op grip strength, pinch strength, visual analog pain scores, DASH scores, and complications. The authors concluded that both procedures produced similar clinical results.
Raven et. al. performed a retrospective analysis of 54 patients who underwent one of three procedures for basal joint osteoarthritis: resection arthroplasty, trapeziectomy with tendon interposition, or trapeziometacarpal arthrodesis.
The authors found resection arthroplasty to be a simple procedure with longterm results pain and functional outcomes comparable to trapeziectomy with tendon interposition.
Naram et. al. retrospectively reviewed 200 patients who underwent simple trapeziectomy with or without LRTI and with or without Kirschner wire stabilization, or a Weilby ligament reconstruction. They found that patients undergoing trapeziectomy with LRTI or a Weilby procedure had a greater incidence of complications compared to trapeziectomy alone, including infection and reoperation.
Figure A is a plain radiograph demonstrating pantrapezial arthritis with the thumb trapeziometacarpal joint being most significantly affected.
Incorrect Answers:
A 31-year-old patient has had a left medial elbow mass for 1 month. The mass has been increasing in size and has now become very painful and erythematous. MRI scans are shown in Figures 76a and 76b. Laboratory studies show an erythrocyte sedimentation rate of 49 mm/h (normal 0 to 20 mm/h) and C-reactive protein level of 23 mg/L (normal 0 to 0.3 mg/L). Histology showed lymphoid tissue and multiple necrotizing granulomas. What organism is responsible for this clinical picture?
Borrelia burgdorferi
Trichophyton tonsurans
Bartonella henselae
Mycobacterium avium
Corynebacterium minutissimum
Cat scratch disease (CSD) is an important diagnosis for the orthopaedic surgeon to consider in the differential diagnosis of soft-tissue masses adjacent to epitrochlear or cervical lymph nodes. It is a soft-tissue tumor simulator and a high index of suspicion is necessary in all patients with upper extremity or head and neck adenopathy and a history of cat exposure. Although generally not required for diagnosis, cross-sectional imaging will reveal a mass with surrounding edema in an area of lymphatic drainage. A peripheral blood sample can be tested for Bartonella henselae - the offending organism with this diagnosis. Classically the histology of these lesions when biopsied will show multiple necrotizing granulomas. Mycobacterium avium is the only other organism that would demonstrate a granulomatous reaction and the location is classic for CSD. Borrelia burgdorferi is associated with Lyme disease.
Mycobacterium avium may be a source of immunocompromised infections in HIV patients. Trichophyton tonsurans and corynebacterium minutissimum are not associated with orthopaedic diseases.
A 45-year-old woman has a painful mass in the dorsum of the right wrist. It is firm and nontender to palpation. She states it has slowly gotten bigger over the past 3 years. You suspect a dorsal wrist ganglion. What is the most definitive way to confirm this diagnosis?
Observe it for 1 year to see if it changes dramatically in size.
Obtain a gadolinium enhanced MRI scan.
Obtain radiographs, looking for scapholunate joint degenerative changes.
Perform a needle aspiration and send the aspirate for cytologic examination.
Apply direct firm manual pressure over the mass to see if it can be ruptured.
Dorsal wrist ganglions are synovial cysts that arise most frequently from the scapholunate joint. They often extend between the extensor digitorum communis and extensor pollicis longus tendons at the wrist. Aspiration of the cyst is both oncologically safe if done appropriately and also the easiest way to definitively confirm the diagnosis. Clear, yellow viscous fluid/gel is most often aspirated. Cytologic evaluation is mandatory to exclude myxoid neoplasms.
Because the lesion has been present for 3 years, further observation is not warranted. The classic presentation, physical examination findings, and location make MRI and radiographs unnecessary. Manual rupture of the mass is not recommended.
A 28-year-old man fell while ice skating 6 months ago and has had ulnar-sided wrist pain ever since. The patient's wrist radiograph is shown in Figure A and a CT scan is shown in Figure B. What is the most appropriate treatment?
Scapholunate ligament repair
Excision of the hook hamate
Excision of the pisiform
Open reduction internal fixation of the hamate
Open reduction internal fixation of the pisiform
Based on clinical history and imaging shown, this patient has developed a pisiform fracture nonunion. Treatment of symptomatic nonunions of the pisiform is by pisiformectomy
Fractures of the pisiform are rare. They often occur in conjunction with injuries to the distal radius or carpus. Non-operative management with cast immobilization in 30 degrees of wrist flexion is the first line of treatment.
Symptomatic nonunions are treated with pisiformectomy.
Palmieri et al. performed pisiformectomies on 21 patients who had pisiform area pain that was refractory to conservative management. Patients had a history of painful union or nonunion of pisiform fractures, arthritis or FCU tendonitis. In all cases, wrist strength and mobility was retained.
Lam et al. reviewed the effect of pisiform excision on wrist function in patients with piso-triquetral dysfunction. After an average follow up of 65 months, 75%
of patients had complete relief of pisiform area symptoms. No differences in grip, wrist motion, strength or power were found in comparison to the contralateral side.
Figure A shows an oblique radiograph of a pisiform fracture nonunion. Figure B shows an axial CT scan sequence of the wrist. A pisiform fracture nonunion is identified with subtle comminution. The pisotriquetral joint appears to be congruent.
Incorrect Answers
A 32-year-old woman jammed her ring finger. Figures 77a and 77b show radiographs of the finger after a closed reduction. Which of the following interventions, if done correctly, is likely to result in the best possible final clinical outcome?
Early removal of a splint and application of continuous passive motion
Application of dynamic extension bracing after the first week
Maintaining reduction of the middle phalanx on the condyles of the proximal phalanx with dynamic external fixation
Open reduction and anatomic restoration of the middle phalanx articular surface
Surgical advancement of the volar plate into the middle phalanx base
The most important determinant in the final clinical outcome in proximal interphalangeal (PIP) joint fracture locations is the maintenance of the PIP joint alignment on the lateral view. This can sometimes be done with just extension block splinting, sometimes the fracture requires dynamic external fixation, and sometimes the fracture requires open reduction or volar plate arthroplasty. Good function can be the result in the setting of an incongruent middle phalanx base as long as the PIP joint alignment is maintained.
Continuous passive motion has not been shown to be of benefit. Whereas dynamic external fixation in a flexed position is a very good treatment, dynamic extension bracing will just precipitate loss of PIP joint reduction and is therefore not indicated. Whereas open reduction of the articular surface is theoretically desirable, it is generally impossible in the setting of the comminution of the volar middle phalanx base. Furthermore, open reduction and internal fixation by itself does not guarantee that the PIP joint alignment will be maintained, and typically it causes finger stiffness given the extensive surgical approach. Likewise, volar plate arthroplasty is a surgery of last resort and requires careful attention to PIP joint alignment before joint pinning. In this case, with characteristics of comminution, dynamic external fixation is the preferred choice.
A 20-year-old woman sustained a laceration to her volar forearm 4 cm proximal to the wrist flexion crease. She has numbness in the thumb, index, and middle fingers. After microscopic repair of the median nerve, 2 weeks of splinting, and commencement of a hand therapy program, the patient is most likely to require what secondary operation 6 months after the injury?
Tenolysis of the profundus tendons at the wrist
Nerve transfer of the ulnar motor nerve to the median motor nerve
Opponensplasty with the extensor indicis
Open carpal tunnel release
Transfer of the extensor digiti minimi to the first dorsal interosseous tendon
The patient sustained a laceration of the median nerve in what would be considered a low median nerve injury. Standard treatment entails exploration and microscopic repair of the median nerve. With a good quality nerve repair in a young adult, return of some sensory function (albeit reduced compared with the normal nerve) is usual. Return of motor function to the thenar muscles is more unpredictable. If the patient begins a therapy program within a few weeks after nerve repair, it is unlikely that tenolysis of the profundus tendons would be required. An open carpal tunnel release would be unlikely to change functional return. The patient would not be expected to have lost first dorsal interosseous function after a median nerve laceration because this muscle is innervated by the ulnar nerve. A neurotization procedure for low median nerve palsy has been described, but it consists of transfer of the distal anterior interosseous nerve into the median nerve motor fascicles, not transfer of the ulnar nerve. Therefore, the most likely secondary procedure required in this scenario is an opponensplasty procedure to improve thumb opposition.
What is the most efficient pressure for use with negative pressure wound therapy?
25 mm Hg
75 mm Hg
125 mm Hg
300 mm Hg
500 mm Hg CORRECT ANSWER: 3
In animal and clinical studies, a range of pressures between 50 mm Hg to 500 mm Hg were tested; the most efficient pressure was 125 mm Hg, resulting in a fourfold increase in blood flow, 63% increase in granulation tissue with continuous pressure, and 103% increase in granulation tissue with intermittent pressure. When 125 mm Hg pressures were compared with either those less than 50, or those greater than 250, there was a decrease in granulation tissue in swine models.
Figures 125a and 125b are the current radiographs of a 52-year-old man who sustained an injury to his dominant wrist 8 weeks ago. He is an alcoholic and does not remember the details of how he injured it. Paperwork showing what treatment he received at an
urgent care facility indicates that he was given a splint for his "sprained wrist." Examination reveals the pain is getting better, but there is persistent swelling and range of motion is very limited.
Recommended treatment at this time should consist of
discontinuation of the splint and commencement of a regimen of hand therapy.
casting for an additional 2 weeks and reassessment of the fracture healing at that time.
open reduction and internal fixation of the injury.
proximal row carpectomy.
wrist arthrodesis.
The injury represents a very uncommon presentation of a perilunate injury pattern. Whereas these injuries are sometimes overlooked on initial radiographic studies, they are usually recognized much sooner. In this case of a late presenting perilunate injury in a patient that is not entirely responsible, a proximal row carpectomy represents the best treatment option. Open reduction and internal fixation is generally not successful because of cartilage degeneration and contracture that has developed in the interim. No further splinting or casting is indicated, and neglecting the injury would be indicated only if the patient refused any further treatment. Wrist arthrodesis is generally indicated only as a salvage procedure if a proximal row carpectomy is unsuccessful.
A 47-year-old woman sustained a nondisplaced distal radius fracture 6 months ago and is unable to extend her thumb. When performing reconstruction using the extensor indicis proprius to the extensor pollicis longus transfer, tension is ideally determined by securing the tendons in what manner?
In maximum tension with the wrist and thumb in extension
In maximum tension with the wrist and thumb in neutral
In maximum tension with the wrist and thumb in flexion
According to the tenodesis effect with wrist flexion and extension
According to functional testing with the patient awake under local anesthesia
Extensor pollicis longus rupture can result from distal radius fractures. Synergistic tendon transfer can be achieved using the extensor pollicis longus as the motor donor. Whereas different schemes for achieving optimal tension are available, the most reliable method is to tension the repair under local anesthesia while asking the patient to perform thumb flexion and extension. Tendon transfer tension can be adjusted accordingly to achieve maximum extension without compromising active flexion range. Other methods of tensioning are estimates at best, and maximum tensioning in patients without neuromuscular disease is rarely used in tendon transfers.
Which of the following substances is likely to cause the most soft-tissue damage in the long term if injected into a fingertip under
high pressure?
Grease
Latex paint
Water
Oil-based paint
Chlorofluorocarbon-based refrigerant
This type of injury represents a difficult problem in hand surgery. The factors that most determine outcome after high-pressure injection injuries into the fingertip include: involvement of the tendon sheath, extent of proximal spread of the injected substance, pressure setting, and delay to surgical treatment.
The other factor that likely is most important is the type of substance injected. Water and latex-based paints are least destructive. Grease and chlorofluorocarbon-based substances are intermediate, but aggressive surgical debridement can restore reasonable function. Oil-based paints are highly inflammatory and can cause such chronic inflammation such that amputation may be the only reasonable treatment option despite early aggressive surgical treatment.
A 37-year-old woman has right-hand numbness and tingling. Based on the history and examination, carpal tunnel syndrome is suspected, and electrodiagnostic tests also point to the same diagnosis. The patient has worn night splints for the last 8 weeks with continued persistent symptoms. What is the next most appropriate step in management?
Continue the night splinting for 1 additional month.
Continue the night splinting for 3 more months.
Switch to full-time splinting and reevaluate in 1 month.
Switch to full-time splinting for 3 more months.
Perform carpal tunnel release.
Various nonsurgical management options exist for carpal tunnel syndrome (local and oral steroids, splinting, and ultrasound). All effective or potentially effective nonsurgical forms of management have measureable effects on symptoms within 2 to 7 weeks of the initiation of treatment. If a treatment is not effective within that time frame, a different treatment option should be
chosen. In this case, continued splinting is unlikely to improve symptoms and steroid injection or surgery is indicated.
A 46-year-old man sustains an injury to his left index finger while cleaning his paint gun with paint thinner. Examination reveals a small puncture wound at the pulp. The finger is swollen. What is the next most appropriate step in management?
Elevation and observation
Surgical debridement and lavage
Infiltration with corticosteroids
Infiltration with a neutralizing agent
Administration of antibiotics
High-pressure injection injuries are associated with a high risk of amputation. The risk of amputation is highest with organic solvents. The presence of infection and the use of steroids do not impact the amputation rate.
Amputation risk is lower if surgical debridement is performed within 6 hours. Elevation and observation would delay necessary care. Neutralizing agents may be used in specific situations, such as hydrofluoric acid exposure or chemotherapeutic agent extravasation, but in high pressure paint thinner injection, the best outcome is achieved through early surgical lavage.
A 54-year-old woman who has a history of undergoing left trapezium excision with ligament reconstruction and tendon interposition using the entire flexor carpi radialis performed by another surgeon, now reports left basilar thumb pain. Examination reveals pain and subluxation of the carpometacarpal joint with axial loading. The metacarpophalangeal joint hyperextends to 60 degrees, but radiographs show intact joint space. What is the best option to improve function?
Bracing with a hand-based thumb spica splint
Pinning of the carpometacarpal joint
Pinning of the carpometacarpal and metacarpophalangeal joints
Carpometacarpal revision stabilization
Carpometacarpal revision stabilization and metacarpophalangeal joint fusion
The patient previously underwent ligament reconstruction and tendon interposition. However, the previous surgeon failed to address metacarpophalangeal joint hyperextension, which leads to adduction contracture and collapse of the basilar joint. With the basilar joint causing pain and instability, repeat ligament reconstruction should be performed. Splinting alone is unlikely to resolve instability problems. Because the flexor carpi radialis was used, the next option is to use the abductor pollicis longus.
Additionally, the severe metacarpophalangeal joint hyperextension should be corrected by fusion. Simple pinning is unlikely to provide long-term stability when this degree of hyperextension exists.
When evaluating a patient with suspected purulent flexor tenosynovitis in the thumb, the distal forearm and little finger are found to be swollen as well. The most likely anatomic explanation is the existence of a potential space in which of the following?
Through the carpal tunnel
Across the midpalmar space
Communicating with the subcutaneous tissue
Superficial to the distal antebrachial fascia
Between the fascia of the pronator quadratus and flexor digitorum profundus conjoined tendon sheaths
Pyogenic flexor tenosynovitis is an infection within the flexor tendon sheath that can involve the fingers or thumb. The tendon sheaths begin at the metacarpal neck level and extend to the distal interphalangeal joint. In the little finger and the thumb, the sheaths usually communicate with the ulnar and radial bursae, respectively. The potential space of communication, Parona's space, lies between the fascia of the pronator quadratus muscle and flexor digitorum profundus conjoined tendon sheaths. Infection tracking through this space presents as a horseshoe abscess.
Which of the following proximal phalanx fractures can most reliably be treated with a closed reduction and avoidance of surgical measures?
Midshaft transverse diaphyseal fracture with 30 degrees of angulation
Long spiral diaphyseal fracture with 15 degrees of malrotation
Open fracture with skin loss and exposed extensor tendon
Distal condylar intra-articular fracture with minimal displacement
Proximal metaphyseal fracture location with 30 degrees of dorsal tilting
Proximal phalanx fractures are very common, but care must be taken to understand which injuries are reliably treated with nonsurgical measures, and which ones are prone to clinically symptomatic malunion without surgical treatment. The proximal metaphyseal location is a problematic fracture to get reduced with closed measures, and due to the forces of the extensor apparatus, is prone to collapse into the original deformity. Imaging is also frequently difficult because of the overlap of the other fingers and frequently the true angulation is underappreciated. With 30 degrees of angulation, consideration should be given to surgical treatment. Long oblique/spiral fractures with malrotation are also most reliably treated with multiple lag screws, because maintaining the reduction with nonsurgical measures is unreliable, and can lead to significant functional problems in the form of crossover of the fingers with gripping. Open fractures with skin loss clearly are treated with surgical measures. Distal condylar fractures with minimal displacement are another fracture pattern that have a high rate of loss of reduction when treated nonsurgically. Like most articular fractures, they are best treated with anatomic reduction and rigid internal fixation. By comparison, closed midshaft transverse diaphyseal fractures can usually be anatomically reduced and held in this position with closed measures.
Figure 3 shows an arthroscopic view of the radiocarpal joint from the 3-4 portal, looking volarly and radially (Sc=scaphoid, R=Radius). What structure is marked by the asterisk?
Radioscaphocapitate ligament
Scapholunate ligament
Palmar oblique ligament
Dorsal intercarpal ligament
Triangular fibrocartilage complex (TFCC)
The radioscaphocapitate ligament is a volar capsular structure running obliquely from the radial styloid to the scaphoid waist, ultimately inserting on the proximal radial aspect of the capitate. The radioscaphocapitate ligament is important in preventing ulnar translocation of the carpus. The scapholunate ligament is located intra-articularly, between the scaphoid and lunate. The dorsal intercarpal ligament is a dorsal structure, and not visible during routine wrist arthroscopy. The palmar oblique ligament connects the first and second metacarpal bases. The TFCC is visible during wrist arthroscopy between the radius and ulna.
A 22-year-old man reports a 2-week history of a burning pain along the dorsoradial aspect of the distal forearm. The pain radiates to the dorsum of the thumb. Examination reveals tenderness and reproduction of symptoms with percussion 8 cm proximal to the radial styloid. Reproduction of symptoms also occurs with forearm pronation
and ulnar deviation of the wrist. No discrete sensory deficit is noted and electrodiagnostic studies are normal. Nonsurgical management consisting of rest, splinting, and anti-inflammatory medications for 6 weeks has failed to provide relief. Treatment should now consist of decompression of the
lateral antebrachial cutaneous nerve in the interval between the abductor pollicis longus and the extensor pollicis brevis in the forearm.
lateral antebrachial cutaneous nerve in the interval between the brachioradialis and the extensor carpi radialis longus in the distal forearm.
radial sensory nerve in the interval between the extensor carpi radialis longus and the extensor carpi radialis brevis in the distal forearm.
radial sensory nerve in the interval between the brachioradialis and the extensor carpi radialis longus in the distal forearm.
radial sensory nerve in the interval between the brachioradialis and the extensor carpi radialis brevis in the distal forearm.
Wartenberg's syndrome, or compression of the sensory branch of the radial nerve, occurs in the interval between the brachioradialis and the extensor carpi radialis longus approximately 8 cm proximal to the radial styloid. There may be history of repetitive wrist/forearm circumduction activity (ie, knitting) or of wearing a tight wristwatch or jewelry. It can occur in patients who have been handcuffed. Typical clinical findings are pain, paresthesia, and/or hypesthesia in the dorsoradial aspect of the wrist and hand in the distribution of the radial sensory nerve. There is often a positive Tinel's sign over the compression site. Hypesthesia may be present in the distribution of the radial sensory nerve which is typically on the dorsal aspect of the first dorsal web space and dorsum of the thumb; however, with overlap in the distribution of the superficial radial nerve and the lateral cutaneous nerve of the forearm this may not always be present. Surgical management consists of release of the nerve as it exits the interval between the brachioradialis and the extensor carpi radialis longus in the distal forearm.
A 55-year-old woman with rheumatoid arthritis reports that she awoke with an inability to flex the interphalangeal joint of her thumb. Figure 8 shows an intraoperative finding. What is the most appropriate surgical treatment?
Primary repair of the tendon
Tendon reconstruction with the palmaris longus tendon
Tendon reconstruction using a transfer of the flexor digitorum profundus (FDP) of the ring finger
Thumb metacarpophalangeal fusion
End-to-side repair of the flexor pollicis longus to the FDP of the index finger
The patient has sustained a chronic flexor pollicis longus rupture (Mannerfelt lesion). The injury is most likely a result of tendinopathy and attritional rupture of the tendon secondary to synovitis and bony osteophytosis at the scaphotrapeziotrapezoid joint. Because of the attritional injury and inherent tendinopathy, primary repair is unlikely to be successful. Among the options listed, tendon graft reconstruction with the palmaris longus tendon is the most appropriate treatment. Tendon reconstruction is possible with the flexor digitorum profundus of the index finger, not the flexor digitorum profundus of the ring finger. If osteophytes are encountered, these should be debrided.
Thumb interphalangeal fusion is an option, but metacarpophalangeal fusion is not beneficial. End-to-side repair of the flexor pollicis longus to the FDP of the index finger is not appropriate and would sacrifice needed function of the index finger.
Figures A and B show the initial radiographs of a 27-year-old snow boarder who fell backward onto his left outstretched hand. Which of the following most accurately describes the sequence of events that occurred during this injury?
Lunotriquetral ligament failure followed by distal row dissociation, scaphoid extension, scaphoid failure, and dorsal dislocation of the carpus
Volar dislocation of the lunate followed by scaphoid extension, scaphoid failure, lunotriquetral failure, and distal row dissociation
Dorsal intercarpal ligament failure followed by distal row dissociation, scaphoid failure, lunotriquetral ligament failure, and dorsal dislocation of the carpus
Short radiolunate ligament failure followed by volar dislocation of the lunate, lunotriquetral ligament failure, scaphoid failure, and distal row dissociation
Scaphoid extension followed by scaphoid failure, distal row dissociation, lunotriquetral ligament failure, and dorsal dislocation of the carpus
As described by Mayfield and associates, the typical sequence of events referred to as "progressive perilunar instability" that result in a volar
perilunate dislocation are as follows: scaphoid extension, followed by opening of the space of Poirer, scaphoid failure, and distal row dissociation, which in turn lead to hyperextension of the triquetrum, lunotriquetral ligament failure, and finally dorsal dislocation of the carpus. The lunate remains in the lunate fossa in a perilunate fracture-dislocation but is dislocated in a lunate dislocation. The short radiolunate and dorsal intercarpal ligaments typically remain intact.
Which of the following is the most consistently proposed tendon transfer for radial nerve palsy?
Pronator teres to extensor carpi radialis brevis
Brachioradialis to extensor carpi radialis brevis
Flexor carpi radialis to extensor digitorum communis
Palmaris longus to extensor pollicis longus
Flexor digitorum superficialis to abductor pollicis longus and extensor pollicis brevis
Whereas there are many variations of tendon transfers for radial nerve palsy, the most consistently proposed tendon transfer is the pronator teres to extensor carpi radialis brevis. The brachioradialis is innervated by the radial nerve so that is not an option. The flexor digitorum superficialis, flexor carpi radialis, and flexor carpi ulnaris are appropriate options to transfer to the extensor digitorum communis. The palmaris longus is not always present. A transfer to the abductor pollicis longus and extensor pollicis brevis may not be necessary if the extensor pollicis longus is rerouted to allow for abduction of the first ray.
A patient has severe cubital tunnel syndrome and marked wasting of the intrinsic muscles of the hand. Why is the little finger held in an abducted position?
Accessory slip of the extensor digiti minimi attaching to the abductor digiti minimi tendon
Tetanic contraction of the abductor digiti minimi
Radial collateral ligament insufficiency of the fifth metacarpophalangeal (MCP) joint
Unopposed pull of the flexor digitorum profundus
Muscle innervation from a Martin-Gruber anastomosis
A Wartenberg's sign, where the little finger is held in an abducted position, is associated with an ulnar nerve palsy. This happens when there is an accessory slip of the extensor digiti minimi, which is innervated by the radial nerve, crossing ulnar to the center of the MCP joint to attach to the tendon of the abductor digiti minimi and the proximal phalanx. The abductor digiti minimi and the volar interosseous muscles are both innervated by the ulnar nerve; therefore, there is no tetanic contraction of the abductor digiti minimi.
Unopposed pull of the flexor digitorum profundus results in excess flexion of the proximal interphalangeal and distal interphalangeal joints of the hand as seen with a clawing-type deformity. A Martin-Gruber anastomosis, which is a neural connection between the ulnar and median nerves in the forearm, cannot explain this finger position.
Figure 38 shows the radiograph of a 41-year-old man who reports ulnar palmar pain, decreased sensibility and tingling in the ring and little fingers, and a grating sensation in the ulnar fingers with motion. He reports that he sustained a fall on an outstretched hand 6 months ago. What is the most appropriate treatment option?
Ulnar gutter cast
Short arm cast
Carpal tunnel release
Decompression of Guyon's canal
Excision of a fractured hook of hamate
Excision of a fractured hook of hamate is the most appropriate management. The patient has a hook of hamate fracture with ulnar nerve compression and irritation of the flexor tendons by the fracture surfaces; this puts the tendons at risk for rupture. Cast treatment will most likely not gain union of the fracture and will not address the nerve or tendon problems. Decompression of Guyon's canal alone will not address the tendon issue.
A 25-year-old man was involved in an altercation. Examination reveals loss of active extension of the middle finger metacarpophalangeal (MCP) joint. A diagnosis of sagittal band rupture is made. Which of the following is considered the key diagnostic finding?
Extensor lag of 30 degrees
Extensor lag of 60 degrees
Positive Bunnell intrinsic tightness test
Ability to maintain active extension of the interphalangeal joints
Ability to maintain MCP extension after passive extension
In sagittal band rupture, the extensor tendon may subluxate into the valley between the metacarpal heads. The patient will not be able to actively extend the MCP joint from a flexed position with the subluxated tendon, but will be able to maintain MCP extension after it has been passively extended. Extensor lags can have other etiologies other than extensor digitorum communis subluxation such as tendon laceration or rupture, posterior interosseous nerve palsy, but in these conditions, patients cannot maintain MCP extension. Active interphalangeal extension can be achieved with the intrinsic muscles that are not affected by sagittal band rupture.
What is the effect of shortening of metacarpal fractures?
Causes the greatest degree of extensor lag in the index finger
Causes the greatest degree of extensor lag in the little finger
Results in an average extensor lag of 7 degrees for every 2 mm of shortening
Results in an average extensor lag of 14 degrees for every 2 mm of
shortening
Has no effect on grip strength
Cadaveric models have demonstrated a 7-degree extensor lag for every 2 mm of metacarpal shortening, with the amount of lag increasing in a linear fashion. There was no statistical difference in the amount of lag in regard to the digit involved. Based on muscle length-tension relationships, cadaveric models have also been used to demonstrate an 8% loss of power secondary to decreased interosseous force generation with 2 mm of shortening. Because the intrinsic muscles of the hand contribute anywhere from 40% to 90% of grip strength, decreased interosseous force generation secondary to metacarpal shortening will invariably cause a decrease in grip strength.
A 22-year-old motorcyclist sustains open fractures to the left radial shaft and second and third metacarpals with exposed extensor tendon and bone. The fractures are approached via the dorsal open wounds of the forearm and hand with no additional incisions made. The radiograph and clinical photograph of the remaining defect in the hand are shown in Figures 55a and 55b. The remaining wound can be most appropriately covered with which of the following?
Split-thickness skin grafting
Posterior interosseous rotational flap
Radial forearm rotational flap
Groin flap
Free lateral arm flap CORRECT ANSWER: 3
After adequate debridement, there is exposed bone, tendon, and hardware. Split-thickness skin grafting over exposed tendon will not have a viable bed to support the graft. The tendons would not have healthy surrounding tissue, resulting in poor tendon gliding. The dorsal wound has disrupted the posterior interosseous artery that runs in the septum between the extensor digiti minimi and the extensor carpi ulnaris. Following the reconstructive ladder, the radial forearm rotational flap accomplishes wound coverage with a local flap rather
than a groin flap (a distant flap) or a lateral arm flap (microvascular free tissue transfer).
What is the effect of performing a flexor tenosynovectomy with an open carpal tunnel release for idiopathic carpal tunnel syndrome?
Increased risk of nerve injury
Improved postoperative finger flexion
No added long-term clinical benefit versus open carpal tunnel release alone
Increased postoperative pain
Decreased recurrence of carpal tunnel syndrome
In patients with idiopathic carpal tunnel syndrome, flexor tenosynovectomy has not been shown to change the clinical outcome compared with open carpal tunnel release alone. This has been demonstrated in a randomized clinical trial of open carpal tunnel release with or without flexor tenosynovectomy. There has also been no evidence to suggest there is an added risk to performing the flexor tenosynovectomy. At time of surgery, the gross or histologic appearance of the flexor tenosynovium does not correlate with preoperative symptoms nor with clinical outcomes. The histology of the tenosynovium has been shown to be that of fibrosis in a setting of chronic inflammatory changes and no evidence of an acute inflammatory process exists. There may be an added role for flexor tenosynovectomy in non-idiopathic carpal tunnel syndrome such as in patients with renal disease or diabetes.
Figures 69a and 69b show the radiographs of a 62-year-old man with severe radially sided wrist pain. Management has consisted of wrist splinting, nonsteroidal anti-inflammatory drugs, and activity modification, but he continues to have pain and reports difficulty sleeping. What is the most appropriate treatment for this patient?
Arthroscopic debridement
Open reduction and internal fixation
Scaphoid nonvascularized bone graft and screw fixation
Scaphoid vascularized bone graft and screw fixation
Scaphoid excision and 4-corner fusion
Scaphoidectomy and 4-bone fusion is the most appropriate management based on the choices available. The patient has arthritic changes of SNAC (scaphoid nonunion advanced collapse) wrist, stage III. Stage I is at the radial styloid, stage II is at the radioscaphoid joint, and stage III is at the midcarpal joint. Arthroscopic debridement is not appropriate in patients with arthrosis.
Attempting to achieve scaphoid union is only appropriate if there is no arthrosis or the changes are classified as stage I where radial styloidectomy can be performed.
A 7-year-old boy is referred to your office 3 months after jamming his finger while playing basketball. Examination reveals 40 degrees of active and passive motion at the proximal interphalangeal (PIP) joint. The PIP joint is stable to radial and ulnar stressing. Radiographs are shown in Figures 76a and 76b. What is the most appropriate management?
Observation
Corrective osteotomy
Ostectomy
Hand therapy for aggressive stretching
Dynamic splinting CORRECT ANSWER: 3
The most appropriate management is an ostectomy, or resection of the bone in the subcondylar fossa region. This is a malunion where the subcondylar fossa is blocked by malaligned bone. Because it is a bony block to motion, stretching or dynamic splinting will be of no benefit. The physis of the proximal phalanx is proximal, making remodeling of a fracture at the distal end very
unlikely. A corrective osteotomy has a risk of osteonecrosis of the very small distal fragment.
Figure 78 shows the clinical photograph of a patient who injured his finger while playing football. He cannot actively flex the distal interphalangeal joint of the ring finger. Which of the following is the most accurate statement regarding the injury shown?
The tendon is attached to the avulsed fragment from the distal phalanx.
There is no difference in time sensitivity in an acute injury whether or not the tendon has retracted into the palm.
In a chronic (> 3 months) case of flexor digitorum profundus (FDP) avulsion, the FDP should be tenodesed to the flexor digitorum sublimis (FDS).
If the FDP is advanced more than 1.5 cm, there is a risk for quadriga effect.
The method of repair does not affect repair gapping or strength of the tendon repair.
Overadvancement of the FDP tendon is one of the causes of the quadriga effect. Relative shortening of an FDP tendon decreases the excursion of the neighboring FDP tendons because they originate from a common muscle belly. The patient reports a weak grasp. Answer 1 is not correct because there can be a fracture and the tendon can avulse off of the fracture fragment (Trumble JHS-A 1992). Whether the tendon has retracted into the palm or not does matter because retraction into the palm allows pulleys to collapse and contract and it also means that the vinculae have been stripped off of the tendon.
Regarding answer 3, in chronic cases where the FDS is intact and strong, many patients may be better off with a sublimis finger and no FDP reconstruction that could, in the worst case scenario, worsen a functional proximal interphalangeal joint. Regarding the repair method, there is recent
research showing method of repair (button vs anchor), suture type, and method do affect the biomechanical properties of the repair.
A 44-year-old woman with cubital tunnel syndrome and associated ulnar nerve subluxation with elbow flexion has failed to respond to nonsurgical management. Which of the following statements is most acccurate regarding in situ simple decompression of the nerve compared with subcutaneous anterior transposition?
Patients undergoing anterior transposition have improved motor outcomes.
Patients undergoing anterior transposition have improved sensory outcomes
Patients undergoing simple decompression have improved motor outcomes.
Patients undergoing simple decompression have improved sensory outcomes.
No differences in outcome are likely between treatment types.
Recent reports comparing outcomes of surgical treatment of ulnar nerve compression at the elbow have demonstrated no differences in outcome between simple decompression and anterior transposition. The presence of subluxation of the ulnar nerve was not a contraindication to in situ decompression in the study by Keiner and associates.
What anatomic structure must be excised when performing a volar plate arthroplasty of the proximal interphalangeal joint?
Central slip
Collateral ligament
Checkrein ligament
Triangular ligament
Flexor digitorum superficialis insertion
The collateral ligament must be excised or released from the proximal phalanx to allow gliding of the middle phalanx on the articular surface of the proximal phalanx. Failure to do so may prevent this gliding motion and make the middle phalanx just hinge on the proximal phalanx.
Figures 97a and 97b show a clinical photograph and radiograph of a patient who has a history of repeated drainage from the lesion. What is the preferred surgical treatment?
Excision of the lesion alone
Removal of the osteophyte alone
Distal interphalangeal joint fusion
Excision of the mass and osteophyte removal
Removal of the mass and skin with skin grafting
The patient has a mucoid cyst. Whereas many of these lesions are associated with osteoarthritis, the best surgical treatment of the lesions in patients who have little or no pain is typically excision of the mass with osteophyte removal. Studies have shown that osteophyte excision helps minimize the risk of recurrence. Distal interphalangeal joint fusion is reserved for patients with pain and more advanced radiographic arthritis. Excision of the lesion alone is a less favorable option than excision of the mass and osteophyte removal. The lesion is independent of the skin and thus, skin removal with the mass is unnecessary.
Which of the following structures cannot be seen during standard radiocarpal arthroscopy?
Scapholunate ligament
Lunotriquetral ligament
Radioscaphocapitate ligament
Extensor carpi ulnaris tendon
Superficial insertion of the triangular fibrocartilage complex (TFCC)
The extensor carpi ulnaris tendon is located in an extra-articular position, and as such, cannot be seen during arthroscopy. Wrist arthroscopy is a useful technique for evaluation and treatment of radiocarpal and midcarpal maladies. During standard radiocarpal arthroscopy, the scapholunate and lunotriquetral ligaments can be easily visualized. The superficial TFCC is seen overlying the ulnar head. Volarly, the radioscaphocapitate ligament can be seen as a discrete band of the capsule.
A 20-year-old skateboarder fell 6 months ago and has had radial-sided wrist pain since. His radiograph upon presentation to your office is shown in figure A. What is the most appropriate treatment at this time?
four corner fusion
long arm thumb spica cast
wrist arthroscopy to evaluate intercarpal ligaments
open reduction internal fixation with autologous bone graft
wrist arthrodesis CORRECT ANSWER: 4
This patient has a scaphoid waist fracture nonunion. Several studies indicate that scaphoid nonunions left untreated have a determined course of collapse and progressive arthritis (scaphoid nonunion advanced collapse - SNAC). Per Markiewitz et al, the standard treatment of scaphoid nonunions is open reduction internal fixation with bone graft; non-operative treatment is not appropriate. Proximal row carpectomy and wrist fusion are salvage procedures reserved for patient that has an advanced scaphoid nonunion, collapse and wrist arthritis.
Figures 112a and 112b show the radiographs of a 28-year-old motorcyclist who sustained a closed hand injury in a collision. What is
the most appropriate definitive treatment?
Closed reduction and a hand/forearm cast in the intrinsic plus position
Closed reduction and a hand splint
Primary fusion of the carpometacarpal joints
Closed versus open reduction and internal fixation
Closed reduction and external fixation
Closed versus open reduction and internal fixation is the most appropriate treatment. The radiographs show fracture-dislocations of all five carpometacarpal joints. These injuries are extremely unstable and not amenable to closed (splint or cast) treatment only. External fixation may be warranted in an open, contaminated injury. Fusion would be an option if this were a chronic, painful condition on presentation.
What additional procedure should be done when performing a radioscapholunate fusion for posttraumatic arthrosis following a distal radius fracture?
Excision of the triquetrum and distal pole of the scaphoid
Anterior interosseous neurectomy
Fascial interposition arthroplasty of the capitolunate joint
Sectioning of the dorsal intercarpal ligament
Ulnar shortening osteotomy
Excision of the triquetrum and distal pole of the scaphoid frees up the midcarpal joint, improving radial deviation and the flexion-extension arc of motion of the wrist. This offers an alternative to complete wrist arthrodesis for posttraumatic arthrosis of the radiocarpal joint. An anterior interosseous neurectomy is believed to decrease some pain transmission from the wrist but because the fusion is done dorsal, cutting this volar structure is not routinely done. Fascial interposition is not needed because the capitolunate should be preserved in posttraumatic radiocarpal arthrosis. Sectioning of the dorsal intercarpal ligament would provide no benefit. If the triquetrum is excised, then an ulnar shortening osteotomy is unnecessary.
Apert's syndrome is caused by a mutation in what gene?
Fibroblast growth factor receptor 2 (FGFR2)
Fibroblast growth factor receptor 3 (FGFR3)
Collagen type II alpha 1 chain (COL2A1)
SED late (SEDL)
Fibrillin
Apert's syndrome (acrocephalosyndactyly type 1) is characterized by anomalies of the cranium, hands, and feet. Mutations in the FGFR2 gene cause Apert syndrome.
Anderson et al report that in Apert's syndrome there is widespread anomalies of the feet, with defects including both predictable dysmorphic changes and progressive fusions of the skeletal components during skeletal maturity.
Incorrect Answers:
2: Achondroplasia is related to abnormalities in the FGFR3, not FGFR2.
3: SED congenita is caused by mutations in COL2A1 (type II collagen alpha 1 chain) on chromosome 12. These result in abnormal type II collagen.
4:The X-linked form of SED tarda is caused by mutation in SEDL (SED late)
gene.
5: Marfan syndrome is caused by defects in the fibrillin gene.
What is the most important measure to take to reduce the risk of frostbite of the toes while hiking in extreme temperatures?
Stop often for recovery breaks.
Drink enough warm liquids.
Reduce thermal heat loss from shoes.
Use triple socks.
Adequately "carbo load" before the start.
Several studies showed the most reliable method to reduce the risk of cold exposure injury is to reduce thermal heat loss. This can be done with a combination of protective socks and shoes, and reducing moisture in the shoes.
Figures 45a through 45e are the MRI scans, gross specimen, and histology of the specimen of a 19-year-old man who has an enlarging mass in the second interspace. He reports forefoot pain that is worse with athletic activity. Radiographs show erosive changes of the third metatarsal head. What is the most common complication associated with incomplete excision?
Metastatic disease
Malignant degeneration
Recurrence
Pathologic fracture
Infection
Giant cell tumor of the tendon sheath often arises from the synovial lining of tendon sheaths. This lesion is frequently found in the hand and foot. The lesion is slow growing and can invade adjacent structures. In the foot, wearing shoes or increased activity can cause pain. Incomplete or piecemeal excision can lead to recurrence.
A 42-year-old construction worker presents with pain in his right wrist. A current radiograph of the wrist is shown in Figure A. He reports that rotating activities, such as turning a screw driver, are bothersome and the pain is preventing him from working. A current MRI reveals a TFCC tear, and nonsurgical treatment has failed to provide relief. Treatment should now consist of:
Repair of the ulnar styloid nonunion
Darrach resection of the distal ulna
Complete ulnar head resection
Ulnar hemiresection arthroplasty and TFCC reconstruction/repair
Isolated arthroscopic TFCC reconstruction
The clinical presentation is consistent with DRUJ arthritis in a heavy laborer. Of the options listed, ulnar hemiresection arthroplasty with concurrent TFCC reconstruction or repair would be the most appropriate treatment.
While there are multiple treatment options, the ulnar hemiresection arthroplasty with concurrent TFCC reconstruction or repair is considered most appropriate in heavy laborers, as it would likely resolve the pain and enable them to return to work sooner. The TFCC should be intact when performing an ulnar hemiresection arthroplasty to prevent distal ulna instability with forearm rotation. One could also consider performing a Suave-Kapandji procedure. This procedure creates a distal radioulnar fusion and an ulnar pseudarthrosis proximal to the fusion site through which rotation can occur. The advantage is that the ulnocarpal joint is not sacrificed, and a stable wrist is created.
Scheker et al reported on the outcome of ulnar shortening performed on 32 wrists with early osteoarthritis of the DRUJ. The postoperative wrist ratings were 7/32 excellent, 11/32 good, 9/32 fair, 5/32 poor, with plate irritation being the most frequent postoperative complication.
Figure A is a radiograph showing significant DRUJ arthritis. Illustration A shows ulnar hemiresection arthroplasty. Illustration B shows a Darrach procedure.
Illustration C shows a Sauve-Kapandji procedure. Illustration D is a treatment schematic of TFCC reconstruction.
Incorrect Answers:
Figures 113a and 113b are the radiographs of a 7-year-old girl who was evaluated for a visible elbow deformity by a foster parent. She thought the child fell, but her history was vague. On physical examination, a large prominence was seen over the posterolateral elbow, and the girl lacks the terminal 20 degrees of elbow extension. She has 75 degrees of elbow pronation and supination. She was nontender on examination. What is the most appropriate next treatment step?
Child abuse workup
Closed reduction
Open reduction with possible osteotomy
Observation CORRECT ANSWER: 4
The most appropriate management of this condition is observation. The patient most likely has a congenital dislocation of the radial head, although this may also represent a posttraumatic deformity. The absence of findings on physical examination speaks against an acute injury. The appearance of the radial head reveals the typical findings of a congenital dislocation, namely the convex appearance of the proximal radial articular surface. These children typically have very functional range of motion and do not require treatment unless they are symptomatic. There is nothing in this child's history to suggest abuse.
The most common mechanism of injury to the triangular fibrocartilage complex (TFCC) involves
wrist extension and forearm pronation.
wrist extension and forearm supination.
wrist flexion and forearm pronation.
wrist flexion and forearm supination.
axial load in ulnar deviation.
TFCC tears are common in athletes. As the athlete braces for a fall, the wrist is most commonly in an extended position and the forearm is pronated.
A 28-year-old woman fell on her right wrist while rollerblading 6 days ago. She was seen in the emergency department at the time of injury and was told she had a sprain. Examination now reveals dorsal tenderness in the proximal wrist but no snuffbox or ulnar tenderness. Standard wrist radiographs are normal. What is the next most appropriate step in management?
Arthroscopy of the wrist
CT of the wrist
Bilateral PA clenched fist radiograph
Electromyography and nerve conduction velocity studies
AP and lateral radiographs of the forearm
When considering the diagnosis of scapholunate ligament injury, standard radiographic views of the hand will not always reveal widening of the scapholunate gap. Although MRI may reveal injury to the ligaments, the PA clenched fist view can be obtained in the office during the initial patient visit. Arthroscopy is not a first-line diagnostic tool.
Figures 12a through 12c show the radiographs of a 28-year-old professional baseball player who has ulnar-sided wrist pain and
numbness and tingling in the fourth and fifth digits for the past 6 weeks. Management should consist of
cast immobilization.
bone stimulation and splinting.
ulnar nerve exploration.
open reduction and internal fixation.
excision of the fragment.
Hook of the hamate fractures typically occur as a result of direct force from swinging a bat, golf club, or racket. Pain is localized to the hypothenar eminence. The injury is best seen on a carpal tunnel view. CT will confirm the diagnosis. Chronic cases can be associated with neuropathy of the ulnar nerve. Excision of the hook through the fracture site usually yields satisfactory results, allowing the athlete to return to competition.
A 40-year-old right-handed professional football player reports persistent right wrist pain after falling during a game 5 days ago. A radiograph is shown in Figure 21. Management should consist of
immobilization in a short arm thumb spica cast.
immobilization in a long arm thumb spica cast.
arthroscopic repair and percutaneous pinning.
open repair and percutaneous pinning.
dorsal capsulodesis.
The radiograph reveals an increased distance between the scaphoid and the lunate, which is indicative of scapholunate disassociation. A ring sign is also present, which represents the distal pole of the scaphoid viewed end on in a palmarly flexed position. In the acute setting, the scapholunate can be repaired. Open repair and percutaneous pinning is the treatment of choice. Dorsal capsulodesis is performed in the chronic setting if such an injury is initially missed.
An 18-year-old rugby player has had pain in his ring finger after missing a tackle 1 week ago. Examination reveals tenderness in the distal palm, and he is unable to actively flex the distal interphalangeal (DIP) joint. Radiographs are normal. What is the most appropriate management?
Acute tendon repair
DIP joint extension splinting for 6 weeks
DIP and proximal interphalangeal joint extension splinting for 6 weeks
Buddy taping to the middle finger for 2 weeks
Early range-of-motion exercises and return to play as pain permits
Flexor digitorum profundus rupture or “rugger jersey finger” often occurs in the ring finger after the player misses a tackle and catches the digit on the shirt of the opposing player. Surgical repair is required for zone I-type injuries.
A 65-year-old right-hand-dominant man has a 5 year history of progressive right wrist pain. He relates spraining his wrist playing football in college, but otherwise has had no prior traumatic injury. He is a pack per day smoker. An AP radiograph of the wrist is shown in Figure A. Wrist immobilization, anti-inflammatory medications, and injections have failed to provide relief. Which appropriate surgical treatment option offers the lowest risk of postoperative complications?
Radial styloidectomy
Total wrist arthroplasty
Proximal row carpectomy
Scaphoid excision with four-corner fusion
Complete radiocarpal arthrodesis
Proximal row carpectomy (PRC) and scaphoid excision with four-corner fusion are both appropriate surgical treatment options for stage II scapholunate advanced collapse (SLAC) wrist; however PRC is associated with fewer postoperative complications, particularly in active smokers.
Scapholunate interosseous ligament disruption leads to abnormal wrist biomechanics and degenerative arthritis. This progression follows a predictable pattern termed scapholunate advanced collapse. In stage II disease where the entire radioscaphoid articulation is affected but the capitolunate articulation is spared, both proximal row carpectomy (PRC) and scaphoid excision with four-corner fusion offer long-term pain relief while preserving wrist motion and grip strength. Scaphoid excision with four-corner fusion has a higher rate of complications owing to nonunion, hardware issues, and dorsal impingement from malunion. PRC is not recommended in the setting of capitolunate arthritis (stage III).
Tomaino, et al. retrospectively compared PRC and limited intercarpal arthrodesis with scaphoid excision (LWF) at a mean of 5.5 years postoperatively in 24 symptomatic SLAC wrists. They noted good pain relief, grip strength, and function in all but 3 patients having undergone PRC - one of whom required revision to wrist arthrodesis (these patients had symptomatic capitate arthrosis). They concluded that in wrists without capitolunate arthritis, PRC had the benefit of being technically easier to perform, did not require prolonged postoperative immobilization, and avoided the risk of nonunion associated with LWF; however it was not an appropriate surgical option in stage III SLAC wrists with capitolunate involvement.
Strauch reviewed the evaluation and treatment of SLAC and SNAC (scaphoid nonunion advanced collapse) wrists. Treatment options for SLAC wrist include four-corner fusion, capitolunate arthrodesis, PRC, radial styloidectomy, wrist denervation, and complete radiocarpal fusion. Excision of the distal ununited scaphoid fragment is an additional option in the setting of SNAC wrist. He additionally highlights current controversies between PRC vs. four-corner fusion.
Figure A shows an AP radiograph with stage II SLAC wrist. The entire radioscaphoid articulation is arthritic with sparing of the capitolunate surface.
Illustration A shows the modified Watson classification of scapholunate advanced collapse.
Incorrect Answers:
A 25-year-old male presents to the clinic with a painful, enlarging mass at the volar radial wrist. He initially noticed the mass 6 months ago after he hurt his wrist golfing. Figure A shows a clinical photograph of the patient's wrist. Radiographs are unremarkable. An ultrasound of the mass is shown in Figure B. Surgical excision is planned. Which of the following is the most appropriate type of resection and histologic finding?
Intralesional excision; synovial cells with mucin accumulation
Incision & drainage; polymorphonuclear cells
Wide excision; histiocytes with frequent giant cells
Marginal excision; synovial cells with mucin accumulation
Intralesional excision; histiocytes with frequent giant cells
The patient presents with a volar wrist ganglion cyst. Surgical treatment consists of marginal excision. Histologic analysis demonstrates synovial cells with mucin accumulation.
Ganglion cysts are the most commonly presenting masses in the hand. These cysts consist of a synovial cell lining filled with mucin. Dorsal wrist ganglion cysts originate from the scapholunate interval and are more common than volar wrist ganglions, which typically originate from the scapho-trapezio-
trapezoidal joint articulation. Ganglion cysts can cause pain related to mass effect. Ultrasound can help differentiate these masses from vascular malformations or other tumors; ganglion cysts present as homogenous anechoic masses with well-defined borders.
Mayerson, et al. reviewed the diagnosis and management of soft-tissue masses. They highlight the typical presentation of ganglion cysts, which wax and wane in size and transilluminate with a pen light. The authors concluded that MRI is diagnostic if there remains any uncertainly after history and clinical exam.
Head et al compared surgical excision versus needle aspiration of 2,239 adult wrist ganglions in a meta-analysis of 35 studies. Surgical excision resulted in a 76% reduction in recurrence compared to aspiration. Mean recurrence for arthroscopic excision (6%), open surgical excision (21%) and aspiration (59%) and mean complication rate for arthroscopic excision (4%) open surgical excision (14%) and aspiration (3%) were also determined. Data from arthroscopic excision was limited but is a promising technique. Open surgical excision has a significantly lower recurrence rate as compared to aspiration.
Figure A shows a clinical photo of a volar wrist ganglion cyst. Figure B shows the ultrasound image of a volar wrist ganglion cyst.
Incorrect Answers:
A 27-year-old man falls on his hand at work. He notices an immediate deformity of his ring finger. Radiographs are provided in Figure A. Which of the following is the most appropriate initial treatment?
Closed reduction, buddy taping, and early motion to prevent stiffness
Closed reduction and full time extension splinting
Open reduction and repair of the central slip of the extensor tendon
Open reduction and repair of the volar plate
Amputation and immediate return to work
The radiograph demonstrates a volar PIP dislocation. The central slip of the extensor tendon is frequently ruptured and will lead to a boutonneire deformity if left untreated. The PIP must be immobilized in extension to allow the extensor mechanism to heal. Immobilization in extension should be maintained for 6 weeks to allow soft tissue healing. Open reduction and repair of the central slip would be the appropriate treatment for a developing boutonneire deformity that presents in a subacute or chronic time basis.
Illustrations A and B demonstrate a schematic and clinical photo of central slip disruption and secondary deformity with PIP flexion and DIP hyperextension (Boutonniere Deformity).
Posner et al reviewed 7 patients with chronic palmar dislocations of the PIP joint who were treated with open reduction and reconstruction of the extensor mechanism. All patients acheived satisfactory range of motion and the authors concluded that this technique is preferable to arthrodesis.
Peimer et al reviewed 15 patients with palmar dislocations of the PIP joint. Twelve of the fifteen were evaluated on a delayed basis (average 11 weeks following injury) and underwent open reduction and surgical repair of the extensor tendon. Three of the fifteen were seen earlier following injury and were treated with closed reduction and pinning. All fifteen patients acheived satisfactory clinical outcomes although finger range of motion was not fully recovered in any case.
Figure A is of a 22-year-old male college basketball player presents for evaluation of a right index finger deformity. He reports a fall during a game 8 weeks ago, with resultant deformity to the index finger. He "popped it back in" and returned to play. Physical exam is most likely to demonstrate:
Inability to passively extend the PIP joint to neutral, able to passively flex and extend the DIP joint
With the PIPJ flexed, resistance to PIPJ extension causes the DIPJ to become supple
Dorsal subluxation of the PIP joint, able to passively flex and extend DIP joint
With the PIPJ flexed, resistance to PIPJ extension causes the DIPJ to become rigid
Inability to actively flex the DIP joint, able to actively flex the PIP and the MCP joints
The patient presents with a Boutonniere deformity secondary to a traumatic central slip disruption in the setting of volar PIP joint dislocation. Physical exam will demonstrate a positive Elson's test, which is described in answer 4.
The digital extensor mechanism consists of the central slip and two lateral bands, all of which arise from the extensor digitorum communis (EDC) tendon. Flexion of the PIP joint puts the central slip on tension, and volarly subluxes the lateral bands causing them to become slack. Tension on the central slip causes extension of the PIP joint, with concomitant dorsal shift of the lateral bands which help to bring the DIP joint into extension.
In 1986, Elson described his physical examination maneuver for diagnosis closed rupture of the central slip. With the hand resting on the edge of a table, the PIP joint is flexed to 90 degrees over the table edge, and the patient is asked to extend the digit against resistance. Active extension of the middle phalanx can only be observed with an intact central slip, and the adjacent lateral bands will remain slack which allows the DIP joint to remain flail. In central slip ruptures, effort to extend the middle phalanx will be accompanied
by DIP rigidity/extension as the lateral bands are forced to contribute to extension.
Rubin et. al. performed a cadaveric study evaluating the efficacy of physical examination maneuvers to identify acute ruptures of the central slip. They
found that Elson’s test was the only maneuver that could discern central slip integrity in both tested scenarios: 1) pre-boutonniere deformity with division of the central slip and 2) passively correctible boutonniere deformity caused by division of the central slip, the triangular ligament, and the oblique fibers of the extensor expansion.
Figure A is a clinical image of an index finger with boutonniere deformity. Video A is a short demonstration of how to perform the Elson test.
Incorrect answers:
A 25-year-old woman presents to the clinic after knife injury to the volar aspect of her long finger 2 weeks ago. She is evaluated and diagnosed with tendon rupture of the flexor digitorum profundus (FDP). What finding on examination can be expected in this patient?
With passive wrist extension, extension remains at the distal interphalangeal joint
With passive wrist extension, extension remains at the proximal interphalangeal joint
With passive wrist flexion, extension is limited at the distal interphalangeal joint
With passive wrist flexion, flexion remains at the distal interphalangeal joint
With passive wrist flexion, flexion remains at the proximal interphalangeal joint
With an FDP rupture, physical exam would likely reveal loss of flexion at the DIP joint both actively and passively with wrist extension.
When the wrist is in extension, flexor tendons are stretched and should result in flexion at the DIP (FDP) and PIP (FDS) joints. The FDP tendon is responsible for flexion of the DIP joint, and this joint would remain extended during normal tenodesis on passive wrist exam. Inversely, with extensor tendon injuries, there may be a loss of digit extension with passive wrist flexion.
Strickland presents a review article (Part 1) on flexor tendon injuries discussing clinical presentation and repair techniques. A commonly tested concept is that tendon repair is proportional to the number of core sutures, and currently recommended repair includes at least 4 core sutures for strength with epitendinous suture to aid in gliding and provide some strength.
Kamal et al. present current evidence regarding flexor tendon injuries, reviewing examination, repair, and rehab. They note that to date there still remains heterogeneity in treatment patterns and no clear standard of care. Rehab options include no motion, early active range of motion, and controlled passive range of motion. The authors note that early loading may lead to improved strength.
Illustration A depicts the usual tenodesis effect of the digits where passive extension of the wrist produces flexion of the fingers.
Incorrect Answers:
A 20-year-old college football lineman sustains an injury to his index finger during a game. A radiograph of the hand is demonstrated in Figure A. What is the mechanism of injury and most common reason for unsuccessful closed reduction?
Hyperextension mechanism causes the metacarpal head to button hole between the flexor tendon and the lumbrical
Hyperextension mechanism causes volar plate avulsion and entrapment dorsal to the metacarpal head
Rotational mechanism causes the metacarpal head to button hole between the flexor tendon and the lumbrical
Hyperflexion mechanism causes volar plate avulsion and entrapment dorsal to the metacarpal head
Hyperflexion mechanism causes the metacarpal head to button hole between the flexor tendon and the lumbrical
Irreducible dorsal metacarpophalangeal (MP) joint dislocations occur from a hyperextension moment, which causes volar plate displacement and incarceration dorsal to the metacarpal head.
MP joint dislocations are most commonly dorsal and occur with hyperextension injuries. Simple dislocations are reducible with wrist flexion (to relax the intrinsic muscles) and direct palpation over the proximal phalanx base.
Complex dislocations occur with interposition of the volar plate. When irreducible, open reduction is required.
Afifi et al. performed a cadaver study defining the anatomy surrounding irreducible dorsal index MP joint dislocations. They found that of all local structures, only release of the volar plate allowed for reduction of the MP joint. They concluded that volar plate interposition dorsal to the metacarpal head was responsible for irreducible MP joint dislocations.
Bohart et al. describe 9 patients with irreducible dorsal MP joint dislocations (5 thumbs and 4 index fingers). A dorsal approach was performed in each case to allow for reduction of the volar plate. A stable MP joint was achieved in each case. They advocate for a dorsal approach, which minimizes the risk of iatrogenic injury to the neurovascular bundles, which are displaced volarly by the metacarpal head.
Figure A shows an oblique radiograph of the hand demonstrating a dorsal dislocation of the index MP joint. Illustration A provides a schematic of both a simple and a complex dorsal MP joint dislocation. In the case of a complex dislocation, the volar plate avulses from its origin and becomes entrapped dorsal to the metacarpal head.
Incorrect Responses:
A 3-year-old patient presents to clinic with her parents for the chest wall anomaly seen in Figure A. What other congenital disorder is associated with this syndrome?
Flexible pes planovalgus
Syndactyly
Polydactyly
Macrodactyly
Accessory navicular CORRECT ANSWER: 2
The figure shows an individual with Poland's Syndrome, as demonstrated by the absent sternoclavicular head of the pectorals major. Syndactyly and symbrachydactyly is often seen, in addition to hypoplasia and shortening of the fingers.
Poland's Syndrome, or Poland anomaly/sequence, is thought to be caused by disruption of the subclavian artery in utero, causing various hypoplastic anomalies of the upper extremity. These are typically ipsilateral ranging from aplasia of the sternocostal head of the pectorals major, radio-ulnar synostosis, symbrachydactyly and other limb hypoplasias, or syndactyly of the central digits. Syndactyly is often simple and either complete or incomplete. It is addressed surgically early on, with the chest wall deformities needing reconstruction and muscle transfers closer to sexual maturity. Thoracic, cardiovascular, and genitourinary anomalies may also be present.
Catena et al. proposed a new classification system for Poland Syndrome based on the degree of clinical severity of the entire upper extremity. The classification type increased with more proximal involvement up the upper extremity. This new system may help guide treatment as is takes into account the functional state of the rest of the upper extremity and not just the hand, as previous systems have.
Ireland et al. analyzed 43 consecutive cases of Poland's Syndrome. All cases involved congenital aplasia and syndactyly which was typically simple and incomplete. The thumb can be involved putting it the same plane as the fingers. Anomalies were more frequently seen on the right side. They noted favorable outcomes with surgical correction by syndactyly release initiated by 1 year, with some requiring periodic revision releases, while others required an amputation producing a three-fingered hand.
Figure A shows an absent stenocostal head of the pec major. Only the right side is involved. Illustrations A-C show pre-op and post-op digital release of an individual with syndactyly
Incorrect Answers:
A 32-year-old man sustains an injury to his left thumb. Examination in the ER demonstrates a 2x4 cm wound on the dorsal thumb overlying the proximal phalanx with exposed tendon and bone. What is the most appropriate option for soft tissue coverage?
Cross-finger flap
Moberg advancement flap
Full-thickness skin graft
First dorsal metacarpal artery flap
V-Y advancement CORRECT ANSWER: 4
The first dorsal metacarpal artery flap (Kite flap) is the most appropriate soft tissue coverage option for dorsal thumb wounds that disrupt vascularized tissue overlying the extensor tendon and bone (including the epidermis, dermis, subcutaneous tissue, and tenosynovium) when primary closure is not possible.
Kite flaps are based off of the first dorsal metacarpal artery, which overlies the index finger metacarpal. It offers a pedicle length up to 7 cm and can reliably cover soft tissue defects up to 3x5 cm in area. Given its location, it is appropriate for the treatment of thumb wounds including those to the web space, dorsum, and volar pulp, particularly when injury compromised the vascularity of the wound bed. It can be modified to include both dorsal branches of the proper digital nerve, thereby conferring sensibility to the covered wound. The donor site can subsequently be covered with a full-thickness skin graft.
Rehim et al. reviewed local flaps of the hand. They offer treatment options and appropriate indications based upon the anatomic location and size of the wound within the hand. They conclude that when there are no clinical limitations, local flaps provide ideal soft tissue coverage and function for hand wounds based upon the local anatomy without the need for more complex free tissue transfers.
Eberlin et al. review soft tissue coverage options in the hand. They present four clinical cases and offer one established and one non-traditional surgical treatment option for each. They recommend the first dorsal metacarpal artery flap as an established treatment option in a case of thumb volar pulp injury as it offers contour restoration as well as sensibility when the digital nerves are included with the vascular pedicle.
Illustration A demonstrates a large dorsal thumb soft-tissue injury that is treated with first dorsal metacarpal artery flap coverage and full-thickness skin grafting to cover the donor site.
Incorrect Answers:
A 65-year-old man complains of numbness and tingling in the thumb, index, and long fingers of his dominant right hand for 3 months. An EMG demonstrates prolonged median sensory latency and low amplitude compound muscle action potentials with fibrillations in the abductor pollicis brevis. What is the most appropriate treatment option and the rate of continued symptoms at 1 year after treatment?
Splinting and corticosteroids; 5%
Open carpal tunnel release; 20%
Splinting and corticosteroids; 30%
Endoscopic carpal tunnel release; 2%
Open carpal tunnel release; 5%
The most appropriate treatment of carpal tunnel syndrome (CTS) with EMG evidence of denervation is surgical release. The rate of residual symptoms at 1 year is approximately 20%.
The American Association of Electrodiagnostic Medicine (AAEM) criteria delineates CTS severity by EMG. Mild CTS is purely sensory. Moderate disease demonstrates prolonged sensory and motor latencies. Severe disease progresses to involve muscle denervation. Mild and moderate CTS may be treated with carpal tunnel release following failure of nonoperative treatment; however, early operative treatment is supported for severe disease to limit further denervation. Patients experience significant improvement in
symptoms; however, recovery is prolonged and persistent symptoms may be present in ~20% at 1 year.
Kronlage et al. compared changes in numbness and pain following carpal tunnel release in 47 patients with moderate and 48 patients with severe CTS diagnosed on EMG. At 1 year or longer, 1 (2%) patient with moderate disease had continued symptoms compared to 9 (19%) of patients with severe CTS. They concluded that patients with severe CTS experience significant reductions in symptoms following carpal tunnel release; however, recovery may be prolonged or incomplete at 1 year postop.
Ono et al. performed a systematic review of 25 studies reporting outcomes for the treatment of carpal tunnel syndrome. They noted an increasing trend towards recommending earlier surgery for CTS with or without median nerve denervation. They conclude that this differed from the 2007 AAOS guidelines, which recommended early surgery only in the setting of muscle denervation.
Incorrect Answers:
A 23-year-old man presents with chronic, progressive right wrist pain. He remembers falling onto an outstretched hand 2 years ago. Radiographs, CT scans and a T1-weighted coronal MRI are shown in Figures A through E. No bleeding was identified at surgery. In addition to surgical stabilization, what is the next best step?
Corticocancellous autograft inserted through a dorsal approach
Pedicled distal radius graft inserted through a dorsal approach
Pedicled distal radius graft inserted through a volar approach
Free vascularized femoral bone graft inserted through a dorsal approach
Free vascularized femoral bone graft inserted through a volar approach
This patient has an old scaphoid waist fracture with nonunion, proximal pole avascular necrosis (AVN), and carpal collapse. Optimal treatment is with a free vascularized medial femoral condyle (MFC) graft through a volar approach.
Where there is proximal pole AVN, union was achieved in 88% of patients with a vascularized graft versus 47% with screw and nonvascularized wedge bone graft fixation. The 1,2 intercompartmental supraretinacular artery (1,2 ICSRA) pedicle graft leads to union rates of 71% for scaphoid nonunions and 50% for AVN. The risk for failure is higher when there is DISI or humpback deformity (underscoring the need to restore scaphoid geometry). The MFC graft uses a pedicle from the descending genicular artery or the superomedial genicular artery when the descending genicular artery is not present. The volar approach is preferred as it allows correction of the humpback deformity and anastomosis of the MFC pedicle to the radial artery.
Jones et al. retrospectively compared 2 vascularized bone grafts for treatment of scaphoid waist nonunions with proximal pole AVN and carpal collapse. 4 of
10 nonunions treated with distal radial pedicle graft healed at 19 weeks. 12 of 12 nonunions treated with free vascularized medial femoral condyle (MFC) graft healed at median of 13 weeks. Rate of union was higher, and time to healing was shorter for the MFC graft. They recommend the MFC vascularized bone graft for treatment of scaphoid waist nonunion with proximal pole AVN and carpal collapse.
Figures A, B, C and D are PA and lateral radiographs and coronal and sagittal CT images showing scaphoid waist nonunion with carpal collapse and osteonecrosis of the proximal pole, respectively. Figure E is a T1-weighted coronal image shows diffusely decreased signal within the proximal pole.
Illustrations A and B show harvest and inlay of the 1,2 ICSRA graft. Illustration C shows the MFC graft.
Incorrect Answers:
A 38-year-old female develops pain and pallor in all the digits of the right hand daily. Her symptoms have progressed over 2 years despite avoiding direct cold exposure and multiple medications including nifedipine. Recently she has developed the lesions seen Figure A. Workup for underlying disease by her rheumatologist was negative. She is a candidate for Botuninum toxin A injections. What is the physiologic effect of botulinum toxin in the hand for her condition?
Improving proprioception in the fingers and hand by binding to postsynaptic acetylcholine receptors
Improving digital perfusion by cleaving pre-synaptic SNAREs and preventing the release of acetylcholine
Decreasing glabrous skin sensation by reducing hyperexcitability of voltage dependent calcium channels
Strengthening the intrinsic muscles by increasing hyperexcitability of voltage dependent calcium channels
Increasing sympathetic innervation by cleaving pre-synaptic SNAREs and preventing the release of acetylcholine
The patient is displaying Raynaud's Disease with the development of ulcerations from chronic vasoconstriction. Botulinum toxin has been shown to increase the blood supply throughout the hand through the its well-known mechanism of pre-synaptic SNARE cleavage.
Botulinum toxin cleaves the pre-synaptic SNAREs (soluble NSF attachment potion receptor) and prevents the release of acetylcholine from the intracellular vesicles. This has been used for multiple medical purposes, including vasospastic disorders. Raynaud's Disease is characterized by idiopathic vasospasm of the digital arteries without known underlying cause. Usually afflicting pre-menopausal women, it begins with pain and pallor in the digits, typically affecting the bilateral hands. Avoiding cold environments and tobacco are the mainstays of treatment, with calcium-channel blockers being the most common medication used. When these and other medications fail, botulinum toxin injections have been shown to be of benefit by relieving vasoconstriction and decreasing ischemia and pain.
Neumeister et al. reviewed the application of botulinum toxin A and individuals with Raynaud's Disease and Syndrome. They showed marked increases (up to 300%) in digital perfusion in patients receiving these injections into the common digital vessel at the level of the palm. They concluded the mechanisms for this response are likely multifactorial, involving central and systemic effects on neurotransmitters involved in chronic pain pathways, local digital vessel tone, and sympathetic innervation.
Iodio et al. reviewed all clinical studies regarding the use of bootulinum toxin A in raynaud's. There was high variability among the studies in terms of dosage and application method, but all studies reported favorable patient outcomes and some showed improved healing of ulcerations. These studies are promising but are limited due to study design and lack of standardization of botulinum toxin application.
Figure A shows non-infected ulcerations in the digits, common in progressive raynaud's disease.
Illustration A shows ischemic digits due to Raynaud's Syndrome. Illustration B is the same hand after botulinum toxin A injection. Illustration C is a laser doppler of a hand both pre- and post-injection perfusion of botulinum toxin A in an individual with Raynaud's Disease. Illustration D depicts the recommended method of injection, placing 10 units of botulinum around the common digital vessel at the level of the palm.
Incorrect Answers: There is no shown effect on digital proprioception, skin sensation, muscle strengthening.
A 27-year-old male injures his thumb during a fall onto an outstretched hand. He has pain at the MCP joint and difficulty grasping objects between the thumb and index finger. He undergoes surgery with the planned incision shown in Figure A. What muscle and corresponding nerve innervates the structure that blocks reduction of the ligament shown in Figure B?
Opponens pollicis, median nerve
Flexor pollicis brevis, ulnar nerve
Adductor pollicis, ulnar nerve
Abductor pollicis brevis, median nerve
Adductor pollicis, median nerve
The patient has an ulnar collateral ligament injury. The structure that blocks reduction of the ligament is the adductor pollicis aponeurosis, which is innervated by the ulnar nerve.
Thumb ulnar collateral ligament injuries occur after a radially directed force on an extended thumb, stressing the ulnar collateral ligament, dorsal capsule and volar plate. The thumb should be radiographed before stress exam if the history warrants so as not to displace a possible bony avulsion. Exam includes valgus stress on the thumb at 0 and 30 degrees of flexion to test the accessory and proper collateral ligaments respectively. With complete rupture of both ligaments, a bump over the ulnar thumb MCP joint may be palpated, signifying a Stener lesion. The ligament usually tears at the distal insertion and displaces proximal and superficial to the adductor aponeurosis. The dorsal capsule and volar plate may also be injured.
Bean et al. evaluated the biomechanics of non-anatomic reconstruction of the ulnar collateral ligaments in cadaveric specimens. They showed that 2mm of volar displacement of the ligament origin will allow for 10 degrees more radial deviation than anatomic placement will. This highlights the need for anatomic reconstruction and that deviation from this will alter joint kinematics.
Figure A shows a planned incision over the ulnar aspect of the thumb MCP joint
Fibure B shows a Stener lesion that is migrated proximally compared to the aponeurosis which is marked by the forceps
Illustration A depicts the retraction of the collateral ligament proximal to the aponeurosis
Illustration B shows a T1 MR coronal image showing a distal avulsion of the UCL and the Stener lesion, denoted by the asterisk, and the arrow pointing to the aponeurosis
Incorrect Answers:
An otherwise healthy 5-year-old female is brought to your office for the deformity shown in Figures A and B. Only the small digit of the left hand is involved and it may be fully flexed, but there is limited passive extension. What is the next best step in treatment?
Observation and reassurance
Nighttime extension splinting and stretching regimen
Nighttime extension splinting and stretching regimen with full genetic workup
FDS transfer to radial lateral band
FDS split with transfer of limbs to A2 pulley and central tendon hood
The patient described has isolated camptodactyly with a mild flexion contracture. The best next step in treatment is to begin a stretching and splinting regimen.
Camptodactyly is a nontraumatic flexion deformity isolated to the proximal interphalangeal joint, typically involving the small finger. This is often seen
bilaterally and sporadically, although many congenital disorders are associated. Many underlying anatomical structures have been implicated in the pathogenesis of this condition, with various surgical techniques having been described to address these. If this condition remains untreated, adjacent joint involvement can develop, with MCP hyperextension seen most commonly.
Intrinsic-plus splinting of the hand with passive stretching exercises should be initiated first. Surgery is usually reserved in cases of failed splinting or significant contractures approaching 60 degrees.
Comer et al. reviewed the complications of campylodactly. Most common complications were progression or failed improvement of both PIP contracture and MP hyperextension, isolated PIP postoperative residual stiffness, and bony remodeling of proximal phalanx head preventing full extension. They note inconsistent results after surgical correction which supports early detection and conservative modalities as the mainstay of treatment, focusing heavily on a stretching program and night splinting.
Rhee et al. reviewed outcomes of passive stretching for isolated camptodactyly flexion contractures in a series of children under the age of three years. They showed marked improvement of contracture deformity in all children across all levels of severity, though to less extent with more severe deformities.
Figures A and B demonstrate early contracture of the left small finger. Illustration A is a radiograph showing maintenance of articular congruity.
Incorrect Answers:
A collegiate rower complains of dorsal wrist pain for 6 weeks refractory to NSAIDs and bracing. Maximal tenderness is palpated on the dorsoradial forearm approximately 5 cm proximal to the wrist. Pain is exacerbated with resisted wrist extension. Radiographs are unremarkable. A steroid injection should be directed into the compartment containing which of the following structures?
APL and EPB tendons
ECRL and ECRB tendons
EPL tendon
APL and ECRB tendons
Brachoradialis tendon CORRECT ANSWER: 2
The clinical scenario is consistent with intersection syndrome, a inflammatory response to overuse at the site of the second dorsal compartment crossing under the first dorsal compartment approximately 5 cm proximal to the wrist. An anatomical depiction is provided in illustration A. Injections of the second dorsal compartment, which includes ECRL and ECRB, may relieve symptoms
and quell inflammation. Intersection must be differentiated from DeQuervain's syndrome, which is tenosynovitis of the first dorsal compartment. Injections of the first dorsal compartment, which includes APL and EPB, are part of the treatment algorithm for Dequervain's. Wood et al summarizes the evaluation and treatment of sports-related wrist injuries. Grundberg et al demonstrates the pathologic abnormality of intersection syndrome is stenosing tenosynovitis of the second compartment explaining the rationale behind steroid injections into the sheath.
A 42-year-old chef has finally been transferred to the hand specialist 15 hours after injuring his non-dominant hand index finger with a butcher's knife as seen in figure A. He has kept the finger with him, which has been wrapped in saline-soaked gauze and placed on ice. What is the best reason the finger tip should not be replanted?
The replanted digit will likely have poor function due to the delay in care
Possible malingering
The replanted digit will likely have poor function due to the local anatomy
Patient age
Workers compensation patients will have worse outcomes
Single digit amputations proximal to the insertion of the flexor digitorum superficialis (FDS), in generally have poor function and severe stiffness following replantation.
Replantation between the FDS insertion and the distal palmar crease (zone 2 flexor tendon injuries) has historically led to poor results due to stiffness at the proximal interphalangeal joint, decreased sensation in the finger, and tendon adhesions between the FDP and slips of the FDS. Furthermore, outcome studies have demonstrated patients with index finger amputations through this region are more likely to bypass their stiff index finger and utilize their long finger for most tasks. However, amputation of multiple digits through zone 2 would be considered for replantation.
Urbaniak et al performed a retrospective case series of 59 patients who
underwent finger (thumb excluded) replantation for traumatic amputation. They found the functional results were most dependent on level of amputation and patients with amputation proximal to the insertion of the FDS had significantly decreased PIP motion. They concluded that replantation through zone 2 is seldom indicated due to severe stiffness.
Boulas et al reviewed digital replantation and recommend initial treatment should consist of wrapping amputated parts in moistened gauze and placing on ice. Sharp and clean amputations are considered more viable candidates for replantation due to limited damage to the replantation junction compared to crush injuries. Additionally, they state the patients with major psychiatric disorders or those that are unable to comply with postoperative protocols should also be considered poor candidates for replantation.
Figure A demonstrates an amputation through the left index finger proximal phalanx with no evidence of comminution or crush injury. Illustration A demonstrates the flexor tendon zones.
Incorrect Answers:
A patient sustains an acute, closed injury to his index finger. The clinical appearance of the finger is shown in Figure A. The patient is asked to extend the finger against resistance, with the PIP joint in 90 degrees of flexion. You note that PIP joint extension was weak, with hyperextension and restricted passive flexion of the DIP joint. When planning to treat this injury non-operatively which active joint motion is encouraged?
DIP flexion
MCP flexion
MCP extension
PIP extension
PIP flexion CORRECT ANSWER: 1
This patient has sustained a central slip injury. Treatment consists of full time extension splinting of the PIP joint for 5 weeks with active DIP motion (flexion) encouraged.
A central slip injury, or a zone 3 extensor tendon injury, is characterized by PIP flexion and DIP extension (boutonniere deformity). This is most often caused by a rupture of the central slip over the PIP joint caused by a laceration, a traumatic avulsion, or capsular distension in rheumatoid arthritis. A rupture of the central slip causes the extrinsic extension mechanism from the EDC to be lost and prevents extension at the PIP joint. This allows the lumbricals' pull to become unopposed, causing PIP flexion and DIP extension. The examination maneuver described in the question stem is the Elson Test. It is the most reliable way to diagnose a central slip injury before the deformity is present. Non-operative treatment may be undertaken if the injury is closed and presents acutely. The PIP is splinted in full extension for 5 weeks. Active DIP extension and flexion in the splint is encouraged to avoid contraction of the oblique retinacular ligament.
Posner et al. describe the diagnosis and treatment of finger deformities following injuries to the extensor tendon mechanism. They suggest that treatment of a boutonniere deformity depends on its stage. For the acute injury (within the first 2 weeks), immobilization of the proximal interphalangeal joint in full extension for 5 weeks using a static splint that permits active and passive flexion of the DIP joint is usually effective.
Figure A is a clinical photograph demonstrating an index finger with the classic boutonniere deformity of flexion at the PIP joint and hyperextension of the DIP joint. Figure B is a diagram showing the Elson test. When the central slip is intact, there is no hyperextension of the distal phalanx. When the central slip is disrupted, the distal phalanx can hyperextend due to the function of the tight lateral bands.
Incorrect Answers:
A 25-year-old male is stabbed in the proximal volar forearm while fighting in a bar. He presents to the ED with a 1 cm wound and moderate oozing of blood. On exam, he has normal sensation throughout all distributions in his hand, normal radial and ulnar pulses, and a normal tenodesis effect. He is unable to actively flex his index finger DIP joint. Which muscle will also likely not function as a result of his injury?
Flexor digitorum brevis
Flexor carpi radialis
Flexor carpi ulnaris
Flexor pollicis longus
Pronator teres CORRECT ANSWER: 4
The patient has sustained a laceration of the anterior interosseous nerve (AIN), which is a branch of the median nerve and innervates the flexor pollicis longus, pronator quadratus, and the flexor digitorum profundus to the index and long fingers. An intact tenodesis effect signifies that all of his tendons are structurally intact.
The AIN can be injured by a penetrating injury or chronic compression. It
arises from the dorsoradial aspect of the median nerve distal to the elbow. It then passes between the FPL and FDP to lie on the anterior interosseous membrane en route to the pronator quadratus and wrist capsule (Illustration A). Compression sites of the AIN include the deep head of the pronator teres, FDS arcade, edge of the lacertus fibrosus, an accessory head of the FPL, or other accessory muscles of the forearm (FDS, FDP, FCR). In this particular scenario of an acute, penetrating AIN injury, exploration and primary end-to-end suture repair is appropriate.
Rodner et al. review AIN syndrome and stress the importance of ruling out a tendon rupture, which can present similarly and can be differentiated by testing the patient's tenodesis effect. Non-traumatic AIN syndrome is usually the result of a neuritis, similar to Parsonage-Turner Syndrome (brachial plexus neuritis), and may have similar triggers such as viral infection or autoimmune disease. They recommend a prolonged period of observation (~12 months; in the absence of an obvious compressive or space-occupying lesion) due to high rates of spontaneous recovery at about one year.
Park et al. report on 11 patients that underwent surgical exploration for spontaneous AIN syndrome at an average of 7.8 months. The most common compressive structure was a fibrous band of the FDS, however, four patients had no obvious compressive structure, emphasizing the importance of at least six months of conservative treatment.
Incorrect answers:
A 38-year-old female presents with 8 months of gradual weakness of her right hand. She denies paresthesias, numbness, and pain in the right upper extremity. She has compensatory thumb interphalangeal flexion during key pinch and intact two point discrimination. She has a negative Tinel's sign at the wrist and elbow. Electromyography (EMG) shows normal sensory conduction velocities but delayed motor conduction to the first dorsal interosseous muscle. Figure A and B show MRI images of pre and post contrast, respectively. Ultrasound is shown in Figure C. What is the next best step?
Biopsy of the mass
Cyst excision
MRI of cervical spine
Excision of the hook of hamate
Cubital tunnel release CORRECT ANSWER: 2
The patient has pure motor symptoms from ulnar nerve compression by a ganglion cyst at Guyon's canal. The next best treatment is excision of the ganglion cyst.
Atraumatic compression of the ulnar nerve at Guyon's canal is caused by a ganglion cyst 80% of the time. Compression may present with mixed motor and sensory or pure motor symptoms. With purely motor compression the deep branch of the ulnar nerve is affected resulting in weakness of adductor pollicis. Subsequent loss of metacarpophalangeal flexion and adduction leads to a positive Froment's sign with compensatory thumb IP flexion. Pure motor compression will result in normal sensory examination and intact two point discrimination as sensory branches are unaffected. EMG will localize decreased velocities at the wrist. When neurologic symptoms are present, cyst excision is recommended. Ganglion cysts in this location often arise from the pisohamate joint and excision of the stalk is important to prevent recurrence.
Wang et al. retrospectively investigated the outcomes of 9 patients with
ganglion cysts with symptomatic compression of the deep branch of the ulnar nerve. At a mean follow-up of 23 months they found all patients had improved grip and tip pinch strength. They conclude that surgical intervention can lead to satisfactory outcomes.
Shen et al review the imaging findings possible in patients with ulnar neuropathy. They present a case of a patient with ulnar neuropathy secondary to a ganglion cyst in guyon's canal.
Maroukis et al. review the history of the clinical anatomy of Guyon's canal. They conclude that the three zone theory helped simplify the complex anatomy of ulnar nerve compression at Guyon's canal.
Figure A (Shen et al) shows a T2 fat saturation MRI of a well circumscribed lesion (black arrow) with homogeneous fluid signal intensity at Guyon's canal compressing the ulnar nerve (white arrow). Figure B (Shen et al) shows a post contrast T1 fat saturation MRI showing rim enhancement consistent with a cyst (black arrow) and compression of the ulnar nerve (white arrow). Figure C shows an longitudinal ultrasound view of a anechoic well defined structure consistent with a cyst. Illustration A shows the areas of potential ulnar nerve compression in Guyon's canal. Illustration B shows a table with potential causes for compression at each zone and expected symptoms.
Incorrect Answers:
A 20-year-old male presents to clinic for evaluation of right wrist pain. He fell playing flag football about 6 weeks ago. He initially had significant pain but since it slowly improved he did not seek immediate treatment. His improvement has now plateaued. Figures A and B are x-rays, and figures C and D select CT scan images of his right wrist. What is the best treatment option?
Percutaneous screw fixation
Open reduction internal fixation through a volar approach
Open reduction internal fixation through a dorsal approach
Open reduction internal fixation with bone grafting through a volar approach
Open reduction internal fixation with bone grafting through a dorsal approach
The patient presents with a displaced right scaphoid waist fracture with cyst formation. The best treatment would open reduction internal fixation (ORIF) with bone grafting through a volar approach.
The surgical management of scaphoid fracture depends on location and characteristics of the fracture as well as time from injury. Displaced distal pole and waist fractures are typically approached from the volar side, especially if there is a humpback deformity; the proximal pole is more easily accessed from the dorsal side. Injuries with significant comminution or cyst formation due to extended time to treatment are often augmented with bone graft. There is controversy as to the use of vascularized bone graft in nonunion cases.
Rettig et al. reported on fourteen patients undergoing acute surgical fixation for displaced scaphoid waist fractures. Thirteen patients united and regained functional wrist range of motion and grip strength. They advocate for early
operative intervention in these fractures.
Raskin et al. describe the utility of the dorsal approach for proximal pole scaphoid fractures. They report good fracture visualization and the ability to bone graft through the same incision with successful union in a majority of cases.
Pinder et al. reviewed the literature on management of scaphoid nonunions. They found no difference in use of nonvascularized or vascularized bone graft, choice of approach, or use of Kirschner wires versus screw fixation.
Figures A and B are postero-anterior lateral right wrist radiographs with a displaced scaphoid waist fracture and mild humpback deformity. Figures C and D are coronal and sagittal CT cuts, respectively, demonstrating cyst formation and better showing the humpback deformity.
Incorrect Answers:
A 53-year-old white male presents with contractures of his ring finger and lesions over the dorsum of his hand. On examination of the lesions, they are subcutaneous, solid, and firm lesions measuring about 5 mm in diameter. They are located over the dorsum of the PIP joints of his ring and long finger. They become more mobile while the joint is in neutral and less mobile when the joint is in flexion. He also has a 5 degree flexion contracture his ring finger MCP joint. Examination of his palm reveals a palpable cord over the volar ring finger. His neurovascular examination is normal. The appearance of the dorsum of his hand is seen in Figure A. What is the next most appropriate step in treatment?
Collagenase injection and resection of dorsal finger lesions
Collagenase injection without resection of dorsal finger lesions
Observation and follow up
Surgical resection/fasciectomy and resection of dorsal finger lesions
Surgical resection/fasciectomy without resection of dorsal finger lesions
This patient has mild Dupuytren's disease with associated dorsal Dupuytren nodules, which may be observed.
Dupuytren’s disease is a proliferative disorder characterized by fascial nodules and contractures of the hand. It is autosomal dominant with variable penetrance. It exhibits a 2:1 male to female ratio and is classically seen in Caucasian males of northern European descent. The main pathology of
Dupuytren’s disease is excessive myofibroblast proliferation and altered collagen matrix composition lead to thickened and contracted palmar fascia. Surgical intervention is often indicated in cases of ≥30° of MCP contracture or any PIP contracture (usually >15°).
Rayan et al report that dorsal Dupuytren's nodules are a subcutaneous, solid, firm, well-defined, tumor-like mass or a nodule 3 mm in diameter or larger, located over the dorsum of the PIP joint. It is seldom painful and becomes more mobile while the joint is in neutral position and less mobile during joint flexion.
Black et al report that diseased tissue is referred to as nodules or cords. The Dupuytren nodule is a palpable subcutaneous lump that may be fixed to the skin. Cords are highly organized collagen structures arranged in parallel with a relatively hypocellular matrix. Cords are predominantly composed of collagen III while normal palmar fascia is predominantly collagen I.
Figure A is a picture of a dorsal Dupuytren's nodule. Incorrect Answers:
at this time. The dorsal finger lesions should not be resected.
A 37-year-old man has a 2-year history of increasing right wrist pain that is worse at night and aggravated by activity. He denies systemic symptoms, history of trauma, or recent weight loss. On physical exam he has tenderness over the dorsal radiocarpal joint. Radiographs of the right wrist are shown in Figure A. Which of the following imaging studies would be most sensitive for determining the stage of this patient's underlying condition?
Ultrasound
Angiography
CT scan of the wrist
Clenched fist AP radiograph of wrist
Bone scan of the wrist CORRECT ANSWER: 3
The clinical presentation of dorsal radiocarpal wrist pain is suggestive of Kienbock’s disease. Figure A shows an AP radiograph of the right wrist with
evidence of lunate sclerosis with no obvious collapse. The imaging study most sensitive for identifying early lunate collapse in Kienbock's disease is CT scanning of the wrist.
Kienbock’s disease is defined by avascular necrosis of the lunate. It is classified into 4 stages under the Lichtman Classification. In stage 1, plain radiographs appear normal and magnetic resonance imaging is required for diagnosis. MRI is useful for detecting early disease when sclerosis is not evident on plain film radiographs. In stage 2, plain radiographs and/or CT scan images will show sclerosis of the lunate but no evidence of collapse. In stage 3, radiographs and/or CT scan images will show lunate collapse. For stage 4, radiographs show degenerative changes to the adjacent carpus and intercarpal joints.
Imaeda et al. examined the use of MRI for the diagnosis and staging of Kienbock's disease. They found that MRI was most sensitive in detecting early focal loss of signal intensity in the lunate on T1-weighted images. This was a key diagnostic feature in early stages of Kienböck's disease when plain radiographs appear normal.
Cross et al. reviewed the latest concepts for diagnosis, staging, and management of Keinbock's disease. They suggest that computed tomography (CT) or tomography will better characterize lunate necrosis and trabecular destruction once collapse or sclerosis has occurred in late stage disease.
Illustration A is a collection of CT scanning images that show osteonecrosis of the lunate. The blue arrow shows lunate flattening and sclerosis. The red double arrow shows a loss of lunate height and the yellow shows fragmentation of the bone.
Incorrect Answers:
widening of the scapholunate interval.
Each of the following are indications for microvascular replantation EXCEPT?
Thumb amputation
Index finger amputation in a child
Through wrist amputation
Long finger amputation through the proximal phalanx
Mid-palm amputation of all four fingers
As reviewed by Soucacos, there are several major indications for single digit replantation: 1) Level of the amputation is distal to the insertion of FDS. 2) Amputations at the level of the distal phalanx. 3) Ring avulsion injuries involving both the dorsal and palmar skin and blood supply in an isolated finger, as long as FDS is intact. 4) Any amputation in a child. 5) Thumb amputation. Replantation of a single digit, which is amputated at the level of the proximal phalanx or at the PIP joint, particularly in avulsion or crush injury is contra-indicated. Soucacos also discusses appropriate surgical teams, transport, and other related issues surrounding a "transplant team."
All of the following are predictive findings for correctly diagnosing carpal tunnel syndrome EXCEPT:
Abnormal hand diagram
Abnormal Semmes-Weinstein testing in wrist-neutral position
Positive median nerve compression test (Durkan's sign)
Presence of night pain
Loss of small digit adduction (Wartenberg sign)
All of the listed physical exam findings, except for loss of small digit adduction (Wartenberg sign), has been found to be predictive for diagnosing carpal tunnel syndrome.
Szabo et al in a Level 3 study used a regression model to analyze the most predictive factors for correctly diagnosing carpal tunnel syndrome (CTS). Their analysis found that with an abnormal hand diagram, abnormal sensibility by Semmes-Weinstein testing in wrist-neutral position, a positive Durkan's test, and night pain, the probability that carpal tunnel syndrome will be correctly diagnosed is 0.86. They found the tests with the highest sensitivity were Durkan's compression test (89%), Semmes-Weinstein testing after Phalen's maneuver (83%), and hand diagram scores (76%). Night pain was a sensitive symptom predictor (96%). The most specific tests were the hand diagram (76%) and Tinel's sign (71%). The authors concluded that the addition of electrodiagnostic tests did not increase the diagnostic power of the combination of these 4 clinical tests, and proceeding with surgical release is appropriate even if the EMG is normal.
Wartenberg sign is persistent abduction and extension of the small digit when a patient is asked to adduct the digits and is seen in cubital tunnel syndrome, but not carpal tunnel syndrome.
Illustration V demonstrate the Durkan's Compression test for carpal tunnel syndrome.
Extrinsic imbalance from splinting a crushed hand with metacarpophalangeal joint extension causes what characteristic hand deformity?
Distal interphalangeal joint extension
Ulnar subluxation of the metacarpophalangeal joints
Proximal interphalangeal joint extension
Proximal interphalangeal joint flexion
Swan-neck deformity CORRECT ANSWER: 4
Failure to splint the hand in an intrinsic positive position leads to increased extrinsic finger flexor tension, leading the DIP and PIP joints to have an increasing flexion position. Illustration A and B show a clinical image and illustration of intrinsic minus hand.
von Schroeder et al present a Level 5 review of hand crush injuries. They conclude that early diagnosis and treatment is critical, but the functional outcome is often poor with associated Volkmann's contracture.
Axon regeneration almost always occurs following a Sunderland second-degree nerve injury because which anatomic structure is not injured?
Epineurium
Endoneurium
Perineurium
Myelin sheath
Schwann cell CORRECT ANSWER: 2
Following a Sunderland second-degree injury, axon regeneration is possible because the endoneurium is intact.
There are two classification schemes for peripheral nerve injuries, which include the Seddon and the Sunderland systems. Under the Sunderland
classification, a second-degree injury is considered a part of the axonotmesis spectrum. The endoneurium, perineurium and epineurium are still intact. This enables complete functional recovery.
Lee et al. review the pathophysiology and evaluation of peripheral nerve injuries. They note that in Sunderland type two injuries, there is physiologic disruption of the axons. Because the endoneurium is still intact, axons are able to regenerate. This process takes months.
Illustration A is a schematic of the various stages of peripheral nerve injury. Incorrect Answers
Sunderland type 2 injury, axon regeneration is possible because of an intact endoneurium.
A 29-year-old intravenous drug user undergoes irrigation and debridement of a ring finger abscess. After adequate eradication of the infection, he is left with the skin defect shown in Figure A. What is the most appropriate treatment at this time?
Local woundcare and healing by secondary intention
V-Y advancement flap
Thenar flap
Moberg flap
Cross-finger flap CORRECT ANSWER: 5
Based on the location of the lesion, a cross-finger flap would be most appropriate.
Cross finger flaps are indicated in patients > 30 years of age when the lesion is a volar oblique finger tip lacerations or a volar proximal finger lesions. The advantage is it leads to less stiffness.
Martin et al review the treatment options available for digit injuries. They report treatment of fingertip injuries is a continuous focus of controversy among hand and orthopaedic surgeons. Different treatment options have been described, depending on the affected segment and finger, type of lesion, gender and age of the patient, location, size, and depth of the defect.
Fassler et al reviews the proper management of fingertip injuries discussing variables such as the severity of soft tissue loss and whether bone is exposed.
Incorrect Answers:
A 4-year-old boy sustains a flexor tendon laceration in Zone 2 of his 4th digit when he attempts to grab a knife. Optimal surgical management and postoperative rehabilitation consists of:
2 strand core suture technique and gentle active flexion and extension exercises with wrist in extension
2 strand core suture technique and cast immobilization for 8 weeks
4 strand core suture technique and gentle active flexion and extension exercises with wrist in extension
4 strand core suture technique and cast immobilization for 4 weeks
4 strand core suture technique and cast immobilization for 8 weeks
4 strand core suture technique and cast immobilization for 4 weeks is the preferred postoperative rehabiltation in a 4 year old child.
Ordinarily, adult flexor tendon repair postoperative rehab protocols call for early light active digital flexion with wrist in gentle flexion as long as the tendon has been repaired with a 4 or 6 strand core suture technique and strong epitendinous suture. However, this method cannot succeed without the cooperation of a mature and motivated patient. Children or the mentally disabled are often lacking some of these prerequisites. Therefore, a flexor tendon repair in a child should be treated like a flexor tendon repair with interposed graft in an adult. Immobilization for a minimum of 3 – 4 weeks with a posterior molded plaster splint or cast from the tips of the fingers to just above the elbow. Wrist is flexed 35 degrees, MCPs flexed 60 – 70 degrees and IP joints relaxed in extension. Active motion can be started after the cast is removed at 4 weeks.
A 45-year-old male sustained a fall onto his right wrist 2 weeks ago. A radiograph is shown in figure A. What joint is first affected if left untreated with subsequent development of a SLAC (scapholunate advanced collapse) wrist?
Capitolunate joint
Radioscaphoid
Radioulnar
Radiolunate
STT (scaphotrapezotrapezoidal)
The clinical presentation is consistent with a SLAC wrist. The radioscaphoid joint is the first to be affected in this process.
The radiographs of the right wrist demonstrate a scapholunate dissociation, as evidenced by an increased scapholunate joint space, referred to as scapholunate diastasis (abnormal when the gap is greater than 2 mm and increased from the opposite extremity and other intercarpal spaces).
If left untreated, the wrist may progress to a "SLAC" wrist, as originally described by Watson and Ballet in 1984, which is the most common form of wrist arthritis. The repetitive sequence of degenerative changes is based on and caused by articular alignment problems between the scaphoid, the lunate and the radius.
Kuo et al. review the stages of SLAC wrist. They report stage I SLAC wrist involves changes limited to an area of abnormal contact between the abnormally rotated scaphoid and the radial styloid. In stage II the remaining radioscaphoid joint is affected, as persistent abnormal load transfer and shear across the cartilaginous surfaces leads to degeneration of the proximal scaphoid facet. In stage III, the dorsally translated capitate migrates proximally into the widened scapholunate interval, and degenerative changes occur at the capitolunate joint. The relative congruency of the radiolunate joint in all positions of lunate rotation due to the spherical shape of the lunate facet preserves this articulation, and at all stages of SLAC wrist the radiolunate joint is not involved. The lunate is congruently loaded in every position and, thus, highly resistant to degenerative changes.
Illustration A below shows the stages of involvement in the SLAC wrist.
A 56-year-old right hand dominant male presents to your office complaining of right thumb pain worsened with pincer grip and using his mobile phone. He is a writer, and is having difficulty holding his pen. Radiographs from this visit are shown in Figure A. Compared with trapeziectomy alone, which of the following treatment options is likely to result in superior pain relief and improvement of key-pinch strength?
Trapeziometacarpal corticosteroid injection followed by aggressive occupational therapy
Trapeziectomy with interpositional palmaris longus arthroplasty
Trapeziectomy, interpositional arthroplasty, and palmar oblique ligament reconstruction using flexor carpi radialis autograft
Partial trapeziectomy with capsular interpositional arthroplasty
None of the above CORRECT ANSWER: 5
This patient has symptomatic basal joint arthritis with radiographic evidence of pantrapezial arthritis. Simple trapeziectomy has been shown to provide pain relief and improvement of key-pinch strength that is comparable to trapeziectomy plus interpositional arthroplasty.
Definitive surgical management of basal joint arthritis commonly involves excision of the diseased trapezium with concomitant interpositional arthroplasty at the carpometacarpal joint in an effort to mantain the height of the metacarpal. This is commonly done with flexor carpi radialis (FCR) or palmaris longus (PL) autograft. Recent studies have called into question the need for interpositional arthroplasty, suggesting that excision of the trapezium alone can provide non-inferior results.
Davis et. al. randomized 183 symptomatic trapeziometacarpal joints to one of three procedures: trapeziectomy alone, trapeziectomy with palmaris longus interpositional arthroplasty, or trapeziectomy with FCR interpositional arthroplasty and reconstruction of the palmar oblique ligament. For all patients, the thumb metacarpal was percutaneously pinned to the distal pole of the scaphoid to maintain the height of the digit. Patients were evaluated at three and 12 months post-operatively. At both time-points, they found no difference between groups with respect to subjective accounts of pain, function, stiffness, and weakness. Objective measures of thumb key-pinch strength were no different at either time point. The authors concluded that there may be no benefit to ligament reconstruction or tendon interposition in
the short term.
Li et. al. performed a systematic review of four randomized controlled trials and two systematic reviews to evaluate outcomes of trapeziectomy with and without LRTI for treatment of basal joint osteoarthritis. In their review, there were no statistically significant differences in post-op grip strength, pinch strength, visual analog pain scores, DASH scores, and complications. The authors concluded that both procedures produced similar clinical results.
Raven et. al. performed a retrospective analysis of 54 patients who underwent one of three procedures for basal joint osteoarthritis: resection arthroplasty, trapeziectomy with tendon interposition, or trapeziometacarpal arthrodesis.
The authors found resection arthroplasty to be a simple procedure with longterm results pain and functional outcomes comparable to trapeziectomy with tendon interposition.
Naram et. al. retrospectively reviewed 200 patients who underwent simple trapeziectomy with or without LRTI and with or without Kirschner wire stabilization, or a Weilby ligament reconstruction. They found that patients undergoing trapeziectomy with LRTI or a Weilby procedure had a greater incidence of complications compared to trapeziectomy alone, including infection and reoperation.
Figure A is a plain radiograph demonstrating pantrapezial arthritis with the thumb trapeziometacarpal joint being most significantly affected.
Incorrect Answers:
A 31-year-old patient has had a left medial elbow mass for 1 month. The mass has been increasing in size and has now become very painful and erythematous. MRI scans are shown in Figures 76a and 76b. Laboratory studies show an erythrocyte sedimentation rate of 49 mm/h (normal 0 to 20 mm/h) and C-reactive protein level of 23 mg/L (normal 0 to 0.3 mg/L). Histology showed lymphoid tissue and multiple necrotizing granulomas. What organism is responsible for this clinical picture?
Borrelia burgdorferi
Trichophyton tonsurans
Bartonella henselae
Mycobacterium avium
Corynebacterium minutissimum
Cat scratch disease (CSD) is an important diagnosis for the orthopaedic surgeon to consider in the differential diagnosis of soft-tissue masses adjacent to epitrochlear or cervical lymph nodes. It is a soft-tissue tumor simulator and a high index of suspicion is necessary in all patients with upper extremity or head and neck adenopathy and a history of cat exposure. Although generally not required for diagnosis, cross-sectional imaging will reveal a mass with surrounding edema in an area of lymphatic drainage. A peripheral blood sample can be tested for Bartonella henselae - the offending organism with this diagnosis. Classically the histology of these lesions when biopsied will show multiple necrotizing granulomas. Mycobacterium avium is the only other organism that would demonstrate a granulomatous reaction and the location is classic for CSD. Borrelia burgdorferi is associated with Lyme disease.
Mycobacterium avium may be a source of immunocompromised infections in HIV patients. Trichophyton tonsurans and corynebacterium minutissimum are not associated with orthopaedic diseases.
A 45-year-old woman has a painful mass in the dorsum of the right wrist. It is firm and nontender to palpation. She states it has slowly gotten bigger over the past 3 years. You suspect a dorsal wrist ganglion. What is the most definitive way to confirm this diagnosis?
Observe it for 1 year to see if it changes dramatically in size.
Obtain a gadolinium enhanced MRI scan.
Obtain radiographs, looking for scapholunate joint degenerative changes.
Perform a needle aspiration and send the aspirate for cytologic examination.
Apply direct firm manual pressure over the mass to see if it can be ruptured.
Dorsal wrist ganglions are synovial cysts that arise most frequently from the scapholunate joint. They often extend between the extensor digitorum communis and extensor pollicis longus tendons at the wrist. Aspiration of the cyst is both oncologically safe if done appropriately and also the easiest way to definitively confirm the diagnosis. Clear, yellow viscous fluid/gel is most often aspirated. Cytologic evaluation is mandatory to exclude myxoid neoplasms.
Because the lesion has been present for 3 years, further observation is not warranted. The classic presentation, physical examination findings, and location make MRI and radiographs unnecessary. Manual rupture of the mass is not recommended.
A 28-year-old man fell while ice skating 6 months ago and has had ulnar-sided wrist pain ever since. The patient's wrist radiograph is shown in Figure A and a CT scan is shown in Figure B. What is the most appropriate treatment?
Scapholunate ligament repair
Excision of the hook hamate
Excision of the pisiform
Open reduction internal fixation of the hamate
Open reduction internal fixation of the pisiform
Based on clinical history and imaging shown, this patient has developed a pisiform fracture nonunion. Treatment of symptomatic nonunions of the pisiform is by pisiformectomy
Fractures of the pisiform are rare. They often occur in conjunction with injuries to the distal radius or carpus. Non-operative management with cast immobilization in 30 degrees of wrist flexion is the first line of treatment.
Symptomatic nonunions are treated with pisiformectomy.
Palmieri et al. performed pisiformectomies on 21 patients who had pisiform area pain that was refractory to conservative management. Patients had a history of painful union or nonunion of pisiform fractures, arthritis or FCU tendonitis. In all cases, wrist strength and mobility was retained.
Lam et al. reviewed the effect of pisiform excision on wrist function in patients with piso-triquetral dysfunction. After an average follow up of 65 months, 75%
of patients had complete relief of pisiform area symptoms. No differences in grip, wrist motion, strength or power were found in comparison to the contralateral side.
Figure A shows an oblique radiograph of a pisiform fracture nonunion. Figure B shows an axial CT scan sequence of the wrist. A pisiform fracture nonunion is identified with subtle comminution. The pisotriquetral joint appears to be congruent.
Incorrect Answers
A 32-year-old woman jammed her ring finger. Figures 77a and 77b show radiographs of the finger after a closed reduction. Which of the following interventions, if done correctly, is likely to result in the best possible final clinical outcome?
Early removal of a splint and application of continuous passive motion
Application of dynamic extension bracing after the first week
Maintaining reduction of the middle phalanx on the condyles of the proximal phalanx with dynamic external fixation
Open reduction and anatomic restoration of the middle phalanx articular surface
Surgical advancement of the volar plate into the middle phalanx base
The most important determinant in the final clinical outcome in proximal interphalangeal (PIP) joint fracture locations is the maintenance of the PIP joint alignment on the lateral view. This can sometimes be done with just extension block splinting, sometimes the fracture requires dynamic external fixation, and sometimes the fracture requires open reduction or volar plate arthroplasty. Good function can be the result in the setting of an incongruent middle phalanx base as long as the PIP joint alignment is maintained.
Continuous passive motion has not been shown to be of benefit. Whereas dynamic external fixation in a flexed position is a very good treatment, dynamic extension bracing will just precipitate loss of PIP joint reduction and is therefore not indicated. Whereas open reduction of the articular surface is theoretically desirable, it is generally impossible in the setting of the comminution of the volar middle phalanx base. Furthermore, open reduction and internal fixation by itself does not guarantee that the PIP joint alignment will be maintained, and typically it causes finger stiffness given the extensive surgical approach. Likewise, volar plate arthroplasty is a surgery of last resort and requires careful attention to PIP joint alignment before joint pinning. In this case, with characteristics of comminution, dynamic external fixation is the preferred choice.
A 20-year-old woman sustained a laceration to her volar forearm 4 cm proximal to the wrist flexion crease. She has numbness in the thumb, index, and middle fingers. After microscopic repair of the median nerve, 2 weeks of splinting, and commencement of a hand therapy program, the patient is most likely to require what secondary operation 6 months after the injury?
Tenolysis of the profundus tendons at the wrist
Nerve transfer of the ulnar motor nerve to the median motor nerve
Opponensplasty with the extensor indicis
Open carpal tunnel release
Transfer of the extensor digiti minimi to the first dorsal interosseous tendon
The patient sustained a laceration of the median nerve in what would be considered a low median nerve injury. Standard treatment entails exploration and microscopic repair of the median nerve. With a good quality nerve repair in a young adult, return of some sensory function (albeit reduced compared with the normal nerve) is usual. Return of motor function to the thenar muscles is more unpredictable. If the patient begins a therapy program within a few weeks after nerve repair, it is unlikely that tenolysis of the profundus tendons would be required. An open carpal tunnel release would be unlikely to change functional return. The patient would not be expected to have lost first dorsal interosseous function after a median nerve laceration because this muscle is innervated by the ulnar nerve. A neurotization procedure for low median nerve palsy has been described, but it consists of transfer of the distal anterior interosseous nerve into the median nerve motor fascicles, not transfer of the ulnar nerve. Therefore, the most likely secondary procedure required in this scenario is an opponensplasty procedure to improve thumb opposition.
What is the most efficient pressure for use with negative pressure wound therapy?
25 mm Hg
75 mm Hg
125 mm Hg
300 mm Hg
500 mm Hg CORRECT ANSWER: 3
In animal and clinical studies, a range of pressures between 50 mm Hg to 500 mm Hg were tested; the most efficient pressure was 125 mm Hg, resulting in a fourfold increase in blood flow, 63% increase in granulation tissue with continuous pressure, and 103% increase in granulation tissue with intermittent pressure. When 125 mm Hg pressures were compared with either those less than 50, or those greater than 250, there was a decrease in granulation tissue in swine models.
Figures 125a and 125b are the current radiographs of a 52-year-old man who sustained an injury to his dominant wrist 8 weeks ago. He is an alcoholic and does not remember the details of how he injured it. Paperwork showing what treatment he received at an
urgent care facility indicates that he was given a splint for his "sprained wrist." Examination reveals the pain is getting better, but there is persistent swelling and range of motion is very limited.
Recommended treatment at this time should consist of
discontinuation of the splint and commencement of a regimen of hand therapy.
casting for an additional 2 weeks and reassessment of the fracture healing at that time.
open reduction and internal fixation of the injury.
proximal row carpectomy.
wrist arthrodesis.
The injury represents a very uncommon presentation of a perilunate injury pattern. Whereas these injuries are sometimes overlooked on initial radiographic studies, they are usually recognized much sooner. In this case of a late presenting perilunate injury in a patient that is not entirely responsible, a proximal row carpectomy represents the best treatment option. Open reduction and internal fixation is generally not successful because of cartilage degeneration and contracture that has developed in the interim. No further splinting or casting is indicated, and neglecting the injury would be indicated only if the patient refused any further treatment. Wrist arthrodesis is generally indicated only as a salvage procedure if a proximal row carpectomy is unsuccessful.
A 47-year-old woman sustained a nondisplaced distal radius fracture 6 months ago and is unable to extend her thumb. When performing reconstruction using the extensor indicis proprius to the extensor pollicis longus transfer, tension is ideally determined by securing the tendons in what manner?
In maximum tension with the wrist and thumb in extension
In maximum tension with the wrist and thumb in neutral
In maximum tension with the wrist and thumb in flexion
According to the tenodesis effect with wrist flexion and extension
According to functional testing with the patient awake under local anesthesia
Extensor pollicis longus rupture can result from distal radius fractures. Synergistic tendon transfer can be achieved using the extensor pollicis longus as the motor donor. Whereas different schemes for achieving optimal tension are available, the most reliable method is to tension the repair under local anesthesia while asking the patient to perform thumb flexion and extension. Tendon transfer tension can be adjusted accordingly to achieve maximum extension without compromising active flexion range. Other methods of tensioning are estimates at best, and maximum tensioning in patients without neuromuscular disease is rarely used in tendon transfers.
Which of the following substances is likely to cause the most soft-tissue damage in the long term if injected into a fingertip under
high pressure?
Grease
Latex paint
Water
Oil-based paint
Chlorofluorocarbon-based refrigerant
This type of injury represents a difficult problem in hand surgery. The factors that most determine outcome after high-pressure injection injuries into the fingertip include: involvement of the tendon sheath, extent of proximal spread of the injected substance, pressure setting, and delay to surgical treatment.
The other factor that likely is most important is the type of substance injected. Water and latex-based paints are least destructive. Grease and chlorofluorocarbon-based substances are intermediate, but aggressive surgical debridement can restore reasonable function. Oil-based paints are highly inflammatory and can cause such chronic inflammation such that amputation may be the only reasonable treatment option despite early aggressive surgical treatment.
A 37-year-old woman has right-hand numbness and tingling. Based on the history and examination, carpal tunnel syndrome is suspected, and electrodiagnostic tests also point to the same diagnosis. The patient has worn night splints for the last 8 weeks with continued persistent symptoms. What is the next most appropriate step in management?
Continue the night splinting for 1 additional month.
Continue the night splinting for 3 more months.
Switch to full-time splinting and reevaluate in 1 month.
Switch to full-time splinting for 3 more months.
Perform carpal tunnel release.
Various nonsurgical management options exist for carpal tunnel syndrome (local and oral steroids, splinting, and ultrasound). All effective or potentially effective nonsurgical forms of management have measureable effects on symptoms within 2 to 7 weeks of the initiation of treatment. If a treatment is not effective within that time frame, a different treatment option should be
chosen. In this case, continued splinting is unlikely to improve symptoms and steroid injection or surgery is indicated.
A 46-year-old man sustains an injury to his left index finger while cleaning his paint gun with paint thinner. Examination reveals a small puncture wound at the pulp. The finger is swollen. What is the next most appropriate step in management?
Elevation and observation
Surgical debridement and lavage
Infiltration with corticosteroids
Infiltration with a neutralizing agent
Administration of antibiotics
High-pressure injection injuries are associated with a high risk of amputation. The risk of amputation is highest with organic solvents. The presence of infection and the use of steroids do not impact the amputation rate.
Amputation risk is lower if surgical debridement is performed within 6 hours. Elevation and observation would delay necessary care. Neutralizing agents may be used in specific situations, such as hydrofluoric acid exposure or chemotherapeutic agent extravasation, but in high pressure paint thinner injection, the best outcome is achieved through early surgical lavage.
A 54-year-old woman who has a history of undergoing left trapezium excision with ligament reconstruction and tendon interposition using the entire flexor carpi radialis performed by another surgeon, now reports left basilar thumb pain. Examination reveals pain and subluxation of the carpometacarpal joint with axial loading. The metacarpophalangeal joint hyperextends to 60 degrees, but radiographs show intact joint space. What is the best option to improve function?
Bracing with a hand-based thumb spica splint
Pinning of the carpometacarpal joint
Pinning of the carpometacarpal and metacarpophalangeal joints
Carpometacarpal revision stabilization
Carpometacarpal revision stabilization and metacarpophalangeal joint fusion
The patient previously underwent ligament reconstruction and tendon interposition. However, the previous surgeon failed to address metacarpophalangeal joint hyperextension, which leads to adduction contracture and collapse of the basilar joint. With the basilar joint causing pain and instability, repeat ligament reconstruction should be performed. Splinting alone is unlikely to resolve instability problems. Because the flexor carpi radialis was used, the next option is to use the abductor pollicis longus.
Additionally, the severe metacarpophalangeal joint hyperextension should be corrected by fusion. Simple pinning is unlikely to provide long-term stability when this degree of hyperextension exists.
When evaluating a patient with suspected purulent flexor tenosynovitis in the thumb, the distal forearm and little finger are found to be swollen as well. The most likely anatomic explanation is the existence of a potential space in which of the following?
Through the carpal tunnel
Across the midpalmar space
Communicating with the subcutaneous tissue
Superficial to the distal antebrachial fascia
Between the fascia of the pronator quadratus and flexor digitorum profundus conjoined tendon sheaths
Pyogenic flexor tenosynovitis is an infection within the flexor tendon sheath that can involve the fingers or thumb. The tendon sheaths begin at the metacarpal neck level and extend to the distal interphalangeal joint. In the little finger and the thumb, the sheaths usually communicate with the ulnar and radial bursae, respectively. The potential space of communication, Parona's space, lies between the fascia of the pronator quadratus muscle and flexor digitorum profundus conjoined tendon sheaths. Infection tracking through this space presents as a horseshoe abscess.
Which of the following proximal phalanx fractures can most reliably be treated with a closed reduction and avoidance of surgical measures?
Midshaft transverse diaphyseal fracture with 30 degrees of angulation
Long spiral diaphyseal fracture with 15 degrees of malrotation
Open fracture with skin loss and exposed extensor tendon
Distal condylar intra-articular fracture with minimal displacement
Proximal metaphyseal fracture location with 30 degrees of dorsal tilting
Proximal phalanx fractures are very common, but care must be taken to understand which injuries are reliably treated with nonsurgical measures, and which ones are prone to clinically symptomatic malunion without surgical treatment. The proximal metaphyseal location is a problematic fracture to get reduced with closed measures, and due to the forces of the extensor apparatus, is prone to collapse into the original deformity. Imaging is also frequently difficult because of the overlap of the other fingers and frequently the true angulation is underappreciated. With 30 degrees of angulation, consideration should be given to surgical treatment. Long oblique/spiral fractures with malrotation are also most reliably treated with multiple lag screws, because maintaining the reduction with nonsurgical measures is unreliable, and can lead to significant functional problems in the form of crossover of the fingers with gripping. Open fractures with skin loss clearly are treated with surgical measures. Distal condylar fractures with minimal displacement are another fracture pattern that have a high rate of loss of reduction when treated nonsurgically. Like most articular fractures, they are best treated with anatomic reduction and rigid internal fixation. By comparison, closed midshaft transverse diaphyseal fractures can usually be anatomically reduced and held in this position with closed measures.
Figure 3 shows an arthroscopic view of the radiocarpal joint from the 3-4 portal, looking volarly and radially (Sc=scaphoid, R=Radius). What structure is marked by the asterisk?
Radioscaphocapitate ligament
Scapholunate ligament
Palmar oblique ligament
Dorsal intercarpal ligament
Triangular fibrocartilage complex (TFCC)
The radioscaphocapitate ligament is a volar capsular structure running obliquely from the radial styloid to the scaphoid waist, ultimately inserting on the proximal radial aspect of the capitate. The radioscaphocapitate ligament is important in preventing ulnar translocation of the carpus. The scapholunate ligament is located intra-articularly, between the scaphoid and lunate. The dorsal intercarpal ligament is a dorsal structure, and not visible during routine wrist arthroscopy. The palmar oblique ligament connects the first and second metacarpal bases. The TFCC is visible during wrist arthroscopy between the radius and ulna.
A 22-year-old man reports a 2-week history of a burning pain along the dorsoradial aspect of the distal forearm. The pain radiates to the dorsum of the thumb. Examination reveals tenderness and reproduction of symptoms with percussion 8 cm proximal to the radial styloid. Reproduction of symptoms also occurs with forearm pronation
and ulnar deviation of the wrist. No discrete sensory deficit is noted and electrodiagnostic studies are normal. Nonsurgical management consisting of rest, splinting, and anti-inflammatory medications for 6 weeks has failed to provide relief. Treatment should now consist of decompression of the
lateral antebrachial cutaneous nerve in the interval between the abductor pollicis longus and the extensor pollicis brevis in the forearm.
lateral antebrachial cutaneous nerve in the interval between the brachioradialis and the extensor carpi radialis longus in the distal forearm.
radial sensory nerve in the interval between the extensor carpi radialis longus and the extensor carpi radialis brevis in the distal forearm.
radial sensory nerve in the interval between the brachioradialis and the extensor carpi radialis longus in the distal forearm.
radial sensory nerve in the interval between the brachioradialis and the extensor carpi radialis brevis in the distal forearm.
Wartenberg's syndrome, or compression of the sensory branch of the radial nerve, occurs in the interval between the brachioradialis and the extensor carpi radialis longus approximately 8 cm proximal to the radial styloid. There may be history of repetitive wrist/forearm circumduction activity (ie, knitting) or of wearing a tight wristwatch or jewelry. It can occur in patients who have been handcuffed. Typical clinical findings are pain, paresthesia, and/or hypesthesia in the dorsoradial aspect of the wrist and hand in the distribution of the radial sensory nerve. There is often a positive Tinel's sign over the compression site. Hypesthesia may be present in the distribution of the radial sensory nerve which is typically on the dorsal aspect of the first dorsal web space and dorsum of the thumb; however, with overlap in the distribution of the superficial radial nerve and the lateral cutaneous nerve of the forearm this may not always be present. Surgical management consists of release of the nerve as it exits the interval between the brachioradialis and the extensor carpi radialis longus in the distal forearm.
A 55-year-old woman with rheumatoid arthritis reports that she awoke with an inability to flex the interphalangeal joint of her thumb. Figure 8 shows an intraoperative finding. What is the most appropriate surgical treatment?
Primary repair of the tendon
Tendon reconstruction with the palmaris longus tendon
Tendon reconstruction using a transfer of the flexor digitorum profundus (FDP) of the ring finger
Thumb metacarpophalangeal fusion
End-to-side repair of the flexor pollicis longus to the FDP of the index finger
The patient has sustained a chronic flexor pollicis longus rupture (Mannerfelt lesion). The injury is most likely a result of tendinopathy and attritional rupture of the tendon secondary to synovitis and bony osteophytosis at the scaphotrapeziotrapezoid joint. Because of the attritional injury and inherent tendinopathy, primary repair is unlikely to be successful. Among the options listed, tendon graft reconstruction with the palmaris longus tendon is the most appropriate treatment. Tendon reconstruction is possible with the flexor digitorum profundus of the index finger, not the flexor digitorum profundus of the ring finger. If osteophytes are encountered, these should be debrided.
Thumb interphalangeal fusion is an option, but metacarpophalangeal fusion is not beneficial. End-to-side repair of the flexor pollicis longus to the FDP of the index finger is not appropriate and would sacrifice needed function of the index finger.
Figures A and B show the initial radiographs of a 27-year-old snow boarder who fell backward onto his left outstretched hand. Which of the following most accurately describes the sequence of events that occurred during this injury?
Lunotriquetral ligament failure followed by distal row dissociation, scaphoid extension, scaphoid failure, and dorsal dislocation of the carpus
Volar dislocation of the lunate followed by scaphoid extension, scaphoid failure, lunotriquetral failure, and distal row dissociation
Dorsal intercarpal ligament failure followed by distal row dissociation, scaphoid failure, lunotriquetral ligament failure, and dorsal dislocation of the carpus
Short radiolunate ligament failure followed by volar dislocation of the lunate, lunotriquetral ligament failure, scaphoid failure, and distal row dissociation
Scaphoid extension followed by scaphoid failure, distal row dissociation, lunotriquetral ligament failure, and dorsal dislocation of the carpus
As described by Mayfield and associates, the typical sequence of events referred to as "progressive perilunar instability" that result in a volar
perilunate dislocation are as follows: scaphoid extension, followed by opening of the space of Poirer, scaphoid failure, and distal row dissociation, which in turn lead to hyperextension of the triquetrum, lunotriquetral ligament failure, and finally dorsal dislocation of the carpus. The lunate remains in the lunate fossa in a perilunate fracture-dislocation but is dislocated in a lunate dislocation. The short radiolunate and dorsal intercarpal ligaments typically remain intact.
Which of the following is the most consistently proposed tendon transfer for radial nerve palsy?
Pronator teres to extensor carpi radialis brevis
Brachioradialis to extensor carpi radialis brevis
Flexor carpi radialis to extensor digitorum communis
Palmaris longus to extensor pollicis longus
Flexor digitorum superficialis to abductor pollicis longus and extensor pollicis brevis
Whereas there are many variations of tendon transfers for radial nerve palsy, the most consistently proposed tendon transfer is the pronator teres to extensor carpi radialis brevis. The brachioradialis is innervated by the radial nerve so that is not an option. The flexor digitorum superficialis, flexor carpi radialis, and flexor carpi ulnaris are appropriate options to transfer to the extensor digitorum communis. The palmaris longus is not always present. A transfer to the abductor pollicis longus and extensor pollicis brevis may not be necessary if the extensor pollicis longus is rerouted to allow for abduction of the first ray.
A patient has severe cubital tunnel syndrome and marked wasting of the intrinsic muscles of the hand. Why is the little finger held in an abducted position?
Accessory slip of the extensor digiti minimi attaching to the abductor digiti minimi tendon
Tetanic contraction of the abductor digiti minimi
Radial collateral ligament insufficiency of the fifth metacarpophalangeal (MCP) joint
Unopposed pull of the flexor digitorum profundus
Muscle innervation from a Martin-Gruber anastomosis
A Wartenberg's sign, where the little finger is held in an abducted position, is associated with an ulnar nerve palsy. This happens when there is an accessory slip of the extensor digiti minimi, which is innervated by the radial nerve, crossing ulnar to the center of the MCP joint to attach to the tendon of the abductor digiti minimi and the proximal phalanx. The abductor digiti minimi and the volar interosseous muscles are both innervated by the ulnar nerve; therefore, there is no tetanic contraction of the abductor digiti minimi.
Unopposed pull of the flexor digitorum profundus results in excess flexion of the proximal interphalangeal and distal interphalangeal joints of the hand as seen with a clawing-type deformity. A Martin-Gruber anastomosis, which is a neural connection between the ulnar and median nerves in the forearm, cannot explain this finger position.
Figure 38 shows the radiograph of a 41-year-old man who reports ulnar palmar pain, decreased sensibility and tingling in the ring and little fingers, and a grating sensation in the ulnar fingers with motion. He reports that he sustained a fall on an outstretched hand 6 months ago. What is the most appropriate treatment option?
Ulnar gutter cast
Short arm cast
Carpal tunnel release
Decompression of Guyon's canal
Excision of a fractured hook of hamate
Excision of a fractured hook of hamate is the most appropriate management. The patient has a hook of hamate fracture with ulnar nerve compression and irritation of the flexor tendons by the fracture surfaces; this puts the tendons at risk for rupture. Cast treatment will most likely not gain union of the fracture and will not address the nerve or tendon problems. Decompression of Guyon's canal alone will not address the tendon issue.
A 25-year-old man was involved in an altercation. Examination reveals loss of active extension of the middle finger metacarpophalangeal (MCP) joint. A diagnosis of sagittal band rupture is made. Which of the following is considered the key diagnostic finding?
Extensor lag of 30 degrees
Extensor lag of 60 degrees
Positive Bunnell intrinsic tightness test
Ability to maintain active extension of the interphalangeal joints
Ability to maintain MCP extension after passive extension
In sagittal band rupture, the extensor tendon may subluxate into the valley between the metacarpal heads. The patient will not be able to actively extend the MCP joint from a flexed position with the subluxated tendon, but will be able to maintain MCP extension after it has been passively extended. Extensor lags can have other etiologies other than extensor digitorum communis subluxation such as tendon laceration or rupture, posterior interosseous nerve palsy, but in these conditions, patients cannot maintain MCP extension. Active interphalangeal extension can be achieved with the intrinsic muscles that are not affected by sagittal band rupture.
What is the effect of shortening of metacarpal fractures?
Causes the greatest degree of extensor lag in the index finger
Causes the greatest degree of extensor lag in the little finger
Results in an average extensor lag of 7 degrees for every 2 mm of shortening
Results in an average extensor lag of 14 degrees for every 2 mm of
shortening
Has no effect on grip strength
Cadaveric models have demonstrated a 7-degree extensor lag for every 2 mm of metacarpal shortening, with the amount of lag increasing in a linear fashion. There was no statistical difference in the amount of lag in regard to the digit involved. Based on muscle length-tension relationships, cadaveric models have also been used to demonstrate an 8% loss of power secondary to decreased interosseous force generation with 2 mm of shortening. Because the intrinsic muscles of the hand contribute anywhere from 40% to 90% of grip strength, decreased interosseous force generation secondary to metacarpal shortening will invariably cause a decrease in grip strength.
A 22-year-old motorcyclist sustains open fractures to the left radial shaft and second and third metacarpals with exposed extensor tendon and bone. The fractures are approached via the dorsal open wounds of the forearm and hand with no additional incisions made. The radiograph and clinical photograph of the remaining defect in the hand are shown in Figures 55a and 55b. The remaining wound can be most appropriately covered with which of the following?
Split-thickness skin grafting
Posterior interosseous rotational flap
Radial forearm rotational flap
Groin flap
Free lateral arm flap CORRECT ANSWER: 3
After adequate debridement, there is exposed bone, tendon, and hardware. Split-thickness skin grafting over exposed tendon will not have a viable bed to support the graft. The tendons would not have healthy surrounding tissue, resulting in poor tendon gliding. The dorsal wound has disrupted the posterior interosseous artery that runs in the septum between the extensor digiti minimi and the extensor carpi ulnaris. Following the reconstructive ladder, the radial forearm rotational flap accomplishes wound coverage with a local flap rather
than a groin flap (a distant flap) or a lateral arm flap (microvascular free tissue transfer).
What is the effect of performing a flexor tenosynovectomy with an open carpal tunnel release for idiopathic carpal tunnel syndrome?
Increased risk of nerve injury
Improved postoperative finger flexion
No added long-term clinical benefit versus open carpal tunnel release alone
Increased postoperative pain
Decreased recurrence of carpal tunnel syndrome
In patients with idiopathic carpal tunnel syndrome, flexor tenosynovectomy has not been shown to change the clinical outcome compared with open carpal tunnel release alone. This has been demonstrated in a randomized clinical trial of open carpal tunnel release with or without flexor tenosynovectomy. There has also been no evidence to suggest there is an added risk to performing the flexor tenosynovectomy. At time of surgery, the gross or histologic appearance of the flexor tenosynovium does not correlate with preoperative symptoms nor with clinical outcomes. The histology of the tenosynovium has been shown to be that of fibrosis in a setting of chronic inflammatory changes and no evidence of an acute inflammatory process exists. There may be an added role for flexor tenosynovectomy in non-idiopathic carpal tunnel syndrome such as in patients with renal disease or diabetes.
Figures 69a and 69b show the radiographs of a 62-year-old man with severe radially sided wrist pain. Management has consisted of wrist splinting, nonsteroidal anti-inflammatory drugs, and activity modification, but he continues to have pain and reports difficulty sleeping. What is the most appropriate treatment for this patient?
Arthroscopic debridement
Open reduction and internal fixation
Scaphoid nonvascularized bone graft and screw fixation
Scaphoid vascularized bone graft and screw fixation
Scaphoid excision and 4-corner fusion
Scaphoidectomy and 4-bone fusion is the most appropriate management based on the choices available. The patient has arthritic changes of SNAC (scaphoid nonunion advanced collapse) wrist, stage III. Stage I is at the radial styloid, stage II is at the radioscaphoid joint, and stage III is at the midcarpal joint. Arthroscopic debridement is not appropriate in patients with arthrosis.
Attempting to achieve scaphoid union is only appropriate if there is no arthrosis or the changes are classified as stage I where radial styloidectomy can be performed.
A 7-year-old boy is referred to your office 3 months after jamming his finger while playing basketball. Examination reveals 40 degrees of active and passive motion at the proximal interphalangeal (PIP) joint. The PIP joint is stable to radial and ulnar stressing. Radiographs are shown in Figures 76a and 76b. What is the most appropriate management?
Observation
Corrective osteotomy
Ostectomy
Hand therapy for aggressive stretching
Dynamic splinting CORRECT ANSWER: 3
The most appropriate management is an ostectomy, or resection of the bone in the subcondylar fossa region. This is a malunion where the subcondylar fossa is blocked by malaligned bone. Because it is a bony block to motion, stretching or dynamic splinting will be of no benefit. The physis of the proximal phalanx is proximal, making remodeling of a fracture at the distal end very
unlikely. A corrective osteotomy has a risk of osteonecrosis of the very small distal fragment.
Figure 78 shows the clinical photograph of a patient who injured his finger while playing football. He cannot actively flex the distal interphalangeal joint of the ring finger. Which of the following is the most accurate statement regarding the injury shown?
The tendon is attached to the avulsed fragment from the distal phalanx.
There is no difference in time sensitivity in an acute injury whether or not the tendon has retracted into the palm.
In a chronic (> 3 months) case of flexor digitorum profundus (FDP) avulsion, the FDP should be tenodesed to the flexor digitorum sublimis (FDS).
If the FDP is advanced more than 1.5 cm, there is a risk for quadriga effect.
The method of repair does not affect repair gapping or strength of the tendon repair.
Overadvancement of the FDP tendon is one of the causes of the quadriga effect. Relative shortening of an FDP tendon decreases the excursion of the neighboring FDP tendons because they originate from a common muscle belly. The patient reports a weak grasp. Answer 1 is not correct because there can be a fracture and the tendon can avulse off of the fracture fragment (Trumble JHS-A 1992). Whether the tendon has retracted into the palm or not does matter because retraction into the palm allows pulleys to collapse and contract and it also means that the vinculae have been stripped off of the tendon.
Regarding answer 3, in chronic cases where the FDS is intact and strong, many patients may be better off with a sublimis finger and no FDP reconstruction that could, in the worst case scenario, worsen a functional proximal interphalangeal joint. Regarding the repair method, there is recent
research showing method of repair (button vs anchor), suture type, and method do affect the biomechanical properties of the repair.
A 44-year-old woman with cubital tunnel syndrome and associated ulnar nerve subluxation with elbow flexion has failed to respond to nonsurgical management. Which of the following statements is most acccurate regarding in situ simple decompression of the nerve compared with subcutaneous anterior transposition?
Patients undergoing anterior transposition have improved motor outcomes.
Patients undergoing anterior transposition have improved sensory outcomes
Patients undergoing simple decompression have improved motor outcomes.
Patients undergoing simple decompression have improved sensory outcomes.
No differences in outcome are likely between treatment types.
Recent reports comparing outcomes of surgical treatment of ulnar nerve compression at the elbow have demonstrated no differences in outcome between simple decompression and anterior transposition. The presence of subluxation of the ulnar nerve was not a contraindication to in situ decompression in the study by Keiner and associates.
What anatomic structure must be excised when performing a volar plate arthroplasty of the proximal interphalangeal joint?
Central slip
Collateral ligament
Checkrein ligament
Triangular ligament
Flexor digitorum superficialis insertion
The collateral ligament must be excised or released from the proximal phalanx to allow gliding of the middle phalanx on the articular surface of the proximal phalanx. Failure to do so may prevent this gliding motion and make the middle phalanx just hinge on the proximal phalanx.
Figures 97a and 97b show a clinical photograph and radiograph of a patient who has a history of repeated drainage from the lesion. What is the preferred surgical treatment?
Excision of the lesion alone
Removal of the osteophyte alone
Distal interphalangeal joint fusion
Excision of the mass and osteophyte removal
Removal of the mass and skin with skin grafting
The patient has a mucoid cyst. Whereas many of these lesions are associated with osteoarthritis, the best surgical treatment of the lesions in patients who have little or no pain is typically excision of the mass with osteophyte removal. Studies have shown that osteophyte excision helps minimize the risk of recurrence. Distal interphalangeal joint fusion is reserved for patients with pain and more advanced radiographic arthritis. Excision of the lesion alone is a less favorable option than excision of the mass and osteophyte removal. The lesion is independent of the skin and thus, skin removal with the mass is unnecessary.
Which of the following structures cannot be seen during standard radiocarpal arthroscopy?
Scapholunate ligament
Lunotriquetral ligament
Radioscaphocapitate ligament
Extensor carpi ulnaris tendon
Superficial insertion of the triangular fibrocartilage complex (TFCC)
The extensor carpi ulnaris tendon is located in an extra-articular position, and as such, cannot be seen during arthroscopy. Wrist arthroscopy is a useful technique for evaluation and treatment of radiocarpal and midcarpal maladies. During standard radiocarpal arthroscopy, the scapholunate and lunotriquetral ligaments can be easily visualized. The superficial TFCC is seen overlying the ulnar head. Volarly, the radioscaphocapitate ligament can be seen as a discrete band of the capsule.
A 20-year-old skateboarder fell 6 months ago and has had radial-sided wrist pain since. His radiograph upon presentation to your office is shown in figure A. What is the most appropriate treatment at this time?
four corner fusion
long arm thumb spica cast
wrist arthroscopy to evaluate intercarpal ligaments
open reduction internal fixation with autologous bone graft
wrist arthrodesis CORRECT ANSWER: 4
This patient has a scaphoid waist fracture nonunion. Several studies indicate that scaphoid nonunions left untreated have a determined course of collapse and progressive arthritis (scaphoid nonunion advanced collapse - SNAC). Per Markiewitz et al, the standard treatment of scaphoid nonunions is open reduction internal fixation with bone graft; non-operative treatment is not appropriate. Proximal row carpectomy and wrist fusion are salvage procedures reserved for patient that has an advanced scaphoid nonunion, collapse and wrist arthritis.
Figures 112a and 112b show the radiographs of a 28-year-old motorcyclist who sustained a closed hand injury in a collision. What is
the most appropriate definitive treatment?
Closed reduction and a hand/forearm cast in the intrinsic plus position
Closed reduction and a hand splint
Primary fusion of the carpometacarpal joints
Closed versus open reduction and internal fixation
Closed reduction and external fixation
Closed versus open reduction and internal fixation is the most appropriate treatment. The radiographs show fracture-dislocations of all five carpometacarpal joints. These injuries are extremely unstable and not amenable to closed (splint or cast) treatment only. External fixation may be warranted in an open, contaminated injury. Fusion would be an option if this were a chronic, painful condition on presentation.
What additional procedure should be done when performing a radioscapholunate fusion for posttraumatic arthrosis following a distal radius fracture?
Excision of the triquetrum and distal pole of the scaphoid
Anterior interosseous neurectomy
Fascial interposition arthroplasty of the capitolunate joint
Sectioning of the dorsal intercarpal ligament
Ulnar shortening osteotomy
Excision of the triquetrum and distal pole of the scaphoid frees up the midcarpal joint, improving radial deviation and the flexion-extension arc of motion of the wrist. This offers an alternative to complete wrist arthrodesis for posttraumatic arthrosis of the radiocarpal joint. An anterior interosseous neurectomy is believed to decrease some pain transmission from the wrist but because the fusion is done dorsal, cutting this volar structure is not routinely done. Fascial interposition is not needed because the capitolunate should be preserved in posttraumatic radiocarpal arthrosis. Sectioning of the dorsal intercarpal ligament would provide no benefit. If the triquetrum is excised, then an ulnar shortening osteotomy is unnecessary.
Apert's syndrome is caused by a mutation in what gene?
Fibroblast growth factor receptor 2 (FGFR2)
Fibroblast growth factor receptor 3 (FGFR3)
Collagen type II alpha 1 chain (COL2A1)
SED late (SEDL)
Fibrillin
Apert's syndrome (acrocephalosyndactyly type 1) is characterized by anomalies of the cranium, hands, and feet. Mutations in the FGFR2 gene cause Apert syndrome.
Anderson et al report that in Apert's syndrome there is widespread anomalies of the feet, with defects including both predictable dysmorphic changes and progressive fusions of the skeletal components during skeletal maturity.
Incorrect Answers:
2: Achondroplasia is related to abnormalities in the FGFR3, not FGFR2.
3: SED congenita is caused by mutations in COL2A1 (type II collagen alpha 1 chain) on chromosome 12. These result in abnormal type II collagen.
4:The X-linked form of SED tarda is caused by mutation in SEDL (SED late)
gene.
5: Marfan syndrome is caused by defects in the fibrillin gene.
What is the most important measure to take to reduce the risk of frostbite of the toes while hiking in extreme temperatures?
Stop often for recovery breaks.
Drink enough warm liquids.
Reduce thermal heat loss from shoes.
Use triple socks.
Adequately "carbo load" before the start.
Several studies showed the most reliable method to reduce the risk of cold exposure injury is to reduce thermal heat loss. This can be done with a combination of protective socks and shoes, and reducing moisture in the shoes.
Figures 45a through 45e are the MRI scans, gross specimen, and histology of the specimen of a 19-year-old man who has an enlarging mass in the second interspace. He reports forefoot pain that is worse with athletic activity. Radiographs show erosive changes of the third metatarsal head. What is the most common complication associated with incomplete excision?
Metastatic disease
Malignant degeneration
Recurrence
Pathologic fracture
Infection
Giant cell tumor of the tendon sheath often arises from the synovial lining of tendon sheaths. This lesion is frequently found in the hand and foot. The lesion is slow growing and can invade adjacent structures. In the foot, wearing shoes or increased activity can cause pain. Incomplete or piecemeal excision can lead to recurrence.
A 42-year-old construction worker presents with pain in his right wrist. A current radiograph of the wrist is shown in Figure A. He reports that rotating activities, such as turning a screw driver, are bothersome and the pain is preventing him from working. A current MRI reveals a TFCC tear, and nonsurgical treatment has failed to provide relief. Treatment should now consist of:
Repair of the ulnar styloid nonunion
Darrach resection of the distal ulna
Complete ulnar head resection
Ulnar hemiresection arthroplasty and TFCC reconstruction/repair
Isolated arthroscopic TFCC reconstruction
The clinical presentation is consistent with DRUJ arthritis in a heavy laborer. Of the options listed, ulnar hemiresection arthroplasty with concurrent TFCC reconstruction or repair would be the most appropriate treatment.
While there are multiple treatment options, the ulnar hemiresection arthroplasty with concurrent TFCC reconstruction or repair is considered most appropriate in heavy laborers, as it would likely resolve the pain and enable them to return to work sooner. The TFCC should be intact when performing an ulnar hemiresection arthroplasty to prevent distal ulna instability with forearm rotation. One could also consider performing a Suave-Kapandji procedure. This procedure creates a distal radioulnar fusion and an ulnar pseudarthrosis proximal to the fusion site through which rotation can occur. The advantage is that the ulnocarpal joint is not sacrificed, and a stable wrist is created.
Scheker et al reported on the outcome of ulnar shortening performed on 32 wrists with early osteoarthritis of the DRUJ. The postoperative wrist ratings were 7/32 excellent, 11/32 good, 9/32 fair, 5/32 poor, with plate irritation being the most frequent postoperative complication.
Figure A is a radiograph showing significant DRUJ arthritis. Illustration A shows ulnar hemiresection arthroplasty. Illustration B shows a Darrach procedure.
Illustration C shows a Sauve-Kapandji procedure. Illustration D is a treatment schematic of TFCC reconstruction.
Incorrect Answers:
Figures 113a and 113b are the radiographs of a 7-year-old girl who was evaluated for a visible elbow deformity by a foster parent. She thought the child fell, but her history was vague. On physical examination, a large prominence was seen over the posterolateral elbow, and the girl lacks the terminal 20 degrees of elbow extension. She has 75 degrees of elbow pronation and supination. She was nontender on examination. What is the most appropriate next treatment step?
Child abuse workup
Closed reduction
Open reduction with possible osteotomy
Observation CORRECT ANSWER: 4
The most appropriate management of this condition is observation. The patient most likely has a congenital dislocation of the radial head, although this may also represent a posttraumatic deformity. The absence of findings on physical examination speaks against an acute injury. The appearance of the radial head reveals the typical findings of a congenital dislocation, namely the convex appearance of the proximal radial articular surface. These children typically have very functional range of motion and do not require treatment unless they are symptomatic. There is nothing in this child's history to suggest abuse.
The most common mechanism of injury to the triangular fibrocartilage complex (TFCC) involves
wrist extension and forearm pronation.
wrist extension and forearm supination.
wrist flexion and forearm pronation.
wrist flexion and forearm supination.
axial load in ulnar deviation.
TFCC tears are common in athletes. As the athlete braces for a fall, the wrist is most commonly in an extended position and the forearm is pronated.
A 28-year-old woman fell on her right wrist while rollerblading 6 days ago. She was seen in the emergency department at the time of injury and was told she had a sprain. Examination now reveals dorsal tenderness in the proximal wrist but no snuffbox or ulnar tenderness. Standard wrist radiographs are normal. What is the next most appropriate step in management?
Arthroscopy of the wrist
CT of the wrist
Bilateral PA clenched fist radiograph
Electromyography and nerve conduction velocity studies
AP and lateral radiographs of the forearm
When considering the diagnosis of scapholunate ligament injury, standard radiographic views of the hand will not always reveal widening of the scapholunate gap. Although MRI may reveal injury to the ligaments, the PA clenched fist view can be obtained in the office during the initial patient visit. Arthroscopy is not a first-line diagnostic tool.
Figures 12a through 12c show the radiographs of a 28-year-old professional baseball player who has ulnar-sided wrist pain and
numbness and tingling in the fourth and fifth digits for the past 6 weeks. Management should consist of
cast immobilization.
bone stimulation and splinting.
ulnar nerve exploration.
open reduction and internal fixation.
excision of the fragment.
Hook of the hamate fractures typically occur as a result of direct force from swinging a bat, golf club, or racket. Pain is localized to the hypothenar eminence. The injury is best seen on a carpal tunnel view. CT will confirm the diagnosis. Chronic cases can be associated with neuropathy of the ulnar nerve. Excision of the hook through the fracture site usually yields satisfactory results, allowing the athlete to return to competition.
A 40-year-old right-handed professional football player reports persistent right wrist pain after falling during a game 5 days ago. A radiograph is shown in Figure 21. Management should consist of
immobilization in a short arm thumb spica cast.
immobilization in a long arm thumb spica cast.
arthroscopic repair and percutaneous pinning.
open repair and percutaneous pinning.
dorsal capsulodesis.
The radiograph reveals an increased distance between the scaphoid and the lunate, which is indicative of scapholunate disassociation. A ring sign is also present, which represents the distal pole of the scaphoid viewed end on in a palmarly flexed position. In the acute setting, the scapholunate can be repaired. Open repair and percutaneous pinning is the treatment of choice. Dorsal capsulodesis is performed in the chronic setting if such an injury is initially missed.
An 18-year-old rugby player has had pain in his ring finger after missing a tackle 1 week ago. Examination reveals tenderness in the distal palm, and he is unable to actively flex the distal interphalangeal (DIP) joint. Radiographs are normal. What is the most appropriate management?
Acute tendon repair
DIP joint extension splinting for 6 weeks
DIP and proximal interphalangeal joint extension splinting for 6 weeks
Buddy taping to the middle finger for 2 weeks
Early range-of-motion exercises and return to play as pain permits
Flexor digitorum profundus rupture or “rugger jersey finger” often occurs in the ring finger after the player misses a tackle and catches the digit on the shirt of the opposing player. Surgical repair is required for zone I-type injuries.
A 65-year-old right-hand-dominant man has a 5 year history of progressive right wrist pain. He relates spraining his wrist playing football in college, but otherwise has had no prior traumatic injury. He is a pack per day smoker. An AP radiograph of the wrist is shown in Figure A. Wrist immobilization, anti-inflammatory medications, and injections have failed to provide relief. Which appropriate surgical treatment option offers the lowest risk of postoperative complications?
Radial styloidectomy
Total wrist arthroplasty
Proximal row carpectomy
Scaphoid excision with four-corner fusion
Complete radiocarpal arthrodesis
Proximal row carpectomy (PRC) and scaphoid excision with four-corner fusion are both appropriate surgical treatment options for stage II scapholunate advanced collapse (SLAC) wrist; however PRC is associated with fewer postoperative complications, particularly in active smokers.
Scapholunate interosseous ligament disruption leads to abnormal wrist biomechanics and degenerative arthritis. This progression follows a predictable pattern termed scapholunate advanced collapse. In stage II disease where the entire radioscaphoid articulation is affected but the capitolunate articulation is spared, both proximal row carpectomy (PRC) and scaphoid excision with four-corner fusion offer long-term pain relief while preserving wrist motion and grip strength. Scaphoid excision with four-corner fusion has a higher rate of complications owing to nonunion, hardware issues, and dorsal impingement from malunion. PRC is not recommended in the setting of capitolunate arthritis (stage III).
Tomaino, et al. retrospectively compared PRC and limited intercarpal arthrodesis with scaphoid excision (LWF) at a mean of 5.5 years postoperatively in 24 symptomatic SLAC wrists. They noted good pain relief, grip strength, and function in all but 3 patients having undergone PRC - one of whom required revision to wrist arthrodesis (these patients had symptomatic capitate arthrosis). They concluded that in wrists without capitolunate arthritis, PRC had the benefit of being technically easier to perform, did not require prolonged postoperative immobilization, and avoided the risk of nonunion associated with LWF; however it was not an appropriate surgical option in stage III SLAC wrists with capitolunate involvement.
Strauch reviewed the evaluation and treatment of SLAC and SNAC (scaphoid nonunion advanced collapse) wrists. Treatment options for SLAC wrist include four-corner fusion, capitolunate arthrodesis, PRC, radial styloidectomy, wrist denervation, and complete radiocarpal fusion. Excision of the distal ununited scaphoid fragment is an additional option in the setting of SNAC wrist. He additionally highlights current controversies between PRC vs. four-corner fusion.
Figure A shows an AP radiograph with stage II SLAC wrist. The entire radioscaphoid articulation is arthritic with sparing of the capitolunate surface.
Illustration A shows the modified Watson classification of scapholunate advanced collapse.
Incorrect Answers:
A 25-year-old male presents to the clinic with a painful, enlarging mass at the volar radial wrist. He initially noticed the mass 6 months ago after he hurt his wrist golfing. Figure A shows a clinical photograph of the patient's wrist. Radiographs are unremarkable. An ultrasound of the mass is shown in Figure B. Surgical excision is planned. Which of the following is the most appropriate type of resection and histologic finding?
Intralesional excision; synovial cells with mucin accumulation
Incision & drainage; polymorphonuclear cells
Wide excision; histiocytes with frequent giant cells
Marginal excision; synovial cells with mucin accumulation
Intralesional excision; histiocytes with frequent giant cells
The patient presents with a volar wrist ganglion cyst. Surgical treatment consists of marginal excision. Histologic analysis demonstrates synovial cells with mucin accumulation.
Ganglion cysts are the most commonly presenting masses in the hand. These cysts consist of a synovial cell lining filled with mucin. Dorsal wrist ganglion cysts originate from the scapholunate interval and are more common than volar wrist ganglions, which typically originate from the scapho-trapezio-
trapezoidal joint articulation. Ganglion cysts can cause pain related to mass effect. Ultrasound can help differentiate these masses from vascular malformations or other tumors; ganglion cysts present as homogenous anechoic masses with well-defined borders.
Mayerson, et al. reviewed the diagnosis and management of soft-tissue masses. They highlight the typical presentation of ganglion cysts, which wax and wane in size and transilluminate with a pen light. The authors concluded that MRI is diagnostic if there remains any uncertainly after history and clinical exam.
Head et al compared surgical excision versus needle aspiration of 2,239 adult wrist ganglions in a meta-analysis of 35 studies. Surgical excision resulted in a 76% reduction in recurrence compared to aspiration. Mean recurrence for arthroscopic excision (6%), open surgical excision (21%) and aspiration (59%) and mean complication rate for arthroscopic excision (4%) open surgical excision (14%) and aspiration (3%) were also determined. Data from arthroscopic excision was limited but is a promising technique. Open surgical excision has a significantly lower recurrence rate as compared to aspiration.
Figure A shows a clinical photo of a volar wrist ganglion cyst. Figure B shows the ultrasound image of a volar wrist ganglion cyst.
Incorrect Answers:
A 27-year-old man falls on his hand at work. He notices an immediate deformity of his ring finger. Radiographs are provided in Figure A. Which of the following is the most appropriate initial treatment?
Closed reduction, buddy taping, and early motion to prevent stiffness
Closed reduction and full time extension splinting
Open reduction and repair of the central slip of the extensor tendon
Open reduction and repair of the volar plate
Amputation and immediate return to work
The radiograph demonstrates a volar PIP dislocation. The central slip of the extensor tendon is frequently ruptured and will lead to a boutonneire deformity if left untreated. The PIP must be immobilized in extension to allow the extensor mechanism to heal. Immobilization in extension should be maintained for 6 weeks to allow soft tissue healing. Open reduction and repair of the central slip would be the appropriate treatment for a developing boutonneire deformity that presents in a subacute or chronic time basis.
Illustrations A and B demonstrate a schematic and clinical photo of central slip disruption and secondary deformity with PIP flexion and DIP hyperextension (Boutonniere Deformity).
Posner et al reviewed 7 patients with chronic palmar dislocations of the PIP joint who were treated with open reduction and reconstruction of the extensor mechanism. All patients acheived satisfactory range of motion and the authors concluded that this technique is preferable to arthrodesis.
Peimer et al reviewed 15 patients with palmar dislocations of the PIP joint. Twelve of the fifteen were evaluated on a delayed basis (average 11 weeks following injury) and underwent open reduction and surgical repair of the extensor tendon. Three of the fifteen were seen earlier following injury and were treated with closed reduction and pinning. All fifteen patients acheived satisfactory clinical outcomes although finger range of motion was not fully recovered in any case.
Figure A is of a 22-year-old male college basketball player presents for evaluation of a right index finger deformity. He reports a fall during a game 8 weeks ago, with resultant deformity to the index finger. He "popped it back in" and returned to play. Physical exam is most likely to demonstrate:
Inability to passively extend the PIP joint to neutral, able to passively flex and extend the DIP joint
With the PIPJ flexed, resistance to PIPJ extension causes the DIPJ to become supple
Dorsal subluxation of the PIP joint, able to passively flex and extend DIP joint
With the PIPJ flexed, resistance to PIPJ extension causes the DIPJ to become rigid
Inability to actively flex the DIP joint, able to actively flex the PIP and the MCP joints
The patient presents with a Boutonniere deformity secondary to a traumatic central slip disruption in the setting of volar PIP joint dislocation. Physical exam will demonstrate a positive Elson's test, which is described in answer 4.
The digital extensor mechanism consists of the central slip and two lateral bands, all of which arise from the extensor digitorum communis (EDC) tendon. Flexion of the PIP joint puts the central slip on tension, and volarly subluxes the lateral bands causing them to become slack. Tension on the central slip causes extension of the PIP joint, with concomitant dorsal shift of the lateral bands which help to bring the DIP joint into extension.
In 1986, Elson described his physical examination maneuver for diagnosis closed rupture of the central slip. With the hand resting on the edge of a table, the PIP joint is flexed to 90 degrees over the table edge, and the patient is asked to extend the digit against resistance. Active extension of the middle phalanx can only be observed with an intact central slip, and the adjacent lateral bands will remain slack which allows the DIP joint to remain flail. In central slip ruptures, effort to extend the middle phalanx will be accompanied
by DIP rigidity/extension as the lateral bands are forced to contribute to extension.
Rubin et. al. performed a cadaveric study evaluating the efficacy of physical examination maneuvers to identify acute ruptures of the central slip. They
found that Elson’s test was the only maneuver that could discern central slip integrity in both tested scenarios: 1) pre-boutonniere deformity with division of the central slip and 2) passively correctible boutonniere deformity caused by division of the central slip, the triangular ligament, and the oblique fibers of the extensor expansion.
Figure A is a clinical image of an index finger with boutonniere deformity. Video A is a short demonstration of how to perform the Elson test.
Incorrect answers:
A 25-year-old woman presents to the clinic after knife injury to the volar aspect of her long finger 2 weeks ago. She is evaluated and diagnosed with tendon rupture of the flexor digitorum profundus (FDP). What finding on examination can be expected in this patient?
With passive wrist extension, extension remains at the distal interphalangeal joint
With passive wrist extension, extension remains at the proximal interphalangeal joint
With passive wrist flexion, extension is limited at the distal interphalangeal joint
With passive wrist flexion, flexion remains at the distal interphalangeal joint
With passive wrist flexion, flexion remains at the proximal interphalangeal joint
With an FDP rupture, physical exam would likely reveal loss of flexion at the DIP joint both actively and passively with wrist extension.
When the wrist is in extension, flexor tendons are stretched and should result in flexion at the DIP (FDP) and PIP (FDS) joints. The FDP tendon is responsible for flexion of the DIP joint, and this joint would remain extended during normal tenodesis on passive wrist exam. Inversely, with extensor tendon injuries, there may be a loss of digit extension with passive wrist flexion.
Strickland presents a review article (Part 1) on flexor tendon injuries discussing clinical presentation and repair techniques. A commonly tested concept is that tendon repair is proportional to the number of core sutures, and currently recommended repair includes at least 4 core sutures for strength with epitendinous suture to aid in gliding and provide some strength.
Kamal et al. present current evidence regarding flexor tendon injuries, reviewing examination, repair, and rehab. They note that to date there still remains heterogeneity in treatment patterns and no clear standard of care. Rehab options include no motion, early active range of motion, and controlled passive range of motion. The authors note that early loading may lead to improved strength.
Illustration A depicts the usual tenodesis effect of the digits where passive extension of the wrist produces flexion of the fingers.
Incorrect Answers:
A 20-year-old college football lineman sustains an injury to his index finger during a game. A radiograph of the hand is demonstrated in Figure A. What is the mechanism of injury and most common reason for unsuccessful closed reduction?
Hyperextension mechanism causes the metacarpal head to button hole between the flexor tendon and the lumbrical
Hyperextension mechanism causes volar plate avulsion and entrapment dorsal to the metacarpal head
Rotational mechanism causes the metacarpal head to button hole between the flexor tendon and the lumbrical
Hyperflexion mechanism causes volar plate avulsion and entrapment dorsal to the metacarpal head
Hyperflexion mechanism causes the metacarpal head to button hole between the flexor tendon and the lumbrical
Irreducible dorsal metacarpophalangeal (MP) joint dislocations occur from a hyperextension moment, which causes volar plate displacement and incarceration dorsal to the metacarpal head.
MP joint dislocations are most commonly dorsal and occur with hyperextension injuries. Simple dislocations are reducible with wrist flexion (to relax the intrinsic muscles) and direct palpation over the proximal phalanx base.
Complex dislocations occur with interposition of the volar plate. When irreducible, open reduction is required.
Afifi et al. performed a cadaver study defining the anatomy surrounding irreducible dorsal index MP joint dislocations. They found that of all local structures, only release of the volar plate allowed for reduction of the MP joint. They concluded that volar plate interposition dorsal to the metacarpal head was responsible for irreducible MP joint dislocations.
Bohart et al. describe 9 patients with irreducible dorsal MP joint dislocations (5 thumbs and 4 index fingers). A dorsal approach was performed in each case to allow for reduction of the volar plate. A stable MP joint was achieved in each case. They advocate for a dorsal approach, which minimizes the risk of iatrogenic injury to the neurovascular bundles, which are displaced volarly by the metacarpal head.
Figure A shows an oblique radiograph of the hand demonstrating a dorsal dislocation of the index MP joint. Illustration A provides a schematic of both a simple and a complex dorsal MP joint dislocation. In the case of a complex dislocation, the volar plate avulses from its origin and becomes entrapped dorsal to the metacarpal head.
Incorrect Responses:
A 3-year-old patient presents to clinic with her parents for the chest wall anomaly seen in Figure A. What other congenital disorder is associated with this syndrome?
Flexible pes planovalgus
Syndactyly
Polydactyly
Macrodactyly
Accessory navicular CORRECT ANSWER: 2
The figure shows an individual with Poland's Syndrome, as demonstrated by the absent sternoclavicular head of the pectorals major. Syndactyly and symbrachydactyly is often seen, in addition to hypoplasia and shortening of the fingers.
Poland's Syndrome, or Poland anomaly/sequence, is thought to be caused by disruption of the subclavian artery in utero, causing various hypoplastic anomalies of the upper extremity. These are typically ipsilateral ranging from aplasia of the sternocostal head of the pectorals major, radio-ulnar synostosis, symbrachydactyly and other limb hypoplasias, or syndactyly of the central digits. Syndactyly is often simple and either complete or incomplete. It is addressed surgically early on, with the chest wall deformities needing reconstruction and muscle transfers closer to sexual maturity. Thoracic, cardiovascular, and genitourinary anomalies may also be present.
Catena et al. proposed a new classification system for Poland Syndrome based on the degree of clinical severity of the entire upper extremity. The classification type increased with more proximal involvement up the upper extremity. This new system may help guide treatment as is takes into account the functional state of the rest of the upper extremity and not just the hand, as previous systems have.
Ireland et al. analyzed 43 consecutive cases of Poland's Syndrome. All cases involved congenital aplasia and syndactyly which was typically simple and incomplete. The thumb can be involved putting it the same plane as the fingers. Anomalies were more frequently seen on the right side. They noted favorable outcomes with surgical correction by syndactyly release initiated by 1 year, with some requiring periodic revision releases, while others required an amputation producing a three-fingered hand.
Figure A shows an absent stenocostal head of the pec major. Only the right side is involved. Illustrations A-C show pre-op and post-op digital release of an individual with syndactyly
Incorrect Answers:
A 32-year-old man sustains an injury to his left thumb. Examination in the ER demonstrates a 2x4 cm wound on the dorsal thumb overlying the proximal phalanx with exposed tendon and bone. What is the most appropriate option for soft tissue coverage?
Cross-finger flap
Moberg advancement flap
Full-thickness skin graft
First dorsal metacarpal artery flap
V-Y advancement CORRECT ANSWER: 4
The first dorsal metacarpal artery flap (Kite flap) is the most appropriate soft tissue coverage option for dorsal thumb wounds that disrupt vascularized tissue overlying the extensor tendon and bone (including the epidermis, dermis, subcutaneous tissue, and tenosynovium) when primary closure is not possible.
Kite flaps are based off of the first dorsal metacarpal artery, which overlies the index finger metacarpal. It offers a pedicle length up to 7 cm and can reliably cover soft tissue defects up to 3x5 cm in area. Given its location, it is appropriate for the treatment of thumb wounds including those to the web space, dorsum, and volar pulp, particularly when injury compromised the vascularity of the wound bed. It can be modified to include both dorsal branches of the proper digital nerve, thereby conferring sensibility to the covered wound. The donor site can subsequently be covered with a full-thickness skin graft.
Rehim et al. reviewed local flaps of the hand. They offer treatment options and appropriate indications based upon the anatomic location and size of the wound within the hand. They conclude that when there are no clinical limitations, local flaps provide ideal soft tissue coverage and function for hand wounds based upon the local anatomy without the need for more complex free tissue transfers.
Eberlin et al. review soft tissue coverage options in the hand. They present four clinical cases and offer one established and one non-traditional surgical treatment option for each. They recommend the first dorsal metacarpal artery flap as an established treatment option in a case of thumb volar pulp injury as it offers contour restoration as well as sensibility when the digital nerves are included with the vascular pedicle.
Illustration A demonstrates a large dorsal thumb soft-tissue injury that is treated with first dorsal metacarpal artery flap coverage and full-thickness skin grafting to cover the donor site.
Incorrect Answers:
A 65-year-old man complains of numbness and tingling in the thumb, index, and long fingers of his dominant right hand for 3 months. An EMG demonstrates prolonged median sensory latency and low amplitude compound muscle action potentials with fibrillations in the abductor pollicis brevis. What is the most appropriate treatment option and the rate of continued symptoms at 1 year after treatment?
Splinting and corticosteroids; 5%
Open carpal tunnel release; 20%
Splinting and corticosteroids; 30%
Endoscopic carpal tunnel release; 2%
Open carpal tunnel release; 5%
The most appropriate treatment of carpal tunnel syndrome (CTS) with EMG evidence of denervation is surgical release. The rate of residual symptoms at 1 year is approximately 20%.
The American Association of Electrodiagnostic Medicine (AAEM) criteria delineates CTS severity by EMG. Mild CTS is purely sensory. Moderate disease demonstrates prolonged sensory and motor latencies. Severe disease progresses to involve muscle denervation. Mild and moderate CTS may be treated with carpal tunnel release following failure of nonoperative treatment; however, early operative treatment is supported for severe disease to limit further denervation. Patients experience significant improvement in
symptoms; however, recovery is prolonged and persistent symptoms may be present in ~20% at 1 year.
Kronlage et al. compared changes in numbness and pain following carpal tunnel release in 47 patients with moderate and 48 patients with severe CTS diagnosed on EMG. At 1 year or longer, 1 (2%) patient with moderate disease had continued symptoms compared to 9 (19%) of patients with severe CTS. They concluded that patients with severe CTS experience significant reductions in symptoms following carpal tunnel release; however, recovery may be prolonged or incomplete at 1 year postop.
Ono et al. performed a systematic review of 25 studies reporting outcomes for the treatment of carpal tunnel syndrome. They noted an increasing trend towards recommending earlier surgery for CTS with or without median nerve denervation. They conclude that this differed from the 2007 AAOS guidelines, which recommended early surgery only in the setting of muscle denervation.
Incorrect Answers:
A 23-year-old man presents with chronic, progressive right wrist pain. He remembers falling onto an outstretched hand 2 years ago. Radiographs, CT scans and a T1-weighted coronal MRI are shown in Figures A through E. No bleeding was identified at surgery. In addition to surgical stabilization, what is the next best step?
Corticocancellous autograft inserted through a dorsal approach
Pedicled distal radius graft inserted through a dorsal approach
Pedicled distal radius graft inserted through a volar approach
Free vascularized femoral bone graft inserted through a dorsal approach
Free vascularized femoral bone graft inserted through a volar approach
This patient has an old scaphoid waist fracture with nonunion, proximal pole avascular necrosis (AVN), and carpal collapse. Optimal treatment is with a free vascularized medial femoral condyle (MFC) graft through a volar approach.
Where there is proximal pole AVN, union was achieved in 88% of patients with a vascularized graft versus 47% with screw and nonvascularized wedge bone graft fixation. The 1,2 intercompartmental supraretinacular artery (1,2 ICSRA) pedicle graft leads to union rates of 71% for scaphoid nonunions and 50% for AVN. The risk for failure is higher when there is DISI or humpback deformity (underscoring the need to restore scaphoid geometry). The MFC graft uses a pedicle from the descending genicular artery or the superomedial genicular artery when the descending genicular artery is not present. The volar approach is preferred as it allows correction of the humpback deformity and anastomosis of the MFC pedicle to the radial artery.
Jones et al. retrospectively compared 2 vascularized bone grafts for treatment of scaphoid waist nonunions with proximal pole AVN and carpal collapse. 4 of
10 nonunions treated with distal radial pedicle graft healed at 19 weeks. 12 of 12 nonunions treated with free vascularized medial femoral condyle (MFC) graft healed at median of 13 weeks. Rate of union was higher, and time to healing was shorter for the MFC graft. They recommend the MFC vascularized bone graft for treatment of scaphoid waist nonunion with proximal pole AVN and carpal collapse.
Figures A, B, C and D are PA and lateral radiographs and coronal and sagittal CT images showing scaphoid waist nonunion with carpal collapse and osteonecrosis of the proximal pole, respectively. Figure E is a T1-weighted coronal image shows diffusely decreased signal within the proximal pole.
Illustrations A and B show harvest and inlay of the 1,2 ICSRA graft. Illustration C shows the MFC graft.
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A 38-year-old female develops pain and pallor in all the digits of the right hand daily. Her symptoms have progressed over 2 years despite avoiding direct cold exposure and multiple medications including nifedipine. Recently she has developed the lesions seen Figure A. Workup for underlying disease by her rheumatologist was negative. She is a candidate for Botuninum toxin A injections. What is the physiologic effect of botulinum toxin in the hand for her condition?
Improving proprioception in the fingers and hand by binding to postsynaptic acetylcholine receptors
Improving digital perfusion by cleaving pre-synaptic SNAREs and preventing the release of acetylcholine
Decreasing glabrous skin sensation by reducing hyperexcitability of voltage dependent calcium channels
Strengthening the intrinsic muscles by increasing hyperexcitability of voltage dependent calcium channels
Increasing sympathetic innervation by cleaving pre-synaptic SNAREs and preventing the release of acetylcholine
The patient is displaying Raynaud's Disease with the development of ulcerations from chronic vasoconstriction. Botulinum toxin has been shown to increase the blood supply throughout the hand through the its well-known mechanism of pre-synaptic SNARE cleavage.
Botulinum toxin cleaves the pre-synaptic SNAREs (soluble NSF attachment potion receptor) and prevents the release of acetylcholine from the intracellular vesicles. This has been used for multiple medical purposes, including vasospastic disorders. Raynaud's Disease is characterized by idiopathic vasospasm of the digital arteries without known underlying cause. Usually afflicting pre-menopausal women, it begins with pain and pallor in the digits, typically affecting the bilateral hands. Avoiding cold environments and tobacco are the mainstays of treatment, with calcium-channel blockers being the most common medication used. When these and other medications fail, botulinum toxin injections have been shown to be of benefit by relieving vasoconstriction and decreasing ischemia and pain.
Neumeister et al. reviewed the application of botulinum toxin A and individuals with Raynaud's Disease and Syndrome. They showed marked increases (up to 300%) in digital perfusion in patients receiving these injections into the common digital vessel at the level of the palm. They concluded the mechanisms for this response are likely multifactorial, involving central and systemic effects on neurotransmitters involved in chronic pain pathways, local digital vessel tone, and sympathetic innervation.
Iodio et al. reviewed all clinical studies regarding the use of bootulinum toxin A in raynaud's. There was high variability among the studies in terms of dosage and application method, but all studies reported favorable patient outcomes and some showed improved healing of ulcerations. These studies are promising but are limited due to study design and lack of standardization of botulinum toxin application.
Figure A shows non-infected ulcerations in the digits, common in progressive raynaud's disease.
Illustration A shows ischemic digits due to Raynaud's Syndrome. Illustration B is the same hand after botulinum toxin A injection. Illustration C is a laser doppler of a hand both pre- and post-injection perfusion of botulinum toxin A in an individual with Raynaud's Disease. Illustration D depicts the recommended method of injection, placing 10 units of botulinum around the common digital vessel at the level of the palm.
Incorrect Answers: There is no shown effect on digital proprioception, skin sensation, muscle strengthening.
A 27-year-old male injures his thumb during a fall onto an outstretched hand. He has pain at the MCP joint and difficulty grasping objects between the thumb and index finger. He undergoes surgery with the planned incision shown in Figure A. What muscle and corresponding nerve innervates the structure that blocks reduction of the ligament shown in Figure B?
Opponens pollicis, median nerve
Flexor pollicis brevis, ulnar nerve
Adductor pollicis, ulnar nerve
Abductor pollicis brevis, median nerve
Adductor pollicis, median nerve
The patient has an ulnar collateral ligament injury. The structure that blocks reduction of the ligament is the adductor pollicis aponeurosis, which is innervated by the ulnar nerve.
Thumb ulnar collateral ligament injuries occur after a radially directed force on an extended thumb, stressing the ulnar collateral ligament, dorsal capsule and volar plate. The thumb should be radiographed before stress exam if the history warrants so as not to displace a possible bony avulsion. Exam includes valgus stress on the thumb at 0 and 30 degrees of flexion to test the accessory and proper collateral ligaments respectively. With complete rupture of both ligaments, a bump over the ulnar thumb MCP joint may be palpated, signifying a Stener lesion. The ligament usually tears at the distal insertion and displaces proximal and superficial to the adductor aponeurosis. The dorsal capsule and volar plate may also be injured.
Bean et al. evaluated the biomechanics of non-anatomic reconstruction of the ulnar collateral ligaments in cadaveric specimens. They showed that 2mm of volar displacement of the ligament origin will allow for 10 degrees more radial deviation than anatomic placement will. This highlights the need for anatomic reconstruction and that deviation from this will alter joint kinematics.
Figure A shows a planned incision over the ulnar aspect of the thumb MCP joint
Fibure B shows a Stener lesion that is migrated proximally compared to the aponeurosis which is marked by the forceps
Illustration A depicts the retraction of the collateral ligament proximal to the aponeurosis
Illustration B shows a T1 MR coronal image showing a distal avulsion of the UCL and the Stener lesion, denoted by the asterisk, and the arrow pointing to the aponeurosis
Incorrect Answers:
An otherwise healthy 5-year-old female is brought to your office for the deformity shown in Figures A and B. Only the small digit of the left hand is involved and it may be fully flexed, but there is limited passive extension. What is the next best step in treatment?
Observation and reassurance
Nighttime extension splinting and stretching regimen
Nighttime extension splinting and stretching regimen with full genetic workup
FDS transfer to radial lateral band
FDS split with transfer of limbs to A2 pulley and central tendon hood
The patient described has isolated camptodactyly with a mild flexion contracture. The best next step in treatment is to begin a stretching and splinting regimen.
Camptodactyly is a nontraumatic flexion deformity isolated to the proximal interphalangeal joint, typically involving the small finger. This is often seen
bilaterally and sporadically, although many congenital disorders are associated. Many underlying anatomical structures have been implicated in the pathogenesis of this condition, with various surgical techniques having been described to address these. If this condition remains untreated, adjacent joint involvement can develop, with MCP hyperextension seen most commonly.
Intrinsic-plus splinting of the hand with passive stretching exercises should be initiated first. Surgery is usually reserved in cases of failed splinting or significant contractures approaching 60 degrees.
Comer et al. reviewed the complications of campylodactly. Most common complications were progression or failed improvement of both PIP contracture and MP hyperextension, isolated PIP postoperative residual stiffness, and bony remodeling of proximal phalanx head preventing full extension. They note inconsistent results after surgical correction which supports early detection and conservative modalities as the mainstay of treatment, focusing heavily on a stretching program and night splinting.
Rhee et al. reviewed outcomes of passive stretching for isolated camptodactyly flexion contractures in a series of children under the age of three years. They showed marked improvement of contracture deformity in all children across all levels of severity, though to less extent with more severe deformities.
Figures A and B demonstrate early contracture of the left small finger. Illustration A is a radiograph showing maintenance of articular congruity.
Incorrect Answers:
A collegiate rower complains of dorsal wrist pain for 6 weeks refractory to NSAIDs and bracing. Maximal tenderness is palpated on the dorsoradial forearm approximately 5 cm proximal to the wrist. Pain is exacerbated with resisted wrist extension. Radiographs are unremarkable. A steroid injection should be directed into the compartment containing which of the following structures?
APL and EPB tendons
ECRL and ECRB tendons
EPL tendon
APL and ECRB tendons
Brachoradialis tendon CORRECT ANSWER: 2
The clinical scenario is consistent with intersection syndrome, a inflammatory response to overuse at the site of the second dorsal compartment crossing under the first dorsal compartment approximately 5 cm proximal to the wrist. An anatomical depiction is provided in illustration A. Injections of the second dorsal compartment, which includes ECRL and ECRB, may relieve symptoms
and quell inflammation. Intersection must be differentiated from DeQuervain's syndrome, which is tenosynovitis of the first dorsal compartment. Injections of the first dorsal compartment, which includes APL and EPB, are part of the treatment algorithm for Dequervain's. Wood et al summarizes the evaluation and treatment of sports-related wrist injuries. Grundberg et al demonstrates the pathologic abnormality of intersection syndrome is stenosing tenosynovitis of the second compartment explaining the rationale behind steroid injections into the sheath.
A 42-year-old chef has finally been transferred to the hand specialist 15 hours after injuring his non-dominant hand index finger with a butcher's knife as seen in figure A. He has kept the finger with him, which has been wrapped in saline-soaked gauze and placed on ice. What is the best reason the finger tip should not be replanted?
The replanted digit will likely have poor function due to the delay in care
Possible malingering
The replanted digit will likely have poor function due to the local anatomy
Patient age
Workers compensation patients will have worse outcomes
Single digit amputations proximal to the insertion of the flexor digitorum superficialis (FDS), in generally have poor function and severe stiffness following replantation.
Replantation between the FDS insertion and the distal palmar crease (zone 2 flexor tendon injuries) has historically led to poor results due to stiffness at the proximal interphalangeal joint, decreased sensation in the finger, and tendon adhesions between the FDP and slips of the FDS. Furthermore, outcome studies have demonstrated patients with index finger amputations through this region are more likely to bypass their stiff index finger and utilize their long finger for most tasks. However, amputation of multiple digits through zone 2 would be considered for replantation.
Urbaniak et al performed a retrospective case series of 59 patients who
underwent finger (thumb excluded) replantation for traumatic amputation. They found the functional results were most dependent on level of amputation and patients with amputation proximal to the insertion of the FDS had significantly decreased PIP motion. They concluded that replantation through zone 2 is seldom indicated due to severe stiffness.
Boulas et al reviewed digital replantation and recommend initial treatment should consist of wrapping amputated parts in moistened gauze and placing on ice. Sharp and clean amputations are considered more viable candidates for replantation due to limited damage to the replantation junction compared to crush injuries. Additionally, they state the patients with major psychiatric disorders or those that are unable to comply with postoperative protocols should also be considered poor candidates for replantation.
Figure A demonstrates an amputation through the left index finger proximal phalanx with no evidence of comminution or crush injury. Illustration A demonstrates the flexor tendon zones.
Incorrect Answers:
A patient sustains an acute, closed injury to his index finger. The clinical appearance of the finger is shown in Figure A. The patient is asked to extend the finger against resistance, with the PIP joint in 90 degrees of flexion. You note that PIP joint extension was weak, with hyperextension and restricted passive flexion of the DIP joint. When planning to treat this injury non-operatively which active joint motion is encouraged?
DIP flexion
MCP flexion
MCP extension
PIP extension
PIP flexion CORRECT ANSWER: 1
This patient has sustained a central slip injury. Treatment consists of full time extension splinting of the PIP joint for 5 weeks with active DIP motion (flexion) encouraged.
A central slip injury, or a zone 3 extensor tendon injury, is characterized by PIP flexion and DIP extension (boutonniere deformity). This is most often caused by a rupture of the central slip over the PIP joint caused by a laceration, a traumatic avulsion, or capsular distension in rheumatoid arthritis. A rupture of the central slip causes the extrinsic extension mechanism from the EDC to be lost and prevents extension at the PIP joint. This allows the lumbricals' pull to become unopposed, causing PIP flexion and DIP extension. The examination maneuver described in the question stem is the Elson Test. It is the most reliable way to diagnose a central slip injury before the deformity is present. Non-operative treatment may be undertaken if the injury is closed and presents acutely. The PIP is splinted in full extension for 5 weeks. Active DIP extension and flexion in the splint is encouraged to avoid contraction of the oblique retinacular ligament.
Posner et al. describe the diagnosis and treatment of finger deformities following injuries to the extensor tendon mechanism. They suggest that treatment of a boutonniere deformity depends on its stage. For the acute injury (within the first 2 weeks), immobilization of the proximal interphalangeal joint in full extension for 5 weeks using a static splint that permits active and passive flexion of the DIP joint is usually effective.
Figure A is a clinical photograph demonstrating an index finger with the classic boutonniere deformity of flexion at the PIP joint and hyperextension of the DIP joint. Figure B is a diagram showing the Elson test. When the central slip is intact, there is no hyperextension of the distal phalanx. When the central slip is disrupted, the distal phalanx can hyperextend due to the function of the tight lateral bands.
Incorrect Answers:
A 25-year-old male is stabbed in the proximal volar forearm while fighting in a bar. He presents to the ED with a 1 cm wound and moderate oozing of blood. On exam, he has normal sensation throughout all distributions in his hand, normal radial and ulnar pulses, and a normal tenodesis effect. He is unable to actively flex his index finger DIP joint. Which muscle will also likely not function as a result of his injury?
Flexor digitorum brevis
Flexor carpi radialis
Flexor carpi ulnaris
Flexor pollicis longus
Pronator teres CORRECT ANSWER: 4
The patient has sustained a laceration of the anterior interosseous nerve (AIN), which is a branch of the median nerve and innervates the flexor pollicis longus, pronator quadratus, and the flexor digitorum profundus to the index and long fingers. An intact tenodesis effect signifies that all of his tendons are structurally intact.
The AIN can be injured by a penetrating injury or chronic compression. It
arises from the dorsoradial aspect of the median nerve distal to the elbow. It then passes between the FPL and FDP to lie on the anterior interosseous membrane en route to the pronator quadratus and wrist capsule (Illustration A). Compression sites of the AIN include the deep head of the pronator teres, FDS arcade, edge of the lacertus fibrosus, an accessory head of the FPL, or other accessory muscles of the forearm (FDS, FDP, FCR). In this particular scenario of an acute, penetrating AIN injury, exploration and primary end-to-end suture repair is appropriate.
Rodner et al. review AIN syndrome and stress the importance of ruling out a tendon rupture, which can present similarly and can be differentiated by testing the patient's tenodesis effect. Non-traumatic AIN syndrome is usually the result of a neuritis, similar to Parsonage-Turner Syndrome (brachial plexus neuritis), and may have similar triggers such as viral infection or autoimmune disease. They recommend a prolonged period of observation (~12 months; in the absence of an obvious compressive or space-occupying lesion) due to high rates of spontaneous recovery at about one year.
Park et al. report on 11 patients that underwent surgical exploration for spontaneous AIN syndrome at an average of 7.8 months. The most common compressive structure was a fibrous band of the FDS, however, four patients had no obvious compressive structure, emphasizing the importance of at least six months of conservative treatment.
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A 38-year-old female presents with 8 months of gradual weakness of her right hand. She denies paresthesias, numbness, and pain in the right upper extremity. She has compensatory thumb interphalangeal flexion during key pinch and intact two point discrimination. She has a negative Tinel's sign at the wrist and elbow. Electromyography (EMG) shows normal sensory conduction velocities but delayed motor conduction to the first dorsal interosseous muscle. Figure A and B show MRI images of pre and post contrast, respectively. Ultrasound is shown in Figure C. What is the next best step?
Biopsy of the mass
Cyst excision
MRI of cervical spine
Excision of the hook of hamate
Cubital tunnel release CORRECT ANSWER: 2
The patient has pure motor symptoms from ulnar nerve compression by a ganglion cyst at Guyon's canal. The next best treatment is excision of the ganglion cyst.
Atraumatic compression of the ulnar nerve at Guyon's canal is caused by a ganglion cyst 80% of the time. Compression may present with mixed motor and sensory or pure motor symptoms. With purely motor compression the deep branch of the ulnar nerve is affected resulting in weakness of adductor pollicis. Subsequent loss of metacarpophalangeal flexion and adduction leads to a positive Froment's sign with compensatory thumb IP flexion. Pure motor compression will result in normal sensory examination and intact two point discrimination as sensory branches are unaffected. EMG will localize decreased velocities at the wrist. When neurologic symptoms are present, cyst excision is recommended. Ganglion cysts in this location often arise from the pisohamate joint and excision of the stalk is important to prevent recurrence.
Wang et al. retrospectively investigated the outcomes of 9 patients with
ganglion cysts with symptomatic compression of the deep branch of the ulnar nerve. At a mean follow-up of 23 months they found all patients had improved grip and tip pinch strength. They conclude that surgical intervention can lead to satisfactory outcomes.
Shen et al review the imaging findings possible in patients with ulnar neuropathy. They present a case of a patient with ulnar neuropathy secondary to a ganglion cyst in guyon's canal.
Maroukis et al. review the history of the clinical anatomy of Guyon's canal. They conclude that the three zone theory helped simplify the complex anatomy of ulnar nerve compression at Guyon's canal.
Figure A (Shen et al) shows a T2 fat saturation MRI of a well circumscribed lesion (black arrow) with homogeneous fluid signal intensity at Guyon's canal compressing the ulnar nerve (white arrow). Figure B (Shen et al) shows a post contrast T1 fat saturation MRI showing rim enhancement consistent with a cyst (black arrow) and compression of the ulnar nerve (white arrow). Figure C shows an longitudinal ultrasound view of a anechoic well defined structure consistent with a cyst. Illustration A shows the areas of potential ulnar nerve compression in Guyon's canal. Illustration B shows a table with potential causes for compression at each zone and expected symptoms.
Incorrect Answers:
A 20-year-old male presents to clinic for evaluation of right wrist pain. He fell playing flag football about 6 weeks ago. He initially had significant pain but since it slowly improved he did not seek immediate treatment. His improvement has now plateaued. Figures A and B are x-rays, and figures C and D select CT scan images of his right wrist. What is the best treatment option?
Percutaneous screw fixation
Open reduction internal fixation through a volar approach
Open reduction internal fixation through a dorsal approach
Open reduction internal fixation with bone grafting through a volar approach
Open reduction internal fixation with bone grafting through a dorsal approach
The patient presents with a displaced right scaphoid waist fracture with cyst formation. The best treatment would open reduction internal fixation (ORIF) with bone grafting through a volar approach.
The surgical management of scaphoid fracture depends on location and characteristics of the fracture as well as time from injury. Displaced distal pole and waist fractures are typically approached from the volar side, especially if there is a humpback deformity; the proximal pole is more easily accessed from the dorsal side. Injuries with significant comminution or cyst formation due to extended time to treatment are often augmented with bone graft. There is controversy as to the use of vascularized bone graft in nonunion cases.
Rettig et al. reported on fourteen patients undergoing acute surgical fixation for displaced scaphoid waist fractures. Thirteen patients united and regained functional wrist range of motion and grip strength. They advocate for early
operative intervention in these fractures.
Raskin et al. describe the utility of the dorsal approach for proximal pole scaphoid fractures. They report good fracture visualization and the ability to bone graft through the same incision with successful union in a majority of cases.
Pinder et al. reviewed the literature on management of scaphoid nonunions. They found no difference in use of nonvascularized or vascularized bone graft, choice of approach, or use of Kirschner wires versus screw fixation.
Figures A and B are postero-anterior lateral right wrist radiographs with a displaced scaphoid waist fracture and mild humpback deformity. Figures C and D are coronal and sagittal CT cuts, respectively, demonstrating cyst formation and better showing the humpback deformity.
Incorrect Answers:
A 53-year-old white male presents with contractures of his ring finger and lesions over the dorsum of his hand. On examination of the lesions, they are subcutaneous, solid, and firm lesions measuring about 5 mm in diameter. They are located over the dorsum of the PIP joints of his ring and long finger. They become more mobile while the joint is in neutral and less mobile when the joint is in flexion. He also has a 5 degree flexion contracture his ring finger MCP joint. Examination of his palm reveals a palpable cord over the volar ring finger. His neurovascular examination is normal. The appearance of the dorsum of his hand is seen in Figure A. What is the next most appropriate step in treatment?
Collagenase injection and resection of dorsal finger lesions
Collagenase injection without resection of dorsal finger lesions
Observation and follow up
Surgical resection/fasciectomy and resection of dorsal finger lesions
Surgical resection/fasciectomy without resection of dorsal finger lesions
This patient has mild Dupuytren's disease with associated dorsal Dupuytren nodules, which may be observed.
Dupuytren’s disease is a proliferative disorder characterized by fascial nodules and contractures of the hand. It is autosomal dominant with variable penetrance. It exhibits a 2:1 male to female ratio and is classically seen in Caucasian males of northern European descent. The main pathology of
Dupuytren’s disease is excessive myofibroblast proliferation and altered collagen matrix composition lead to thickened and contracted palmar fascia. Surgical intervention is often indicated in cases of ≥30° of MCP contracture or any PIP contracture (usually >15°).
Rayan et al report that dorsal Dupuytren's nodules are a subcutaneous, solid, firm, well-defined, tumor-like mass or a nodule 3 mm in diameter or larger, located over the dorsum of the PIP joint. It is seldom painful and becomes more mobile while the joint is in neutral position and less mobile during joint flexion.
Black et al report that diseased tissue is referred to as nodules or cords. The Dupuytren nodule is a palpable subcutaneous lump that may be fixed to the skin. Cords are highly organized collagen structures arranged in parallel with a relatively hypocellular matrix. Cords are predominantly composed of collagen III while normal palmar fascia is predominantly collagen I.
Figure A is a picture of a dorsal Dupuytren's nodule. Incorrect Answers:
at this time. The dorsal finger lesions should not be resected.
A 37-year-old man has a 2-year history of increasing right wrist pain that is worse at night and aggravated by activity. He denies systemic symptoms, history of trauma, or recent weight loss. On physical exam he has tenderness over the dorsal radiocarpal joint. Radiographs of the right wrist are shown in Figure A. Which of the following imaging studies would be most sensitive for determining the stage of this patient's underlying condition?
Ultrasound
Angiography
CT scan of the wrist
Clenched fist AP radiograph of wrist
Bone scan of the wrist CORRECT ANSWER: 3
The clinical presentation of dorsal radiocarpal wrist pain is suggestive of Kienbock’s disease. Figure A shows an AP radiograph of the right wrist with
evidence of lunate sclerosis with no obvious collapse. The imaging study most sensitive for identifying early lunate collapse in Kienbock's disease is CT scanning of the wrist.
Kienbock’s disease is defined by avascular necrosis of the lunate. It is classified into 4 stages under the Lichtman Classification. In stage 1, plain radiographs appear normal and magnetic resonance imaging is required for diagnosis. MRI is useful for detecting early disease when sclerosis is not evident on plain film radiographs. In stage 2, plain radiographs and/or CT scan images will show sclerosis of the lunate but no evidence of collapse. In stage 3, radiographs and/or CT scan images will show lunate collapse. For stage 4, radiographs show degenerative changes to the adjacent carpus and intercarpal joints.
Imaeda et al. examined the use of MRI for the diagnosis and staging of Kienbock's disease. They found that MRI was most sensitive in detecting early focal loss of signal intensity in the lunate on T1-weighted images. This was a key diagnostic feature in early stages of Kienböck's disease when plain radiographs appear normal.
Cross et al. reviewed the latest concepts for diagnosis, staging, and management of Keinbock's disease. They suggest that computed tomography (CT) or tomography will better characterize lunate necrosis and trabecular destruction once collapse or sclerosis has occurred in late stage disease.
Illustration A is a collection of CT scanning images that show osteonecrosis of the lunate. The blue arrow shows lunate flattening and sclerosis. The red double arrow shows a loss of lunate height and the yellow shows fragmentation of the bone.
Incorrect Answers:
widening of the scapholunate interval.
Each of the following are indications for microvascular replantation EXCEPT?
Thumb amputation
Index finger amputation in a child
Through wrist amputation
Long finger amputation through the proximal phalanx
Mid-palm amputation of all four fingers
As reviewed by Soucacos, there are several major indications for single digit replantation: 1) Level of the amputation is distal to the insertion of FDS. 2) Amputations at the level of the distal phalanx. 3) Ring avulsion injuries involving both the dorsal and palmar skin and blood supply in an isolated finger, as long as FDS is intact. 4) Any amputation in a child. 5) Thumb amputation. Replantation of a single digit, which is amputated at the level of the proximal phalanx or at the PIP joint, particularly in avulsion or crush injury is contra-indicated. Soucacos also discusses appropriate surgical teams, transport, and other related issues surrounding a "transplant team."
All of the following are predictive findings for correctly diagnosing carpal tunnel syndrome EXCEPT:
Abnormal hand diagram
Abnormal Semmes-Weinstein testing in wrist-neutral position
Positive median nerve compression test (Durkan's sign)
Presence of night pain
Loss of small digit adduction (Wartenberg sign)
All of the listed physical exam findings, except for loss of small digit adduction (Wartenberg sign), has been found to be predictive for diagnosing carpal tunnel syndrome.
Szabo et al in a Level 3 study used a regression model to analyze the most predictive factors for correctly diagnosing carpal tunnel syndrome (CTS). Their analysis found that with an abnormal hand diagram, abnormal sensibility by Semmes-Weinstein testing in wrist-neutral position, a positive Durkan's test, and night pain, the probability that carpal tunnel syndrome will be correctly diagnosed is 0.86. They found the tests with the highest sensitivity were Durkan's compression test (89%), Semmes-Weinstein testing after Phalen's maneuver (83%), and hand diagram scores (76%). Night pain was a sensitive symptom predictor (96%). The most specific tests were the hand diagram (76%) and Tinel's sign (71%). The authors concluded that the addition of electrodiagnostic tests did not increase the diagnostic power of the combination of these 4 clinical tests, and proceeding with surgical release is appropriate even if the EMG is normal.
Wartenberg sign is persistent abduction and extension of the small digit when a patient is asked to adduct the digits and is seen in cubital tunnel syndrome, but not carpal tunnel syndrome.
Illustration V demonstrate the Durkan's Compression test for carpal tunnel syndrome.
Extrinsic imbalance from splinting a crushed hand with metacarpophalangeal joint extension causes what characteristic hand deformity?
Distal interphalangeal joint extension
Ulnar subluxation of the metacarpophalangeal joints
Proximal interphalangeal joint extension
Proximal interphalangeal joint flexion
Swan-neck deformity CORRECT ANSWER: 4
Failure to splint the hand in an intrinsic positive position leads to increased extrinsic finger flexor tension, leading the DIP and PIP joints to have an increasing flexion position. Illustration A and B show a clinical image and illustration of intrinsic minus hand.
von Schroeder et al present a Level 5 review of hand crush injuries. They conclude that early diagnosis and treatment is critical, but the functional outcome is often poor with associated Volkmann's contracture.
Axon regeneration almost always occurs following a Sunderland second-degree nerve injury because which anatomic structure is not injured?
Epineurium
Endoneurium
Perineurium
Myelin sheath
Schwann cell CORRECT ANSWER: 2
Following a Sunderland second-degree injury, axon regeneration is possible because the endoneurium is intact.
There are two classification schemes for peripheral nerve injuries, which include the Seddon and the Sunderland systems. Under the Sunderland
classification, a second-degree injury is considered a part of the axonotmesis spectrum. The endoneurium, perineurium and epineurium are still intact. This enables complete functional recovery.
Lee et al. review the pathophysiology and evaluation of peripheral nerve injuries. They note that in Sunderland type two injuries, there is physiologic disruption of the axons. Because the endoneurium is still intact, axons are able to regenerate. This process takes months.
Illustration A is a schematic of the various stages of peripheral nerve injury. Incorrect Answers
Sunderland type 2 injury, axon regeneration is possible because of an intact endoneurium.
A 29-year-old intravenous drug user undergoes irrigation and debridement of a ring finger abscess. After adequate eradication of the infection, he is left with the skin defect shown in Figure A. What is the most appropriate treatment at this time?
Local woundcare and healing by secondary intention
V-Y advancement flap
Thenar flap
Moberg flap
Cross-finger flap CORRECT ANSWER: 5
Based on the location of the lesion, a cross-finger flap would be most appropriate.
Cross finger flaps are indicated in patients > 30 years of age when the lesion is a volar oblique finger tip lacerations or a volar proximal finger lesions. The advantage is it leads to less stiffness.
Martin et al review the treatment options available for digit injuries. They report treatment of fingertip injuries is a continuous focus of controversy among hand and orthopaedic surgeons. Different treatment options have been described, depending on the affected segment and finger, type of lesion, gender and age of the patient, location, size, and depth of the defect.
Fassler et al reviews the proper management of fingertip injuries discussing variables such as the severity of soft tissue loss and whether bone is exposed.
Incorrect Answers:
A 4-year-old boy sustains a flexor tendon laceration in Zone 2 of his 4th digit when he attempts to grab a knife. Optimal surgical management and postoperative rehabilitation consists of:
2 strand core suture technique and gentle active flexion and extension exercises with wrist in extension
2 strand core suture technique and cast immobilization for 8 weeks
4 strand core suture technique and gentle active flexion and extension exercises with wrist in extension
4 strand core suture technique and cast immobilization for 4 weeks
4 strand core suture technique and cast immobilization for 8 weeks
4 strand core suture technique and cast immobilization for 4 weeks is the preferred postoperative rehabiltation in a 4 year old child.
Ordinarily, adult flexor tendon repair postoperative rehab protocols call for early light active digital flexion with wrist in gentle flexion as long as the tendon has been repaired with a 4 or 6 strand core suture technique and strong epitendinous suture. However, this method cannot succeed without the cooperation of a mature and motivated patient. Children or the mentally disabled are often lacking some of these prerequisites. Therefore, a flexor tendon repair in a child should be treated like a flexor tendon repair with interposed graft in an adult. Immobilization for a minimum of 3 – 4 weeks with a posterior molded plaster splint or cast from the tips of the fingers to just above the elbow. Wrist is flexed 35 degrees, MCPs flexed 60 – 70 degrees and IP joints relaxed in extension. Active motion can be started after the cast is removed at 4 weeks.
A 45-year-old male sustained a fall onto his right wrist 2 weeks ago. A radiograph is shown in figure A. What joint is first affected if left untreated with subsequent development of a SLAC (scapholunate advanced collapse) wrist?
Capitolunate joint
Radioscaphoid
Radioulnar
Radiolunate
STT (scaphotrapezotrapezoidal)
The clinical presentation is consistent with a SLAC wrist. The radioscaphoid joint is the first to be affected in this process.
The radiographs of the right wrist demonstrate a scapholunate dissociation, as evidenced by an increased scapholunate joint space, referred to as scapholunate diastasis (abnormal when the gap is greater than 2 mm and increased from the opposite extremity and other intercarpal spaces).
If left untreated, the wrist may progress to a "SLAC" wrist, as originally described by Watson and Ballet in 1984, which is the most common form of wrist arthritis. The repetitive sequence of degenerative changes is based on and caused by articular alignment problems between the scaphoid, the lunate and the radius.
Kuo et al. review the stages of SLAC wrist. They report stage I SLAC wrist involves changes limited to an area of abnormal contact between the abnormally rotated scaphoid and the radial styloid. In stage II the remaining radioscaphoid joint is affected, as persistent abnormal load transfer and shear across the cartilaginous surfaces leads to degeneration of the proximal scaphoid facet. In stage III, the dorsally translated capitate migrates proximally into the widened scapholunate interval, and degenerative changes occur at the capitolunate joint. The relative congruency of the radiolunate joint in all positions of lunate rotation due to the spherical shape of the lunate facet preserves this articulation, and at all stages of SLAC wrist the radiolunate joint is not involved. The lunate is congruently loaded in every position and, thus, highly resistant to degenerative changes.
Illustration A below shows the stages of involvement in the SLAC wrist.
Question 91
1mg/L (normal 1-3mg/L). Knee aspiration yields WBC of 673 cells/mm(3) with 30% polymorphonucleocytes, and a negative gram stain. There is no surrounding erythema but there is a 1cm area at the inferior aspect of the wound that has a large amount of serous drainage able to be expressed. She has a painless range of motion is 0° to 117°. What would be the next most appropriate step in management?
Explanation
Irrigation and débridement with possible polyethylene exchange is the most appropriate treatment for persistent drainage within a few weeks from total joint arthroplasty surgery.
Malinzak et al performed a Level 4 review of 8494 patients undergoing a total knee arthroplasty. They found that patients with a body mass index greater
than 50 had an increased odds ratio of infection of 21.3 (P < .0001). Diabetic patients were 3 times as likely to become infected compared to nondiabetic patients (P = .0027).
Rasul et al performed a Level 4 review of 24 patients for a duration of 2 years with total knee arthroplasty infections. They found that patients with chronic (>1 month) deep infections were successfully treated 75% with debridement, intravenous antibiotics, tobramycin-impregnated polymethylmethacrylate beads, and delayed exchange arthroplasty with mean interval of staged reimplantation being 8 weeks.
OrthoCash 2020
A 47-year-old man presents with 1 week of left leg pain. 6 months prior he underwent a vascularized free-fibula bone graft from his left leg to his right hip for avascular necrosis. The pain is located at the level of his donor site and is worse with weight-bearing and relieved by rest. Physical exam shows focal tenderness over his tibia. A lateral radiograph from the day of presentation is shown in Figure A. WBC, ESR, and CRP are all within normal limits. What is the next best step in management to confirm the diagnosis?
Compartment pressure measurements
CT scan
MRI scan
Ultrasound to rule out deep abscess
Bone biopsy
The clinical presentation is suspicious for a stress fracture of the tibia following free-fibula bone grafting. If plain radiographs are negative, more sensitive imaging such as a MRI or bone scan should be performed.
Tibial stress fractures are a known complication following free-fibula bone grafting. Radiographs may be normal (as is the case in figure A), or might show the "dreaded black line" and/or new periosteal bone formation. If a stress fracture is confirmed with imaging, appropriate management would then consist of protective weight bearing until symptoms subside.
Pacifico et al detail a case report of tibial stress fractures after vascularised free-fibula graft to the mandible. They report non-traumatic stress fracture to the tibia following a vascularised free-fibula graft is an uncommon but important complication.
Ivey et al detail a case report of a tibial stress fracture after vascularised free-fibula graft for repair of non-union of the humerus.
Emery et al report a case-series of 5 patients who sustained tibial stress fractures after a graft had been obtained from the ipsilateral fibula for use in anterior reconstruction of the spine. They theorize that the increased load the tibia bears as a result of the missing fibular graft may result in stress fractures.
Illustration A shows new periosteal bone formation on the lateral cortex of the tibia consistent with a stress fracture.
Incorrect Answer Choices:
1: While compartment syndrome is on the differential diagnosis, his signs and symptoms are not most consistent with that diagnosis.
2: While CT scan may show evidence of a stress fracture, MRI/bone scans have been shown to be superior methods for detection.
4: As infectious laboratories are normal, an ultrasound to rule out a deep abscess would likely be negative.
5: Bone biopsy is not appropriate without evidence of a lesion or concern for
osteomyelitis.
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A 65-year-old female with a history of developmental dysplasia of the hip (DDH) undergoes a total hip arthroplasty (THA) utlizing a posterior approach. Following THA, she notices an inability to dorsiflex the ankle of her operative extremity. Her pre-operative and postoperative radiographs are seen in figues A and B. Which of the following intra-operative techniques could have avoided this complication in this patient?
Utilization of an anterior approach
Modular components
Use of a larger femoral head
Femoral shortening osteotomy
Acetabular osteotomy
Patients with DDH undergoing THA are at risk for post-operative sciatic nerve palsy due to intra-operative limb lengthening which increases tension on the sciatic nerve. Appropriate management after discovering a sciatic nerve palsy
after surgery should include immediate knee flexion and hip extension to decrease tension on the sciatic nerve. Sciatic nerve palsy following THA most commonly only affects the common peroneal nerve branch, and spares the tibial nerve and can present as an inability to dorsiflex and evert the ankle.
Farrell et al retrospectively looked at the risk factors for motor nerve palsy after THA. They found while motor nerve palsy is uncommon following primary THA, it can be a devastating complication. Some risk factors include: preoperative diagnosis of developmental dysplasia of the hip, posttraumatic arthritis, the use of a posterior approach, lengthening of the extremity, and use of an uncemented femoral implant. In their review, many of the motor nerve deficits did not fully resolve.
Barrack et al reviewed neurovascular complications following THA. They stated that sciatic nerve injury is the most common nerve injury following THA utilizing a posterior approach. In comparison, femoral nerve injury is much less common and is usually from an anterior approach.
OrthoCash 2020
A cane held in the contralateral hand reduces joint reactive forces through the affected hip approximately 50% by which of the following mechanisms?
Reducing hip abductor muscle pull
Increasing hip flexor muscle pull
Moving the center of rotation for the femoroacetabular joint
Increasing joint congruence at the femoroacetabular joint
Moving the center of gravity posterior to the second sacral vertebra Corrent answer: 1
A cane held in the contralateral hand reduces joint reactive forces through the affected hip up to 50% by reducing abductor muscle pull.
A cane create an additional force that keeps the pelvis level in the face of gravity's tendency to adduct the hip during unilateral stance. The cane's force must substitute for the hip abductors of the affected hip and creates a moment arm that is relatively long and originates on the side opposite the hip whose abductor muscles are weak. Additionally, the person needs adequate strength in the muscles of the wrist, elbow, shoulder girdle, and trunk.
Brand and Crowninshield performed a 3-dimensional hip joint reactive force evaluation of 4 different groups of patients. The groups included normal
subjects, preoperative THA subjects walking without a cane, preoperative THA subjects walking with a cane, and subjects following total hip reconstruction. Each of the 3 groups evaluated without the cane had statistically similar hip joint reactive forces. The preoperative THA subjects walking with a cane and significantly lower joint reactive forces (approximately 60%).
The article by Blount was named by JBJS as a "Classics in JBJS" in 2003. It is a commentary encouraging the use of canes by describing how the biomechanics of the hip joint are altered while using a cane.
Illustration A shows some of the mathematics behind cane use.
OrthoCash 2020
Which of the following is an example of an antalgic gait pattern not typically seen in clinical practice?
Patient's knee is maintained in slight flexion throughout the stance period for ipsilateral knee arthritis
Patient's contralateral step length is shortened with ipsilateral ankle arthritis
Patient leans their trunk laterally over the painful leg during stance phase with ipsilateral hip arthritis
Patient ambulates on their toes with an ipsilateral calcaneal stress fracture
Patient ambulates predominately through the heel for ipsilateral knee arthritis
The term antalgic gait is non-specific and describes any gait abnormality resulting from pain. A patient with knee arthritis maintains slight flexion throughout the gait cycle. This compensatory knee flexion is exacerbated if the patient has a concomitant effusion in the knee as flexion reduces tension on
the knee joint capsule. Gait compensation for knee arthritis also involves toe walking on the affected side, reducing the stride length, and reducing time of weight bearing on the painful leg.
Gok et al performed a case-control gait analysis study of 13 patients with OA and 13 normal patients. They found that walking velocity, cadence and stride length were reduced in the OA group and that the overall stance phase was prolonged in the OA group. They concluded that computerized gait analysis can be used to reveal various mechanical abnormalities accompanying arthrosis of the knee joint at an early stage.
Cole and Harner present Level 5 evidence about knee arthritis in the active patient. They stress that weightbearing radiographs are important in the diagnosis of arthritis. They also discuss the importance of looking for medial or lateral thrusts during gait and dynamic gait changes such as quadriceps avoidance or out-toeing.
Incorrect Answers:
OrthoCash 2020
A 78-year-old male falls at home four months following a right total hip arthroplasty. Right leg deformity, pain, and inability to bear weight are present on physical exam. An injury radiograph is provided in Figure A, while radiographs taken immediately following the initial total hip arthroplasty are provided in Figures B and C. The patient denies any prodromal groin pain prior to his fall. Which of the following is the best treatment option?
Traction for 6 weeks followed by slow return to weight bearing
Open reduction and internal fixation
Revision to a long, cementless femoral stem
Revision to a long, cementless stem with strut allograft
Revision to a long, cemented stem Corrent answer: 2
The clinical presentation and radiograph are consistent with a Vancouver B1 periprosthetic femur fracture. The stem appears stable within the femur, and there is no evidence of subsidence with comparison to the initial post-THA radiographs. This fracture pattern is best treated with internal fixation.
Illustrations A and B are radiographs of this patient following fixation. Illustrations C and D show bone healing at 2 years following the fracture.
Duwelius et al report on 33 periprosthetic femur fractures. All fractures that demonstrated a stable stem at the time of surgery were treated with internal fixation, while those that were unstable were treated with a long, cementless revision femoral stem. At 2.5 years complications were minimal and the patients had regained their pre-fracture level of function.
The review article by Kelley outlines the evaluation, classification, and treatment of periprosthetic femur fractures reinforcing the importance of stem stability within the femur. Periprosthetic fractures around a hemiarthroplasty should be treated with the same algorithm. However, if the patient had antecedent groin pain, then conversion to a total hip arthroplasty should be considered to prevent continued groin pain.
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A 64-year-old male underwent the procedure shown in Figures A and B 7 weeks ago. He complains of difficulty with going down stairs. He reports no pain and denies constitutional symptoms. On examination the incision is well healed and no effusion is present. He is able to perform a straight leg raise with 5/5 strength. He lacks 2 degrees of terminal extension and has 80 degrees of active flexion. The knee is stable to varus and valgus stress testing at extension and mid flexion. His C-reactive protein and erythrocyte sedimentation rate are normal. What is the next most appropriate step in management?
Manipulation under anesthesia
Cortisone injection followed by physical therapy for quadriceps strengthening
Aspiration to evaluate for septic arthritis
Revise femoral component by downsizing A-P diameter
Revise tibial component and add 5 degrees of posterior tibial slope Corrent answer: 1
The history, physical examination, laboratory studies, and imaging are consistent with a total knee arthroplasty patient with arthrofibrosis. The next most appropriate option includes a manipulation under anesthesia to increase the patient's flexion.
Maloney presents Level 4 evidence discussing TKA postoperative arthrofibrosis. They report that manipulation under anesthesia was successful in improving flexion from an average of 67 degrees premanipulation to 111 degrees
postmanipulation.
Keating et al report Level 4 evidence of 113 patients that underwent manipulation following TKA. They found that 90% of the patients achieved improvement of ultimate knee flexion following manipulation. The average improvement in flexion from the measurement made before manipulation to that recorded at the five-year follow-up was 35 degrees.
OrthoCash 2020
Which of the following total hip arthroplasty patients appropriately meets the criteria for a surgical debridement with isolated femoral head and polyethylene liner exchange?
Prosthesis infection of 4 months duration
Prosthesis infection 8 weeks following implantation
Prosthesis infection 3 days following a systemic infection
Acetabular component loosening due to osteolysis
Vancouver Type A periprosthetic fracture.
Femoral head and polyethylene liner exchange is an appropriate treatment for the acutely infected arthroplasty. Acute infection has been defined as 3-6 weeks following surgery or following a systemic infection depending on the literature source. Subacute and chronic infections must be treated with a complete explant and exchange of all components. (One-stage or two-stage is controversial).
Salvati et al review the management of total hip arthroplasty infection. Most importantly, the pathogen must be isolated to direct antibiotic treatment. The acuity of the infection must also be recognized to direct surgical management.
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A 54-year-old woman is at physical therapy 3 months after a total knee arthroplasty when she feels a pop and develops increased pain in her knee. She continues therapy for another 3 months but reports weakness and frequent buckling. On exam, she has full passive extension but a 60 degree extensor lag. A lateral radiograph is shown in Figure A. What is the treatment of choice?
Reconstruction with a bone-tendon allograft
Repair augmented with hamstring autograft
Continued therapy and strengthening
Arthrodesis
Treatment with orthotics for support Corrent answer: 1
The patient has a chronic patellar tendon rupture following a TKA with marked extensor lag and patella alta on radiograph. A study by Barrack et al concluded that allograft reconstruction for the chronically-disrupted extensor mechanism after TKA could restore active extension and improve ambulatory function. In chronic cases, primary repair with or without local tissue augmentation have had disappointing results. Extensor mechanism injuries after TKA was reviewed by Parker et al. Patellar tendon ruptures are rare complications after TKA with an incidence reported <2.5%. Quadriceps tendon ruptures are even more rare with an incidence ~1%.
OrthoCash 2020
When compared to the standard medial parapatellar approach for revision total knee arthroplasties, the oblique rectus snip approach
showed impairment in which of the following post-operative outcomes?
range-of-motion
patient satisfaction
pain
WOMAC function score
no difference in outcomes Corrent answer: 5
Meek et al compared the rectus snip to a standard medial parapatellar approach for revision total knee arthroplasty. The WOMAC function, pain, stiffness and satisfaction scores demonstrated no statistical difference. They concluded that use of a rectus snip as an extensile procedure had no adverse effect on outcome.
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What is the range of pore size of cementless porous implants to allow for optimal bony ingrowth?
Less than 1 micron
50 to 400 microns
1,000 to 5,000 microns
10,000 to 50,000 microns
100,000 to 500,000 microns
The range of 50 to 400 microns is the optimal pore size for cementless porous implants to allow for optimal bony ingrowth.
Bobyn et al looked at the optimum pore size for fixation of porous surfaced metallic implants. Four different pore sizes were examined and placed in canine femurs for 4, 8, and 12 weeks and tested to measure the shear strength based on pore sizes. A pore size of 50 to 400 microns provided the maximum fixation strength in the shortest time period (8 weeks), implying maximal bony ingrowth.
Pilliar et al discussed two independent canine studies which showed that initial implant movement relative to host bone can result in attachment by a nonmineralized fibrous connective tissue layer. They state that implant movement of greater than 150 microns leads to fibrous ingrowth.
Jasty et al implanted porous-coated implants in the distal femoral metaphyses of twenty dogs and subjected them to zero, twenty, forty, or 150 micrometers of oscillatory motion. They found that that the implants that had been subjected to 150 micrometers of motion were surrounded by dense fibrous tissue.
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An active 73-year-old male presents with progressive pain and instability 15 years after undergoing a left total knee arthroplasty. He denies any recent trauma. A comprehensive workup for infection is negative. What is the most appropriate management of this patient?
Protected weight bearing for 6 weeks
Revision total knee arthroplasty
Bisphosphonate therapy
Routine follow-up in 1 year
Polyethylene liner exchange and bone grafting Corrent answer: 2
This patient has evidence of periarticular osteolysis and component loosening around a previous total knee arthroplasty. He is symptomatic and would benefit from revision total knee arthroplasty (TKA).
Osteolysis is one of the leading causes for late reoperation in patients who undergo TKA. Osteolysis occurs as the result of a foreign body response to particulate wear debris from the prosthetic joint. These particles consist of polyethylene, polymethylmethacrylate cement, and metal, all of which have been shown to elicit a distinct inflammatory response. Once the particles are generated from and around the implant, they become phagocytosed by macrophages and giant cells in the synovial or periprosthetic tissue. These cells, in turn, become activated and can directly or indirectly cause osteolysis. The femur is prone to osteolysis in the region of the femoral condyles and near the attachments of the collateral ligaments of the femur. Osteolysis around the tibia tends to occur along the periphery of the component or along the access channels to the cancellous bone.
Maloney & Rosenberg reviewed the management and outcome of periprosthetic osteolysis around hip and knee implants. They recommended surgical intervention for periprosthetic osteolysis around a TKA with (1) first-time presentation of advanced osteolysis in the presence of an identifiable cause of wear particle production or in the presence of associated bone loss that places the structural integrity of the bone or fixation of the components at risk, (2) bearing surface wear in the presence of impending wear-through or related mechanical symptoms, (3) progressive osteolysis in an active individual, and (4) symptoms of wear debris-related synovitis that are refractory to conservative treatment.
Griffin et al. evaluated the results of isolated polyethylene exchange for wear and/or osteolysis in 68 press-fit condylar TKAs from four centers. At a minimum of 24 months after polyethylene exchange surgery, there were 11 failures (16.2%).
Gupta et al. discuss the etiology, diagnosis, contributing factors, and management of osteolysis as it relates to TKAs. They recommend that if the patient is asymptomatic with minimal osteolysis on plain radiographs, regular
follow-up at 6 months to 1 year with medical management including calcium and bisphosphonates would be adequate. If the patient becomes symptomatic or the osteolysis is progressive, then early liner exchange with or without tibial baseplate exchange is considered.
Figure A & B are AP and lateral radiographs of periarticular osteolysis and component loosening. Illustration A is an AP and lateral radiograph of the revision TKA.
Incorrect Answers:
OrthoCash 2020
Which of the following statements is true regarding the thirty-year follow-up data obtained from the Charnley "low-friction" total hip arthroplasty?
Acetabular component failure was the least common reason for revision surgery
The number of revisions required for periprosthetic fractures was higher than that for deep infections
Acetabular component failure was a more common reason for revision than deep infection
Femoral component failure was a more common reason for revision than acetabular component failure
Deep infection was the most common reason for revision Corrent answer: 3
Failure of the acetabular component was the most common reason for revision at thirty-years for the Charnley "low-friction" total hip arthroplasty.
The Charnley low-friction torque arthroplasty was introduced in 1962. It consisted of a 22mm diameter metal head, a cemented femoral component, and a cemented ultra-high-molecular-weight polyethylene acetabular component. Overall, the results were very good at thirty years with only 11.8% requiring revision.
Charnley et al. in 1972 reported the 4-7 year results of 379 "low-friction" total hip arthroplasties. Overall, their short-term results were very good with only 2 loose acetabular components, 0 loose femoral components, and 1 late dislocation.
Wroblewski et al. in 2009 reported the 30 year follow-up of 110 patients who underwent the "low-friction" total hip arthroplasty. 13 hips (11.8%) had to be revised. Of these, 5 were for problems with the acetabular component, 4 were for loosening of both components, 2 were for deep infection, 1 was from a loose femoral component, and 1 was from a fractured femoral component.
Illustration A shows a radiograph after a Charnley low-friction total hip arthroplasty. Note the all poly-ethylene acetabular component. Illustration B shows the components used for the operation.
Incorrect Answers:
OrthoCash 2020
A 71 year old gentleman underwent left total hip arthroplasty 10 years ago. Eighteen months ago he began having hip and thigh pain. Over the past 6 weeks, the pain has become excruciating and he has been unable to ambulate, even with the aid of a walker. He has mild pain with passive internal and external rotation of the hip. He is unable to ambulate in the office. Laboratory values are notable for a WBC of 10,300, CRP of 0.2, and ESR of 13. A radiograph is provided in figure A. Which of the following is the best treatment option?
Radionuclide bone scan and MRI
Open reduction internal fixation with a cable plate and allograft strut
Revision arthroplasty with a fully coated cementless stem, cable wiring, and bone graft
Revision arthroplasty with a modular, tapered stem and bone grafting of the diaphyseal fixation
Revision arthroplasty with a total femur prosthesis Corrent answer: 3
The radiograph is consistent with a periprosthetic femur fracture, with a loose femoral stem, and a Paprosky IIIA femoral defect. This is best treated with a fully-coated cementless stem with metaphyseal onlay allograft.
Paprosky devised a classification for femoral bone loss following THA. The classification is as follows:
Type I: minimal metaphyseal bone loss and intact diaphyseal fixation Type II: extensive metaphyseal bone loss with intact diaphyseal fixation
Type IIIA: severe metaphyseal bone loss with greater than 4 cm of diaphyseal bone preservation for distal fixation.
Type IIIB: severe metaphyseal bone loss and less than 4 cm of diaphyseal
bone preservation for distal fixation
Type IV: extensive metaphyseal and diaphyseal bone loss.
Type IIIA may be treated with a fully coated stem. Type IIIB should consider a tapered, modular stem and/or bone grafting. Type IV likely needs a megaprosthesis. In this patient, given the preserved diaphyseal bone, revision arthroplasty with a fully coated femoral stem is the most appropriate treatment.
The Sporer article reviews a case series of patients undergoing revision hip arthroplasty for femoral bone loss. Type IIIB defects with a femoral canal less than 19 mm may be treated with a fully porous-coated stem. However, patients with Type IIIB defect and a cavernous canal greater than 19 mm or a Type IV defect may need a modular tapered stem or a bone grafting procedure.
The Paprosky article summarizes his classification of femoral bone loss in revision hip arthroplasty and provides an algorithm for treatment. Extensively porous-coated, diaphyseal filling femoral components showed excellent results in Paprosky IIIA defects.
Radiograph A shows a total hip arthroplasty with severe metaphyseal bone loss and a supportive diaphysis.
Incorrect Answers:
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A 74-year-old man presents with start-up thigh pain following a total hip replacement 10 years ago. Immediate post-operative radiograph is shown in Figure A. A current radiograph is shown in Figure B. Aspiration of the hip yields 1,005 white blood cells/ml. ESR is 12 (normal <40) and CRP is 0.4 (normal <1.2). Which of the following is the most appropriate management at this time?
Revision of the femoral component to an uncemented, long, fully porous-coated stem
Revision of the femoral component to a cemented stem
Revision of the femoral component to an allograft prosthetic composite
Revision of the femoral component to a proximal femoral replacement
Removal of prosthesis with insertion of antibiotic spacer Corrent answer: 1
The clinical presentation is consistent with symptomatic, aseptic femoral component loosening with no evidence of femoral bone defects. Appropriate management consists of revision of the femoral component to an uncemented, fully porous-coated stem.
Aseptic loosening remains one of the most common indications for revision total hip arthroplasty. After infection has been ruled-out, management is determined by gauging the patients symptoms, the rate of progression of the subsidence, and the amount of femoral bone loss. Uncemented revision femoral components have shown superior results to cemented revision femoral components in the long-term. In the setting of Paprosky Type I, II, and IIIA defects of the femur, revision to an uncemented, fully porous-coated stem is advised.
Moreland et al. review the results of 134 patients (137 hips) who underwent revision arthroplasty with an extensively porous-coated cobalt chrome femoral prosthesis. At a mean follow-up of 9.3 years, only 10 (7%) had to removed for any reason.
Sporer et al. review the results of fully porous-coated stems, impaction bone grafting, and modular tapered stems for Paprosky III and IV femoral defects. They found a high rate of failure with fully porous-coated stems when used in patients with Type IIIB defects >19mm and Type IV defects. They attribute these failures to instability and the inability to eliminate micromotion.
Figure A shows a cementless, metaphyseal engaging femoral component in good alignment. Figure B is a post-operative radiograph from 10 years later showing significant subsidence of the femoral component.
Incorrect Answers:
OrthoCash 2020
A 72-year old female who underwent an uncemented right total hip arthroplasty 2 years ago complains of right hip pain after a fall. Figure A shows her current radiograph. Which acetabular bone defect classification and treatment option best describes this scenario?
AAOS Type III - anti-protrusio cage with augmentation and a posterior column plate
AAOS Type IV - anti-protrusio cage with screw fixation and a posterior column plate
AAOS Type II - jumbo cup with augmentation and a posterior column plate
AAOS Type I - total acetabular allograft with a cemented cup
AAOS Type II - custom triflange acetabular component Corrent answer: 2
Figure A shows pelvic discontinuity, which is consistent with a AAOS Type IV defect. Acetabular antiprotrusio cage with screw fixation and a posterior column plate is a reasonable treatment option for this condition.
Acetabular bone loss following total hip arthroplasty is a challenging problem with a wide variety of treatment options available. The two most widely accepted classification systems are the AAOS and Paprosky classifications.
AAOS type I defects are segmental, type II are cavitary, type III are combined cavitary and segmental, type IV is discontinuity, and type V is arthrodesis. All of the treatment options listed above are described for pelvic discontinuity,
with none being described as superior.
DeBoer et al. describe the results of 28 patients with pelvic discontinuity treated with a custom-made porous-coated triflange acetabular prosthesis. 20 of these patients were followed for 10 years. There were no re-operations, 5 hip dislocations, 1 sciatic nerve palsy, and an average improvement in the Harris hip score from 41 to 80.
Paprosky et al. retrospectively reviewed patients who had an acetabular revision using a trabecular metal acetabular component for a pelvic discontinuity and compared these patients with a cohort of patients who had a previous reconstruction for a pelvic discontinuity using an acetabular cage.
They found a decreased incidence of pain and need for walking aids in those patients who had revision with a trabecular metal acetabular component.
Figure A shows pelvic discontinuity, likely acute given the lack of associated bony defects and recent fall. Illustration A details the AAOS hip acetabular defect classification and Illustration B is the often cited Paprosky classification.
Incorrect Answers:
OrthoCash 2020
Which of the following is indicative of type 1 collagen breakdown and can be utilized as a marker of bone turnover?
Increased urinary N-telopeptide
Increased urinary cAMP and phosphate
Increased urinary phosphoethanolamine
Increased urinary Bence Jones proteins
Increased serum bone sialoprotein Corrent answer: 1
Urinary N-telopeptide is a marker of increased bone turnover and is a breakdown product of Type 1 collagen.
Increased serum alkaline phosphatase level and increased urinary markers of N-telopeptide, hydroxylproline, deoxypyridinoline indicate high bone turnover and can be seen in metabolic bone diseases such as Paget's disease.
von Schewelov et al. reviewed 160 patients that underwent total hip replacements and examined their urine specimens to see if N-telopeptide levels correlated to periprosthetic osteolysis. They found that n-telopeptide levels were 1/3 higher in the patients that had evidence of osteolysis. N-
telopeptide release and annual wear were both associated with increased prevalence of osteolysis in the study.
Illustration A shows a radiograph of Pagets disease of the femur, an example of a condition where there is an increased level of N-telopeptide in the urine. Illustration B is a radiograph showing periprosthetic osteolysis, another condition where there is an increased level of N-telopeptide in the urine.
Incorrect Answers:
OrthoCash 2020
A 78-year-old female undergoes total hip arthroplasty through a minimally invasive surgical approach. During insertion of a metaphyseal fixation stem with a cementless press-fit technique, a crack in the calcar is identified. The stem is removed, two cable wires are passed around the calcar, and the same stem is reinserted. Which of the following statements is true?
The patient should be advised she is at greater risk of stem subsidence and early revision
Female sex is a risk factor for intraoperative calcar fracture
A better outcome would be expected if a long-stem diaphyseal fixation stem had been inserted after recognition of the calcar fracture
Cementless press-fit technique is not a risk factor for intraoperative fracture
Minimally invasive surgical approach is not a risk factor for intraoperative fracture
Of the statements listed, the only true statement is that female gender is a risk factor for intraoperative calcar fracture.
Calcar fractures are a documented complication of total hip arthroplasty. Studies have shown that successful outcomes can be achieved with stem removal, cable wiring of the calcar, and re-insertion of the primary stem.
Berend et al. reviewed a series of 58 total hip arthroplasties who sustained an intraoperative calcar fracture. All were treated with cable wiring of the calcar and stem insertion. The authors report no femoral component subsidence or failure otherwise at 16 year follow-up.
Graw et al. review a series of 46 revision THA's. Of the 46, fifteen underwent primary THA through a minimally invasive technique. The average length of time from primary THA to revision was 1.4 years for the minimally invasive group versus 14.7 years for the traditional exposure THA's. The authors conclude minimally invasive THA is a risk for early revision.
Davidson et al. review intraoperative periprosthetic hip fractures. "Risk factors for intraoperative periprosthetic fractures include the use of minimally invasive techniques; the use of press-fit cementless stems; revision operations, especially when a long cementless stem is used or when a short stem with impaction allografting is used; female sex; metabolic bone disease; bone diseases leading to altered morphology such as Paget disease; and technical errors at the time of the operation." The authors summarize techniques for treatment and postulate that long term outcome is unaffected when the intraoperative fracture is identified and treated appropriately.
Illustration A shows a nondisplaced calcar crack that was treated with a single Luque wire.
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OrthoCash 2020
Which of the following types of prosthetic designs, seen in figures A-E, has been shown to have a high rate of loosening secondary to overconstraint?
Figure C shows an example of an Walldius hinge total knee prosthesis. This design had a higher rate of aseptic loosening (up to 20%) secondary to a high-degree of constraint.
Constraint is defined as the effect of the elements of knee implant design that provides the stability needed to counteract forces about the knee after arthroplasty in the presence of a deficient soft-tissue envelope. While increasing component constraint increases the stability of the knee, it also transmits forces to the fixation and implant interfaces, which may lead to premature aseptic loosening. First-generation total knee hinged prostheses were highly constrained devices that only allowed a single axis of rotation.
Lombardi et al. provide an Instructional Course Lecture on the different prosthetic designs in total knee arthroplasty. They argue that PCL sacrificing implants are more appropriate than cruciate-retaining implants in rheumatoid arthritis, previous patellectomy, previous high tibial osteotomy or distal femoral osteotomy, and in cases where the PCL is absent secondary to trauma.
Morgan et al. discuss constraint in primary total knee arthroplasty. They argue that a hinge total knee arthroplasty should be reserved for severe instability, elderly patients with comminuted distal femur fractures, patients with
extensor-mechanism disruption and unstable knees, and those with substantial bone loss not amenable to augmentation.
Figure C shows an example of a Walldius hinged prosthesis.
Illustration A shows an intra-operative example of a constrained-hinged knee prosthesis. Note the link between the tibial and femoral components, which differentiates it from a constrained, non-hinged prosthesis.
Incorrect Answers: The following responses are incorrect as they all have lower rates of aseptic loosening than than varus/valgus constrained prostheses or hinged designs.
OrthoCash 2020
A 28-year-old football player sustains a contact knee injury while being tackled. On physical exam, he has a 1A Lachman, and a normal McMurray test. His posterior drawer, dial, and varus stress tests are normal. He has pain and 5mm opening on valgus stress at 30 degrees of flexion. Which statement is true regarding the injured structure?
Resides between layers 1 and 2 on medial side of knee
Inserts onto Gerdy's tubercle
Originates slightly posterior and proximal to the medial epicondyle
Courses intraarticularly thru hiatus of lateral meniscus
Has an attachment between adductor tubercle and medial epicondyle at Schöttle's point
The clinical presentation is consistent with an injury to the superficial medial collateral ligament (MCL) of the knee, which originates slightly posterior and proximal to the medial epicondyle.
The superficial portion of the MCL is the primary stabilizer to valgus stress at all angles, contributing 57% and 78% of medial stability at 5 degrees and 25 degrees of knee flexion, respectively. Anatomic studies have shown that the superficial MCL originates approximately 3.2 mm proximal and 4.8 mm posterior from the medial femoral epicondyle and inserts into the periosteum of the proximal tibia (deep to pes anserinus). The superficial MCL lies in layer 2, just deep to gracilis and semitendinosus tendons.
Wijdicks et al. (2009) looked at radiographic identification of the primary medial knee structures including the superficial MCL. On the lateral radiograph, they found that the attachment of the superficial MCL was an average of 6.0 mm from the medial epicondyle.
Wijdicks et al. (2010) reviewed injuries to the MCL and associated medial structures of the knee. They state that physical examination is the initial method of choice for the diagnosis of medial knee injuries through the application of a valgus load both at full knee extension and between 20 degrees and 30 degrees of knee flexion. Treatment of isolated grade-III injuries to the MCL, or such injuries combined with an anterior cruciate ligament tear, should start with nonoperative treatment of the MCL due to high rates of success with nonoperative treatment. If operative treatment is required, an anatomic repair or reconstruction is recommended.
Illustration A shows the femoral and tibial attachments of the superficial MCL. Illustration B shows the osseous landmarks and attachments of medial knee structures (AT, adductor tubercle; GT, gastrocnemius tubercle; ME, medial epicondyle; AMT, adductor magnus tubercle; MGT, medial gastrocnemius tendon; sMCL, superficial MCL; MPFL, medial patellofemoral ligament; POL, posterior oblique ligament).
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OrthoCash 2020
Which of the following best describes normal tibio-femoral joint kinematics ?
The femur undergoes internal rotation with knee flexion
The lateral femoral condyle remains stationary on the lateral tibia plateau during knee flexion from 0 to 120 degrees
The tibia undergoes internal rotation with knee flexion
The medial femoral condyle moves posteriorly on the medial tibial plateau during knee flexion from 0 to 120 degrees
Beyond 120 degrees of flexion only the lateral femoral condyle participates in femoral rollback
Tibia is subjected to internal rotation with knee flexion and the tibia EXternally rotates on femur as the knee EXtends.
The axis of rotation shifts posterior on the lateral condyle with knee flexion. Flexion and extension at the knee occur about a constantly changing center of rotation (polycentric rotation).
Freeman et al. conducted a biomechanical experiment and found that the medial femoral condyle does not move much from 0 to 120 degrees of flexion. They also found that the lateral femoral condyle and the contact area between that condyle and the tibia move posteriorly and tibial internal rotation occurs with knee flexion. They found that from 120 degrees to full flexion both condyles participate in "roll back".
Illustration A shows why the screw-home mechanism occurs. The medial tibial plateau is longer than the lateral tibial plateau, leading to external rotation of the tibia during extension as the femoral condyle rotates about the tibia. Video V shows an example of external tibial rotation during extension.
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OrthoCash 2020
Which of the following molecules is associated with macrophage induced osteolysis surrounding orthopaedic implants?
BMP-7
IL-10
SOX-9
Osteoprotegrin
IL-1
Of the options provided, IL-1 is most associated with macrophage induced osteolysis surrounding orthopaedic implants.
Macrophages initiate the inflammatory cascade associated with aseptic loosening of orthopaedic implants by secreting platelet-derived growth factor (PDGF), prostaglandin E2 (PGE2), TNF-alpha, IL-1, and IL-6.
Archibeck et al. state the primary cells involved in the process of periprosthetic loosening include the macrophage, osteoblast, fibroblast, and osteoclast. They report the chemical mediators that are responsible for the cellular interactions and effects on bone primarily include PGE2, TNF-alpha, IL-1, and IL-6.
Drees et al. discuss the molecular pathway of aseptic loosening of orthopedic implants. They describe the following steps: 1) Wear debris particles released at the cement–bone interface attract macrophages, which, in turn, are stimulated to produce proinflammatory mediators and proteolytic enzymes; 2) RANKL, TNF-alpha, IL-1, IL-6, IL-17, and M-CSF mediate the differentiation of myeloid precursor cells into multinucleated osteoclasts, which release cathepsin K and acid and cause resorption lacunae; 3) Mesenchymal cells (prosthesis-loosening fibroblasts) present at the bone surface contribute actively to bone resorption.
Illustration A shows the pathway described by Drees et al.
Incorrect Answers
OrthoCash 2020
Which of the following templates, seen in Figures A-E, will increase the offset while keeping the leg lengths the same?
If the total hip prosthesis is inserted according to the template in Figure E, the offset will be increased, while the leg lengths will remain unchanged.
Restoration of limb length is essential following total hip arthroplasty. The amount of limb-length change will be the vertical distance between the center of rotation of the femoral component and the center of rotation of the acetabular component. Thus, when the femoral center of rotation on templating is inferior to that of the acetabular component, the limb will be shortened. Restoring femoral offset is also important. If the center of rotation of the prosthetic head lies lateral to that of the cup on templating, the reconstruction will produce decreased offset.
Scheerlinck et al. present a stepwise approach to hip templating through four steps. Step 1 involves identifying landmarks, step 2 involves assessing the
quality of the radiograph, step 3 identifies mechanical references, and step 4 optimizes implant positioning.
Tripuraneni et al. discuss the common errors encountered when templating for total hip arthroplasty. They found the most common error was excessive limb lengthening and incomplete medialization of the acetabular component.
Della Valle et al. review hip templating. They stress the importance of preoperative planning, but also discuss the importance of tactile feedback during the surgery in choosing the correct implants.
Illustration A shows a table of how offset and leg lengths can be changed through positioning and selection of components.
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OrthoCash 2020
A 91-year-old male with a history of chronic leukemia and dementia falls and sustains the hip fracture shown in Figure A. He undergoes a hemiarthroplasty through a posterior approach. A postoperative radiograph is shown in Figure B. Three weeks later he dislocates the hip arising from the toilet seat. A radiograph is shown in Figure C. The patient undergoes a closed reduction and is placed in a hip abduction brace. Post reduction radiograph is shown in Figure D. One month later he returns to clinic complaining of pain and inability to bear weight through the leg. A radiograph of the hip is included in Figure E. Which of the following factors has MOST likely contributed to the instability of the hip hemiarthroplasty?
Femoral stem subsidence
Increased offset
Inadequate femoral stem neck length
Patient's dementia status
Patient's gender
The most likely contributing factor to the instability include the patient's dementia.
Sultan et al use a basic science model to show liners with elevated rims placed in the posterior superior quadrant allow greater range of motion to dislocation than standard liners. They also show that 32 mm heads have greater range of motion to dislocation compared to 28 mm heads.
Morrey et al reviewed a series of 19,680 primary THA's for late dislocation (first dislocation greater than 5 years after surgery). 165 hips (0.8%) had a late dislocation. Factors associated with late dislocation include implant malposition, neurologic decline, trauma, and polyethylene wear.
Figure A shows a femoral neck fracture. Figures B and D show a hip hemiarthroplasty in appropriate position. Figure C and E show a dislocated hip hemiarthroplasty
This patient's instability was managed by converting the hip hemiarthroplasty to a total hip arthroplasty with a constrained liner as shown in illustration A. No further instability episodes occurred following the revision.
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OrthoCash 2020
What surgeon is credited for designing the prosthesis seen in Figure A?
John Charnley
San Baw
Sir Harry Platt
Austin T. Moore
Charles Frederick Thackray Corrent answer: 4
Figure A shows an example of an Austin-Moore hemiarthroplasty.
Austin Moore developed the most popular long-stemmed prosthesis in the 1950s. The Austin-Moore prosthesis was a large, uncemented femoral stem that didn't use polyethylene. The Austin-Moore prosthesis had fenestrations for self-locking which later became the impetus for biological fixation. These implants were originally used to treat hip fractures and certain cases of degenerative arthritis. Later, in the 1960s, John Charnley introduced the idea of replacing the eroded acetabulum with a Teflon component.
Moore et al. describe the first metallic hip replacement surgery in 1940. The patient had a proximal femoral resection for a giant cell tumor. The original prosthesis he designed was a proximal femoral replacement, with a large fixed head, made of the Cobalt-Chrome alloy Vitallium.
Charnley et al. discuss the long-term results (up to 7 years) of the "low-friction" total hip arthroplasty. Infection rate was 3.8%, late mechanical failure was 1.3%, and most patients had excellent pain relief.
Figure A shows a radiograph of an Austin-Moore hemiarthroplasty. Illustration A shows an Austin-Moore prosthesis. Illustration B shows an example of Charnley's "low-friction" total hip arthroplasty, with a stainless steel head and
stem and a polyethylene acetabular component.
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OrthoCash 2020
A 45-year-old man has had the gait disturbance shown in Video A ever since a total hip replacement two years ago. Since then he has undergone physical therapy and nerve exploration without any clinical improvement. Extensive AFO bracing was attempted but was not tolerated by the patient. A recent ankle radiograph is shown in Figure
A. The Silfverskiold test reveals dorsiflexion of 20 degrees with knee flexion, and 10 degrees with full knee extension. The results of muscle
testing using a Cybex dynamometer are shown in Figure B. What is the most appropriate next step in in treatment.
Ankle arthrodesis in 30 degrees of dorsiflexion
Posterior tibial tendon transfer to the lateral cuneiform through the interosseous membrane
Split anterior tibial tendon transfer to the cuboid
Peroneus longus transfer to the navicular and gastrocnemius recession
Flexor hallucis transfer to the navicular and tendo Achilles lengthening (TAL) Corrent answer: 2
The clinical presentation is consistent with a sciatic neuropathy following THA in a patient that does not tolerate AFO bracing. Posterior tibialis tendon transfer is the next most appropriate step in treatment.
Sciatic neuropathy, especially involving the common peroneal branch, is a known complication of total hip arthroplasty. Typically a patient is adequately treated with an AFO. In some clinical situations an AFO is not tolerated, and a tendon transfer is required. The posterior tibial tendon is the most commonly used donor muscle. A tendon transfer is feasible only if the tendon possesses at least 4/5 power. There is a loss of 1 MRC grade of strength following transfer.
Rodriguez et al. retrospectively reviewed the results of the Bridle procedure 10 patients (11 feet) with a foot drop. The Bridle procedure consists of a posterior tibial tendon transfer through the interosseous membrane to the dorsum of the foot with a dual anastomosis to the tendon of the anterior tibial and a rerouted peroneus longus in front of the lateral malleolus. In their study all 11 feet were brace-free at final followup at 6.68 years.
Yeap et al. retrospectively reviewed 12 patients who were treated with tibialis posterior tendon transfer for footdrop. They found good/excellent patient satisfaction in 10/12 patients. Additionally they found favorable variables for a good outcome include common peroneal nerve palsy over sciatic nerve palsy, male gender less than 30 years of age.
Figure V is a Video that shows a right footdrop with high steppage gait. Figure A shows normal ankle radiographs. Figure B shows the results of dynamometer testing described above. Illustration A shows the Bridle procedure. The left panel shows how the tibialis posterior tendon (C) is tunneled through the interosseous membrane and through a slit in the tibialis anterior tendon (A) and inserted into the second cuneiform. The peroneus longus (B) is also transected and the distal stump is routed anterior the lateral malleolus and anastomosed to the tibialis anterior and tibialis posterior (at the slit where it passes through the tibialis anterior). The right panel shows retrieval of the tibialis posterior tendon above the ankle and passage through a window in the interosseous membrane.
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OrthoCash 2020
Which of the following variables is associated with elevated serum metal ion levels following metal-on-metal hip resurfacing arthroplasty?
Smaller implant diameter
Smaller acetabular cup abduction angle
Higher postoperative functional scores
Severe preoperative osteoarthritis
Anteversion of acetabular cup between 10 and 20 degrees Corrent answer: 1
Smaller femoral head diameter is associated with elevated serum metal ion levels with metal-on-metal hip resurfacing arthroplasty.
Metal-on-metal (MOM) hip resurfacing arthroplasty has the advantage of better wear properties (lower linear wear rate and volume of particles) than metal on polyethylene. However, elevated serum metal ion levels is one of the negatives which has received much attention recently. Studies have found smaller implant diameter and acetabular cup abduction angle >55 degrees are associated with elevated serum metal ion levels. Cup abduction angles of greater than 55 degrees lead to a more vertical cup and edge loading.
Desy et al. found that smaller implant diameter, larger cup inclination, and lower postoperative functional scores are associated with increased cobalt and chromium levels after metal-on-metal hip resurfacing. They found that severity of preoperative osteoarthritis, acetabular version, femoral stem-shaft and valgus angle, and anterior orientation of the femoral component had no effect on the circulating metal ion levels.
DeHaan et al. obtained serum ion levels in 214 MOM resurfacing patients at least 1 year following surgery. They found that cup abduction angles greater than 55 degrees combined with smaller component sizes led to edge loading and elevated ion levels.
Illustration A shows how a metal-on-metal prosthesis design allows you to have a larger femoral head as opposed to a metal on polyethylene design (example in THA). Illustrations B and C show a photo of a metal on metal resurfacing implant and radiographs of the implant.
Incorrect Answers:
2: Elevated cup abduction angle leads to elevated serum metal ions.
3: Higher postoperative functional scores have not been shown to increase serum metal ions.
4: Severity of pre-operative arthritis has not been associated with increased serum metal ions.
5: Anteversion of the acetabular cup between 10 and 20 degrees has not been shown to increase serum metal ions.
OrthoCash 2020
Which of the following intra-operative steps would put a patient at risk for lateral patellar maltracking during total knee arthroplasty (TKA)?
External rotation of the femoral component
Medial placement of the patellar component
Internal rotation of the tibial component
Lateral translation of the femoral component
Superior placement of the patellar component Corrent answer: 3
Internal rotation of the tibial component increases the Q angle and causes an increased risk of lateral patellar maltracking.
During TKA, useful techniques that help prevent patellar maltracking include: external rotation of the femoral and tibial components, lateral translation of the femoral component, and medial placement of the patellar component.
In an instructional course lecture, McPherson looked at patellar tracking in primary TKA. He reviews the concept of patellofemoral maltracking, the importance of the Q angle, mechanical alignment, femoral component rotation, tibial component positioning, patellar component positioning, patellar height, and patellar resurfacing as factors related to patellofemoral tracking.
Bengs et al. studied the effect of patellar thickness on intra-operative knee flexion and patellar tracking during PCL retaining TKAs. Using 2mm increments (2-8 mm), passive knee flexion was recorded and gross mechanics of patellofemoral tracking were assessed. On average, passive knee flexion decreased 3 degrees for every 2-mm increment of patellar thickness, there was no gross effect on patellar subluxation or tilt.
Illustration A shows how internal rotation of the tibial component would increase the Q angle, and thus be more likely to have lateral patellar maltracking.
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OrthoCash 2020
A patient undergoes a primary total hip arthroplasty with a highly cross-linked ultra-high molecular weight (UHMW) polyethylene acetabular liner. In comparison to a 28mm femoral head, a 32mm femoral head will provide which of the following?
Increased risk of dislocation
Decreased range of motion
Decreased risk of osteolysis
Equivalent wear rate of the polyethylene acetabular liner
Increased risk of periprosthetic fracture Corrent answer: 4
Wear rates of highly cross-linked UHMW polyethylene liners are independent of femoral head size between 22 and 46 mm in diameter.
While the wear rates of old polyethylene liners increased with increasing femoral head size, wear rates of the new highly cross-linked UHMW polyethylene liners have shown to be independent of head size. This is extremely advantageous, as increasing the femoral head size improves range of motion and increases jump distance, thereby decreasing dislocation rates.
Geller et al. report a prospective series of 42 patients that had a total hip arthroplasty with a highly cross-linked UHMW polyethylene liner and a femoral head >32 mm in diameter. After three years, there were no cases of osteolysis or failure due to aseptic loosening.
Muratoglu et al. studied the wear rates of several polyethylene liners with varying femoral head sizes. In the highly cross-linked UHMW polyethylene group, wear rates were independent of femoral head size.
Illustration A shows how increasing femoral head size increases the jump distance required for dislocation.
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OrthoCash 2020
A 56-year-old male undergoes an uncomplicated revision total knee arthroplasty. Post-operatively, he is noted to have a foot drop that has persisted despite conservative management including bracing and physical therapy. At two months, the patient undergoes external neurolysis with no improvement in function. At 18 months follow-up, he demonstrates passive ankle dorsiflexion 10 degrees past neutral, complete absence of active dorsiflexion, and 5/5 inversion strength. Which of the following is the most appropriate treatment at this time?
Continue Ankle-foot orthosis (AFO) and physical therapy
Repeat neurolysis with possible nerve repair
Peroneus tertius transfer
Peroneus tertius transfer with achilles tendon lengthening
Posterior tibial tendon transfer to dorsum of foot Corrent answer: 5
A peroneal nerve palsy (with intact posterior tibial tendon strength) that has failed conservative management is best treated with a posterior tibial tendon transfer to the dorsum of the foot.
Peroneal nerve palsy following total knee arthroplasty or knee dislocation is a potentially devastating complication that may lead to lack of active dorsiflexion and a compensatory steppage gait pattern. Initial management consists of an ankle-foot orthosis (AFO) and physical therapy to maintain passive ankle dorsiflexion. If nerve function fails to return during the course of conservative management and the patient demonstrates intact posterior tibialis muscle strength, posterior tibial tendon transfer to the dorsum of the foot has been shown to improve functional outcomes and eliminate the need for continued bracing. The most common procedure for posterior tibial tendon transfer involves transferring the tendon through the interosseous membrane and inserting the tendon onto the lateral cuneiform.
Prahinski et al. review the results of 10 patients at 61 months' follow-up who underwent the Bridle transfer (posterior tibialis transfer through interosseous membrane and peroneus longus to front of lateral malleolus) for peroneal nerve palsies. They conclude the Bridle procedure is adequate for return to function in low-demand individuals, but may fail over time in those who return to vigorous physical activity.
Rodriguez et al. review the results of 10 patients who underwent the Bridle procedure for peroneal nerve palsy in an attempt to balance their foot and
provide dorsiflexion. All of their patients were brace free at an average followup of 6.8 years.
Video V shows the clinical results 10 weeks after transfer of the tibialis posterior tendon for a drop foot.
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OrthoCash 2020
An 82-year-old male sustains a ground level fall and sustains the injury shown in Figure A. Which of the following treatment methods is most appropriate for treating this injury?
Closed reduction and functional bracing
Open reduction and fixation with a plate with screws and cerclage cables
Open reduction and fixation with a cortical allograft strut and cerclage cables
Revision hip arthroplasty with bridging of the fracture with a plate with screws and cerclage cables
Total femoral replacement Corrent answer: 2
This fracture pattern is typically referred to as an interprosthetic fracture; this is increasing in incidence due to increasing numbers of patients with ipsilateral hip and knee arthroplasty.
The first reference by Ricci et al reviewed 50 Vancouver B1 fractures treated with a lateral plate without allograft. They reported 100% union rate at a mean of 12 weeks and only one deep infection. Nearly 75% of patients were able to return to their baseline ambulatory status.
The second reference by Ricci et al reviewed 59 patients with periprosthetic femur fractures (THA or TKA) treated with ORIF without bone grafting. They report 58/59 patients healed after the index procedure and 49/59 were able to
return to their baseline functional level.
The reference by Fulkerson et al reported on 24 patients who underwent LISS plate fixation of periprosthetic femur fractures around well-fixed THA or TKA. They reported union in 21/24 at a mean of 6.2 months, with only one failure of fixation. They note that percutaneous fixation is effective although technically demanding.
Figure A shows an interprosthetic femur fracture between well-fixed hip and knee arthroplasties.
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OrthoCash 2020
A 62-year-old female undergoes an uncomplicated primary total knee replacement. Her knee range-of-motion pre-operatively was 0-135 degrees of flexion. Which of the following is true regarding the immediate post-operative use of a continuous passive motion machine in this patient?
Reduced risk of venous thromboembolism
No long-term difference in ROM compared to patients not using CPM
Increased passive knee flexion at 6 months
Increased length of hospitalization
Decreased risk of surgical site infection Corrent answer: 2
The use of a continuous passive motion (CPM) machine following primary total knee arthroplasty has not shown any long-term benefits with regards to
range-of-motion.
The concept of CPM was created by Dr. Robert Salter in 1970 and is currently being used in select patients following total knee replacement, ACL
reconstruction, and a variety of other procedures about the knee. In theory, the CPM allows for movement of synovial fluid to allow for better diffusion of nutrients into damaged cartilage. Additionally, it has been thought to prevent fibrous scar tissue formation about the joint. While some studies have shown increased early active knee flexion at two weeks, these results were not significant at later follow-up. Controversy exists as to whether these small benefits offset the patient inconvenience and expense of the CPM.
Lotke et al. expolre the effects of tourniquets and CPM machines in 121 patients undergoing total knee arthroplasty. They found that immediate CPM combined with intraoperative release of the tourniquet increased blood loss. The patients with the least amount of blood loss had the tourniquet released after a compressive dressing was applied and in whom CPM was delayed for a few days.
Bourne et al. perform a meta-analysis on the effectiveness of CPM following total knee arthroplasty. They found the CPM plus physical therapy increased active knee flexion more than physical therapy alone 2 weeks after surgery with a decreased length of hospitalization. The benefits of increased active knee flexion were not maintained after 2 weeks.
Illustration A shows an example of a CPM machine. Incorrect Answers:
from available RCTs to conclude that CPM reduces the risk of venous thromboembolism following total knee arthroplasty.
OrthoCash 2020
A 67-year-old female complains of anterior groin pain one year following a primary, uncemented total hip arthroplasty. The pain is exacerbated when she tries to climb stairs or get up from a seated position. She denies any recent fevers or chills. On physical exam, the pain is reproduced with resisted seated hip flexion. Laboratory analysis, including WBC, ESR, and CRP are within normal limits. Radiographs reveal that the components are appropriately positioned without evidence of loosening or fracture. Which of the following is the most appropriate at this time?
Revision of the acetabular component
Image-guided diagnostic injection of lidocaine into the iliopsoas tendon sheath
Hip aspiration
Bone scan
Conservative management including activity modifications, NSAIDs, and physical therapy
The patients history and physical exam are most consistent with iliopsoas impingement. This diagnosis is most reliably confirmed with a diagnostic/therapeutic injection of steroid or lidocaine into the iliopsoas tendon sheath.
Iliopsoas tendinitis following total hip arthroplasty is an uncommon but treatable cause of anterior groin pain following total hip arthroplasty. The true incidence is unknown, but some studies suggest it is the cause of a painful
total hip arthroplasty in up to 4.3% of cases. Potential causes include a malpositioned acetabular component, excessively long screws, limb length discrepancy, or retained cement. Diagnosis is confirmed by injecting the iliopsoas tendon sheath. Most cases are refractory to conservative management and often require surgical intervention. In the case of a malpositioned acetabular component, revision to a more agreeable position is advisable. In the absence of a defined etiology, iliopsoas tendon release offers adequate pain relief and return to function in a majority of patients.
Lachiewicz et al. review anterior iliopsoas impingement after total hip arthroplasty. They state that most patients with iliopsoas impingement often require surgical treatment, with options including iliopsoas tendon release or resection, removal of protruding cement or screws, and acetabular revision.
O' Sullivan et al. review 16 cases of iliopsoas impingement following primary total hip arthroplasty. Only 1 of the cases was secondary to a malpositioned acetabular component, with the other 15 cases being attributed to altered anatomy of the iliopsoas tendon as a result of the surgery. These 15 patients underwent iliopsoas tendon release, and all had improvement in pain and function following surgery.
Nunley et al. review 27 patients with a presumed diagnosis of iliopsoas impingement following total hip arthroplasty who were treated with fluoroscopically guided injections of the iliopsoas bursa. The average modified Harris hip score in the patients who underwent injection improved, however, 30% required an additional injection and 22% underwent surgical release for continued pain.
Illustration A shows a flouroscopic injection into the iliopsoas tendon sheath. Incorrect Answers:
revision of the acetabular component without a confirmed diagnosis is not advisable.
OrthoCash 2020
A 72-year-old female underwent an uncomplicated primary total hip replacement 18 years ago. Current radiographs reveal the abnormality shown in Figure A. Which of the following cell types (Figures B-F) is implicated in the process shown by the arrow?
Figure F shows an example of a macrophage, which is a key mediator in the osteolytic process shown in Figure A.
Osteolysis is the end result of a biologic process that begins when the number of wear particles following a joint replacement overwhelms the body's capacity to clear them from circulation. The residual particles are phagocytosed by macrophages, which then release an array of cytokines and other inflammatory mediators that recruit osteoclasts to resorb bone.
Gupta et al. review osteolysis following total knee arthroplasty, including etiology, diagnosis, and management. Amongst other things, they highlight the importance of design changes to minimize osteolysis including highly cross-linked polyethylene and alternative bearing materials.
Ren et al. performed a study where they implanted a hollow titanium rod into the distal femur and pumped polyethylene particles into the femoral bone marrow cavity. They found that macrophage migration occurs at a systemic (rather than local) level, and that the recruitment of macrophages led to localized osteolysis.
Holt et al. review the biology behind aseptic osteolysis. Specifically, they highlight the importance of the RANK-RANKL-OPG pathway as the final
common pathway to osteoclastogenesis, and the possibility of eliminating osteolysis by blocking this pathway. AMG-162 is a human immunoglobulin monoclonal antibody with a high affinity for RANKL, and studies are currently being undertaken to determine its safety and efficacy.
Figure F shows an example of a macrophage, which may be identified by its irregular shape and phagocytic inclusions. Illustration A shows the pathway by which marcrophages induce osteolysis following a joint replacement surgery.
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OrthoCash 2020
A 45-year-old with a history of sickle cell anemia reports hip pain for the past 6 months. A radiograph of the affected hip is shown in Figure A. Which of the following interventions has been shown to have the best outcomes in this patient population?
Observation
Bisphosphonates
Hemi-arthroplasty
Uncemented metal on polyethylene total hip arthroplasty
Cemented metal on polyethylene total hip arthroplasty Corrent answer: 4
Based on the radiographs and current literature, the best intervention is an uncemented metal on polyethylene total hip arthroplasty.
Avascular necrosis of the hip may be idiopathic in nature or associated with alcoholism, steroid use, or as in this case, sickle cell anemia. The Ficat staging system is used to classify avascular necrosis of the hip. Changes in treatment are driven by development of symptoms as well as the development of subchondral bone collapse (Ficat Stage 3). In those with with femoral head flattening (Ficat Stage 4) and acetabular degenerative changes (Ficat Stage 5), total hip replacement has good to excellent outcomes.
Mont et al. review surgical options for avascular necrosis of the hip. Head preserving procedures are generally reserved for those patients where the femoral head has not collapsed. Collapse and associated arthritis warrant utilization of arthroplasty procedures.
Mont et al. conducted a systematic review to better delineate the symptomatic progression of asymptomatic avascular necrosis of the hip. They found that patients with sickle cell disease have the highest rate of progression to
collapse. Medium sized, laterally located lesions were associated with a higher frequency of collapse and joint preserving procedures are recommended for these.
Figure A shows radiograph of a patient with avascular necrosis; note the femoral head flattening, narrowing of the joint space and acetabular sclerosis.
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OrthoCash 2020
The function of which of the following structures is to resist internal tibial rotation with the knee in full extension?
Anterior cruciate ligament
Iliotibial band
Popliteus tendon
Popliteofibular ligament
Posterior oblique ligament Corrent answer: 5
The primary function of the posterior oblique ligament is to resist internal tibial rotation with the knee in full extension.
The posterior oblique ligament is a structure within the posteromedial corner of the knee, with attachments proximally to the adductor tubercle of the femur and distally to the tibia/posterior knee capsule. The posterior oblique ligament and posteromedial capsule play a significant role in the prevention of additional posterior tibial translation in the knee in the setting of posterior cruciate ligament injury. They also act to resist internal tibial rotation with the knee in full extension.
Griffith et al. reports that the posterior oblique ligament provides significant resistance to valgus and internal rotation forces with knee extension. They used a cadaver model and demonstrated that the superficial MCL resists valgus and external rotation forces more than the posterior oblique ligament, while the posterior oblique ligament is more involved in resisting internal rotation.
Tibor et al. reviews the anatomy of the posteromedial corner of the knee. They report that failing to recognize injury to these structures may cause failure of cruciate ligament reconstruction surgery, and that reconstruction or repair of the posteromedial corner may be indicated in the face of multiple ligament injuries.
Illustration A shows the posteromedial corner of the knee, including the posterior oblique ligament.
Incorrect answers:
4: These structures are not primary restraints to internal tibial rotation in full extension.
OrthoCash 2020
Increasing the porosity of a cement spacer for an infected total knee arthroplasty leads to which of the following?
Increased strength
Increased elution of antibiotics
Increased cement density
Improved cement-prosthesis bonding
Increased reinfection rate Corrent answer: 2
Elution of an antibiotic is increased with increased porosity of a cement spacer. This porosity increase can be obtained with hand mixing and avoiding the use of a vacuum-type mixing device.
Joseph et al. reviews antibiotic-impregnated cement in hip arthroplasty. They note that use of this cement in one- or two-stage revisions has lowered reinfection rates, with the spacers acting to reduce dead space while stabilizing the joint.
Cui et al. reviews antibiotic impregnated cement for TKA and THA. They report that use of greater than 2 grams of antibiotic per 40 gram unit of cement weakens the cement and that use of two antibiotics in conjunction may potentially increase elution.
The reference by Stevens et al compared Simplex and Palacos bone cement in regards to elution in a TKA mold model. They found that initial as well as weekly (9 weeks total) elution rates were greater in the Palacos spacers than the Simplex models. They recommend use of the Palacos cement in TKA model to target antimicrobial delivery while limiting the potential for systemic antibiotic-related toxicity.
Illustrations A and B show an antibiotic spacer in a two-stage revision TKA. Illustration C shows a PROSTALAC in a two-stage revision THA.
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OrthoCash 2020
A 65-year-old patient was treated with an open reduction/internal fixation for a left femoral neck fracture sustained 25 years ago. Five years ago he developed hip pain and was converted to a left hip hemiarthroplasty. He presents with complaints of groin pain for the past 6 weeks. A recent radiograph is shown in Figure A. The patient’s physical exam is limited secondary to pain. Serum laboratory values are WBC-8.0, ESR-20, CRP-0.5. A synovial fluid aspirate of the hip demonstrates < 500 cells (60% PMN). What is the most likely cause of this patient's symptoms?
Acetabular protrusio
Infected hip hemiarthroplasty
Lumbar radiculopathy
Impingement of the hip hemiarthroplasty
Iliopsoas tendinitis
Based on the history, radiographs, and laboratory values, the patient has developed failure of his hip hemiarthroplasty. At this point in time he warrants a conversion to a total hip arthroplasty.
Avascular necrosis (AVN) of the femoral head after traumatic injury to the femoral neck occurs at an incidence of 10-45%. Although the risk increases with failure to anatomically reduce the fractue, it can still occur in non displaced settings. Treatment of avascular necrosis in older patients includes hip hemiarthroplasty or a total hip replacement. With the former, development of acetabular protrusio can contribute to groin symptoms. Functional outcomes have been reported to be higher in those receiving total hip replacement for AVN of the femoral head.
Lee et al. prospectively compared the use of bipolar hip hemiarthroplasty versus total hip arthroplasty for advanced stages of AVN of the femoral head (Ficat Stage 3). Total hip scores were most improved in the total hip arthroplasty group. Migration of the outer head in the hemiarthroplasty group was seen in 23% of patients. They recommend use of a total hip arthroplasty in patients with Ficat Stage 3 AVN of the femoral head
Ito et al. evaluated the outcomes of patients who underwent bipolar hemiarthroplasties for femoral head avascular necrosis. They found that proximal migration and acetabular degeneration were risk factors for groin symptoms. They also found that outcomes were inferior to patients who had undergone total hip arthroplasty for AVN of the femoral head. They recommend use of total hip arthroplasty in advanced osteonecrosis of the femoral head
Diwanji et al. evaluated outcomes of patients who underwent a conversion from a bipolar hip arthroplasty to total hip arthroplasty in 25 patients. Thirteen (52%) patients were revised to THA because of acetabular erosions. Follow up was completed for an average of 7.2 years. At final follow-up, they found improvement of the Harris Hip Scores and improvement of the pain portion of the WOMAC index. They recommend use of total hip replacement as an option to salvage failed bipolar hip hemiarthroplasty
Figure A shows the radiograph of a hip hemiarthroplasty where acetabular protrusion has developed.
Incorrect Answers
OrthoCash 2020
A 38-year-old female patient presents to your office three years after a hip resurfacing. She complains of worsening left hip discomfort for the last 6 months. Her ESR is 12 (normal 0-20) and CRP is 1.2 (0-5). A radiograph and axial and coronal MRI scans are shown in Figures A, B, and C. What is the most likely diagnosis?
Infection
Type I Hypersensitivity reaction
Femoral neck fracture
Prosthesis Loosening
Pseudotumor
The clinical presentation is consistent with a young woman who has developed a symptomatic pseudotumor following hip resurfacing. Her hip discomfort is related to a mass that has developed around the left hip.
Pseudotumors, also referred to as Aseptic Lymphocyte-Dominated Vascular-Associated Lesions (ALVAL), are sterile inflammatory lesions that most commonly occur from metal-on-metal articulations. They occur at an incidence of 0-39% with metal-on-metal resurfacing hip components. The exact mechanishm of formation is unclear, however excessive wear is considered the initiating process, leading to the release of microscopic metal particles. These are cytotoxic to macrophages once phagozytised, leading to necrosis within the lesions and the development of semi-solid or fluid-filled masses around the implant. Lymphocytes are thought to be responsible for the tissue reaction.
Patients often do not complain of pain, but present with a mass around the hip that causes discomfort.
Hart et al. performed a case-control study comparing patients with well-functioning metal-on-metal hip resurfacing to those who have painful prostheses. They found no significant difference between the painfree and painful groups with MRI diagnosed pseudtumors (61% vs. 57%). They concluded that the presence of a pseudotumor should not automatically necessitate revision surgery.
Daniel et al. reviewed the current concepts surrounding pseudotumor. Risk factors associated with pseudotumor formation and failure are female gender, age under 40, hip dysplasia, metal hypersensitivity, and small components.
Larger components have been found to decrease the risk of failure.
Figure A is an AP pelvis radiograph of a patient following a left hip resurfacing surgery. Figures B and C are axial and coronal MR images demonstrating a large pseudotumor around the left hip resurfacing. Illustrations A and B identify the large pseudotumor as outlined in red.
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OrthoCash 2020
After total hip arthroplasty (THA) for osteoarthritis a patient is unable to dorsiflex her ankle or extend her great toe. She is treated conservatively with an orthosis and after 3 months on physical therapy she ambulates with a "slapping gait." What is the most appropriate next treatment option?
MRI of her spine
Ankle Fusion
Continue Ankle-Foot Orthosis
Revision total hip arthroplasty
Sural nerve grafting Corrent answer: 3
The patient has suffered from a peroneal nerve injury most likely from errant retractor placement during the hip replacement resulting in a foot drop. The most appropriate next treatment is an ankle-foot orthosis.
The ankle joint of an ankle-foot orthoses (AFOs) should restrict plantarflexion to prevent foot drop during the swing phase. In a patient who can not actively dorsiflex the foot the AFO keeps the foot in a neutral position during gait allowing for uninterrupted swing during ambulation.
Park et al reviewed common peroneal nerve injury after THA. Only one-half of the patients in the study who developed common peroneal nerve palsy following total hip arthroplasty recovered fully. The mean time to recovery was approximately one year for partial peroneal palsy and one and one-half years for complete palsy. Obesity adversely influenced the nerve recovery. Thus, at 3 months, the nerve should continue to be monitored and the use of an AFO would assist in ambulation.
Yokoyama et al. developed an AFO with an oil damper to adjust the plantarflexion resistive moment as excessive plantarflexion resistance will cause excessive knee flexion during the stance phase. They found the AFO with the oil damper achieved sufficient plantarflexion of the ankle and mild flexion of the knee by adjusting a proper plantarflexion resistive moment during initial stance phase, and provided a more comfortable gait than did the traditional AFOs.
Illustration A shows the location of the sciatic nerve relative to the short external rotators when performing a posterior approach to the hip.
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OrthoCash 2020
Which of the following statements is true about racial disparities in total joint arthroplasty?
The rate of surgical intervention for African American males is lower than white or Hispanic males
The rate of surgical intervention for Hispanics is higher than that for whites
The rate of surgical intervention for white males is lower than for African American males
There is no difference in the rate of surgical intervention between whites, Hispanics, or African Americans
The rate of surgical intervention is equal for Hispanic and white males Corrent answer: 1
The rate of surgical intervention for African American males is lower than either white or Hispanic males.
Numerous studies have shown clear racial disparities in the utilization of total joint arthroplasty for the treatment of osteoarthritis. African American and Hispanic patients undergo total joint arthroplasty at a rate much lower than
white patients, even in areas where insurance coverage is more equitable. Currently, little is known about the reasons for such disparities.
Skinner et al. reviewed the Medicare claims between 1998 through 2000 to determine any racial or ethnic disparities amongst patients undergoing total knee arthroplasty. Amongst other things, they showed that the arthroplasty rates for black men were consistently lower than white men in nearly every region.
Nelson reviews health disparities in orthopaedic surgery. Amongst other things, they discuss how African American patients and white patients perceive the same pain and functional limitations for similar radiographic disease. Thus, ethnic differences in perception of symptoms cannot explan the racial disparities noted in total joint arthroplasty.
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OrthoCash 2020
A 65-year-old man presents with aseptic loosening 3 years after total knee arthroplasty. The surgeon reviews radiographs of his knee and takes him to the operating room for revision total knee arthroplasty. During surgery, the exposure technique shown in Figure A is used. Which of the following radiographs (Figures B-F) has the greatest likelihood of needing this exposure technique?
Figure A shows a tibial tubercle osteotomy (TTO). Patella baja (Figure D) is an indication for a TTO.
In revision total knee arthroplasty (TKA), surgical exposure should be extensile. Different exposure techniques have been described (see below). Patella baja may indicate that there is patellar tendon contracture. In this instance, a TTO can be used to prevent inadvertent patellar tendon avulsion which is difficult to repair and may lead to loss of function. Further, proximal transfer of the osteotomized tibial tubercle may be used to correct patella baja, bearing in mind that excessive superior translation alters the mechanics of the knee by making the quadriceps less efficient.
Younger et al. reviewed surgical approaches in revision TKA. They include quadriceps snip, patellar turndown, TTO, femoral peel, medial epicondylar osteotomy and quadriceps myocutaneous approach.
Mendes et al. reviewed the results of TTO in revision TKA. They advocate TTO for cases where the patellar cannot be retracted laterally with knee in 90deg of flexion. Complications include nonunion, tubercle fragment fracture and displacement, and tibial metaphyseal fracture (at the level of the distal cut of the osteotomy).
Della Valle et al. reviewed surgical approaches for revision TKA. They advocate TTO because repair is stronger than patellar turndown, there is less tension on the tibial tubercle in flexion than on the quadriceps tendon, and where multiple operations are required (as multiple VY approaches lead to excessive scar, making the approach difficult) or where stemmed tibial components need to be removed.
Illustration A shows tibial tubercle osteotomy hinged on a lateral periosteal flap. Illustration B shows quadriceps snip. Illustration C shows patellar turndown. Illustration D shows medial epicondyle osteotomy.
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situation.
OrthoCash 2020
Which of the following is the most common intraoperative complication in a patient with sickle cell disease undergoing a total hip arthroplasty?
Periprosthetic fracture distal to the implant
Iatrogenic fracture causing pelvic discontinuity
Perforation of the femoral canal
Cardiac arrest from fat embolization to lungs
Injury to the sciatic nerve Corrent answer: 3
Perforation of the femoral canal during preparation of the femur is not an uncommon complication, with rates ranging from 4.9-18.2%.
While total hip arthroplasty is extremely effective for pain relief in patients with osteonecrosis of the hip secondary to sickle cell disease, the procedure carries a higher rate of complications compared with non-sickle cell disease patients. Particular attention should be given to the preparation of the femur as femoral medullary widening from chronic marrow hyperplasia adjacent to patchy areas of dense sclerosis can make preparation of the canal difficult.
Some surgeons prefer to ream over a guide-wire to avoid perforation.
Jeong et al. reviewed total hip arthroplasty in patients with sickle cell disease. Amongst other things, they discuss the difficulties associated with preparation of the femoral canal, quoting a perforation rate between 4.9-18.2%. They also state there are no prospective studies comparing cementless to cemented THA, but retrospective data has shown promising results with cementless components.
Hernigou et al. retrospectively reviewed 244 patients with sickle cell disease that underwent cemented total hip arthroplasty. They had a 3% infection rate, a relatively low rate of revision for aseptic loosening, and a 27% rate of medical complications. Overall, they viewed their results as favorable.
Illustration A shows a patient with bilateral AVN secondary to sickle cell disease. Note the areas of patchy dense sclerosis in the metaphyseal region of the proximal femur.
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to be more common in this patient population. The rate of post-operative hematoma causing sciatic nerve dysfunction may be higher in this patient population.
OrthoCash 2020
A 63-year-old patient presents with periprosthetic joint infection 3 years after primary total knee arthroplasty. A radiograph of her knee is seen in Figure A. She undergoes 2-stage revision total knee arthroplasty. Radiographs taken at the time of explantation are seen in Figure B. An articulating antibiotic spacer is placed. Two months later, she is deemed to be free of infection and is taken to the operating room for the second stage operation. Intraoperatively, it is noted that the collaterals are intact and the previous tibial tubercle osteotomy had healed. What is the most appropriate surgical strategy at this point?
Address epiphyseal defects with impaction particulate bone grafting
Address metaphyseal defects with structural allograft and uncemented, unstemmed implants
Address metaphyseal defects with uncemented, porous metaphyseal
sleeves and uncemented, stemmed implants
Address diaphyseal defects with porous metal cones and uncemented, stemmed implants
Address diaphyseal defects with cemented stemmed implants Corrent answer: 3
This patient has massive metaphyseal defects following resection of primary TKA implants. Metaphyseal defects may be addressed with uncemented, porous metaphyseal sleeves and uncemented stemmed implants.
In revision settings, metaphyseal bone is often deficient. The Anderson Orthopaedic Research Institute classification (AORI) is most commonly used to classify defects. Stemmed implants are necessary to divert stress away from deficient metaphyseal defects to structurally sound cortical bone. These may be cemented or uncemented.
Haidukewych et al. reviewed metaphyseal fixation in revision TKA. For large defects, they advocate structural allograft, porous metal cones, and stepped metaphyseal sleeves.
Bush et al. reviewed managing bone loss in TKA. They cautioned that joint line elevation, distal femoral bone loss, and femoral prosthesis downsizing leads to flexion instability. They advocate cement filling for Type I defects, modular augments for Type 2, impaction grafting for Type 1 or 3, structural allograft for Types 2 and 3, metaphyseal filling or megaprosthesis for Type 3, including porous metal implants.
Figure A shows an infected primary TKA with a stemmed tibial component with medial augments. This suggests that the revision implant will require at least a stemmed, augmented component. Figure B shows massive metaphyseal defects (AORI Type 2) at the time of explantation. Illustration A comprises postop images of osseointegrated metaphyseal sleeves and stemmed implants. Illustration B depicts the AORI classification (see Review Topic for detailed description). Images courtesy of Haidukewych et al (Ref 1).
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OrthoCash 2020
During templating for a total hip arthroplasty, placing the femoral head center of rotation directly superior to the center of rotation of the acetabular component will have which of the following effects?
Increase offset
Decrease limb length
Decrease offset
Increase limb length
No change in length or offset Corrent answer: 4
Placing the femoral head center of rotation directly superior (above) the acetabular center of rotation will lengthen the limb without changing offset.
When templating the femoral component for a total hip arthroplasty, it is imperative to restore limb length and offset. To change limb length, the femoral component center of rotation (COR) can be adjusted in a superior or inferior direction. If the femoral component COR is superior to the acetabular component COR, the limb will be lengthened (as in the example above).
Conversely, if the femoral component COR is inferior to the acetabular component COR, the hip will be shortened. A change in offset will be determined by the medial/lateral relationship between the acetabular and femoral components. In the example above, the COR of the femoral component is directly above the COR of the acetabular component. In this situation, there is no change in offset.
Merle et al. performed a retrospective cohort study to identify differences in femoral offset as measured on an AP pelvis radiograph, AP hip radiograph, and a CT scan. They found that femoral offset is significantly underestimated on AP radiographs of the pelvis. In contrast, AP radiographs of the hip are much more accurate in representing true offset.
Della Valle et al. review the importance of preoperative planning prior to total hip arthroplasty. While they mention that templating can be very accurate, determination of stem and cup size should also be determined by tactile feedback during broaching and reaming.
Illustration A shows the femoral head COR inferior to the acetabular COR. This will result in a decreased limb length.
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OrthoCash 2020
Which of the following intra-operative errors most commonly leads to patellar maltracking during a total knee arthroplasty?
Using the gap balancing technique instead of measured resection technique
Internal rotation of the femoral component
External rotation of the tibial component
Lateralization of the femoral prosthesis
Overresection of the patella
Internal rotation of the femoral component increases the Q-angle and will increase the likelihood of patellar maltracking.
Patellar maltracking is one of the most common complications following a total knee arthroplasty. Any alteration that results in increased lateral retinaculum tension or an increased Q-angle may lead to patellofemoral instability.
Common causes include internal rotation of the femoral or tibial components, medialization of the femoral component, and placement of the patellar prosthesis on the lateral border of the patella. If a patient presents with postoperative maltracking and component rotation is thought to be the cause, a CT scan is the diagnostic study of choice.
Rhoads et al. analyze 7 cadaveric specimens to define the kinematics of the intact knee and to evaluate the effects of prosthetic replacement on those kinematics. Amongst other things, they showed that lateralization of the femoral component improved patellar tracking and prevented dislocation.
Malo et al. review patellar maltracking following a total knee replacement. They discuss the importance of externally rotating the femoral component on the femur relative to the posterior articular condyles to establish a rectangular and balanced flexion gap and to accommodate central patellar tracking.
Illustration A shows how an internally rotated femoral component displaces the patella medially. The blue line is a straight line upwards from the tibial tubercle, and the green line represents a line from the tibial tubercle to the center of the patella. The difference between the blue and green lines in the internally rotated prosthesis is the amount the patella has displaced medially. If you deviate the patella medially, this increases the Q-angle and could lead to patellar maltracking in a total knee replacement.
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OrthoCash 2020
When performing a total knee arthroplasty on a 60-year-old female patient, a surgeon chooses not to resurface the patella. Instead, he performs a patelloplasty by excising the marginal osteophytes and reshaping the patella. All of the following statements comparing the results of patelloplasty to patella resurfacing are true EXCEPT:
There is no difference in relative risk of anterior knee pain.
There is no difference in relative risk for revision surgery involving the tibial and femoral components.
There is an increased risk that she will need secondary resurfacing.
No difference in rates of patellar avascular necrosis or patellar tendon injury.
Total knee arthroplasty improved function regardless of whether the patella was resurfaced.
In TKA with an unresurfaced patella, there is an increased risk of anterior knee pain and secondary resurfacing.
Surgeons can choose to resurface or not resurface all patellae, or selectively resurface patellae. In unresurfaced patellae, they may perform a patelloplasty (excise marginal osteophytes and reshape the patella). Unresurfaced patellae have increased risk of anterior knee pain requiring secondary resurfacing.
Indications for resurfacing include inflammatory arthritis, patella maltracking, patellofemoral osteoarthritis as the main indication for TKA.
Meneghini et al. reviewed the literature on patellar resurfacing. Prospective, randomized studies show conflicting results with regards to satisfaction rates between groups. Meta-analyses show increased risk of re-operation and anterior knee pain in the unresurfaced group.
Parvizi et al. performed meta-analysis on 1519 knees. They found there was
(1) lower relative risk of re-operation (resurfaced group), (2) lower relative risk of anterior knee pain (resurfaced group), (3) increased rate of secondary resurfacing (unresurfaced group), (4) no difference in patient satisfaction, (5) TKA improved function regardless of whether the patella was resurfaced, (6) no difference in complications.
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OrthoCash 2020
A 55-year-old patient returns for followup 2 years after a left ceramic-on-ceramic total hip arthroplasty. He has no pain or symptoms of instability. The video in Figure V shows him ascending stairs. All of the following factors may contribute to this phenomenon EXCEPT
Impingement
Edge-loading
Loss of fluid film lubrication.
Third-body particles
Subclinical infection
The clinical presentation is consistent for prosthesis squeaking following a THA. Squeaking is multifactorial and may include impingement, edge-loading, loss of fluid film lubrication, and third-body particles. Subclinical infection does not play a role in squeaking.
Squeaking is defined as a high-pitched, audible sound occurring during movement of the hip. In ceramic-on-ceramic (COC) hips, the incidence is 0.5-10%. The incidence of revision because of squeaking is 0.5%. Squeaking is less common in metal-on-metal bearing surfaces (4-5%).
Chevilotte et al. reviewed COC bearing surfaces. They found that without lubrication, squeaking occurred with normal gait, high load, stripe wear, material transfer, edge wear and microfractures. In contrast, with lubrication, squeaking only occurred with material transfer.
Finkbone et al. reviewed COC total hip arthroplasty in patients <20-years-old after 52-month (average) follow-up. They found that survival rate was 96% with 1 revision for a loose acetabular component (failure of bone ingrowth). They found no cases of osteolysis, which can theoretically occur because of stripe wear, or femoral neck-on-liner impingement.
Walter et al. reviewed squeaking hips. They found that this phenomenon is associated with (1) walking, bending, rising (cyclical gait movements or extreme flexion), (2) maloriented acetabular components, (3) impingement,
(4) third-body particles, (5) edge loading, (6) loss of fluid film lubrication and
(7) thin, flexible (titanium) stem.
The video shows squeaking of a left total hip arthroplasty during hip extension from a flexed position. This is consistent with edge loading. Illustration A shows superior edge loading in the walking position. The arrow represents the loading force. The superolateral edge of the liner is in contact with the superior surface of the head. The dark area (area of edge loading) is anteverted with respect to a line of latitude (dark line) on the head. Illustration B shows posterior edge loading in the bending position. The arrow represents the loading force. The posterior edge of the liner is in contact with the superior surface of the head. The shaded area represents the area of edge loading and the dark stripe indicates wear on the femoral head.
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OrthoCash 2020
Figure A shows the image of a 72-year-old male who sustained a fall from standing. Past medical history is significant for hypertension. He was a community ambulator without the use of a cane or walker prior to the fall. During the operation, he is noted to have a well-fixed acetabular component without significant wear of his polyethylene liner, but his femoral component is easily extractable. Which of the following correctly pairs his Vancouver classification and appropriate surgical intervention?
Vancouver A, Revision of femoral component to cemented stem with fixation of the fracture
Vancouver B1, Revision of femoral component to cemented stem with fixation of the fracture
Vanvouver B1, Revision of femoral component to a long, porous-coated, cementless stem with fixation of the fracture
Vancouver B2, Fixation of the fracture with a plate and cerclage wires
Vancouver B2, Revision of femoral component to a long, porous-coated, cementless stem with fixation of the fracture
Figure A shows a Vancouver B fracture around the femoral prosthesis. Because the prosthesis is noted to be loose during the operation, it is classified as a Vancouver B2 fracture. The most appropriate operation would be revision of the femoral component to a long, porous-coated, cementless stem in addition to fixation of fracture with a plate and cerclage wires.
According to the Vancouver classification, a type B2 fracture occurs around or just distal to a loose femoral stem with adequate proximal bone. Revision of the femoral component is necessary, with uncemented stems showing superior clinical results to cemented stems in most studies. The revision prosthesis should bypass the distal fracture by 2 cortical widths.
Corten et al. reviewed thirty-one patients with Vancouver B2 fractures that
were treated with a long cemented stem with additional allograft or plate fixation. At 46 months, none of the implants had to be revised, but it should be noted that 43% of the patients died within the first year.
Mulay et al. reviewed 24 patients with Vancouver B2 and B3 fractures managed with a cementless, tapered, fluted, and distally fixed stem. 91% of fractures united uneventfully. Complications included dislocations (5), nonunions (2), and infection (1).
Springer et al. review 116 patients with Vanvouver B fractures treated with revision of the femoral component. The uncemented, extensively porous-coated implants had the highest likelihood of stable fixation and were not associated with any nonunions.
Illustration A reviews the Vancouver classification for periprosthetic femur fractures. Illustration B shows a post-operative radiograph following a Vancouver B2 fracture. In this case, a trochanteric plate with cerclage wires was used to fix the fracture. A long-stemmed, porous-coated, cementless femoral prosthesis was used for the revision.
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OrthoCash 2020
A 56-year-old male undergoes revision of his right hip arthroplasty for acute pain and radiographs suggestive of ceramic femoral head fracture. At the time of the revision, multiple fragments of the ceramic femoral head were seen in the joint and soft tissues. The components were noted to be in good position. He was copiously irrigated and the ceramic head was exchanged with a metallic femoral head. 12 months later, the patient presents with insidious onset right groin pain. Radiographs show no gross abnormalities without signs of loosening. Which of the following is the most likely cause of the patient's pain?
Periprosthetic infection
Massive third body wear
Pseudotumor formation
Soft tissue metallosis
Iliopsoas tendonitis
The most likely cause of the patient's pain is massive third body wear caused by retained ceramic fragments.
Cermamic femoral head fractures create many fragments that are difficult to extract at the time of revision surgery. During the revision surgery, it is imperative to remove all fragments that can be visualized. Despite a thorough debridement, microscopic fragments will still remain. These particles may cause pain through the creation of an inflammatory response in the tissues.
Exchange of the femoral head should be performed with another ceramic head, as opposed to a metal head. If a metal head is used, abrasive wear will ensue as the microscopic fragments will scratch the femoral head due to differences in hardness.
Traina et al. describe their experiences with revision of ceramic components. Most commonly, fractures of ceramic components occur as a result of trauma, dislocation, or errors in operative technique. These include head-neck taper mismatch, impacting the ceramic head with too much force, debris, and intraoperative damage to the metal neck taper.
Hannouche et al. review ceramics in total hip replacement. They state that if the ceramic is properly manufactured, it can be a highly effective, low-wear solution for the young patient in need of a total hip replacement.
Illustration A shows the typical ceramic femoral head used for a total hip arthroplasty. Illustration B shows a fractured ceramic head in many pieces.
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OrthoCash 2020
Figure A and B are radiographs of a 77-year-old patient presenting with right hip and upper thigh pain for the past 3 months. He is an avid golfer and plans to travel south for 6 months on a golf tour. He denies fever, chills or weight loss. His past medical history includes hypertension and a right total hip replacement 15 years ago. Physical examination reveals minimal pain with range of motion. ESR=10 (normal range 0-20) and CRP=4 (normal range 0-10). He does not want any further surgery. The patient is at the highest risk of which complication with non-operative care?
Infection
Pseudotumour formation
Periprosthetic femoral fracture
Periprosthetic acetabular fracture
Dislocation
This patient has presented with significant osteolysis and aseptic loosening of his femoral THA component. If untreated, he is at an increased risk of a periprosthetic femur fracture.
Indications for surgery for periprosthetic osteolysis include: pathological fracture, impending pathological fracture, symptomatic THA with evidence of osteolysis, and extensive osteolysis that would compromise revision surgery in the future. The goal of surgery is to remove the loose component, repair/bypass/replace bone deficiency, and obtain stable component fixation.
Robbins et al. reviewed the causes of pain in THA. They report that hip pain can originate from the implant, soft tissue, or bone. The use of laboratory tests (e.g. ESR/CRP), radiographic and fluoroscopic imaging, hip aspirate, contrast arthrography and local anesthetic injections can help to determine the origin of pain.
Ollivere et al. report that the most frequent cause of failure after total hip replacement in all reported arthroplasty registries is periprosthetic osteolysis. Osteolysis occurs with the activation of macrophages and a complex biological cascade that results in bone loss.
Hirakawa et al. analyzed the circumstances around retrieved failed THA components. They showed that cement mantle defects, noncircumferential porous coatings, and screw holes are risk factors for osteolysis. They conclude by saying that the formation of a granulomatous tissue that ultimately invades the bone-implant interface is the final step in the pathogenesis of aseptic loosening.
Figure A and B show AP and lateral views of a right THA. The femoral stem shows gross loosening in all zones. Subsidence is obvious with a high-riding greater trochanter. The lateral cement mantle is fractured. There is endosteal erosion distally with the tip of the stem showing radiographic toggle.
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osteolysis, but it remains well fixed. Acetabular fractures are less likely when there is minimal osteolysis.
OrthoCash 2020
A 60-year-old woman undergoes a total knee arthroplasty for end-stage osteoarthritis. Preoperative knee range of motion is 5 to 100 degrees. Postoperatively, she experiences reduced range of motion. She is scheduled to undergo manipulation under anesthesia. In which of the following scenarios is this procedure best indicated?
Knee range of motion 0 to 60 degrees at 2 months postoperatively
Knee range of motion 0 to 60 degrees at 8 months postoperatively
Knee range of motion 30 to 120 degrees at 2 months postoperatively
Knee range of motion 30 to 120 degrees at 8 months postoperatively
Knee range of motion 30 to 120 degrees at 2 weeks postoperatively
Manipulation under anesthesia (MUA) can achieve the greatest gains in flexion when performed for patients with less than 90 degrees of flexion within the first three months.
There are many risk factors for postoperative stiffness, the most important being preoperative stiffness. MUA is indicated when flexion is less than 90 degrees. Flexion gains are generally greater when applied early (6-12 weeks postoperatively) rather than late (>12 weeks). In cases with late-presenting stiffness (>12wks), MUA may still be attempted. Failed MUA is addressed with arthroscopic or open adhesiolysis +/- MUA, quadricepsplasty, or component revision.
Namba et al. compared the results of early (<90 days) vs late (>90 days) MUA. They found that: (1) knee flexion improved a mean of 32 deg and 20 deg after early and late MUA respectively, (2) extension improved in the early MUA group, but not the late MUA group, and (3) pain improved after early but not late MUA. Despite early MUA being more desirable, the authors state that patients with limited flexion at 6-12 months may still benefit from late MUA.
Keating et al. assessed the outcomes of MUA in 113 knees at a mean of 10 weeks after surgery. They found that (1) 90% of patients achieved
improvement in knee flexion of 35 degrees at 5 year followup, (2) there was no difference in flexion gains between early (<12 weeks) and late (>12 weeks) MUA and (3) patients treated with MUA had better pain control than those without MUA. They concluded that manipulation can result in significant and lasting improvement in knee flexion.
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A 62-year-old man is scheduled for a total knee arthroplasty. In his pre-operative office visit, he asks questions about different tibial components. You tell him that compared with the tibial component shown in Figure A, the tibial component shown in Figure B:
Is less expensive
Has greater durability
Has greater instability because of its monobloc nature
Provides improved short-term functional status, but no difference in long term functional status
Is associated with fewer adverse events because of easier implantation Corrent answer: 1
Figure B shows an all-polyethylene tibia (APT) component, which is $470 to
$1650 less expensive than metal-backed tibia (MBT) designs.
It was traditionally thought that modular MBT may have lower survivorship (compared to APT) because of locking mechanism dysfunction, breakage,
backside wear, and osteolysis. However, many studies now show the two to be comparable, with the only difference being that APT are less expensive.
Voight et al. performed a systematic review comparing APT and MBT. They found that the former was cheaper. There was no difference in adverse events, durability (need for revision or radiographic failure) at 2, 10, and 15 years, and functional status at 2, 8, and 10 years.
Toman et al. compared APT and MBT retrospectively. They found that APT implants perform as well as MBT implants in patients with BMI <37.5. There were 4 tibial implant failures in the MBT group in patients BMI >40.
Dalury et al. examined APT performance in obese patients (125 knees) after a minimum of 7 years. There were no implant failures. There were 5 nonprogressive tibial radiolucencies and 1 case of nonprogressive osteolysis.
Figure A shows a cemented metal-backed tibia component. Figure B shows a cemented all-polyethylene tibia component.
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Figures A and B show pre- and post-operative radiographs of a sedentary 75-year-old female who underwent surgery on her left hip. Based on the radiographic findings, what was the most likely indication for revision surgery?
Left acetabular fracture
Left acetabular cup osteolysis
Left femoral stem osteolysis
Left hip instability
Left femoral stem valgus malalignment Corrent answer: 4
Figure A shows a left total hip arthroplasty with eccentric polyethylene wear. Figure B shows that her left hip was revised to a constrained acetabular liner, most likely a result of recurrent instability.
Revision strategies for hip instability are typically directed at correcting the underlying cause of instability. For example, instability most commonly occurs as a result of poor implant design, positioning or loosening, or the loss of soft-tissue function or tensioning. Operative strategies are designed to correct these etiologies by repositioning or exchanging components, integrating modular designs and improving soft tissue tensioning, etc. Constrained acetabular liners are often used in conjunction with these modalities to address the problem of recurrent instability relating to soft tissue deficiency and dysfunction in the affected hip.
Alberton et al. retrospectively reviewed 1548 revision arthroplasties for the incidence of dislocation. They found the overall dislocation rate to be 7.8%. Factors contributing to increased dislocations were found to be trochanteric non-unions, femoral heads <28mm in diameter and extensive soft-tissue dissection. Protective factors were modular acetabular components or liners, larger femoral heads >28mm and re-establishing abductor tensioning.
Paterno et al. retrospectively reviewed 438 primary and 181 revision total hip arthroplasties for patient factors contributing to dislocation. They found an overall dislocation rate of 6%. 23% of patients with a history of excessive intake of alcoholic beverages (more than six ounces a day) had at least one dislocation. There was no relationship between the variables of age, gender, obesity, or preoperative diagnosis and the incidence of dislocation.
Figure A shows bilateral primary cementless, nonconstrained total hip replacements. The left hip shows eccentric femoral head placement within the acetabulum indicative of eccentric polyethylene wear. Figure B shows the conversion to a constrained, dual-mobility, polyethylene liner. The overall metal component position appears satisfactory.
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A 62-year-old woman is brought to the emergency room after falling down a flight of stairs. Prior to her fall, she had no knee pain and was a community ambulator without assistance. Intraoperatively,
it is determined that the implants are well-fixed. What is the best next treatment step to optimize her quality of life?
Closed reduction and long leg casting at 20 degrees of flexion for 6 weeks, followed by hinged-knee brace for 6 weeks.
Open reduction and internal fixation with a distal femoral locking plate
Open reduction and internal fixation with a condylar buttress plate
Distal femoral replacement arthroplasty
Closed reduction and fixation with an antegrade intramedullary nail Corrent answer: 2
This patient has a displaced far-distal supracondylar fracture around a stable TKA femoral component. Locked plating is the best option for management of this fracture.
Surgical fixation of periprosthetic fractures around a stable femoral component is challenging. Locked plating allows for multiple angle-stable fixation points around stems and lugs and does not depend on TKA design or quality of distal bone stock for fixation. Su Type I fractures may be treated with retrograde or antegrade intramedullary nailing. Type II fractures require retrograde intramedullary nailing or fixed-angle plating. Type III fractures require fixation with a fixed-angle device or revision arthroplasty when bone stock is poor.
Ricci et al. evaluated indirect reduction and locked lateral plating of Vancouver B1 THA fractures without allograft struts. They found that all fractures healed with satisfactory alignment and without implant loosening at an average of 12 weeks. They recommend this technique for stable Vancouver B1 fractures.
Streubel et al. examined the outcomes of locked plating in treatment of extreme distal periprosthetic supracondylar fractures located proximal to the flange (Su Types I and II) compared with fractures distal to the flange (Su Type III, see Illustration B). They found no difference in delayed union, nonunion, infection and failure rates between the 2 groups.
Figure A shows a Su Type III periprosthetic fracture around a TKA femoral component. Illustration A shows fixation of the same fracture with a distal femur locking plate. Illustration B shows the Su classification of fractures around the femoral component (Type I, proximal to the femoral component; Type II, starting at the anterior flange and extending proximally; Type III, fracture line distal to the anterior flange).
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Which of the following fractures would most likely require revision arthroplasty with a long-stemmed, uncemented prosthesis?
Figure B shows a Vancouver B2 periprosthetic femur fracture with an unstable femoral stem that requires revision arthroplasty with a long-stemmed prosthesis.
The Vancouver classification for periprosthetic femur fractures can help guide treatment of these challenging problems. Vancouver A fractures involve the greater and lesser trochanter and can be initially managed with non-operative measures. Vancouver B fractures occur around the stem and are broken down into B1 (stable prosthesis), B2 (unstable prosthesis) and B3 (poor proximal bone quality) fractures. B1 fractures may be treated with internal fixation, B2 fractures require a revision arthroplasty, and B3 fractures often require more advanced reconstruction with a proximal femoral replacement versus revision with a distally fixed prosthesis. Vancouver C fractures occur distal to the stem and require internal fixation.
Springer et al. reviewed 118 patients who underwent revision arthroplasty for Vancouver B2 periprosthetic fractures. They had a 90% survival rate at 5-years and a 79.2% survival rate at 10-years. The most common reasons for revision were loosening, infection, and non-union.
Illustration A shows the Vancouver classification of periprosthetic fractures about the femur.
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A 65-year-old female sustains a periprosthetic supracondylar femur fracture proximal to a well-fixed implant. She undergoes direct reduction and locked plating with a titanium distal femoral locking plate via an extensile lateral approach. At 9 months post-operatively, weightbearing is at 50% and is painful. Examination reveals mild swelling and warmth around the distal incision. Erythrocyte sedimentation rate and C-reactive protein are normal. Radiographs taken 9 months post-operatively are shown in Figure A. Which of the following may have increased the risk of this complication?
Neglecting to add topical rhBMP-2 on a carrier-scaffold
Neglecting to use lag screws and cerclage cables
Locked plating instead of locked antegrade nailing
Use of a titanium plate instead of a stainless steel plate
Use of an extensile lateral approach instead of a submuscular approach Corrent answer: 5
A submuscular approach has been shown to have less risk of nonunion than an extensile lateral approach. There is less disruption of soft tissue attachments and devitalization of fracture fragments with the submuscular approach.
The risks for periprosthetic fractures include notching, knee stiffness, osteoporosis, poor mobility and falls. The risk is higher in females and after revision surgery. The treatment of periprosthetic supracondylar fractures depends on the location of the fracture, fixation of the implant, and bone stock.
Hoffman et al. retrospectively reviewed 36 periprosthetic supracondylar femur fractures treated with locked plating. They found that submuscular plating had reduced nonunion risk compared to an extensive lateral approach. They recommend indirect reduction and submuscular plating to reduce the incidence of nonunion.
Hou et al. retrospectively reviewed 53 fractures fixed with retrograde nailing
(18) and locked plating (34). They found no difference in blood loss, time to union, operating time and hospital stay. They believe locked plating can
provide the same favorable results as retrograde nailing and recommend this technique for most patients and prosthetic designs.
Figure A shows nonunion and surrounding osteopenia after locked plating of a periprosthetic supracondylar fracture. Illustration A shows management of these fractures according to the Su classification.
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Immediately following a total hip arthroplasty (THA), a healthy 55-year-old patient is unable to dorsiflex her ankle or extend her great toe. After 4 weeks she continues to ambulate with a "slapping gait." Examination reveals passive ankle joint dorsiflexion to 10 degrees. What is the most appropriate next treatment option?
MRI of her spine and pelvis
Revision total hip arthroplasty
Ankle-foot orthosis
Posterior tibial tendon transfer to navicular bone
Neurology consult
This patient is presenting with foot drop after a THA for hip dysplasia (Crowe 4). The most appropriate treatment at this stage would be providing her with an ankle foot orthosis (AFO) for mobility.
Sciatic nerve injury after THA is an uncommon and difficult situation to manage. Patients with DDH that have undergone a large limb-lengthening procedure are at a greater risk due to the significant stretch of the sciatic nerve. Intra-operative procedures that have been shown to prevent this outcome include good pre-operative planning, limb lengthening <3 cm, subtrochanteric osteotomy, intra-operative wake-up test, and downsizing implant components if presenting with deficits peri-operatively. An ankle-foot orthosis may be used for foot drop when surgery is not warranted or during neurologic recovery.
Prahinski et al. reviewed the Bridle transfer for paresis of the anterior and lateral compartment musculature. Indications for the procedure include no neurological recovery for at least 18 months after injury or 18 months after the most recent attempt at exploration or repair of the nerve.
Electrodiagnostic changes must indicate permanent damage. In addition, there must be good passive range of motion, with at least 90° of dorsiflexion.
Edwards et al. reported on twenty-three peroneal and sciatic nerve palsies that occurred in patients following total hip arthroplasty. They showed that peroneal nerve palsy occurred with an average lengthening of 2.7 cm (1.9 cm-3.7 cm) in comparison with 4.4 cm (4.0 cm-5.1 cm) for sciatic nerve palsies.
Figure A and B show pre- and post-operative images of a patient with severe hip dysplasia treated with primary total hip arthroplasty.
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A 60-year-old male with history of renal transplantation and previous intravenous drug abuse undergoes total knee arthroplasty. Two years later, he begins to have mild knee pain and low-grade swelling that persists for 10 months before he finally comes to the emergency room. Examination reveals no fever. Range of motion is 5 to 70 degrees. Erythrocyte sedimentation rate is 22mm/h, and C-reactive protein is 0.8mg/L. Knee aspiration reveals 12,000/mm3 nucleated cells with 76% neutrophils. Gram stain is negative and aerobic and anaerobic cultures are negative after 4 days in culture. His symptoms do not resolve after 5 days of empiric intravenous antibiotics and he is taken to the operating room for arthroscopic irrigation and debridement. Operative synovial tissue cultures are shown in Figure A. What is the best next step?
Cessation of immunosuppressant medication, lifelong antimycobacterial suppression
Open irrigation and debridement, implant retention and lifelong antifungal suppression
Open irrigation and debridement, resection arthroplasty, antimycobacterial drugs for 6 to 12 months
Open irrigation and debridement, single-stage exchange, antifungal drugs for 6 to 12 months
Open irrigation and debridement, two-stage exchange, antifungal drugs for 6 to 12 months
This patient has a fungal prosthetic joint infection (PJI) with Candida albicans. Optimal treatment involves resection arthroplasty, delayed reimplantation
arthroplasty, and antifungal drugs for 6-12 months.
Fungal PJI are uncommon. Risk factors include immune suppression and systemic illness e.g. diabetes and chronic renal failure. Candida species is usually the causative organism. The infection is usually indolent and systemic symptoms (e.g. fever) may be absent. ESR and CRP may be only minimally elevated. Two-stage exchange arthroplasty is standard of care.
Phelan et al. described delayed reimplantation in 10 patients with fungal PJI. They found that the median time from resection to reimplantation arthroplasty was 9 and 2 months for total hip and total knee arthroplasty respectively. Two patients had recurrence of infection. They recommend antifungal therapy and delayed reimplantation arthroplasty after confirmation of an infection-free period as the best chance for cure.
Azzam et al. retrospectively reviewed arthroplasty database data to identify 31 fungal PJIs in 6 centers. Delayed implantation was performed in 19 of 29 patients who underwent resection arthroplasty at an average of 7 months.
They recommend two-stage exchange arthroplasty as the treatment of choice, addition of antibacterial drugs to the cement spacer to prevent superinfection, antifungal drugs for 6-12 months, repeat joint aspirations prior to reimplantation, and optimization of host nutritional status prior to reimplantation.
Figure A is a high-powered micrograph showing synovial tissue covered by fibrinopurulent exudates containing fungal colonies of Candida albicans.
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Which of the following non-operative treatments for osteoarthritis has the best evidence to support its use?
Combination of supervised and home exercise programs
Hyaluronic acid injections
Lateral heel wedge
Acetaminophen
Glucosamine
Of the options listed, a combination of home and supervised exercise has the best supporting evidence for the treatment of osteoarthritis.
The AAOS has recently developed guidelines for the treatment of osteoarthritis. Therapies that are recommended by the AAOS include weight loss, home and supervised exercise programs, and NSAIDs/tramadol.
Therapies that remain inconclusive (lack of supporting evidence) include electrotherapeutic modalities, manual therapy, bracing, acetaminophen/opiods, steroid injections and PRP. Glucosamine, lateral heel wedges and hyaluronic acid injections are not recommended, as current literature has shown them to be ineffective. Keep in mind that these guidelines are subject to change as new literature is published.
Zhang et al. present a systematic review of the literature on arthritis management in the three years following the original OA Research Society International (OARSI) guidelines published in 2006. While weight loss showed an increase in effectiveness with the addition of new studies, electromagnetic therapy, glucosamine, chondroitin sulfate, and hyaluronic acid injections showed a decrease in effectiveness.
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Figure A shows the 2 bundles of the ACL dissected from a cadaveric knee off their bony attachments. They are labeled Bundle A and Bundle B, respectively. Which of the following is true?
The tibial attachment of Bundle A is anterior to Bundle B. In extension, Bundle B is loose and Bundle A is tight.
The tibial attachment of Bundle A is anterior to Bundle B. In flexion, Bundle B is loose and Bundle A is tight.
The tibial attachment of Bundle B is anterior to Bundle A. In flexion, Bundle B is loose and Bundle A is tight.
The tibial attachment of Bundle B is anterior to Bundle A. In flexion, Bundle A is loose and Bundle B is tight.
The tibial attachment of Bundle B is anterior to Bundle A. In extension, Bundle A is loose and Bundle B is tight.
Bundle A is the anteromedial (AM) bundle, which is longer, and is tight in flexion. Bundle B is the posterolateral (PL) bundle, which is shorter, and is loose in flexion. The AM bundle is attached anterior to the PL bundle on the tibia.
The ACL is comprised of 2 bundles. The AM bundle is longer than the PL bundle. Their names reflect their relative anatomic positions on the tibial insertion site. On the femur, the AM bundle begins at the proximal-anterior aspect of the femoral insertion site, while the PL bundle begins at the posterior-inferior part. In flexion, the AM bundle is tight and the PL bundle is loose. In extension, the AM bundle is loose and the PL bundle is tight.
Bicer et al. reviewed the anatomy of the ACL. They found that the AM bundle was longer (32mm) compared with the PL bundle (18mm). PL bundle carries greater force near full extension, and the AM bundle carries greater force after 15-45° of flexion. Under combined rotatory loads (valgus and internal tibial torque at knee flexion >30°), the AM bundle bore more force than the PL bundle.
Figure A shows the 2 bundles of the ACL. The AM bundle is longer than the PL bundle. The oft referred to length of ACL refers mainly to the length of the AM bundle. Illustrations A and B show the spatial relationships of the AM and PL bundles in a cadaveric knee. Illustration C shows the relative positions of the attachments of each bundle.
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An 83-year-old man, who had a total hip arthroplasty performed 13 years ago, is referred to your office for evaluation. He reports worsening groin pain over the past year, which has been increasing in frequency. Prior to this past year, he had no other complaints. His current radiograph is shown in Figure A. If he continues to ambulate with this implant, he is at greatest risk for which of the following?
Infection
Acetabular component loosening
Femoral component loosening
Dislocation
Periprosthetic fracture
The patient has eccentric polyethylene wear secondary to component malpositioning. He is at highest risk for dislocation.
Late dislocation following total hip arthroplasty(THA) can occur and has a high recurrence rate, thereafter. Risk factors include eccentric polyethylene, THA at an early age, neurologic decline or associated neurologic conditions (i.e.
Parkinson's disease), or associated trauma.
Parvizi et al. noted in this instructional course lecture that eccentric, excessive polyethylene wear is one of the most common reasons for late, recurrent dislocation. Revision is recommended.
Pulido et al. in this review, reiterated that polyethylene wear can lead to increased inflammation, capsular distention, and instability, increasing risk for dislocation.
von Knoch et al. reviewing over 500 dislocated hips, also noted that eccentric wear was one of major causes linked to late dislocation.
Figure A. exhibits a left total hip arthroplasty with eccentric wear. Incorrect answers:
OrthoCash 2020
Figure A shows a radiograph of a 62-year-old female that underwent a left total hip arthroplasty 5 years ago. She presents to your office with insidious onset of left groin and buttock pain. She denies trauma, fever or chills. On physical examination, her left hip has mild pain with range of motion. She has a normal gait cycle, normal power across the hip and her vitals signs are stable. A left hip aspirate was performed and results are shown in Figure B. What is the most likely cause of her hip pain?
Periprosthetic bacterial hip infection
Periprosthetic hip fracture
Large-particle wear debris disease
Pseudotumor hypersensitivity response
Abductor tendon tear Corrent answer: 4
This patient is presenting with a metal induced system hypersensitivity response in the setting of a metal-on-metal total hip arthroplasty.
A hip aspiration of a painful THR is a very useful investigation for the work up of infection, having a sensitivity of 75-85% and specificity of 85-100% for
infection. Metal-on-metal THA may mimic infection as aspirate results will often show increased inflammatory infiltrate, with synovial WBC counts in the thousands. However, infected THA are more likely to produce higher percentages of PMNs (>70%) in comparison to hypersensitivity reactions/ adverse reaction to metal debris, which are more likely to produce a higher percentage of lymphocytes (>40%).
Campbell et al. looked at the histological features of pseudotumor-like tissues from metal-on-metal hips. They found that the patients with hip pain and suspected metal sensitivity had fewer metal particles but more aseptic lymphocytic vasculitis-associated lesions compared to patients with evidence of metallic wear. They concluded that pseudotumors occur more because of a hypersensitivity reaction than particle wear.
Kwon et al. examined a small cohort of patients with metal-on-metal hip arthroplasties to investigate the incidence and level of metal-induced systemic hypersensitivity. They found that lymphocyte reactivity to Co, Cr, and Ni did not significantly differ in patients with pseudotumors compared to those patients without pseudotumors. This suggests that systemic hypersensitivity type IV reactions may not be the dominant biological reaction involved in the occurrence of the soft tissue pseudotumors.
Figure A shows a patient with bilateral metal-on-metal total hip arthroplasties. There are no identifiable fractures. The position of the left acetabular cup is slightly vertical, which can increase edge loading and particle wear. Figure B shows the results from the hip aspirate.
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A 72-year-old patient is scheduled to undergo revision total hip arthroplasty. A 3D-model of the patient's hemipelvis is constructed for pre-operative planning and is shown in Figure A. A custom-designed implant shown in Figure B is created. Which of the following is TRUE of the planned reconstruction?
The implant is a bilobed cup.
The most common complication is dislocation.
The acetabular defect can be classified as AAOS Type V.
Radiation-compromised bone stock is a contraindication.
The winged profile of the implant facilitates insertion through both anterior and anterolateral approaches.
The patient has pelvic discontinuity that will be reconstructed with a custom triflange acetabular component. Dislocation is the most common complication.
Custom triflange acetabular components are indicated for severe acetabular bone loss and pelvic discontinuity that are not amenable to treatment with off-the-shelf implants such as reconstruction plates, jumbo cups and antiprotrusio cages. Dislocation is common and possible etiologies include extensive dissection, less reliable soft tissue repair, deficient abductors/trochanteric nonunion, superior gluteal nerve stretch neuropraxia, and surgeon reluctance to use constrained liners in the face of poor bone stock.
Christie et al. reviewed reconstruction with the triflange cup in 78 hips with AAOS Type III (combined deficiency) or Type IV (pelvic discontinuity) defects. They found improvement in Harris hip scores, limp, need for walking aids.
Dislocation was the most common complication (15.6%, 12 patients), and half of these patients (6/12) needed re-operation for recurrent dislocation. They recommend the triflange cup for difficult reconstructions involving severe bone loss.
Taunton et al. reviewed 57 patients with pelvic discontinuity treated with a custom triflange component. They found that 21% developed instability (10 required revision, and 2 treated nonoperatively). Of note, 51% had preop trochanteric escape (nonunion of the greater trochanter to the femoral component or femur with >1cm of displacement. They recommend the custom triflange implant for discontinuity as it provides predictable midterm fixation and consistent healing.
Figure A is a 3D hemipelvis model generated by stereolithography from a patient’s CT scan. It shows massive bone loss and pelvic discontinuity. Figure B is a custom hydroxyapatite (HA)-coated porous triflange acetabular prosthesis with ilial and ischial screw holes. Illustration A shows a bilobed cup and its appearance on an AP radiograph.
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All of the following are risk factors for wear-related failure in total knee arthroplasty when using a polyethylene liner that underwent sterilization via gamma irradiation in air EXCEPT?
Increasing shelf age of polyethylene liner
Younger age of patient
Male gender
Posterior cruciate retaining knee design
Use of a rough tibial baseplate Corrent answer: 4
Increasing shelf age, younger age, male gender, and a rough tibial baseplate are all risk factors for wear-related failure in total knee arthroplasty when using a polyethylene liner. Posterior cruciate retaining knee design is not a documented risk factor.
Fehring et al reviewed 2091 TKA using the Press fit condylar system and noted that the 13-year survivorship for all patients was 82.6% with a 8.3% prevalence of wear-related failure. Cox hazards analysis revealed five variables that were correlated with wear-related failure: patient age, patient gender, polyethylene sheet vendor, polyethylene finishing method, and polyethylene shelf age. They were unable to identify one factor as the defining reason for these wear-related failures. They cautioned that these findings may only be specific to inserts that underwent sterilization via gamma irradiation in air.
Collier et al followed 365 TKA (PCL-retaining) for 5-10 yrs and noted that
factors related to polyethylene insert osteolysis included advanced shelf age, sterilization method, and the material from which it was machined. Osteolysis was identified in 34% with an insert that had been gamma-irradiated in air and affixed to a rough baseplate surface, but only 9% when the insert had been gamma-irradiated in an inert gas or not irradiated at all and joined to a polished surface.
OrthoCash 2020
A 65-year-old healthy patient fell 18 years after a total hip arthroplasty and sustained the fracture shown in Figure A. Which of the following would be the most appropriate treatment?
Percutaneous locked plating
Open reduction internal fixation with a cable plate and allograft strut
Revision to a long femoral stem with allograft bone
Revision to a cemented revision femoral stem that bypasses the fracture site by 5 cm
Three months of non-weight bearing Corrent answer: 3
The Vancouver classification of periprosthetic femur fractures is based on the fracture site, implant stability, and remaining bone stock. The patient in the question has a type B3 fracture. The cemented stem is loose and there is very poor remaining bone stock. He should be treated with a long, cementless
revision stem with biplanar strut grafts. A tumor prosthesis or allograft-prosthesis composite would be alternate possibilities. Illustrations A and B are a diagram and table of the Vancouver classification of periprosthetic hip fractures.
Springer, et al. looked at the results and complications of revision total hip arthroplasty for the treatment of acute Vancouver type-B periprosthetic femoral fracture. In their series they treated these fractures in multiple ways, including cemented stems, uncemented stems, allograft-prosthetic composite, or tumor prosthesis. They concluded that the best results were with an uncemented, porous coated femoral stem, and the most common cause of revision was loosening.
Parvizi, et al. concluded that due to the poor bone quality and delayed healing of older patients & their periprosthetic fractures that it is imperative that a strong mechanical construct be achieved in the treatment of these fractures. They “advocate the use of numerous screws with purchase of at least ten cortices and reinforcement of fixation with biplanar strut allografts whenever possible. When a revision stem is used, we ensure that adequate diaphyseal fixation is obtained and the fracture is traversed by at least 5 to 8 cm.”
OrthoCash 2020
A 85-year-old man who underwent hemiarthroplasty 5 years ago now complains of thigh pain for the past four months. Laboratory studies show a normal white blood cell count (WBC), erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). An aspiration of the hip is performed and is negative for infection. A radiograph is shown in Figure A. Which of the following is the best management option for the femoral implant?
Bone scan to look for loosening
Touch down weight bearing and physical therapy
Revision with a tumor prosthesis
Revision of femoral component with metaphyseal cement fixation of the stem
Revision to a cementless femoral component with diaphyseal press-fit fixation of the stem
The radiograph shows lucency around the femoral stem cement mantle consistent with loosening. There is bone loss in the proximal femur. Diaphyseal fixation is the best option from the choices available. Revision to a cementless femoral stem is the most appropriate management.
Paprosky et al. described their results of revision to cementless femoral components and report 95% survivorship with a minimum of 10 years follow
up.
Haydon et al showed that despite historical literature discouraging the use of cemented femurs for revision, in their experience cemented femoral revision had 91% survivorship when the cause was aseptic loosening. They found early generation cementing techniques, poor cement mantle, poor bone quality, age of less than 60, and male gender to be risk factors for failure in cemented revisions.
OrthoCash 2020
Figure A is a diagram showing the medial side of the knee. During a total knee arthroplasty, proximal tibia resection results in the transection of the ligament in Figure A along the red line. Intraoperative examination reveals coronal plane instability. What are the best next steps?
Use of the implant shown in Figure B, and use of a hinged knee brace postoperatively
Suture repair of the torn ligament, use of the implant shown in Figure C
Use of the implant shown in Figure D, and use of a knee immobilizer postoperatively
Suture repair of the torn ligament, use of the implant shown in Figure D, and use of a hinged knee brace postoperatively
Use of the implant shown in Figure C alone Corrent answer: 4
This patient has intraoperative midsubstance transection of the MCL. MCL repair, use of either a CR or PS implant, and postoperative knee bracing for 6 weeks is recommended. A possible alternative is the use of an unlinked constrained implant.
The MCL is likely to be compromised by medially placed retractors or during medial subperiosteal elevation (tibial avulsion) or injured by oscillating saw-blade during the tibial or posterior femoral condyle cut. There is no consensus for the treatment of intraoperative rupture. Acceptable salvage options include
(1) direct repair (heavy sutures for midsubstance rupture, and suture anchors for tibial sleeve avusions) and postop knee bracing for 6 weeks with either CR or PS implants, or (2) use of unlinked constrained implants with or without repair.
Lee and Lotke reviewed 37 patients with intraoperative MCL injury out of 1478 patients. They attempted repair in 14 patients, and increased constraint in 30
patients. They found higher failure rates (regardless of MCL repair technique) for cruciate retaining components. They recommend use of an unlinked constrained prosthesis (with or without ligament repair), especially for midsubstance injuries.
Leopold et al. reviewed 16 MCL injuries in 600 knees. They performed suture or suture anchor repair and used a hinged knee brace for 6 weeks postoperatively. All limbs were stable and did not require bracing beyond 6 weeks, demonstrated acceptable alignment, and did not require revision at 45 months. They recommend the use of primary MCL repair or reattachment and postoperative bracing instead of implants with increased constraint.
Figure A shows MCL transection in its midsubstance. Figure B shows a cruciate retaining implant. Figure C shows a hinged knee prosthesis (linked constrained implant). Figure D shows a posterior stabilized implant. Illustration A shows an unlinked constrained implant.
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A 65-year-old woman complains of intermittent knee pain 12 years after a total knee arthroplasty. She has no history of fever or recent infections. Radiographs are shown in Figures A and B. Examination reveals minimal warmth and a moderate knee effusion. Range of motion is 5 to 100 degrees bilaterally. The C-reactive protein level is 15 mg/L (normal, 0.0-0.8mg/L), and erythrocyte sedimentation rate is 45mm/h (normal, 0-10mm/h). Arthrocentesis reveals 7500 white blood cells and 90% neutrophils. Gram stain is negative. Cultures are negative at 3 days. What is the next best step?
MRI with metal subtraction protocol
Arthroscopic debridement
Open debridement and polyethylene liner exchange
Single-stage revision total knee arthroplasty (TKA)
Explantation of components with two-stage revision TKA Corrent answer: 5
By the updated 2018 Musculoskeletal Infection Society (MSIS) criteria, this presentation is consistent with a diagnosis of periprosthetic joint infection (PJI). The patient has an elevated CRP (2), ESR (1), synovial WBC >3,000 (3), and >80% PMNs (2), for a total of 8 points. Given the chronicity of the infection, the patietn would be a candidate for two-stage revision.
This patient has clinical signs of PJI such as elevated laboratory values and radiographs suggestive of implant loosening. Even in the absence of positive cultures, the next most supported step in management if two-stage revision with explantation of the prosthesis and insertion of an antibiotic spacer.
Intraoperative cultures should be taken to guide post-operative antibiotic treatment.
Parvizi et al. recently released the updated 2018 MSI crtieria for diagnosis of PJI. The updated criteria (Illustration A) included new diagnostic tests and studies from the seven-year period since the previous criteria were established. Alpha defensin was a new addition. The two major criteria remained, each individually diagnostic of PJI. However the minor crtieria were broken down into pre-operative and intra-operative. The authors showed that a total of 6 points or more had a 97.7% SN and 99.5% SP for PJI.
Huang et al. retrospectively reported the infection control rates in 2-stage exchanges in 55 patients, and compared culture-negative cases with 295 culture-positive cases. They found that infection control in culture-negative cases was 73% at 1-year. Infection control rates were similar in culture-negative and culture-positive cases, and that infection-free survival is highest after 2-stage exchange with postoperative vancomycin. They recommend 2-stage exchange with postoperative vancomycin.
Buller et al. retrospectively assessed traits that would predict the success of debridement and liner exchange for 62 hips and 247 knees. They found that 149 (48.2%) cases failed to eradicate infection. Risks for recurrent infection include longer symptom, higher ESR, previous PJI or infection in the same joint, and an infection by a group 1 (MRSA, VRE, and methicillin-resistant S. epidermidis) or group 2 (MSSA or methicillin-sensitive coagulase-negative Staphylococcus) organism.
Della Valle et al. discuss the AAOS recommendations on diagnosis of periprosthetic hip and knee infections. They recommend repeat hip and knee aspirations when there is discrepancy between probability of PJI and initial aspiration culture result.
Aggarwal et al. prospectively compared the yield of intraoperative tissue and swab cultures in 74 hip, 43 knee, 30 septic and 87 aseptic cases. They found that tissue cultures had higher sensitivity, specificity, positive and negative predictive values for identifying PJI. Swab cultures had higher false positive and negative values. They recommend not using swab cultures, and only using tissue cultures.
Figures A and B are AP and lateral radiographs showing areas of bony erosion suggestive of loosening of the femoral and tibial components.
Illustration A is the 2018 MSIS criteria with point values.
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OrthoCash 2020
What are the affects on limb-length and offset according to the total hip arthroplasty template shown in Figure A?
Limb-length will stay the same, offset will be increased
Limb-length will be decreased, offset will be increased
Limb-length will stay the same, offset will be decreased
Limb-length will be increased, offset will be increased
No change in either limb-length or offset Corrent answer: 1
In Figure A, the center of rotation of the femoral component lies medial to the center of rotation of the acetabular component. If these components are implanted as shown, the offset will be increased and the leg-lengths will remain equal.
Offset and leg-length changes during templating and insertion of a total hip replacement are determined by the changes in the center of rotation (COR) of the femur relative to the acetabulum. If changes are made in the horizontal plane (x-axis), a change in offset will occur. If changes are made in the vertical plane (y-axis), changes in leg-lengths will occur. If the femoral COR is templated superior to the acetabular COR, the leg will be lengthened. In
contrast, if the femoral COR is templated inferior to the acetabular COR, the leg will be shortened. For offset, the same principles apply. If the femoral COR is templated medial to the acetabular COR, offset will be increased. In contrast, if the femoral COR is templated lateral to the acetabular COR, offset will be decreased. One should aim to restore native offset and leg-lengths in uncomplicated primary total hip arthroplasty.
Merle et al. retrospectively reviewed 152 patients to evaluate femoral offset on an AP pelvis and AP hip radiograph compared to a CT scan of the affected hip. They found that AP pelvis radiograph underestimated femoral offset by 13% when compared to a CT scan. In contrast, the AP hip radiograph showed no difference when compared to the CT scan. They recommend obtaining AP of the hip prior to templating for accurate assessment of femoral offset.
Della Valle et al. review preoperative planning for total hip arthroplasty. While they state that templating has a high predictive value in achieving the desired plan, the surgeon should always be prepared to make intraoperative adjustments based on tactile feedback.
Illustration A shows an example where leg-length will be shortened (femoral COR is inferior to acetabular COR) and offset will stay the same (femoral COR and acetabular COR are in the same horizontal plane). Illustration B is a table which summarizes the points we have discussed.
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OrthoCash 2020
A 65-year-old patient is diagnosed with a periprosthetic joint infection 6 years after total knee arthroplasty. He recalls a history of knee realignment surgery many years prior. Examination reveals lateral patellar tracking and passive flexion to 65 degrees. A recent radiograph is shown in Figure A. During the exposure for explantation, a standard medial parapatellar approach is performed through the previous incision. It is found that adequate knee flexion to allow exposure of the prosthesis cannot be achieved even after release of the lateral gutters and excision of the scar. Which surgical exposure technique (depicted in Figures B through F) would provide the best
surgical exposure for the procedure and preserve the blood supply to the patella?
Fig B
Fig C
Fig D
Fig E
Fig F
A tibial tubercle osteotomy (TTO) would provide the best surgical exposure without compromising patellar blood supply. This patient has patella baja arising from previous high tibial osteotomy, with a scarred, contracted patellar tendon leading to knee stiffness.
A TTO is able to provide good exposure while protecting the extensor mechanism and preventing inadvertent avulsion of a contracted patellar tendon. Further, proximal transfer of the osteotomized tibial tubercle may be used to correct patella baja, bearing in mind that excessive superior translation alters the mechanics of the knee by making the quadriceps less efficient.
Mendes et al. used TTO for surgical exposure in 67 knees undergoing revision TKA. There were good-excellent knee scores at 30 months in 87%. There were no patellofemoral complications, no component malalignments, and no avulsions of the patellar tendon occurred. They advocate TTO for cases where the patellar cannot be retracted laterally with knee in 90deg of flexion.
Whiteside described a series of TTO in 136 TKA. At 2 years, mean range of motion was 94deg. There were 2 tibial tubercle avulsion fractures and 3 tibial fractures (2 in a patient with Charcot arthropathy, and 1 following manipulation after open adhesiolysis. He advises using stemmed tibial components in patients with insensate knees and in cases where manipulation is expected.
Figure A is a lateral radiograph showing severe patella baja. Figure D shows a TTO. See below for Figures B, C, E and F. Illustration A shows the surgical technique for TTO. The distal saw cut angles out of the anterior cortex at a gentle angle to reduce the stress riser effect and risk of postoperative tibial stress fracture.
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sufficient in the presence of severe patellar baja and patellar tendon contracture.
OrthoCash 2020
Figure A show pre- and post-operative radiographs, from left to right respectively, of a 79-year-old male that underwent revision total hip arthroplasty 2 years ago. He presents today for consultation after 4 episodes of right hip dislocation within the past 6 months. Physical examination reveals a trendelenburg gait with no clinical or radiographic limb length discrepancy. An Infection work-up is negative. Results from a CT scan are shown in Figure B. What would be the best treatment option?
Physiotherapy and application of abductor brace
Revision arthroplasty to medialize the cementless cup and surgical repair of the abductor tendon
Revision arthroplasty to a constrained polyethylene liner
Revision arthroplasty to a femoral component with extended offset
Revision arthroplasty to a large ceramic femoral head and offset polyethylene cup
On the left, Figure A shows a metal-on-metal (MOM) bearing hip resurfacing. On the right, Figure A shows a large head, uncemented metal-on-polyethylene (MOP) total hip replacement. In this setting, the most appropriate treatment option would be revision arthroplasty with constrained polyethylene liner.
Constrained liners should be reserved for patients demonstrating recurrent instability despite treatment with a large femoral head. Other indications include elderly patients who do not require implant longevity or have a low functional demand, as well as patients with deficient or non-repairable abductor mechanisms.
Sikes et al. report on the results of a series of 41 patients (52 hips) with recurrent dislocations. They recommend that large femoral heads (LFH) be used as a first-line treatment in high-risk patients (patients of any age with dementia, neuromuscular disability, and inability to comply with precautions). Constrained liners should be reserved for patients demonstrating recurrent
instability despite treatment with an LFH.
Kilampali et al. reviewed late instability of bilateral metal on metal hip resurfacings. They suggest that late instability of hip resurfacing should raise concerns relating to possible local tissue reaction and muscle damage.
Concerning features include steeply-inclined acetabular components a large abduction angle of more than 55 degrees along with a combination of small size component.
Figure A shows an image of a revised socket which was performed to convert the MOM THA to a MOP THA. Figure B shows normal parameters of THA components. The recommendation for acetabular position is anteversion 20° ± 10° and abduction 45° ± 10°. For the femur, recommendations are 10°- 15° of anteversion and 41mm - 45mm of offset.
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OrthoCash 2020
Which of the following has been shown to increase the rate of failure of cemented femoral components in total hip arthroplasty?
Stems that are precoated with polymethylmethacrylate
Calcar contact of the collar
Smoother implant corners
Cement mantle of 2 millimeters
Stem material with a Young's modulus higher than 115 GPa Corrent answer: 1
Precoating a stem with PMMA adds an additional inferface at risk of failure.
Stiffer stem materials (higher Young's modulus) improve performance. Titanium has a Young's modulus of 115 GPa with alloy and stainless steel
having a higher Young's modulus than titanium. Calcar collar contact adds minimal strength to the construct, but does not lead to premature failure. Smoother corners decrease the rate of failure since they decrease stress risers. The ideal cement mantle is ~2mm. Obtaining less than this would decrease the strength of the construct.
OrthoCash 2020
An 80-year-old male sustains a fall down the stairs and presents with knee swelling. He is a community ambulator who does not use walking aids. Injury radiographs are shown in Figures A and B. What is the next best step?
Intramedullary nailing
Locked plating
Long leg casting
External fixation
Revision total knee arthroplasty Corrent answer: 5
This patient sustained a periprosthetic femoral fracture around the femoral component which is now loose. Revision of the femoral component is necessary.
Various classifications exist for periprosthetic fractures around TKA. In general, for the femoral component, treatment depends on fracture displacement, fracture location, bone stock, and whether the component is loose. For loose femoral components, revision TKA using distal femoral replacement prosthesis is an option.
Kim et al. proposed a new classification for periprosthetic fractures. Type IA fractures (good bone stock, well fixed, nondisplaced or easily reducible) are managed conservatively. Type IB fractures (good bone stock, well fixed, irreducible closed) are managed with reduction and fixation. Type II fractures (good bone stock, reducible, loose or malpositioned components) are managed with revision. Type III fractures (poor bone stock, loose or malpositioned components) are treated with distal femoral replacement.
Johnston et al. reviewed the options for treating periprosthetic fractures about the knee. They advocate revision of the femoral component when the prosthesis is loose, where there is poor bone stock, or insufficient bone to gain purchase for locked plates or distal locking screws of intramedullary nails.
Nauth et al. review the current concepts in treatment of periprosthetic fractures. They prefer minimally invasive locked plating unless the fracture is significantly proximal to the anterior flange and amenable to retrograde intramedullary nailing. Then they choose nails with options for distal interlocking screws and locking condylar bolts. In extreme osteopenia, they use intramedullary fibular strut allografts (with locked plating). For loose prostheses or poor bone stock, they perform alloprosthetic composite in younger patients and a distal femoral replacement in elderly patients.
Figures A and B are AP and lateral radiographs showing periprosthetic femoral fracture around a loose femoral component. Illustrations A and B are postoperative radiographs showing revision to a hinged prosthesis with long-stemmed components. Illustration C shows Kim' proposed classification of
periprosthetic fractures around the femoral component of a TKA.
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OrthoCash 2020
Utility of the implant seen in Figure A would be best considered in which of the following revision total hip arthroplasty scenarios?
Minimal acetabular deformity, intact rim
Superior acetabular bone lysis with intact superior rim
Localized acetabular destruction of medial wall
Absent superior acetabular rim, superolateral migration
Significant acetabular bone loss, pelvic discontinuity Corrent answer: 5
Paprosky Type 3B acetabular bone defects describes significant acetabular bone loss, with pelvic discontinuity. Type 3 defects often require reconstruction cages (as seen in Figure A) or acetabular distraction techniques
to treat severe bone loss with an associated pelvic discontinuity.
Deficient acetabular bone stock poses a technical challenge in hip arthroplasty surgery. Paprosky classification for acetabular bone loss to helps guide treatment for revision total hip arthroplasty. The classification is as follows:
Type 1: Minimal deformity, intact rim
Type 2A: Superior bone lysis with intact superior rim Type 2B: Absent superior rim, superolateral migration Type 2C: Localized destruction of medial wall
Type 3A: Significant bone loss, superolateral cup migration Type 3B: Significant bone loss, pelvic discontinuity
Sheth et al. reviewed acetabular bone loss in revision total hip arthroplasty. They state that Paprosky Type 1 and 2 defects can usually be managed with porous-coated hemisphere cup secured with screws. Type 3 defects require reconstruction cages to protect with cups and structural augments or custom triflange implants.
Taunton et al. investigated clinical outcomes and cost-effectiveness of using a custom triflange acetabular component to treat pelvic discontinuity in revision THA. They found satisfactory clinical outcomes (81% had a stable triflange component with healed pelvic discontinuity) and cost equivalence with Trabecular Metal cup-cage constructs.
Figure A shows a lateral image of the pelvis with a reconstruction cage and cup construct. Illustration A shows an illustration of the Paprosky classification. Illustration B shows a table of the Saleh/Gross classification. Illustration C shows a table of the AAOS classification.
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OrthoCash 2020
A 65-year-old male who had a total knee arthroplasty 8 years ago comes into the office with worsening knee pain. The orthopaedic surgeon is concerned about infection and aspirates the knee. Which of the following are the lowest laboratory values from a synovial aspirate suggestive of infection?
WBC of 500 cells/ml and PMN 25%
WBC of 1,000 cells/ml and PMN 25%
WBC of 1,500 cells/ml and PMN 70%
WBC of 5,000 cells/ml and PMN 70%
WBC of 25,000 cells/ml and PMN 70%
WBC of 1,500 cells/ml and PMN 70% indicates the lowest synovial aspirate suggestive of infection.
Mason et al in 2003 reviewed 440 revision TKA's of which 86 had preoperative aspirations. The aspirations yield 55 aseptic failures and 31 septic failures. The mean WBC of the aseptic group was 645 cells/mm(3) compared to 25,951 cells/mm(3) for the septic group (P=<.001). The mean percentage of polymorphonuclear cells (PMNs) was statistically higher in the septic group compared with the aseptic group (72.8% vs 27.3%; P=<.001). With these results, the authors concluded that aspirates with a WBC count greater than 2,500 and 60% PMNs are highly suggestive of infection.
However, in a more recent and larger study, Ghanem et al reviewed 161 infected TKA's vs 268 aseptic failures and concluded that aspiration with WBC of >1100 cells/mm3 and PMN > 64% are suggestive of infection. When both tests yielded results below their cutoff values, the negative predictive value was 98.2% (95% confidence interval, 95.5% to 99.5%), whereas when both tests yielded results greater, infection was confirmed in 98.6% (95% confidence interval, 94.9% to 99.8%) of the cases. Thus, according to the most recent literature, WBC >1100 and PMN > 64% should be considered suggestive of infection in a TKA.
OrthoCash 2020
A 50-year-old man with a past medical history significant for diabetes and end-stage renal disease presents with a chief complaint of instability 6-months following a total knee arthroplasty. Preoperative radiographs are shown in Figures A-C. Physical exam at that time was notable for a large effusion, maltracking patella, extensor lag of 15 degrees, medial instability, and gross laxity to anterior and posterior forces. The procedure was uncomplicated, and was completed using a posterior-stabilized prosthesis with tibial augements and uncemented intramedullary rods in both the femur and tibia. Which of the following surgical techniques should have been implemented to avoid this complication?
Cementing the intramedullary rods in the tibia and femur
Explant with placement of an antibiotic spacer
Taking 5mm of extra bone from the distal femur to elevate the joint line
Use of a hinged total knee arthroplasty
Taking 5mm of extra bone from the tibia to distalize the joint line Corrent answer: 4
The patient has a neuropathic joint with ligamentous instability and a maltracking patella. The appropriate procedure would have included use of a hinged total knee arthroplasty.
Choosing the appropriate constraint during a total knee arthroplasty ensures the best possible outcome. Hinged total knee arthroplasty prostheses are indicated in the setting of global instability, massive bone loss in a neuropathic joint, oncologic procedures, and hyperextension instability. In a hinged prosthesis, the tibial and femoral components are linked with an axle that restricts varus/valgus and translational stresses. While hinged prostheses are useful in the setting of major revision surgery, they are at increased risk for aseptic loosening due to the high degree of constraint inherent to the device.
Petrou et al. review the results of 100 primary cemented rotating-hinge total knee arthroplasty at 7- to 15-years. At 15 years, survival was 96.1%.
Complications included DVT (n=3), skin necrosis (n=2), subcutaneous hematoma (n=5), intra-operative fracture of either the femur or tibia (n=4), and early infection (n=2).
Figures A-C show a neuropathic joint with considerable lateral bone loss and a frankly dislocated patella. Illustration A shows an example of a hinged total knee arthroplasty. Note how the tibial and femoral components are linked using an axle.
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OrthoCash 2020
A 63-year-old man returns for follow-up 4 years after metal-on-metal left total hip arthroplasty complaining of mild chronic hip pain with ambulation. He is afebrile and ESR and CRP are within normal limits. Radiograph of the left hip is shown in Figure A. What is the best next step?
Anti-inflammatory medication
Serum cobalt and chromium levels
MRI with metal subtraction
Physical therapy
Revision hip arthroplasty Corrent answer: 2
Metal-on-metal total hip arthroplasties (THA) have been associated with complications presumably due to metal debris and toxicity. Serum cobalt and chromium levels are recommended as part of follow-up evaluation for patients with metal-on-metal hips, even when asymptomatic.
Many patients with metal-on-metal hips have been found to have elevated serum cobalt and chromium levels, for which MR with metal subtraction is recommended to look for pseudotumors and other pathologies. These solid or cystic masses are thought to be related to metal debris and macrophage infiltration and may be associated with pain in some patients.
Lombardi et al summarize and present on behalf of The Hip Society an algorithmic approach to evaluating and treating patients with metal-on-metal THA in follow-up. They state the goals of care as determining the etiology of any pain, managing any intrinsic problems with the arthroplasty, and reassuring/observing when appropriate. They organize the types of patients seen in followup and components of the evaluation.
Chang et al evaluate the correlation between symptoms and MRI findings and report that symptomatic patients tend to have bone marrow edema and tendon tearing on MRI. They report a 69% prevalence of pseudotumors on MRI after metal-on-metal hip arthroplasty, but did not find a correlation between pseudotumor presence and pain.
Hayter et al focus on MRI findings in symptomatic (painful) patients with metal-on-metal THA in a review including 31 hip resurfacing and 29 THA. In the THA group, they report 86% rate of synovitis, 10% extracapsular disease, and 24% osteolysis, with no statistically significant difference in rates between resurfacing and THA.
Figure A is an AP view radiograph of a left hip after metal-on-metal total hip arthroplasty with components well positioned and no osteolysis.
Illustrations A and B from Lombardi et al depict a recommended algorithm for the workup and management of symptomatic and asymptomatic patients, respectively, with metal-on-metal THA.
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OrthoCash 2020
A 72-year-old woman sustains a fall onto her knee three years after an uncomplicated total knee replacement. The fracture pattern is seen in Figure A. The operative note reveals that a cemented patellar component was used. On exam, she has a large effusion and an
inability to straight leg raise. If the patellar component is well fixed, what is the best treatment option?
Patellectomy
Extensor mechanism allograft
Revision of the patellar component with cement and bone grafting of any residual defect
Open reduction and internal fixation of the patella fracture
Non-operative treatment in a knee brace locked in extension for 6 weeks Corrent answer: 4
Displaced, periprosthetic patella fractures with a deficient extensor mechanism and adequate bone stock are best treated with open reduction and suture or implant fixation.
Periprosthetic patella fractures are a rare, but potentially devastating complication associated with total knee arthroplasty. When evaluating patella fractures, it is important to consider 1) is the extensor mechanism intact, 2) is the patellar component well fixed or loose, and 3) is there sufficient bone stock remaining. Stable implants with an intact extensor mechanism should almost exclusively be treated non-operatively in a brace. In contrast, a deficient
extensor mechanism is an absolute indication for surgical management.
Adigweme et al. review the epidemiology, diagnosis, and treatment of periprosthetic patella fractures. When analyzing patella fractures, they suggest treatment should be based on fracture severity, remaining bone stock, patellar component stability, as well as extensor mechanism function.
Sarmah et al. review periprosthetic fracture around total knee arthroplasty. They provide an algorithm for treatment of periprosthetic patella fractures based on displacement, viability of remaining bone stock, and fracture type.
Figure A is a preoperative lateral radiograph showing a periprosthetic patellar fracture. The distal fragment is comminuted and separated from the proximal fragment by approximately 15 mm. The patellar component appears to be well fixed. Illustration A is intraoperative photograph showing the threads of the suture anchors in the proximal fragment passing through the tunnels in the distal fragment and exiting at the inferior pole of the patella. Illustration B demonstrates anatomical reduction after the knots were tied at the inferior pole of the patella. Illustration C is a lateral x-ray 1 year postoperatively showing fracture union.
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OrthoCash 2020
Knee pain and osteoarthritis are associated with "metabolic syndrome." All of the following are included in the collection of risk factors known as "metabolic syndrome" EXCEPT:
Peripheral vascular disease
Dyslipidemia
Hypertension
Impaired glucose tolerance
Central obesity
Peripheral vascular disease (PVD) may develop in patients with metabolic syndrome. However, no direct relationship between metabolic syndrome and PVD is known, and it is not a part of metabolic syndrome itself. Metabolic syndrome has been shown to be associated with knee pain and development of knee osteoarthritis (OA).
Metabolic syndrome is a collection of medical comorbidities that are known to
be risk factors for developing cardiovascular disease. Metabolic syndrome includes central (abdominal) obesity, dyslipidemia (high triglycerides and low-density lipoproteins), high blood pressure, and elevated fasting glucose levels. There is an increased prevalence of knee pain (and OA) among patients with metabolic syndrome. It is felt that the most important contributing factor to knee pain and OA in metabolic syndrome is obesity. Patients presenting with knee pain or OA and the risk factors included in metabolic syndrome should be counseled on the need to control those risk factors.
Inoue et al. present a study comparing metabolic syndrome and knee OA in a Japanese population. They found that knee OA and metabolic syndrome were highly correlated in females, but not in males.
Engström et al. present a study comparing metabolic syndrome with hip and knee OA. They found no relationship to hip OA, but did find a strong correlation between patients with metabolic syndrome and risk of developing knee arthritis. Patient BMI was the most predictive factor. They also compared prevalence of knee OA to CRP levels, but found no significant relationship.
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OrthoCash 2020
A 75-year-old male presents with recurrent dislocations of this left hip. He underwent bilateral total hip arthroplasties 12 and 8 years ago. There were no early post-operative complications with either hip. Despite a total of 5 dislocations in 6 months, he does not have pain or weakness across the left hip. On examination, there is a healthy appearing left lateral scar, equal limb lengths, normal gait and full abductor strength. Radiographs of the pelvis are shown in Figure A. His laboratory results show an erythrocyte sedimentation rate of 8 mm/h (reference range, 0-20 mm/h), and C-reactive protein of 3 mg/L (reference range, 0-5.0 mg/L). A hip aspirate culture is negative. What is the next best management option for this patient?
Magnetic resonance imaging of left hip to exclude an abductor muscle tear
Re-aspiration of left hip to exclude a subclinical infection
Continued observation for trochanteric bursitis
Supervised physiotherapy and gait training for abductor strengthening
Left revision total hip arthroplasty for polyethylene wear Corrent answer: 5
This patient presents with recurrent late hip instability with radiographic evidence of eccentric polyethylene wear. The best treatment option for this patient would be revision total hip arthroplasty (THA).
The etiology of late instability includes polyethylene wear, component malpositioning or loosening, trauma, infection or deterioration in neurological status of the patient. Identifying the cause of late instability will require a thorough work up. A good history, examination and scrutiny of radiographs can identify most causes. Advanced imaging may be requires when bone or soft-tissue pathology is suspected or radiographic evidence of osteolysis or malpositioning needs further assessment. Blood work to assess for an acute inflammatory response (ESR and CRP) should be ordered routinely as elevated markers may indicate an underlying infection.
Parvizi et al. evaluated the outcome of revision arthroplasty for polyethylene wear presenting as late dislocation. They found that revision surgery restored stability to eighteen of the twenty-two patients. Surgical treatment options may include liner-only exchange (contained or unconstrained) +/- soft-tissue repair, or revision of one or all components.
Berry et al. evaluated the long-term risk of dislocation in 6,623 consecutive primary total hip arthroplasties with a Charnley prosthesis. They found a 7% incidence of late dislocation at 25 years compared to 1% after 5 years.
Patients at highest risk were females, patients with osteonecrosis of the femoral head or an acute fracture, and nonunion of the proximal part of the femur.
Figure A shows an AP pelvis with bilateral, uncemented, total hip arthroplasties. There is eccentric wear of the left acetabular component. No fracture or loosening of the components can be identified. The components appear well-positioned.
Incorrect Answers:
This patient has no pain or weakness in the affected hip. Therefore, soft tissues can be evaluated intra-operatively during the revision THA procedure. Answer 2: A hip aspirate would not be warranted. There are no risk factors for infection in this patient (for example, no pain, no early wound complications or antibiotics, etc). Additionally, his inflammatory markers are normal.
OrthoCash 2020
A 58-year-old woman undergoes a total knee arthroplasty with a posterior stabilized design. Two years later, she returns with recurrent sterile joint effusions, a sensation of instability without giving way and difficulty with ascending and descending stairs. Examination reveals diffuse tenderness around the pes anserinus and peripatellar region, and increased anterior tibial translation most notable at 90° of flexion. Radiographs demonstrate well cemented implants with 5° of posterior tibial slope. Figure A represents a femoral cutting block with lines 1 through 5 corresponding to femoral bone cuts. The most likely cause of her symptoms is over-resection at:
Resection line 1
Resection line 2
Resection line 3
Resection line 4
Resection line 5
Over-resection of the posterior femoral condyles (resection line 2) in posterior-stabilized (PS) TKA leads to flexion instability without frank dislocation.
There are 7 bone cuts in a total knee replacement. The posterior condylar cut determines the flexion gap. Flexion instability in PS knees arises because of an enlarged flexion gap (excessive posterior condylar resection, or increased tibial slope), allowing anterior tibial translation, which is pathognomonic. There will not be posterior subluxation because of the cam-post design. Symptoms include sensation of instability without giving way, especially with stair climbing, recurrent knee effusions, and diffuse knee pain. Signs include anterior tibial translation at 90° flexion, tenderness at multiple sites (including pes anserinus, peripatellar, posterior hamstrings), and effusion. Revision surgery is indicated for symptomatic patients.
Clarke et al. reviewed flexion instability after primary TKA. They caution that most cases arise from failure to create symmetric balanced flexion and extension spaces. Treatment is usually revision TKA using the same principles. If this is not possible, increased constraint is required (constrained condylar prosthesis or hinged prosthesis).
Schwab et al. reviewed flexion instability without dislocation in PS knees in 10 patients. Revision surgery focused on flexion-extension gap balancing and filling the enlarged flexion gaps and successfully relieved pain, and improved stability to anterior tibial translation. Flexion space reconstruction includes using a larger femoral component or posterior augments. Isolated polyethylene exchange is not recommended.
Figure A shows a 5-in-1 cutting block with anterior femoral cut (line 1), posterior femoral cut (line 2), posterior chamfer cut (line 3), anterior chamfer cut (line 4), and distal femoral cut (line 5). Of note, most TKA systems have a 4-in-1 cutting block and the distal femoral cut is made separately. Illustration A shows restoration of the posterior condylar offset (line A) with the femoral component (line B).
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OrthoCash 2020
Which of the following is true regarding intra-operative fractures during total knee arthroplasty?
They occur more commonly in cruciate-retaining total knee replacements
Fractures of the medial femoral condyle are the most common fracture type
Fractures of the patella are the most common fracture type
Most can be treated without additional fixation at the time of surgery
Tibial fractures are more common than femoral fractures Corrent answer: 2
Fractures of the medial femoral condyle are the most common type of intraoperative fracture during a total knee arthroplasty.
Intra-operative fractures during total knee replacement are rare, but usually requiring alterations in surgical technique once they occur. The most common time for fractures to occur is during exposure and bone preparation, with fracture during trialing being the next most common. Fractures occur more commonly in posterior cruciate substituting designs, likely due the box cut.
Osteoporosis, female gender, chronic steroid use, advanced age, rheumatoid arthritis, and neurologic disorders are risk factors for post-operative fracture, but are also thought to be risk factors for intra-operative fractures.
Alden et al. reviewed 17,389 primary TKAs and found an intra-operative fracture rate of 0.39%. Of the 67 fractures, 49 were femur fractures, 18 were tibia fractures, and none were patella fractures. They recommend careful surgical technique in patients at high risk for fracture to avoid such a complication.
Sharkey et al. reviewed 10 intra-operative femoral fractures during primary, cementless total hip arthroplasty. They matched these with 20 patients who did not have this complication. At follow-up, there were no differences found between the two groups.
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OrthoCash 2020
A 68-year-old male complains of increasing medial sided knee pain and buckling. The pain is exacerbated by sharp turns while
running. He undergoes knee arthroscopy. Recent radiographs and an arthroscopic photograph of the medial compartment are shown in Figure A. His pain has worsened since the arthroscopy. Which of the following images (Figures B through F) represents the best treatment recommendation for this patient?
This patient has isolated medial compartment osteoarthritis with Outerbridge IV medial compartment cartilage wear on arthroscopy. The best surgical option is a medial unicompartmental knee arthroplasty (UKA).
Indications for UKA include range of motion >100deg with <5deg flexion contracture, angular deformity <15deg valgus or <5deg varus that is passively correctable to neutral. Relative contra-indications include younger patients (age <60), obesity (BMI >30), and ACL deficiency in medial UKA. Asymptomatic patellofemoral chondromalacia is not a contraindication. In general, a UKA is preferred for older, less active patients with minimal varus, more severe arthritis, and no/little knee instability. A HTO is preferred for younger, active patients, with milder arthritis, more malalignment, and AP instability.
Steadman et al. retrospectively examined outcomes of TKA after arthroscopic treatment of OA in 73 patients. They found that mean survival time (conversion to TKA) after arthroscopy was 6.8 years (5.7 years in patients with Kellgren-Lawrence grade 4, and 7.5 years in those with grade 3). They conclude that in patients who want to avoid TKA, arthroscopy may help postpone TKA.
LaPrade et al. examined the results of proximal tibial opening wedge
osteotomies in 47 patients <55 years old with medial compartment osteoarthritis (OA) and genu varus. They found that there was improvement in knee scores and the mechanical axis at 3.6 years. They recommend this technique for patients with medial compartment OA and malalignment.
Figure A is a composite image showing isolated medial compartment osteoarthritis, and Outerbridge IV cartilage wear with large areas of visible subchondral bone. (See below for Figures B through F). Illustration A is a table comparing the indications of HTO vs UKA.
Incorrect Answers:
OrthoCash 2020
A 58-year-old female, with a BMI of 34 kg/m2, underwent a total knee arthroplasty for osteoarthritis 6 weeks ago. She has been participating in supervised rehabilitation since the procedure. Her preoperative, intra-operative and 6 week post-operative knee flexion are shown in Figure A. Current radiographs are shown in Figure B. What is the best step in management?
Convert to a resurfaced patella
Downsize the polyethylene liner
Arthroscopic lysis of adhesions and release of posterior capsule
Continuous passive motion at home for two weeks
Manipulation under anesthesia Corrent answer: 5
This patient has early post-operative stiffness after total knee arthroplasty (TKA). The next best step would be manipulation under anesthesia.
Management of stiffness following TKA can be challenging. The standard initial treatment option for post-operative knee stiffness is physical therapy. When this fails to achieve knee range of motion (ROM) greater than or equal to 90°, alternative treatment modalities should be considered, such as knee manipulation under anesthesia (MUA). MUA is a non-invasive treatment shown to achieve dramatic improvement in knee flexion during the early postoperative period (usually considered less than three months). Periprosthetic fracture during manipulation is rare, with an overall incidence less than 1%.
Issa et al. examined a cohort of patients that underwent MUA after TKA. At a mean follow-up of 51 months (range, 24 to 85 months), the mean gain in flexion in the MUA cohort was 33° (range, 5° to 65°). There was one periprosthetic fracture in 134 patients. The authors noted a significant improvement in ROM from pre-manipulation values.
Manrique et al. reviewed stiffness after total knee arthroplasty. MUA may be considered within the first three months after the index TKA if physical therapy fails to improve the ROM. Beyond this point, consideration should be given to surgical intervention such as lysis of adhesions, either arthroscopic or open.
Maniar et al. looked at the effectiveness of continuous passive motion immediately after TKA. A total of 84 patients were allocated to no CPM; 1 day CPM; or 3 day CPM. They found that continuous passive motion immediately after TKA did not improve short or mid-term knee ROM.
Figure B shows a cruciate sacrificing total knee arthroplasty with implants in a good position.
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OrthoCash 2020
Which of the following fracture patterns (Figures A-E) would require revision of the femoral component to a long-stemmed, cementless prosthesis?
Figure C depicts a Vancouver B2 periprosthetic fracture, which is optimally treated with a long-stem, fully porous-coated, revision femoral prosthesis.
The Vancouver classification for total hip periprosthetic femoral fractures takes into account the three most important factors in management of these injuries: the site of the fracture, the stability of the femoral component, and the quality of the surrounding femoral bone stock. Type A fractures include those involving the lesser trochanter or the greater trochanter. Type B fractures occur around the stem or just below it. More specifically, B1 fractures have a well fixed stem, B2 fractures have a loose stem but good proximal bone stock and B3 fractures have a loose stem with proximal bone that is of poor quality or severely comminuted. Type C fractures are well below the tip of the femoral stem.
O'Shea et al. assessed the outcome of patients with Vancouver type B2 and B3 periprosthetic fractures treated with femoral revision using an uncemented extensively porous-coated implant. Union of the fracture was successfully achieved in 20 of the 22 patients. Overall, they found good early survival rates and a low incidence of nonunion using this implant.
Figure A depicts a radiograph of a Vancouver type C periprosthetic femur fracture, occurring distal to the stem of the total hip arthroplasty. Figure B demonstrates a Vancouver type A periprosthetic fracture of the greater trochanter. Figure C is an x-ray of a Vancouver type B2 periprosthetic fracture adjacent to the stem with an unstable implant, but adequate bone stock.
Figure D depicts a radiograph of a Vancouver type C periprosthetic femur fracture, occurring distal to the stem of the total hip arthroplasty. Figure E is a Vancouver type B1 periprosthetic fracture at the level of the stem that is well fixed. Illustration A shows a table summarizing the Vancouver classification of periprosthetic femur fractures and the corresponding management options.
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OrthoCash 2020
Which of the following maneuvers places the obturator artery at greatest risk during a total hip arthroplasty?
Placement of a posterior retractor along the posterior wall
Placement of an acetabular screw in the posterior-superior quadrant
Placement of an inferior retractor under the transverse acetabular ligament
Placement of an acetabular screw in the anterior-superior quadrant
Placement of an anterior retractor along the anterior wall Corrent answer: 3
Damage to the obturator artery most commonly occurs from placement of an inferior retractor inferior to the transverse acetabular ligament (into the obtrator foramen), and/or placement of an acetabular screw in the anterior-inferior quadrant.
Vascular injury during total hip arthroplasty is a rare but devastating complication with a reported incidence of 0.1%-0.2%. The obturator artery travels along the quadrilateral surface of the acetabulum and exits the pelvis at the superolateral corner of the obturator foramen. If the vessel is severely
damaged and bleeding cannot be controlled, ligation of the internal iliac artery has been reported.
Nachbur et al. report on 15 cases of severe arterial injury during hip reconstructive surgery over a period of 8 years. The most common injury was injury to the external iliac artery, the common femoral artery, or main branches of the lateral and medial circumflex femoral artery. These were thought to be caused by the tip of a narrow-pointed Hohmann retractor used for exposure of the hip joint.
Rue et al. review neurovascular injuries during total hip arthroplasty. Among other things, they recommend against placement of screws in the anterior-superior quadrant, prudent retractor placement, and avoiding excessive tension on the sciatic nerve.
Della Valle and Di Cesare review complications resulting from total hip replacement. They state that injury to the obturator artery can occur with acetabular screw fixation in the antero-inferior quadrant or from retractors placed underneath the transverse acetabular ligament.
Illustration A shows the obturator artery as it exits the pelvis at the superolateral corner of the obturator foramen. Illustration B reviews acetabular screw placement and the structures at risk in each quadrant.
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OrthoCash 2020
A 65-year-old male sustains a fall onto his left hip 3 years after a total hip arthroplasty. A radiograph taken at the emergency room is shown in Figure A. What is the next best step?
Open reduction and internal fixation with locked plates and cables through an extensile approach
Revision with a proximally porous-coated stem
Revision with an extensively porous-coated stem
Nonoperative management
Minimally invasive plate osteosynthesis Corrent answer: 3
The patient has a Vancouver B2 periprosthetic fracture. There is a loose stem that should be treated with revision to an extensively coated stem that bypasses the fracture site.
Revision of the femoral component is recommended for Vancouver B2 and B3 periprosthetic fractures. Type B1 fractures are treated with ORIF and stem retention, and proximally deficient B3 fractures may be treated with alloprosthetic composites or tumor prostheses.
Springer et al. retrospectively reviewed 118 hips with Vancouver B fractures. Seventy-seven percent of 30 extensively coated stems, 60% of 42 cemented stems, 36% of 28 proximally coated stems, and 61% of 18 tumor prosthesis/allo-prosthetic composite stems were well fixed and demonstrated
fracture union. Nonunion and loosening were the most common complications. They recommend extensively porous-coated stems for better results.
Haidukewych et al. review revision of periprosthetic fractures. They found that most acetabular components are well fixed. When the distal fragment has parallel endosteal cortices with >=5 cm of tubular diaphysis (usually with a diameter of <18 mm), they recommend an extensively coated, uncemented, monoblock long-stemmed prosthesis. If the distal diaphysis is divergent, has
<5 cm of parallel endosteal cortex, or large endosteal diameters, a fluted, grit-blasted, titanium, tapered modular stem can be used.
Figure A shows Vancouver B2 fracture. The stem has subsided relative to the proximal fracture fragment, indicating that it is loose. Illustration A shows revision of the same fracture with an extensively porous-coated stem.
Illustration B shows the endoskeleton technique using an osteotomy to split the proximal fragment coronally for stem removal, followed by insertion of a modular, fluted, tapered stem and cerclage fixation of the proximal fragments.
Incorrect Answers:
Malinzak et al performed a Level 4 review of 8494 patients undergoing a total knee arthroplasty. They found that patients with a body mass index greater
than 50 had an increased odds ratio of infection of 21.3 (P < .0001). Diabetic patients were 3 times as likely to become infected compared to nondiabetic patients (P = .0027).
Rasul et al performed a Level 4 review of 24 patients for a duration of 2 years with total knee arthroplasty infections. They found that patients with chronic (>1 month) deep infections were successfully treated 75% with debridement, intravenous antibiotics, tobramycin-impregnated polymethylmethacrylate beads, and delayed exchange arthroplasty with mean interval of staged reimplantation being 8 weeks.
OrthoCash 2020
A 47-year-old man presents with 1 week of left leg pain. 6 months prior he underwent a vascularized free-fibula bone graft from his left leg to his right hip for avascular necrosis. The pain is located at the level of his donor site and is worse with weight-bearing and relieved by rest. Physical exam shows focal tenderness over his tibia. A lateral radiograph from the day of presentation is shown in Figure A. WBC, ESR, and CRP are all within normal limits. What is the next best step in management to confirm the diagnosis?
Compartment pressure measurements
CT scan
MRI scan
Ultrasound to rule out deep abscess
Bone biopsy
The clinical presentation is suspicious for a stress fracture of the tibia following free-fibula bone grafting. If plain radiographs are negative, more sensitive imaging such as a MRI or bone scan should be performed.
Tibial stress fractures are a known complication following free-fibula bone grafting. Radiographs may be normal (as is the case in figure A), or might show the "dreaded black line" and/or new periosteal bone formation. If a stress fracture is confirmed with imaging, appropriate management would then consist of protective weight bearing until symptoms subside.
Pacifico et al detail a case report of tibial stress fractures after vascularised free-fibula graft to the mandible. They report non-traumatic stress fracture to the tibia following a vascularised free-fibula graft is an uncommon but important complication.
Ivey et al detail a case report of a tibial stress fracture after vascularised free-fibula graft for repair of non-union of the humerus.
Emery et al report a case-series of 5 patients who sustained tibial stress fractures after a graft had been obtained from the ipsilateral fibula for use in anterior reconstruction of the spine. They theorize that the increased load the tibia bears as a result of the missing fibular graft may result in stress fractures.
Illustration A shows new periosteal bone formation on the lateral cortex of the tibia consistent with a stress fracture.
Incorrect Answer Choices:
1: While compartment syndrome is on the differential diagnosis, his signs and symptoms are not most consistent with that diagnosis.
2: While CT scan may show evidence of a stress fracture, MRI/bone scans have been shown to be superior methods for detection.
4: As infectious laboratories are normal, an ultrasound to rule out a deep abscess would likely be negative.
5: Bone biopsy is not appropriate without evidence of a lesion or concern for
osteomyelitis.
OrthoCash 2020
A 65-year-old female with a history of developmental dysplasia of the hip (DDH) undergoes a total hip arthroplasty (THA) utlizing a posterior approach. Following THA, she notices an inability to dorsiflex the ankle of her operative extremity. Her pre-operative and postoperative radiographs are seen in figues A and B. Which of the following intra-operative techniques could have avoided this complication in this patient?
Utilization of an anterior approach
Modular components
Use of a larger femoral head
Femoral shortening osteotomy
Acetabular osteotomy
Patients with DDH undergoing THA are at risk for post-operative sciatic nerve palsy due to intra-operative limb lengthening which increases tension on the sciatic nerve. Appropriate management after discovering a sciatic nerve palsy
after surgery should include immediate knee flexion and hip extension to decrease tension on the sciatic nerve. Sciatic nerve palsy following THA most commonly only affects the common peroneal nerve branch, and spares the tibial nerve and can present as an inability to dorsiflex and evert the ankle.
Farrell et al retrospectively looked at the risk factors for motor nerve palsy after THA. They found while motor nerve palsy is uncommon following primary THA, it can be a devastating complication. Some risk factors include: preoperative diagnosis of developmental dysplasia of the hip, posttraumatic arthritis, the use of a posterior approach, lengthening of the extremity, and use of an uncemented femoral implant. In their review, many of the motor nerve deficits did not fully resolve.
Barrack et al reviewed neurovascular complications following THA. They stated that sciatic nerve injury is the most common nerve injury following THA utilizing a posterior approach. In comparison, femoral nerve injury is much less common and is usually from an anterior approach.
OrthoCash 2020
A cane held in the contralateral hand reduces joint reactive forces through the affected hip approximately 50% by which of the following mechanisms?
Reducing hip abductor muscle pull
Increasing hip flexor muscle pull
Moving the center of rotation for the femoroacetabular joint
Increasing joint congruence at the femoroacetabular joint
Moving the center of gravity posterior to the second sacral vertebra Corrent answer: 1
A cane held in the contralateral hand reduces joint reactive forces through the affected hip up to 50% by reducing abductor muscle pull.
A cane create an additional force that keeps the pelvis level in the face of gravity's tendency to adduct the hip during unilateral stance. The cane's force must substitute for the hip abductors of the affected hip and creates a moment arm that is relatively long and originates on the side opposite the hip whose abductor muscles are weak. Additionally, the person needs adequate strength in the muscles of the wrist, elbow, shoulder girdle, and trunk.
Brand and Crowninshield performed a 3-dimensional hip joint reactive force evaluation of 4 different groups of patients. The groups included normal
subjects, preoperative THA subjects walking without a cane, preoperative THA subjects walking with a cane, and subjects following total hip reconstruction. Each of the 3 groups evaluated without the cane had statistically similar hip joint reactive forces. The preoperative THA subjects walking with a cane and significantly lower joint reactive forces (approximately 60%).
The article by Blount was named by JBJS as a "Classics in JBJS" in 2003. It is a commentary encouraging the use of canes by describing how the biomechanics of the hip joint are altered while using a cane.
Illustration A shows some of the mathematics behind cane use.
OrthoCash 2020
Which of the following is an example of an antalgic gait pattern not typically seen in clinical practice?
Patient's knee is maintained in slight flexion throughout the stance period for ipsilateral knee arthritis
Patient's contralateral step length is shortened with ipsilateral ankle arthritis
Patient leans their trunk laterally over the painful leg during stance phase with ipsilateral hip arthritis
Patient ambulates on their toes with an ipsilateral calcaneal stress fracture
Patient ambulates predominately through the heel for ipsilateral knee arthritis
The term antalgic gait is non-specific and describes any gait abnormality resulting from pain. A patient with knee arthritis maintains slight flexion throughout the gait cycle. This compensatory knee flexion is exacerbated if the patient has a concomitant effusion in the knee as flexion reduces tension on
the knee joint capsule. Gait compensation for knee arthritis also involves toe walking on the affected side, reducing the stride length, and reducing time of weight bearing on the painful leg.
Gok et al performed a case-control gait analysis study of 13 patients with OA and 13 normal patients. They found that walking velocity, cadence and stride length were reduced in the OA group and that the overall stance phase was prolonged in the OA group. They concluded that computerized gait analysis can be used to reveal various mechanical abnormalities accompanying arthrosis of the knee joint at an early stage.
Cole and Harner present Level 5 evidence about knee arthritis in the active patient. They stress that weightbearing radiographs are important in the diagnosis of arthritis. They also discuss the importance of looking for medial or lateral thrusts during gait and dynamic gait changes such as quadriceps avoidance or out-toeing.
Incorrect Answers:
OrthoCash 2020
A 78-year-old male falls at home four months following a right total hip arthroplasty. Right leg deformity, pain, and inability to bear weight are present on physical exam. An injury radiograph is provided in Figure A, while radiographs taken immediately following the initial total hip arthroplasty are provided in Figures B and C. The patient denies any prodromal groin pain prior to his fall. Which of the following is the best treatment option?
Traction for 6 weeks followed by slow return to weight bearing
Open reduction and internal fixation
Revision to a long, cementless femoral stem
Revision to a long, cementless stem with strut allograft
Revision to a long, cemented stem Corrent answer: 2
The clinical presentation and radiograph are consistent with a Vancouver B1 periprosthetic femur fracture. The stem appears stable within the femur, and there is no evidence of subsidence with comparison to the initial post-THA radiographs. This fracture pattern is best treated with internal fixation.
Illustrations A and B are radiographs of this patient following fixation. Illustrations C and D show bone healing at 2 years following the fracture.
Duwelius et al report on 33 periprosthetic femur fractures. All fractures that demonstrated a stable stem at the time of surgery were treated with internal fixation, while those that were unstable were treated with a long, cementless revision femoral stem. At 2.5 years complications were minimal and the patients had regained their pre-fracture level of function.
The review article by Kelley outlines the evaluation, classification, and treatment of periprosthetic femur fractures reinforcing the importance of stem stability within the femur. Periprosthetic fractures around a hemiarthroplasty should be treated with the same algorithm. However, if the patient had antecedent groin pain, then conversion to a total hip arthroplasty should be considered to prevent continued groin pain.
OrthoCash 2020
A 64-year-old male underwent the procedure shown in Figures A and B 7 weeks ago. He complains of difficulty with going down stairs. He reports no pain and denies constitutional symptoms. On examination the incision is well healed and no effusion is present. He is able to perform a straight leg raise with 5/5 strength. He lacks 2 degrees of terminal extension and has 80 degrees of active flexion. The knee is stable to varus and valgus stress testing at extension and mid flexion. His C-reactive protein and erythrocyte sedimentation rate are normal. What is the next most appropriate step in management?
Manipulation under anesthesia
Cortisone injection followed by physical therapy for quadriceps strengthening
Aspiration to evaluate for septic arthritis
Revise femoral component by downsizing A-P diameter
Revise tibial component and add 5 degrees of posterior tibial slope Corrent answer: 1
The history, physical examination, laboratory studies, and imaging are consistent with a total knee arthroplasty patient with arthrofibrosis. The next most appropriate option includes a manipulation under anesthesia to increase the patient's flexion.
Maloney presents Level 4 evidence discussing TKA postoperative arthrofibrosis. They report that manipulation under anesthesia was successful in improving flexion from an average of 67 degrees premanipulation to 111 degrees
postmanipulation.
Keating et al report Level 4 evidence of 113 patients that underwent manipulation following TKA. They found that 90% of the patients achieved improvement of ultimate knee flexion following manipulation. The average improvement in flexion from the measurement made before manipulation to that recorded at the five-year follow-up was 35 degrees.
OrthoCash 2020
Which of the following total hip arthroplasty patients appropriately meets the criteria for a surgical debridement with isolated femoral head and polyethylene liner exchange?
Prosthesis infection of 4 months duration
Prosthesis infection 8 weeks following implantation
Prosthesis infection 3 days following a systemic infection
Acetabular component loosening due to osteolysis
Vancouver Type A periprosthetic fracture.
Femoral head and polyethylene liner exchange is an appropriate treatment for the acutely infected arthroplasty. Acute infection has been defined as 3-6 weeks following surgery or following a systemic infection depending on the literature source. Subacute and chronic infections must be treated with a complete explant and exchange of all components. (One-stage or two-stage is controversial).
Salvati et al review the management of total hip arthroplasty infection. Most importantly, the pathogen must be isolated to direct antibiotic treatment. The acuity of the infection must also be recognized to direct surgical management.
OrthoCash 2020
A 54-year-old woman is at physical therapy 3 months after a total knee arthroplasty when she feels a pop and develops increased pain in her knee. She continues therapy for another 3 months but reports weakness and frequent buckling. On exam, she has full passive extension but a 60 degree extensor lag. A lateral radiograph is shown in Figure A. What is the treatment of choice?
Reconstruction with a bone-tendon allograft
Repair augmented with hamstring autograft
Continued therapy and strengthening
Arthrodesis
Treatment with orthotics for support Corrent answer: 1
The patient has a chronic patellar tendon rupture following a TKA with marked extensor lag and patella alta on radiograph. A study by Barrack et al concluded that allograft reconstruction for the chronically-disrupted extensor mechanism after TKA could restore active extension and improve ambulatory function. In chronic cases, primary repair with or without local tissue augmentation have had disappointing results. Extensor mechanism injuries after TKA was reviewed by Parker et al. Patellar tendon ruptures are rare complications after TKA with an incidence reported <2.5%. Quadriceps tendon ruptures are even more rare with an incidence ~1%.
OrthoCash 2020
When compared to the standard medial parapatellar approach for revision total knee arthroplasties, the oblique rectus snip approach
showed impairment in which of the following post-operative outcomes?
range-of-motion
patient satisfaction
pain
WOMAC function score
no difference in outcomes Corrent answer: 5
Meek et al compared the rectus snip to a standard medial parapatellar approach for revision total knee arthroplasty. The WOMAC function, pain, stiffness and satisfaction scores demonstrated no statistical difference. They concluded that use of a rectus snip as an extensile procedure had no adverse effect on outcome.
OrthoCash 2020
What is the range of pore size of cementless porous implants to allow for optimal bony ingrowth?
Less than 1 micron
50 to 400 microns
1,000 to 5,000 microns
10,000 to 50,000 microns
100,000 to 500,000 microns
The range of 50 to 400 microns is the optimal pore size for cementless porous implants to allow for optimal bony ingrowth.
Bobyn et al looked at the optimum pore size for fixation of porous surfaced metallic implants. Four different pore sizes were examined and placed in canine femurs for 4, 8, and 12 weeks and tested to measure the shear strength based on pore sizes. A pore size of 50 to 400 microns provided the maximum fixation strength in the shortest time period (8 weeks), implying maximal bony ingrowth.
Pilliar et al discussed two independent canine studies which showed that initial implant movement relative to host bone can result in attachment by a nonmineralized fibrous connective tissue layer. They state that implant movement of greater than 150 microns leads to fibrous ingrowth.
Jasty et al implanted porous-coated implants in the distal femoral metaphyses of twenty dogs and subjected them to zero, twenty, forty, or 150 micrometers of oscillatory motion. They found that that the implants that had been subjected to 150 micrometers of motion were surrounded by dense fibrous tissue.
OrthoCash 2020
An active 73-year-old male presents with progressive pain and instability 15 years after undergoing a left total knee arthroplasty. He denies any recent trauma. A comprehensive workup for infection is negative. What is the most appropriate management of this patient?
Protected weight bearing for 6 weeks
Revision total knee arthroplasty
Bisphosphonate therapy
Routine follow-up in 1 year
Polyethylene liner exchange and bone grafting Corrent answer: 2
This patient has evidence of periarticular osteolysis and component loosening around a previous total knee arthroplasty. He is symptomatic and would benefit from revision total knee arthroplasty (TKA).
Osteolysis is one of the leading causes for late reoperation in patients who undergo TKA. Osteolysis occurs as the result of a foreign body response to particulate wear debris from the prosthetic joint. These particles consist of polyethylene, polymethylmethacrylate cement, and metal, all of which have been shown to elicit a distinct inflammatory response. Once the particles are generated from and around the implant, they become phagocytosed by macrophages and giant cells in the synovial or periprosthetic tissue. These cells, in turn, become activated and can directly or indirectly cause osteolysis. The femur is prone to osteolysis in the region of the femoral condyles and near the attachments of the collateral ligaments of the femur. Osteolysis around the tibia tends to occur along the periphery of the component or along the access channels to the cancellous bone.
Maloney & Rosenberg reviewed the management and outcome of periprosthetic osteolysis around hip and knee implants. They recommended surgical intervention for periprosthetic osteolysis around a TKA with (1) first-time presentation of advanced osteolysis in the presence of an identifiable cause of wear particle production or in the presence of associated bone loss that places the structural integrity of the bone or fixation of the components at risk, (2) bearing surface wear in the presence of impending wear-through or related mechanical symptoms, (3) progressive osteolysis in an active individual, and (4) symptoms of wear debris-related synovitis that are refractory to conservative treatment.
Griffin et al. evaluated the results of isolated polyethylene exchange for wear and/or osteolysis in 68 press-fit condylar TKAs from four centers. At a minimum of 24 months after polyethylene exchange surgery, there were 11 failures (16.2%).
Gupta et al. discuss the etiology, diagnosis, contributing factors, and management of osteolysis as it relates to TKAs. They recommend that if the patient is asymptomatic with minimal osteolysis on plain radiographs, regular
follow-up at 6 months to 1 year with medical management including calcium and bisphosphonates would be adequate. If the patient becomes symptomatic or the osteolysis is progressive, then early liner exchange with or without tibial baseplate exchange is considered.
Figure A & B are AP and lateral radiographs of periarticular osteolysis and component loosening. Illustration A is an AP and lateral radiograph of the revision TKA.
Incorrect Answers:
OrthoCash 2020
Which of the following statements is true regarding the thirty-year follow-up data obtained from the Charnley "low-friction" total hip arthroplasty?
Acetabular component failure was the least common reason for revision surgery
The number of revisions required for periprosthetic fractures was higher than that for deep infections
Acetabular component failure was a more common reason for revision than deep infection
Femoral component failure was a more common reason for revision than acetabular component failure
Deep infection was the most common reason for revision Corrent answer: 3
Failure of the acetabular component was the most common reason for revision at thirty-years for the Charnley "low-friction" total hip arthroplasty.
The Charnley low-friction torque arthroplasty was introduced in 1962. It consisted of a 22mm diameter metal head, a cemented femoral component, and a cemented ultra-high-molecular-weight polyethylene acetabular component. Overall, the results were very good at thirty years with only 11.8% requiring revision.
Charnley et al. in 1972 reported the 4-7 year results of 379 "low-friction" total hip arthroplasties. Overall, their short-term results were very good with only 2 loose acetabular components, 0 loose femoral components, and 1 late dislocation.
Wroblewski et al. in 2009 reported the 30 year follow-up of 110 patients who underwent the "low-friction" total hip arthroplasty. 13 hips (11.8%) had to be revised. Of these, 5 were for problems with the acetabular component, 4 were for loosening of both components, 2 were for deep infection, 1 was from a loose femoral component, and 1 was from a fractured femoral component.
Illustration A shows a radiograph after a Charnley low-friction total hip arthroplasty. Note the all poly-ethylene acetabular component. Illustration B shows the components used for the operation.
Incorrect Answers:
OrthoCash 2020
A 71 year old gentleman underwent left total hip arthroplasty 10 years ago. Eighteen months ago he began having hip and thigh pain. Over the past 6 weeks, the pain has become excruciating and he has been unable to ambulate, even with the aid of a walker. He has mild pain with passive internal and external rotation of the hip. He is unable to ambulate in the office. Laboratory values are notable for a WBC of 10,300, CRP of 0.2, and ESR of 13. A radiograph is provided in figure A. Which of the following is the best treatment option?
Radionuclide bone scan and MRI
Open reduction internal fixation with a cable plate and allograft strut
Revision arthroplasty with a fully coated cementless stem, cable wiring, and bone graft
Revision arthroplasty with a modular, tapered stem and bone grafting of the diaphyseal fixation
Revision arthroplasty with a total femur prosthesis Corrent answer: 3
The radiograph is consistent with a periprosthetic femur fracture, with a loose femoral stem, and a Paprosky IIIA femoral defect. This is best treated with a fully-coated cementless stem with metaphyseal onlay allograft.
Paprosky devised a classification for femoral bone loss following THA. The classification is as follows:
Type I: minimal metaphyseal bone loss and intact diaphyseal fixation Type II: extensive metaphyseal bone loss with intact diaphyseal fixation
Type IIIA: severe metaphyseal bone loss with greater than 4 cm of diaphyseal bone preservation for distal fixation.
Type IIIB: severe metaphyseal bone loss and less than 4 cm of diaphyseal
bone preservation for distal fixation
Type IV: extensive metaphyseal and diaphyseal bone loss.
Type IIIA may be treated with a fully coated stem. Type IIIB should consider a tapered, modular stem and/or bone grafting. Type IV likely needs a megaprosthesis. In this patient, given the preserved diaphyseal bone, revision arthroplasty with a fully coated femoral stem is the most appropriate treatment.
The Sporer article reviews a case series of patients undergoing revision hip arthroplasty for femoral bone loss. Type IIIB defects with a femoral canal less than 19 mm may be treated with a fully porous-coated stem. However, patients with Type IIIB defect and a cavernous canal greater than 19 mm or a Type IV defect may need a modular tapered stem or a bone grafting procedure.
The Paprosky article summarizes his classification of femoral bone loss in revision hip arthroplasty and provides an algorithm for treatment. Extensively porous-coated, diaphyseal filling femoral components showed excellent results in Paprosky IIIA defects.
Radiograph A shows a total hip arthroplasty with severe metaphyseal bone loss and a supportive diaphysis.
Incorrect Answers:
OrthoCash 2020
A 74-year-old man presents with start-up thigh pain following a total hip replacement 10 years ago. Immediate post-operative radiograph is shown in Figure A. A current radiograph is shown in Figure B. Aspiration of the hip yields 1,005 white blood cells/ml. ESR is 12 (normal <40) and CRP is 0.4 (normal <1.2). Which of the following is the most appropriate management at this time?
Revision of the femoral component to an uncemented, long, fully porous-coated stem
Revision of the femoral component to a cemented stem
Revision of the femoral component to an allograft prosthetic composite
Revision of the femoral component to a proximal femoral replacement
Removal of prosthesis with insertion of antibiotic spacer Corrent answer: 1
The clinical presentation is consistent with symptomatic, aseptic femoral component loosening with no evidence of femoral bone defects. Appropriate management consists of revision of the femoral component to an uncemented, fully porous-coated stem.
Aseptic loosening remains one of the most common indications for revision total hip arthroplasty. After infection has been ruled-out, management is determined by gauging the patients symptoms, the rate of progression of the subsidence, and the amount of femoral bone loss. Uncemented revision femoral components have shown superior results to cemented revision femoral components in the long-term. In the setting of Paprosky Type I, II, and IIIA defects of the femur, revision to an uncemented, fully porous-coated stem is advised.
Moreland et al. review the results of 134 patients (137 hips) who underwent revision arthroplasty with an extensively porous-coated cobalt chrome femoral prosthesis. At a mean follow-up of 9.3 years, only 10 (7%) had to removed for any reason.
Sporer et al. review the results of fully porous-coated stems, impaction bone grafting, and modular tapered stems for Paprosky III and IV femoral defects. They found a high rate of failure with fully porous-coated stems when used in patients with Type IIIB defects >19mm and Type IV defects. They attribute these failures to instability and the inability to eliminate micromotion.
Figure A shows a cementless, metaphyseal engaging femoral component in good alignment. Figure B is a post-operative radiograph from 10 years later showing significant subsidence of the femoral component.
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OrthoCash 2020
A 72-year old female who underwent an uncemented right total hip arthroplasty 2 years ago complains of right hip pain after a fall. Figure A shows her current radiograph. Which acetabular bone defect classification and treatment option best describes this scenario?
AAOS Type III - anti-protrusio cage with augmentation and a posterior column plate
AAOS Type IV - anti-protrusio cage with screw fixation and a posterior column plate
AAOS Type II - jumbo cup with augmentation and a posterior column plate
AAOS Type I - total acetabular allograft with a cemented cup
AAOS Type II - custom triflange acetabular component Corrent answer: 2
Figure A shows pelvic discontinuity, which is consistent with a AAOS Type IV defect. Acetabular antiprotrusio cage with screw fixation and a posterior column plate is a reasonable treatment option for this condition.
Acetabular bone loss following total hip arthroplasty is a challenging problem with a wide variety of treatment options available. The two most widely accepted classification systems are the AAOS and Paprosky classifications.
AAOS type I defects are segmental, type II are cavitary, type III are combined cavitary and segmental, type IV is discontinuity, and type V is arthrodesis. All of the treatment options listed above are described for pelvic discontinuity,
with none being described as superior.
DeBoer et al. describe the results of 28 patients with pelvic discontinuity treated with a custom-made porous-coated triflange acetabular prosthesis. 20 of these patients were followed for 10 years. There were no re-operations, 5 hip dislocations, 1 sciatic nerve palsy, and an average improvement in the Harris hip score from 41 to 80.
Paprosky et al. retrospectively reviewed patients who had an acetabular revision using a trabecular metal acetabular component for a pelvic discontinuity and compared these patients with a cohort of patients who had a previous reconstruction for a pelvic discontinuity using an acetabular cage.
They found a decreased incidence of pain and need for walking aids in those patients who had revision with a trabecular metal acetabular component.
Figure A shows pelvic discontinuity, likely acute given the lack of associated bony defects and recent fall. Illustration A details the AAOS hip acetabular defect classification and Illustration B is the often cited Paprosky classification.
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OrthoCash 2020
Which of the following is indicative of type 1 collagen breakdown and can be utilized as a marker of bone turnover?
Increased urinary N-telopeptide
Increased urinary cAMP and phosphate
Increased urinary phosphoethanolamine
Increased urinary Bence Jones proteins
Increased serum bone sialoprotein Corrent answer: 1
Urinary N-telopeptide is a marker of increased bone turnover and is a breakdown product of Type 1 collagen.
Increased serum alkaline phosphatase level and increased urinary markers of N-telopeptide, hydroxylproline, deoxypyridinoline indicate high bone turnover and can be seen in metabolic bone diseases such as Paget's disease.
von Schewelov et al. reviewed 160 patients that underwent total hip replacements and examined their urine specimens to see if N-telopeptide levels correlated to periprosthetic osteolysis. They found that n-telopeptide levels were 1/3 higher in the patients that had evidence of osteolysis. N-
telopeptide release and annual wear were both associated with increased prevalence of osteolysis in the study.
Illustration A shows a radiograph of Pagets disease of the femur, an example of a condition where there is an increased level of N-telopeptide in the urine. Illustration B is a radiograph showing periprosthetic osteolysis, another condition where there is an increased level of N-telopeptide in the urine.
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OrthoCash 2020
A 78-year-old female undergoes total hip arthroplasty through a minimally invasive surgical approach. During insertion of a metaphyseal fixation stem with a cementless press-fit technique, a crack in the calcar is identified. The stem is removed, two cable wires are passed around the calcar, and the same stem is reinserted. Which of the following statements is true?
The patient should be advised she is at greater risk of stem subsidence and early revision
Female sex is a risk factor for intraoperative calcar fracture
A better outcome would be expected if a long-stem diaphyseal fixation stem had been inserted after recognition of the calcar fracture
Cementless press-fit technique is not a risk factor for intraoperative fracture
Minimally invasive surgical approach is not a risk factor for intraoperative fracture
Of the statements listed, the only true statement is that female gender is a risk factor for intraoperative calcar fracture.
Calcar fractures are a documented complication of total hip arthroplasty. Studies have shown that successful outcomes can be achieved with stem removal, cable wiring of the calcar, and re-insertion of the primary stem.
Berend et al. reviewed a series of 58 total hip arthroplasties who sustained an intraoperative calcar fracture. All were treated with cable wiring of the calcar and stem insertion. The authors report no femoral component subsidence or failure otherwise at 16 year follow-up.
Graw et al. review a series of 46 revision THA's. Of the 46, fifteen underwent primary THA through a minimally invasive technique. The average length of time from primary THA to revision was 1.4 years for the minimally invasive group versus 14.7 years for the traditional exposure THA's. The authors conclude minimally invasive THA is a risk for early revision.
Davidson et al. review intraoperative periprosthetic hip fractures. "Risk factors for intraoperative periprosthetic fractures include the use of minimally invasive techniques; the use of press-fit cementless stems; revision operations, especially when a long cementless stem is used or when a short stem with impaction allografting is used; female sex; metabolic bone disease; bone diseases leading to altered morphology such as Paget disease; and technical errors at the time of the operation." The authors summarize techniques for treatment and postulate that long term outcome is unaffected when the intraoperative fracture is identified and treated appropriately.
Illustration A shows a nondisplaced calcar crack that was treated with a single Luque wire.
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OrthoCash 2020
Which of the following types of prosthetic designs, seen in figures A-E, has been shown to have a high rate of loosening secondary to overconstraint?
Figure C shows an example of an Walldius hinge total knee prosthesis. This design had a higher rate of aseptic loosening (up to 20%) secondary to a high-degree of constraint.
Constraint is defined as the effect of the elements of knee implant design that provides the stability needed to counteract forces about the knee after arthroplasty in the presence of a deficient soft-tissue envelope. While increasing component constraint increases the stability of the knee, it also transmits forces to the fixation and implant interfaces, which may lead to premature aseptic loosening. First-generation total knee hinged prostheses were highly constrained devices that only allowed a single axis of rotation.
Lombardi et al. provide an Instructional Course Lecture on the different prosthetic designs in total knee arthroplasty. They argue that PCL sacrificing implants are more appropriate than cruciate-retaining implants in rheumatoid arthritis, previous patellectomy, previous high tibial osteotomy or distal femoral osteotomy, and in cases where the PCL is absent secondary to trauma.
Morgan et al. discuss constraint in primary total knee arthroplasty. They argue that a hinge total knee arthroplasty should be reserved for severe instability, elderly patients with comminuted distal femur fractures, patients with
extensor-mechanism disruption and unstable knees, and those with substantial bone loss not amenable to augmentation.
Figure C shows an example of a Walldius hinged prosthesis.
Illustration A shows an intra-operative example of a constrained-hinged knee prosthesis. Note the link between the tibial and femoral components, which differentiates it from a constrained, non-hinged prosthesis.
Incorrect Answers: The following responses are incorrect as they all have lower rates of aseptic loosening than than varus/valgus constrained prostheses or hinged designs.
OrthoCash 2020
A 28-year-old football player sustains a contact knee injury while being tackled. On physical exam, he has a 1A Lachman, and a normal McMurray test. His posterior drawer, dial, and varus stress tests are normal. He has pain and 5mm opening on valgus stress at 30 degrees of flexion. Which statement is true regarding the injured structure?
Resides between layers 1 and 2 on medial side of knee
Inserts onto Gerdy's tubercle
Originates slightly posterior and proximal to the medial epicondyle
Courses intraarticularly thru hiatus of lateral meniscus
Has an attachment between adductor tubercle and medial epicondyle at Schöttle's point
The clinical presentation is consistent with an injury to the superficial medial collateral ligament (MCL) of the knee, which originates slightly posterior and proximal to the medial epicondyle.
The superficial portion of the MCL is the primary stabilizer to valgus stress at all angles, contributing 57% and 78% of medial stability at 5 degrees and 25 degrees of knee flexion, respectively. Anatomic studies have shown that the superficial MCL originates approximately 3.2 mm proximal and 4.8 mm posterior from the medial femoral epicondyle and inserts into the periosteum of the proximal tibia (deep to pes anserinus). The superficial MCL lies in layer 2, just deep to gracilis and semitendinosus tendons.
Wijdicks et al. (2009) looked at radiographic identification of the primary medial knee structures including the superficial MCL. On the lateral radiograph, they found that the attachment of the superficial MCL was an average of 6.0 mm from the medial epicondyle.
Wijdicks et al. (2010) reviewed injuries to the MCL and associated medial structures of the knee. They state that physical examination is the initial method of choice for the diagnosis of medial knee injuries through the application of a valgus load both at full knee extension and between 20 degrees and 30 degrees of knee flexion. Treatment of isolated grade-III injuries to the MCL, or such injuries combined with an anterior cruciate ligament tear, should start with nonoperative treatment of the MCL due to high rates of success with nonoperative treatment. If operative treatment is required, an anatomic repair or reconstruction is recommended.
Illustration A shows the femoral and tibial attachments of the superficial MCL. Illustration B shows the osseous landmarks and attachments of medial knee structures (AT, adductor tubercle; GT, gastrocnemius tubercle; ME, medial epicondyle; AMT, adductor magnus tubercle; MGT, medial gastrocnemius tendon; sMCL, superficial MCL; MPFL, medial patellofemoral ligament; POL, posterior oblique ligament).
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OrthoCash 2020
Which of the following best describes normal tibio-femoral joint kinematics ?
The femur undergoes internal rotation with knee flexion
The lateral femoral condyle remains stationary on the lateral tibia plateau during knee flexion from 0 to 120 degrees
The tibia undergoes internal rotation with knee flexion
The medial femoral condyle moves posteriorly on the medial tibial plateau during knee flexion from 0 to 120 degrees
Beyond 120 degrees of flexion only the lateral femoral condyle participates in femoral rollback
Tibia is subjected to internal rotation with knee flexion and the tibia EXternally rotates on femur as the knee EXtends.
The axis of rotation shifts posterior on the lateral condyle with knee flexion. Flexion and extension at the knee occur about a constantly changing center of rotation (polycentric rotation).
Freeman et al. conducted a biomechanical experiment and found that the medial femoral condyle does not move much from 0 to 120 degrees of flexion. They also found that the lateral femoral condyle and the contact area between that condyle and the tibia move posteriorly and tibial internal rotation occurs with knee flexion. They found that from 120 degrees to full flexion both condyles participate in "roll back".
Illustration A shows why the screw-home mechanism occurs. The medial tibial plateau is longer than the lateral tibial plateau, leading to external rotation of the tibia during extension as the femoral condyle rotates about the tibia. Video V shows an example of external tibial rotation during extension.
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OrthoCash 2020
Which of the following molecules is associated with macrophage induced osteolysis surrounding orthopaedic implants?
BMP-7
IL-10
SOX-9
Osteoprotegrin
IL-1
Of the options provided, IL-1 is most associated with macrophage induced osteolysis surrounding orthopaedic implants.
Macrophages initiate the inflammatory cascade associated with aseptic loosening of orthopaedic implants by secreting platelet-derived growth factor (PDGF), prostaglandin E2 (PGE2), TNF-alpha, IL-1, and IL-6.
Archibeck et al. state the primary cells involved in the process of periprosthetic loosening include the macrophage, osteoblast, fibroblast, and osteoclast. They report the chemical mediators that are responsible for the cellular interactions and effects on bone primarily include PGE2, TNF-alpha, IL-1, and IL-6.
Drees et al. discuss the molecular pathway of aseptic loosening of orthopedic implants. They describe the following steps: 1) Wear debris particles released at the cement–bone interface attract macrophages, which, in turn, are stimulated to produce proinflammatory mediators and proteolytic enzymes; 2) RANKL, TNF-alpha, IL-1, IL-6, IL-17, and M-CSF mediate the differentiation of myeloid precursor cells into multinucleated osteoclasts, which release cathepsin K and acid and cause resorption lacunae; 3) Mesenchymal cells (prosthesis-loosening fibroblasts) present at the bone surface contribute actively to bone resorption.
Illustration A shows the pathway described by Drees et al.
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OrthoCash 2020
Which of the following templates, seen in Figures A-E, will increase the offset while keeping the leg lengths the same?
If the total hip prosthesis is inserted according to the template in Figure E, the offset will be increased, while the leg lengths will remain unchanged.
Restoration of limb length is essential following total hip arthroplasty. The amount of limb-length change will be the vertical distance between the center of rotation of the femoral component and the center of rotation of the acetabular component. Thus, when the femoral center of rotation on templating is inferior to that of the acetabular component, the limb will be shortened. Restoring femoral offset is also important. If the center of rotation of the prosthetic head lies lateral to that of the cup on templating, the reconstruction will produce decreased offset.
Scheerlinck et al. present a stepwise approach to hip templating through four steps. Step 1 involves identifying landmarks, step 2 involves assessing the
quality of the radiograph, step 3 identifies mechanical references, and step 4 optimizes implant positioning.
Tripuraneni et al. discuss the common errors encountered when templating for total hip arthroplasty. They found the most common error was excessive limb lengthening and incomplete medialization of the acetabular component.
Della Valle et al. review hip templating. They stress the importance of preoperative planning, but also discuss the importance of tactile feedback during the surgery in choosing the correct implants.
Illustration A shows a table of how offset and leg lengths can be changed through positioning and selection of components.
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OrthoCash 2020
A 91-year-old male with a history of chronic leukemia and dementia falls and sustains the hip fracture shown in Figure A. He undergoes a hemiarthroplasty through a posterior approach. A postoperative radiograph is shown in Figure B. Three weeks later he dislocates the hip arising from the toilet seat. A radiograph is shown in Figure C. The patient undergoes a closed reduction and is placed in a hip abduction brace. Post reduction radiograph is shown in Figure D. One month later he returns to clinic complaining of pain and inability to bear weight through the leg. A radiograph of the hip is included in Figure E. Which of the following factors has MOST likely contributed to the instability of the hip hemiarthroplasty?
Femoral stem subsidence
Increased offset
Inadequate femoral stem neck length
Patient's dementia status
Patient's gender
The most likely contributing factor to the instability include the patient's dementia.
Sultan et al use a basic science model to show liners with elevated rims placed in the posterior superior quadrant allow greater range of motion to dislocation than standard liners. They also show that 32 mm heads have greater range of motion to dislocation compared to 28 mm heads.
Morrey et al reviewed a series of 19,680 primary THA's for late dislocation (first dislocation greater than 5 years after surgery). 165 hips (0.8%) had a late dislocation. Factors associated with late dislocation include implant malposition, neurologic decline, trauma, and polyethylene wear.
Figure A shows a femoral neck fracture. Figures B and D show a hip hemiarthroplasty in appropriate position. Figure C and E show a dislocated hip hemiarthroplasty
This patient's instability was managed by converting the hip hemiarthroplasty to a total hip arthroplasty with a constrained liner as shown in illustration A. No further instability episodes occurred following the revision.
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OrthoCash 2020
What surgeon is credited for designing the prosthesis seen in Figure A?
John Charnley
San Baw
Sir Harry Platt
Austin T. Moore
Charles Frederick Thackray Corrent answer: 4
Figure A shows an example of an Austin-Moore hemiarthroplasty.
Austin Moore developed the most popular long-stemmed prosthesis in the 1950s. The Austin-Moore prosthesis was a large, uncemented femoral stem that didn't use polyethylene. The Austin-Moore prosthesis had fenestrations for self-locking which later became the impetus for biological fixation. These implants were originally used to treat hip fractures and certain cases of degenerative arthritis. Later, in the 1960s, John Charnley introduced the idea of replacing the eroded acetabulum with a Teflon component.
Moore et al. describe the first metallic hip replacement surgery in 1940. The patient had a proximal femoral resection for a giant cell tumor. The original prosthesis he designed was a proximal femoral replacement, with a large fixed head, made of the Cobalt-Chrome alloy Vitallium.
Charnley et al. discuss the long-term results (up to 7 years) of the "low-friction" total hip arthroplasty. Infection rate was 3.8%, late mechanical failure was 1.3%, and most patients had excellent pain relief.
Figure A shows a radiograph of an Austin-Moore hemiarthroplasty. Illustration A shows an Austin-Moore prosthesis. Illustration B shows an example of Charnley's "low-friction" total hip arthroplasty, with a stainless steel head and
stem and a polyethylene acetabular component.
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OrthoCash 2020
A 45-year-old man has had the gait disturbance shown in Video A ever since a total hip replacement two years ago. Since then he has undergone physical therapy and nerve exploration without any clinical improvement. Extensive AFO bracing was attempted but was not tolerated by the patient. A recent ankle radiograph is shown in Figure
A. The Silfverskiold test reveals dorsiflexion of 20 degrees with knee flexion, and 10 degrees with full knee extension. The results of muscle
testing using a Cybex dynamometer are shown in Figure B. What is the most appropriate next step in in treatment.
Ankle arthrodesis in 30 degrees of dorsiflexion
Posterior tibial tendon transfer to the lateral cuneiform through the interosseous membrane
Split anterior tibial tendon transfer to the cuboid
Peroneus longus transfer to the navicular and gastrocnemius recession
Flexor hallucis transfer to the navicular and tendo Achilles lengthening (TAL) Corrent answer: 2
The clinical presentation is consistent with a sciatic neuropathy following THA in a patient that does not tolerate AFO bracing. Posterior tibialis tendon transfer is the next most appropriate step in treatment.
Sciatic neuropathy, especially involving the common peroneal branch, is a known complication of total hip arthroplasty. Typically a patient is adequately treated with an AFO. In some clinical situations an AFO is not tolerated, and a tendon transfer is required. The posterior tibial tendon is the most commonly used donor muscle. A tendon transfer is feasible only if the tendon possesses at least 4/5 power. There is a loss of 1 MRC grade of strength following transfer.
Rodriguez et al. retrospectively reviewed the results of the Bridle procedure 10 patients (11 feet) with a foot drop. The Bridle procedure consists of a posterior tibial tendon transfer through the interosseous membrane to the dorsum of the foot with a dual anastomosis to the tendon of the anterior tibial and a rerouted peroneus longus in front of the lateral malleolus. In their study all 11 feet were brace-free at final followup at 6.68 years.
Yeap et al. retrospectively reviewed 12 patients who were treated with tibialis posterior tendon transfer for footdrop. They found good/excellent patient satisfaction in 10/12 patients. Additionally they found favorable variables for a good outcome include common peroneal nerve palsy over sciatic nerve palsy, male gender less than 30 years of age.
Figure V is a Video that shows a right footdrop with high steppage gait. Figure A shows normal ankle radiographs. Figure B shows the results of dynamometer testing described above. Illustration A shows the Bridle procedure. The left panel shows how the tibialis posterior tendon (C) is tunneled through the interosseous membrane and through a slit in the tibialis anterior tendon (A) and inserted into the second cuneiform. The peroneus longus (B) is also transected and the distal stump is routed anterior the lateral malleolus and anastomosed to the tibialis anterior and tibialis posterior (at the slit where it passes through the tibialis anterior). The right panel shows retrieval of the tibialis posterior tendon above the ankle and passage through a window in the interosseous membrane.
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OrthoCash 2020
Which of the following variables is associated with elevated serum metal ion levels following metal-on-metal hip resurfacing arthroplasty?
Smaller implant diameter
Smaller acetabular cup abduction angle
Higher postoperative functional scores
Severe preoperative osteoarthritis
Anteversion of acetabular cup between 10 and 20 degrees Corrent answer: 1
Smaller femoral head diameter is associated with elevated serum metal ion levels with metal-on-metal hip resurfacing arthroplasty.
Metal-on-metal (MOM) hip resurfacing arthroplasty has the advantage of better wear properties (lower linear wear rate and volume of particles) than metal on polyethylene. However, elevated serum metal ion levels is one of the negatives which has received much attention recently. Studies have found smaller implant diameter and acetabular cup abduction angle >55 degrees are associated with elevated serum metal ion levels. Cup abduction angles of greater than 55 degrees lead to a more vertical cup and edge loading.
Desy et al. found that smaller implant diameter, larger cup inclination, and lower postoperative functional scores are associated with increased cobalt and chromium levels after metal-on-metal hip resurfacing. They found that severity of preoperative osteoarthritis, acetabular version, femoral stem-shaft and valgus angle, and anterior orientation of the femoral component had no effect on the circulating metal ion levels.
DeHaan et al. obtained serum ion levels in 214 MOM resurfacing patients at least 1 year following surgery. They found that cup abduction angles greater than 55 degrees combined with smaller component sizes led to edge loading and elevated ion levels.
Illustration A shows how a metal-on-metal prosthesis design allows you to have a larger femoral head as opposed to a metal on polyethylene design (example in THA). Illustrations B and C show a photo of a metal on metal resurfacing implant and radiographs of the implant.
Incorrect Answers:
2: Elevated cup abduction angle leads to elevated serum metal ions.
3: Higher postoperative functional scores have not been shown to increase serum metal ions.
4: Severity of pre-operative arthritis has not been associated with increased serum metal ions.
5: Anteversion of the acetabular cup between 10 and 20 degrees has not been shown to increase serum metal ions.
OrthoCash 2020
Which of the following intra-operative steps would put a patient at risk for lateral patellar maltracking during total knee arthroplasty (TKA)?
External rotation of the femoral component
Medial placement of the patellar component
Internal rotation of the tibial component
Lateral translation of the femoral component
Superior placement of the patellar component Corrent answer: 3
Internal rotation of the tibial component increases the Q angle and causes an increased risk of lateral patellar maltracking.
During TKA, useful techniques that help prevent patellar maltracking include: external rotation of the femoral and tibial components, lateral translation of the femoral component, and medial placement of the patellar component.
In an instructional course lecture, McPherson looked at patellar tracking in primary TKA. He reviews the concept of patellofemoral maltracking, the importance of the Q angle, mechanical alignment, femoral component rotation, tibial component positioning, patellar component positioning, patellar height, and patellar resurfacing as factors related to patellofemoral tracking.
Bengs et al. studied the effect of patellar thickness on intra-operative knee flexion and patellar tracking during PCL retaining TKAs. Using 2mm increments (2-8 mm), passive knee flexion was recorded and gross mechanics of patellofemoral tracking were assessed. On average, passive knee flexion decreased 3 degrees for every 2-mm increment of patellar thickness, there was no gross effect on patellar subluxation or tilt.
Illustration A shows how internal rotation of the tibial component would increase the Q angle, and thus be more likely to have lateral patellar maltracking.
Incorrect answers:
OrthoCash 2020
A patient undergoes a primary total hip arthroplasty with a highly cross-linked ultra-high molecular weight (UHMW) polyethylene acetabular liner. In comparison to a 28mm femoral head, a 32mm femoral head will provide which of the following?
Increased risk of dislocation
Decreased range of motion
Decreased risk of osteolysis
Equivalent wear rate of the polyethylene acetabular liner
Increased risk of periprosthetic fracture Corrent answer: 4
Wear rates of highly cross-linked UHMW polyethylene liners are independent of femoral head size between 22 and 46 mm in diameter.
While the wear rates of old polyethylene liners increased with increasing femoral head size, wear rates of the new highly cross-linked UHMW polyethylene liners have shown to be independent of head size. This is extremely advantageous, as increasing the femoral head size improves range of motion and increases jump distance, thereby decreasing dislocation rates.
Geller et al. report a prospective series of 42 patients that had a total hip arthroplasty with a highly cross-linked UHMW polyethylene liner and a femoral head >32 mm in diameter. After three years, there were no cases of osteolysis or failure due to aseptic loosening.
Muratoglu et al. studied the wear rates of several polyethylene liners with varying femoral head sizes. In the highly cross-linked UHMW polyethylene group, wear rates were independent of femoral head size.
Illustration A shows how increasing femoral head size increases the jump distance required for dislocation.
Incorrect Answers:
OrthoCash 2020
A 56-year-old male undergoes an uncomplicated revision total knee arthroplasty. Post-operatively, he is noted to have a foot drop that has persisted despite conservative management including bracing and physical therapy. At two months, the patient undergoes external neurolysis with no improvement in function. At 18 months follow-up, he demonstrates passive ankle dorsiflexion 10 degrees past neutral, complete absence of active dorsiflexion, and 5/5 inversion strength. Which of the following is the most appropriate treatment at this time?
Continue Ankle-foot orthosis (AFO) and physical therapy
Repeat neurolysis with possible nerve repair
Peroneus tertius transfer
Peroneus tertius transfer with achilles tendon lengthening
Posterior tibial tendon transfer to dorsum of foot Corrent answer: 5
A peroneal nerve palsy (with intact posterior tibial tendon strength) that has failed conservative management is best treated with a posterior tibial tendon transfer to the dorsum of the foot.
Peroneal nerve palsy following total knee arthroplasty or knee dislocation is a potentially devastating complication that may lead to lack of active dorsiflexion and a compensatory steppage gait pattern. Initial management consists of an ankle-foot orthosis (AFO) and physical therapy to maintain passive ankle dorsiflexion. If nerve function fails to return during the course of conservative management and the patient demonstrates intact posterior tibialis muscle strength, posterior tibial tendon transfer to the dorsum of the foot has been shown to improve functional outcomes and eliminate the need for continued bracing. The most common procedure for posterior tibial tendon transfer involves transferring the tendon through the interosseous membrane and inserting the tendon onto the lateral cuneiform.
Prahinski et al. review the results of 10 patients at 61 months' follow-up who underwent the Bridle transfer (posterior tibialis transfer through interosseous membrane and peroneus longus to front of lateral malleolus) for peroneal nerve palsies. They conclude the Bridle procedure is adequate for return to function in low-demand individuals, but may fail over time in those who return to vigorous physical activity.
Rodriguez et al. review the results of 10 patients who underwent the Bridle procedure for peroneal nerve palsy in an attempt to balance their foot and
provide dorsiflexion. All of their patients were brace free at an average followup of 6.8 years.
Video V shows the clinical results 10 weeks after transfer of the tibialis posterior tendon for a drop foot.
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OrthoCash 2020
An 82-year-old male sustains a ground level fall and sustains the injury shown in Figure A. Which of the following treatment methods is most appropriate for treating this injury?
Closed reduction and functional bracing
Open reduction and fixation with a plate with screws and cerclage cables
Open reduction and fixation with a cortical allograft strut and cerclage cables
Revision hip arthroplasty with bridging of the fracture with a plate with screws and cerclage cables
Total femoral replacement Corrent answer: 2
This fracture pattern is typically referred to as an interprosthetic fracture; this is increasing in incidence due to increasing numbers of patients with ipsilateral hip and knee arthroplasty.
The first reference by Ricci et al reviewed 50 Vancouver B1 fractures treated with a lateral plate without allograft. They reported 100% union rate at a mean of 12 weeks and only one deep infection. Nearly 75% of patients were able to return to their baseline ambulatory status.
The second reference by Ricci et al reviewed 59 patients with periprosthetic femur fractures (THA or TKA) treated with ORIF without bone grafting. They report 58/59 patients healed after the index procedure and 49/59 were able to
return to their baseline functional level.
The reference by Fulkerson et al reported on 24 patients who underwent LISS plate fixation of periprosthetic femur fractures around well-fixed THA or TKA. They reported union in 21/24 at a mean of 6.2 months, with only one failure of fixation. They note that percutaneous fixation is effective although technically demanding.
Figure A shows an interprosthetic femur fracture between well-fixed hip and knee arthroplasties.
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OrthoCash 2020
A 62-year-old female undergoes an uncomplicated primary total knee replacement. Her knee range-of-motion pre-operatively was 0-135 degrees of flexion. Which of the following is true regarding the immediate post-operative use of a continuous passive motion machine in this patient?
Reduced risk of venous thromboembolism
No long-term difference in ROM compared to patients not using CPM
Increased passive knee flexion at 6 months
Increased length of hospitalization
Decreased risk of surgical site infection Corrent answer: 2
The use of a continuous passive motion (CPM) machine following primary total knee arthroplasty has not shown any long-term benefits with regards to
range-of-motion.
The concept of CPM was created by Dr. Robert Salter in 1970 and is currently being used in select patients following total knee replacement, ACL
reconstruction, and a variety of other procedures about the knee. In theory, the CPM allows for movement of synovial fluid to allow for better diffusion of nutrients into damaged cartilage. Additionally, it has been thought to prevent fibrous scar tissue formation about the joint. While some studies have shown increased early active knee flexion at two weeks, these results were not significant at later follow-up. Controversy exists as to whether these small benefits offset the patient inconvenience and expense of the CPM.
Lotke et al. expolre the effects of tourniquets and CPM machines in 121 patients undergoing total knee arthroplasty. They found that immediate CPM combined with intraoperative release of the tourniquet increased blood loss. The patients with the least amount of blood loss had the tourniquet released after a compressive dressing was applied and in whom CPM was delayed for a few days.
Bourne et al. perform a meta-analysis on the effectiveness of CPM following total knee arthroplasty. They found the CPM plus physical therapy increased active knee flexion more than physical therapy alone 2 weeks after surgery with a decreased length of hospitalization. The benefits of increased active knee flexion were not maintained after 2 weeks.
Illustration A shows an example of a CPM machine. Incorrect Answers:
from available RCTs to conclude that CPM reduces the risk of venous thromboembolism following total knee arthroplasty.
OrthoCash 2020
A 67-year-old female complains of anterior groin pain one year following a primary, uncemented total hip arthroplasty. The pain is exacerbated when she tries to climb stairs or get up from a seated position. She denies any recent fevers or chills. On physical exam, the pain is reproduced with resisted seated hip flexion. Laboratory analysis, including WBC, ESR, and CRP are within normal limits. Radiographs reveal that the components are appropriately positioned without evidence of loosening or fracture. Which of the following is the most appropriate at this time?
Revision of the acetabular component
Image-guided diagnostic injection of lidocaine into the iliopsoas tendon sheath
Hip aspiration
Bone scan
Conservative management including activity modifications, NSAIDs, and physical therapy
The patients history and physical exam are most consistent with iliopsoas impingement. This diagnosis is most reliably confirmed with a diagnostic/therapeutic injection of steroid or lidocaine into the iliopsoas tendon sheath.
Iliopsoas tendinitis following total hip arthroplasty is an uncommon but treatable cause of anterior groin pain following total hip arthroplasty. The true incidence is unknown, but some studies suggest it is the cause of a painful
total hip arthroplasty in up to 4.3% of cases. Potential causes include a malpositioned acetabular component, excessively long screws, limb length discrepancy, or retained cement. Diagnosis is confirmed by injecting the iliopsoas tendon sheath. Most cases are refractory to conservative management and often require surgical intervention. In the case of a malpositioned acetabular component, revision to a more agreeable position is advisable. In the absence of a defined etiology, iliopsoas tendon release offers adequate pain relief and return to function in a majority of patients.
Lachiewicz et al. review anterior iliopsoas impingement after total hip arthroplasty. They state that most patients with iliopsoas impingement often require surgical treatment, with options including iliopsoas tendon release or resection, removal of protruding cement or screws, and acetabular revision.
O' Sullivan et al. review 16 cases of iliopsoas impingement following primary total hip arthroplasty. Only 1 of the cases was secondary to a malpositioned acetabular component, with the other 15 cases being attributed to altered anatomy of the iliopsoas tendon as a result of the surgery. These 15 patients underwent iliopsoas tendon release, and all had improvement in pain and function following surgery.
Nunley et al. review 27 patients with a presumed diagnosis of iliopsoas impingement following total hip arthroplasty who were treated with fluoroscopically guided injections of the iliopsoas bursa. The average modified Harris hip score in the patients who underwent injection improved, however, 30% required an additional injection and 22% underwent surgical release for continued pain.
Illustration A shows a flouroscopic injection into the iliopsoas tendon sheath. Incorrect Answers:
revision of the acetabular component without a confirmed diagnosis is not advisable.
OrthoCash 2020
A 72-year-old female underwent an uncomplicated primary total hip replacement 18 years ago. Current radiographs reveal the abnormality shown in Figure A. Which of the following cell types (Figures B-F) is implicated in the process shown by the arrow?
Figure F shows an example of a macrophage, which is a key mediator in the osteolytic process shown in Figure A.
Osteolysis is the end result of a biologic process that begins when the number of wear particles following a joint replacement overwhelms the body's capacity to clear them from circulation. The residual particles are phagocytosed by macrophages, which then release an array of cytokines and other inflammatory mediators that recruit osteoclasts to resorb bone.
Gupta et al. review osteolysis following total knee arthroplasty, including etiology, diagnosis, and management. Amongst other things, they highlight the importance of design changes to minimize osteolysis including highly cross-linked polyethylene and alternative bearing materials.
Ren et al. performed a study where they implanted a hollow titanium rod into the distal femur and pumped polyethylene particles into the femoral bone marrow cavity. They found that macrophage migration occurs at a systemic (rather than local) level, and that the recruitment of macrophages led to localized osteolysis.
Holt et al. review the biology behind aseptic osteolysis. Specifically, they highlight the importance of the RANK-RANKL-OPG pathway as the final
common pathway to osteoclastogenesis, and the possibility of eliminating osteolysis by blocking this pathway. AMG-162 is a human immunoglobulin monoclonal antibody with a high affinity for RANKL, and studies are currently being undertaken to determine its safety and efficacy.
Figure F shows an example of a macrophage, which may be identified by its irregular shape and phagocytic inclusions. Illustration A shows the pathway by which marcrophages induce osteolysis following a joint replacement surgery.
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OrthoCash 2020
A 45-year-old with a history of sickle cell anemia reports hip pain for the past 6 months. A radiograph of the affected hip is shown in Figure A. Which of the following interventions has been shown to have the best outcomes in this patient population?
Observation
Bisphosphonates
Hemi-arthroplasty
Uncemented metal on polyethylene total hip arthroplasty
Cemented metal on polyethylene total hip arthroplasty Corrent answer: 4
Based on the radiographs and current literature, the best intervention is an uncemented metal on polyethylene total hip arthroplasty.
Avascular necrosis of the hip may be idiopathic in nature or associated with alcoholism, steroid use, or as in this case, sickle cell anemia. The Ficat staging system is used to classify avascular necrosis of the hip. Changes in treatment are driven by development of symptoms as well as the development of subchondral bone collapse (Ficat Stage 3). In those with with femoral head flattening (Ficat Stage 4) and acetabular degenerative changes (Ficat Stage 5), total hip replacement has good to excellent outcomes.
Mont et al. review surgical options for avascular necrosis of the hip. Head preserving procedures are generally reserved for those patients where the femoral head has not collapsed. Collapse and associated arthritis warrant utilization of arthroplasty procedures.
Mont et al. conducted a systematic review to better delineate the symptomatic progression of asymptomatic avascular necrosis of the hip. They found that patients with sickle cell disease have the highest rate of progression to
collapse. Medium sized, laterally located lesions were associated with a higher frequency of collapse and joint preserving procedures are recommended for these.
Figure A shows radiograph of a patient with avascular necrosis; note the femoral head flattening, narrowing of the joint space and acetabular sclerosis.
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OrthoCash 2020
The function of which of the following structures is to resist internal tibial rotation with the knee in full extension?
Anterior cruciate ligament
Iliotibial band
Popliteus tendon
Popliteofibular ligament
Posterior oblique ligament Corrent answer: 5
The primary function of the posterior oblique ligament is to resist internal tibial rotation with the knee in full extension.
The posterior oblique ligament is a structure within the posteromedial corner of the knee, with attachments proximally to the adductor tubercle of the femur and distally to the tibia/posterior knee capsule. The posterior oblique ligament and posteromedial capsule play a significant role in the prevention of additional posterior tibial translation in the knee in the setting of posterior cruciate ligament injury. They also act to resist internal tibial rotation with the knee in full extension.
Griffith et al. reports that the posterior oblique ligament provides significant resistance to valgus and internal rotation forces with knee extension. They used a cadaver model and demonstrated that the superficial MCL resists valgus and external rotation forces more than the posterior oblique ligament, while the posterior oblique ligament is more involved in resisting internal rotation.
Tibor et al. reviews the anatomy of the posteromedial corner of the knee. They report that failing to recognize injury to these structures may cause failure of cruciate ligament reconstruction surgery, and that reconstruction or repair of the posteromedial corner may be indicated in the face of multiple ligament injuries.
Illustration A shows the posteromedial corner of the knee, including the posterior oblique ligament.
Incorrect answers:
4: These structures are not primary restraints to internal tibial rotation in full extension.
OrthoCash 2020
Increasing the porosity of a cement spacer for an infected total knee arthroplasty leads to which of the following?
Increased strength
Increased elution of antibiotics
Increased cement density
Improved cement-prosthesis bonding
Increased reinfection rate Corrent answer: 2
Elution of an antibiotic is increased with increased porosity of a cement spacer. This porosity increase can be obtained with hand mixing and avoiding the use of a vacuum-type mixing device.
Joseph et al. reviews antibiotic-impregnated cement in hip arthroplasty. They note that use of this cement in one- or two-stage revisions has lowered reinfection rates, with the spacers acting to reduce dead space while stabilizing the joint.
Cui et al. reviews antibiotic impregnated cement for TKA and THA. They report that use of greater than 2 grams of antibiotic per 40 gram unit of cement weakens the cement and that use of two antibiotics in conjunction may potentially increase elution.
The reference by Stevens et al compared Simplex and Palacos bone cement in regards to elution in a TKA mold model. They found that initial as well as weekly (9 weeks total) elution rates were greater in the Palacos spacers than the Simplex models. They recommend use of the Palacos cement in TKA model to target antimicrobial delivery while limiting the potential for systemic antibiotic-related toxicity.
Illustrations A and B show an antibiotic spacer in a two-stage revision TKA. Illustration C shows a PROSTALAC in a two-stage revision THA.
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OrthoCash 2020
A 65-year-old patient was treated with an open reduction/internal fixation for a left femoral neck fracture sustained 25 years ago. Five years ago he developed hip pain and was converted to a left hip hemiarthroplasty. He presents with complaints of groin pain for the past 6 weeks. A recent radiograph is shown in Figure A. The patient’s physical exam is limited secondary to pain. Serum laboratory values are WBC-8.0, ESR-20, CRP-0.5. A synovial fluid aspirate of the hip demonstrates < 500 cells (60% PMN). What is the most likely cause of this patient's symptoms?
Acetabular protrusio
Infected hip hemiarthroplasty
Lumbar radiculopathy
Impingement of the hip hemiarthroplasty
Iliopsoas tendinitis
Based on the history, radiographs, and laboratory values, the patient has developed failure of his hip hemiarthroplasty. At this point in time he warrants a conversion to a total hip arthroplasty.
Avascular necrosis (AVN) of the femoral head after traumatic injury to the femoral neck occurs at an incidence of 10-45%. Although the risk increases with failure to anatomically reduce the fractue, it can still occur in non displaced settings. Treatment of avascular necrosis in older patients includes hip hemiarthroplasty or a total hip replacement. With the former, development of acetabular protrusio can contribute to groin symptoms. Functional outcomes have been reported to be higher in those receiving total hip replacement for AVN of the femoral head.
Lee et al. prospectively compared the use of bipolar hip hemiarthroplasty versus total hip arthroplasty for advanced stages of AVN of the femoral head (Ficat Stage 3). Total hip scores were most improved in the total hip arthroplasty group. Migration of the outer head in the hemiarthroplasty group was seen in 23% of patients. They recommend use of a total hip arthroplasty in patients with Ficat Stage 3 AVN of the femoral head
Ito et al. evaluated the outcomes of patients who underwent bipolar hemiarthroplasties for femoral head avascular necrosis. They found that proximal migration and acetabular degeneration were risk factors for groin symptoms. They also found that outcomes were inferior to patients who had undergone total hip arthroplasty for AVN of the femoral head. They recommend use of total hip arthroplasty in advanced osteonecrosis of the femoral head
Diwanji et al. evaluated outcomes of patients who underwent a conversion from a bipolar hip arthroplasty to total hip arthroplasty in 25 patients. Thirteen (52%) patients were revised to THA because of acetabular erosions. Follow up was completed for an average of 7.2 years. At final follow-up, they found improvement of the Harris Hip Scores and improvement of the pain portion of the WOMAC index. They recommend use of total hip replacement as an option to salvage failed bipolar hip hemiarthroplasty
Figure A shows the radiograph of a hip hemiarthroplasty where acetabular protrusion has developed.
Incorrect Answers
OrthoCash 2020
A 38-year-old female patient presents to your office three years after a hip resurfacing. She complains of worsening left hip discomfort for the last 6 months. Her ESR is 12 (normal 0-20) and CRP is 1.2 (0-5). A radiograph and axial and coronal MRI scans are shown in Figures A, B, and C. What is the most likely diagnosis?
Infection
Type I Hypersensitivity reaction
Femoral neck fracture
Prosthesis Loosening
Pseudotumor
The clinical presentation is consistent with a young woman who has developed a symptomatic pseudotumor following hip resurfacing. Her hip discomfort is related to a mass that has developed around the left hip.
Pseudotumors, also referred to as Aseptic Lymphocyte-Dominated Vascular-Associated Lesions (ALVAL), are sterile inflammatory lesions that most commonly occur from metal-on-metal articulations. They occur at an incidence of 0-39% with metal-on-metal resurfacing hip components. The exact mechanishm of formation is unclear, however excessive wear is considered the initiating process, leading to the release of microscopic metal particles. These are cytotoxic to macrophages once phagozytised, leading to necrosis within the lesions and the development of semi-solid or fluid-filled masses around the implant. Lymphocytes are thought to be responsible for the tissue reaction.
Patients often do not complain of pain, but present with a mass around the hip that causes discomfort.
Hart et al. performed a case-control study comparing patients with well-functioning metal-on-metal hip resurfacing to those who have painful prostheses. They found no significant difference between the painfree and painful groups with MRI diagnosed pseudtumors (61% vs. 57%). They concluded that the presence of a pseudotumor should not automatically necessitate revision surgery.
Daniel et al. reviewed the current concepts surrounding pseudotumor. Risk factors associated with pseudotumor formation and failure are female gender, age under 40, hip dysplasia, metal hypersensitivity, and small components.
Larger components have been found to decrease the risk of failure.
Figure A is an AP pelvis radiograph of a patient following a left hip resurfacing surgery. Figures B and C are axial and coronal MR images demonstrating a large pseudotumor around the left hip resurfacing. Illustrations A and B identify the large pseudotumor as outlined in red.
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OrthoCash 2020
After total hip arthroplasty (THA) for osteoarthritis a patient is unable to dorsiflex her ankle or extend her great toe. She is treated conservatively with an orthosis and after 3 months on physical therapy she ambulates with a "slapping gait." What is the most appropriate next treatment option?
MRI of her spine
Ankle Fusion
Continue Ankle-Foot Orthosis
Revision total hip arthroplasty
Sural nerve grafting Corrent answer: 3
The patient has suffered from a peroneal nerve injury most likely from errant retractor placement during the hip replacement resulting in a foot drop. The most appropriate next treatment is an ankle-foot orthosis.
The ankle joint of an ankle-foot orthoses (AFOs) should restrict plantarflexion to prevent foot drop during the swing phase. In a patient who can not actively dorsiflex the foot the AFO keeps the foot in a neutral position during gait allowing for uninterrupted swing during ambulation.
Park et al reviewed common peroneal nerve injury after THA. Only one-half of the patients in the study who developed common peroneal nerve palsy following total hip arthroplasty recovered fully. The mean time to recovery was approximately one year for partial peroneal palsy and one and one-half years for complete palsy. Obesity adversely influenced the nerve recovery. Thus, at 3 months, the nerve should continue to be monitored and the use of an AFO would assist in ambulation.
Yokoyama et al. developed an AFO with an oil damper to adjust the plantarflexion resistive moment as excessive plantarflexion resistance will cause excessive knee flexion during the stance phase. They found the AFO with the oil damper achieved sufficient plantarflexion of the ankle and mild flexion of the knee by adjusting a proper plantarflexion resistive moment during initial stance phase, and provided a more comfortable gait than did the traditional AFOs.
Illustration A shows the location of the sciatic nerve relative to the short external rotators when performing a posterior approach to the hip.
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OrthoCash 2020
Which of the following statements is true about racial disparities in total joint arthroplasty?
The rate of surgical intervention for African American males is lower than white or Hispanic males
The rate of surgical intervention for Hispanics is higher than that for whites
The rate of surgical intervention for white males is lower than for African American males
There is no difference in the rate of surgical intervention between whites, Hispanics, or African Americans
The rate of surgical intervention is equal for Hispanic and white males Corrent answer: 1
The rate of surgical intervention for African American males is lower than either white or Hispanic males.
Numerous studies have shown clear racial disparities in the utilization of total joint arthroplasty for the treatment of osteoarthritis. African American and Hispanic patients undergo total joint arthroplasty at a rate much lower than
white patients, even in areas where insurance coverage is more equitable. Currently, little is known about the reasons for such disparities.
Skinner et al. reviewed the Medicare claims between 1998 through 2000 to determine any racial or ethnic disparities amongst patients undergoing total knee arthroplasty. Amongst other things, they showed that the arthroplasty rates for black men were consistently lower than white men in nearly every region.
Nelson reviews health disparities in orthopaedic surgery. Amongst other things, they discuss how African American patients and white patients perceive the same pain and functional limitations for similar radiographic disease. Thus, ethnic differences in perception of symptoms cannot explan the racial disparities noted in total joint arthroplasty.
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OrthoCash 2020
A 65-year-old man presents with aseptic loosening 3 years after total knee arthroplasty. The surgeon reviews radiographs of his knee and takes him to the operating room for revision total knee arthroplasty. During surgery, the exposure technique shown in Figure A is used. Which of the following radiographs (Figures B-F) has the greatest likelihood of needing this exposure technique?
Figure A shows a tibial tubercle osteotomy (TTO). Patella baja (Figure D) is an indication for a TTO.
In revision total knee arthroplasty (TKA), surgical exposure should be extensile. Different exposure techniques have been described (see below). Patella baja may indicate that there is patellar tendon contracture. In this instance, a TTO can be used to prevent inadvertent patellar tendon avulsion which is difficult to repair and may lead to loss of function. Further, proximal transfer of the osteotomized tibial tubercle may be used to correct patella baja, bearing in mind that excessive superior translation alters the mechanics of the knee by making the quadriceps less efficient.
Younger et al. reviewed surgical approaches in revision TKA. They include quadriceps snip, patellar turndown, TTO, femoral peel, medial epicondylar osteotomy and quadriceps myocutaneous approach.
Mendes et al. reviewed the results of TTO in revision TKA. They advocate TTO for cases where the patellar cannot be retracted laterally with knee in 90deg of flexion. Complications include nonunion, tubercle fragment fracture and displacement, and tibial metaphyseal fracture (at the level of the distal cut of the osteotomy).
Della Valle et al. reviewed surgical approaches for revision TKA. They advocate TTO because repair is stronger than patellar turndown, there is less tension on the tibial tubercle in flexion than on the quadriceps tendon, and where multiple operations are required (as multiple VY approaches lead to excessive scar, making the approach difficult) or where stemmed tibial components need to be removed.
Illustration A shows tibial tubercle osteotomy hinged on a lateral periosteal flap. Illustration B shows quadriceps snip. Illustration C shows patellar turndown. Illustration D shows medial epicondyle osteotomy.
Incorrect Answers
situation.
OrthoCash 2020
Which of the following is the most common intraoperative complication in a patient with sickle cell disease undergoing a total hip arthroplasty?
Periprosthetic fracture distal to the implant
Iatrogenic fracture causing pelvic discontinuity
Perforation of the femoral canal
Cardiac arrest from fat embolization to lungs
Injury to the sciatic nerve Corrent answer: 3
Perforation of the femoral canal during preparation of the femur is not an uncommon complication, with rates ranging from 4.9-18.2%.
While total hip arthroplasty is extremely effective for pain relief in patients with osteonecrosis of the hip secondary to sickle cell disease, the procedure carries a higher rate of complications compared with non-sickle cell disease patients. Particular attention should be given to the preparation of the femur as femoral medullary widening from chronic marrow hyperplasia adjacent to patchy areas of dense sclerosis can make preparation of the canal difficult.
Some surgeons prefer to ream over a guide-wire to avoid perforation.
Jeong et al. reviewed total hip arthroplasty in patients with sickle cell disease. Amongst other things, they discuss the difficulties associated with preparation of the femoral canal, quoting a perforation rate between 4.9-18.2%. They also state there are no prospective studies comparing cementless to cemented THA, but retrospective data has shown promising results with cementless components.
Hernigou et al. retrospectively reviewed 244 patients with sickle cell disease that underwent cemented total hip arthroplasty. They had a 3% infection rate, a relatively low rate of revision for aseptic loosening, and a 27% rate of medical complications. Overall, they viewed their results as favorable.
Illustration A shows a patient with bilateral AVN secondary to sickle cell disease. Note the areas of patchy dense sclerosis in the metaphyseal region of the proximal femur.
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to be more common in this patient population. The rate of post-operative hematoma causing sciatic nerve dysfunction may be higher in this patient population.
OrthoCash 2020
A 63-year-old patient presents with periprosthetic joint infection 3 years after primary total knee arthroplasty. A radiograph of her knee is seen in Figure A. She undergoes 2-stage revision total knee arthroplasty. Radiographs taken at the time of explantation are seen in Figure B. An articulating antibiotic spacer is placed. Two months later, she is deemed to be free of infection and is taken to the operating room for the second stage operation. Intraoperatively, it is noted that the collaterals are intact and the previous tibial tubercle osteotomy had healed. What is the most appropriate surgical strategy at this point?
Address epiphyseal defects with impaction particulate bone grafting
Address metaphyseal defects with structural allograft and uncemented, unstemmed implants
Address metaphyseal defects with uncemented, porous metaphyseal
sleeves and uncemented, stemmed implants
Address diaphyseal defects with porous metal cones and uncemented, stemmed implants
Address diaphyseal defects with cemented stemmed implants Corrent answer: 3
This patient has massive metaphyseal defects following resection of primary TKA implants. Metaphyseal defects may be addressed with uncemented, porous metaphyseal sleeves and uncemented stemmed implants.
In revision settings, metaphyseal bone is often deficient. The Anderson Orthopaedic Research Institute classification (AORI) is most commonly used to classify defects. Stemmed implants are necessary to divert stress away from deficient metaphyseal defects to structurally sound cortical bone. These may be cemented or uncemented.
Haidukewych et al. reviewed metaphyseal fixation in revision TKA. For large defects, they advocate structural allograft, porous metal cones, and stepped metaphyseal sleeves.
Bush et al. reviewed managing bone loss in TKA. They cautioned that joint line elevation, distal femoral bone loss, and femoral prosthesis downsizing leads to flexion instability. They advocate cement filling for Type I defects, modular augments for Type 2, impaction grafting for Type 1 or 3, structural allograft for Types 2 and 3, metaphyseal filling or megaprosthesis for Type 3, including porous metal implants.
Figure A shows an infected primary TKA with a stemmed tibial component with medial augments. This suggests that the revision implant will require at least a stemmed, augmented component. Figure B shows massive metaphyseal defects (AORI Type 2) at the time of explantation. Illustration A comprises postop images of osseointegrated metaphyseal sleeves and stemmed implants. Illustration B depicts the AORI classification (see Review Topic for detailed description). Images courtesy of Haidukewych et al (Ref 1).
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OrthoCash 2020
During templating for a total hip arthroplasty, placing the femoral head center of rotation directly superior to the center of rotation of the acetabular component will have which of the following effects?
Increase offset
Decrease limb length
Decrease offset
Increase limb length
No change in length or offset Corrent answer: 4
Placing the femoral head center of rotation directly superior (above) the acetabular center of rotation will lengthen the limb without changing offset.
When templating the femoral component for a total hip arthroplasty, it is imperative to restore limb length and offset. To change limb length, the femoral component center of rotation (COR) can be adjusted in a superior or inferior direction. If the femoral component COR is superior to the acetabular component COR, the limb will be lengthened (as in the example above).
Conversely, if the femoral component COR is inferior to the acetabular component COR, the hip will be shortened. A change in offset will be determined by the medial/lateral relationship between the acetabular and femoral components. In the example above, the COR of the femoral component is directly above the COR of the acetabular component. In this situation, there is no change in offset.
Merle et al. performed a retrospective cohort study to identify differences in femoral offset as measured on an AP pelvis radiograph, AP hip radiograph, and a CT scan. They found that femoral offset is significantly underestimated on AP radiographs of the pelvis. In contrast, AP radiographs of the hip are much more accurate in representing true offset.
Della Valle et al. review the importance of preoperative planning prior to total hip arthroplasty. While they mention that templating can be very accurate, determination of stem and cup size should also be determined by tactile feedback during broaching and reaming.
Illustration A shows the femoral head COR inferior to the acetabular COR. This will result in a decreased limb length.
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OrthoCash 2020
Which of the following intra-operative errors most commonly leads to patellar maltracking during a total knee arthroplasty?
Using the gap balancing technique instead of measured resection technique
Internal rotation of the femoral component
External rotation of the tibial component
Lateralization of the femoral prosthesis
Overresection of the patella
Internal rotation of the femoral component increases the Q-angle and will increase the likelihood of patellar maltracking.
Patellar maltracking is one of the most common complications following a total knee arthroplasty. Any alteration that results in increased lateral retinaculum tension or an increased Q-angle may lead to patellofemoral instability.
Common causes include internal rotation of the femoral or tibial components, medialization of the femoral component, and placement of the patellar prosthesis on the lateral border of the patella. If a patient presents with postoperative maltracking and component rotation is thought to be the cause, a CT scan is the diagnostic study of choice.
Rhoads et al. analyze 7 cadaveric specimens to define the kinematics of the intact knee and to evaluate the effects of prosthetic replacement on those kinematics. Amongst other things, they showed that lateralization of the femoral component improved patellar tracking and prevented dislocation.
Malo et al. review patellar maltracking following a total knee replacement. They discuss the importance of externally rotating the femoral component on the femur relative to the posterior articular condyles to establish a rectangular and balanced flexion gap and to accommodate central patellar tracking.
Illustration A shows how an internally rotated femoral component displaces the patella medially. The blue line is a straight line upwards from the tibial tubercle, and the green line represents a line from the tibial tubercle to the center of the patella. The difference between the blue and green lines in the internally rotated prosthesis is the amount the patella has displaced medially. If you deviate the patella medially, this increases the Q-angle and could lead to patellar maltracking in a total knee replacement.
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OrthoCash 2020
When performing a total knee arthroplasty on a 60-year-old female patient, a surgeon chooses not to resurface the patella. Instead, he performs a patelloplasty by excising the marginal osteophytes and reshaping the patella. All of the following statements comparing the results of patelloplasty to patella resurfacing are true EXCEPT:
There is no difference in relative risk of anterior knee pain.
There is no difference in relative risk for revision surgery involving the tibial and femoral components.
There is an increased risk that she will need secondary resurfacing.
No difference in rates of patellar avascular necrosis or patellar tendon injury.
Total knee arthroplasty improved function regardless of whether the patella was resurfaced.
In TKA with an unresurfaced patella, there is an increased risk of anterior knee pain and secondary resurfacing.
Surgeons can choose to resurface or not resurface all patellae, or selectively resurface patellae. In unresurfaced patellae, they may perform a patelloplasty (excise marginal osteophytes and reshape the patella). Unresurfaced patellae have increased risk of anterior knee pain requiring secondary resurfacing.
Indications for resurfacing include inflammatory arthritis, patella maltracking, patellofemoral osteoarthritis as the main indication for TKA.
Meneghini et al. reviewed the literature on patellar resurfacing. Prospective, randomized studies show conflicting results with regards to satisfaction rates between groups. Meta-analyses show increased risk of re-operation and anterior knee pain in the unresurfaced group.
Parvizi et al. performed meta-analysis on 1519 knees. They found there was
(1) lower relative risk of re-operation (resurfaced group), (2) lower relative risk of anterior knee pain (resurfaced group), (3) increased rate of secondary resurfacing (unresurfaced group), (4) no difference in patient satisfaction, (5) TKA improved function regardless of whether the patella was resurfaced, (6) no difference in complications.
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OrthoCash 2020
A 55-year-old patient returns for followup 2 years after a left ceramic-on-ceramic total hip arthroplasty. He has no pain or symptoms of instability. The video in Figure V shows him ascending stairs. All of the following factors may contribute to this phenomenon EXCEPT
Impingement
Edge-loading
Loss of fluid film lubrication.
Third-body particles
Subclinical infection
The clinical presentation is consistent for prosthesis squeaking following a THA. Squeaking is multifactorial and may include impingement, edge-loading, loss of fluid film lubrication, and third-body particles. Subclinical infection does not play a role in squeaking.
Squeaking is defined as a high-pitched, audible sound occurring during movement of the hip. In ceramic-on-ceramic (COC) hips, the incidence is 0.5-10%. The incidence of revision because of squeaking is 0.5%. Squeaking is less common in metal-on-metal bearing surfaces (4-5%).
Chevilotte et al. reviewed COC bearing surfaces. They found that without lubrication, squeaking occurred with normal gait, high load, stripe wear, material transfer, edge wear and microfractures. In contrast, with lubrication, squeaking only occurred with material transfer.
Finkbone et al. reviewed COC total hip arthroplasty in patients <20-years-old after 52-month (average) follow-up. They found that survival rate was 96% with 1 revision for a loose acetabular component (failure of bone ingrowth). They found no cases of osteolysis, which can theoretically occur because of stripe wear, or femoral neck-on-liner impingement.
Walter et al. reviewed squeaking hips. They found that this phenomenon is associated with (1) walking, bending, rising (cyclical gait movements or extreme flexion), (2) maloriented acetabular components, (3) impingement,
(4) third-body particles, (5) edge loading, (6) loss of fluid film lubrication and
(7) thin, flexible (titanium) stem.
The video shows squeaking of a left total hip arthroplasty during hip extension from a flexed position. This is consistent with edge loading. Illustration A shows superior edge loading in the walking position. The arrow represents the loading force. The superolateral edge of the liner is in contact with the superior surface of the head. The dark area (area of edge loading) is anteverted with respect to a line of latitude (dark line) on the head. Illustration B shows posterior edge loading in the bending position. The arrow represents the loading force. The posterior edge of the liner is in contact with the superior surface of the head. The shaded area represents the area of edge loading and the dark stripe indicates wear on the femoral head.
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OrthoCash 2020
Figure A shows the image of a 72-year-old male who sustained a fall from standing. Past medical history is significant for hypertension. He was a community ambulator without the use of a cane or walker prior to the fall. During the operation, he is noted to have a well-fixed acetabular component without significant wear of his polyethylene liner, but his femoral component is easily extractable. Which of the following correctly pairs his Vancouver classification and appropriate surgical intervention?
Vancouver A, Revision of femoral component to cemented stem with fixation of the fracture
Vancouver B1, Revision of femoral component to cemented stem with fixation of the fracture
Vanvouver B1, Revision of femoral component to a long, porous-coated, cementless stem with fixation of the fracture
Vancouver B2, Fixation of the fracture with a plate and cerclage wires
Vancouver B2, Revision of femoral component to a long, porous-coated, cementless stem with fixation of the fracture
Figure A shows a Vancouver B fracture around the femoral prosthesis. Because the prosthesis is noted to be loose during the operation, it is classified as a Vancouver B2 fracture. The most appropriate operation would be revision of the femoral component to a long, porous-coated, cementless stem in addition to fixation of fracture with a plate and cerclage wires.
According to the Vancouver classification, a type B2 fracture occurs around or just distal to a loose femoral stem with adequate proximal bone. Revision of the femoral component is necessary, with uncemented stems showing superior clinical results to cemented stems in most studies. The revision prosthesis should bypass the distal fracture by 2 cortical widths.
Corten et al. reviewed thirty-one patients with Vancouver B2 fractures that
were treated with a long cemented stem with additional allograft or plate fixation. At 46 months, none of the implants had to be revised, but it should be noted that 43% of the patients died within the first year.
Mulay et al. reviewed 24 patients with Vancouver B2 and B3 fractures managed with a cementless, tapered, fluted, and distally fixed stem. 91% of fractures united uneventfully. Complications included dislocations (5), nonunions (2), and infection (1).
Springer et al. review 116 patients with Vanvouver B fractures treated with revision of the femoral component. The uncemented, extensively porous-coated implants had the highest likelihood of stable fixation and were not associated with any nonunions.
Illustration A reviews the Vancouver classification for periprosthetic femur fractures. Illustration B shows a post-operative radiograph following a Vancouver B2 fracture. In this case, a trochanteric plate with cerclage wires was used to fix the fracture. A long-stemmed, porous-coated, cementless femoral prosthesis was used for the revision.
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OrthoCash 2020
A 56-year-old male undergoes revision of his right hip arthroplasty for acute pain and radiographs suggestive of ceramic femoral head fracture. At the time of the revision, multiple fragments of the ceramic femoral head were seen in the joint and soft tissues. The components were noted to be in good position. He was copiously irrigated and the ceramic head was exchanged with a metallic femoral head. 12 months later, the patient presents with insidious onset right groin pain. Radiographs show no gross abnormalities without signs of loosening. Which of the following is the most likely cause of the patient's pain?
Periprosthetic infection
Massive third body wear
Pseudotumor formation
Soft tissue metallosis
Iliopsoas tendonitis
The most likely cause of the patient's pain is massive third body wear caused by retained ceramic fragments.
Cermamic femoral head fractures create many fragments that are difficult to extract at the time of revision surgery. During the revision surgery, it is imperative to remove all fragments that can be visualized. Despite a thorough debridement, microscopic fragments will still remain. These particles may cause pain through the creation of an inflammatory response in the tissues.
Exchange of the femoral head should be performed with another ceramic head, as opposed to a metal head. If a metal head is used, abrasive wear will ensue as the microscopic fragments will scratch the femoral head due to differences in hardness.
Traina et al. describe their experiences with revision of ceramic components. Most commonly, fractures of ceramic components occur as a result of trauma, dislocation, or errors in operative technique. These include head-neck taper mismatch, impacting the ceramic head with too much force, debris, and intraoperative damage to the metal neck taper.
Hannouche et al. review ceramics in total hip replacement. They state that if the ceramic is properly manufactured, it can be a highly effective, low-wear solution for the young patient in need of a total hip replacement.
Illustration A shows the typical ceramic femoral head used for a total hip arthroplasty. Illustration B shows a fractured ceramic head in many pieces.
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OrthoCash 2020
Figure A and B are radiographs of a 77-year-old patient presenting with right hip and upper thigh pain for the past 3 months. He is an avid golfer and plans to travel south for 6 months on a golf tour. He denies fever, chills or weight loss. His past medical history includes hypertension and a right total hip replacement 15 years ago. Physical examination reveals minimal pain with range of motion. ESR=10 (normal range 0-20) and CRP=4 (normal range 0-10). He does not want any further surgery. The patient is at the highest risk of which complication with non-operative care?
Infection
Pseudotumour formation
Periprosthetic femoral fracture
Periprosthetic acetabular fracture
Dislocation
This patient has presented with significant osteolysis and aseptic loosening of his femoral THA component. If untreated, he is at an increased risk of a periprosthetic femur fracture.
Indications for surgery for periprosthetic osteolysis include: pathological fracture, impending pathological fracture, symptomatic THA with evidence of osteolysis, and extensive osteolysis that would compromise revision surgery in the future. The goal of surgery is to remove the loose component, repair/bypass/replace bone deficiency, and obtain stable component fixation.
Robbins et al. reviewed the causes of pain in THA. They report that hip pain can originate from the implant, soft tissue, or bone. The use of laboratory tests (e.g. ESR/CRP), radiographic and fluoroscopic imaging, hip aspirate, contrast arthrography and local anesthetic injections can help to determine the origin of pain.
Ollivere et al. report that the most frequent cause of failure after total hip replacement in all reported arthroplasty registries is periprosthetic osteolysis. Osteolysis occurs with the activation of macrophages and a complex biological cascade that results in bone loss.
Hirakawa et al. analyzed the circumstances around retrieved failed THA components. They showed that cement mantle defects, noncircumferential porous coatings, and screw holes are risk factors for osteolysis. They conclude by saying that the formation of a granulomatous tissue that ultimately invades the bone-implant interface is the final step in the pathogenesis of aseptic loosening.
Figure A and B show AP and lateral views of a right THA. The femoral stem shows gross loosening in all zones. Subsidence is obvious with a high-riding greater trochanter. The lateral cement mantle is fractured. There is endosteal erosion distally with the tip of the stem showing radiographic toggle.
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osteolysis, but it remains well fixed. Acetabular fractures are less likely when there is minimal osteolysis.
OrthoCash 2020
A 60-year-old woman undergoes a total knee arthroplasty for end-stage osteoarthritis. Preoperative knee range of motion is 5 to 100 degrees. Postoperatively, she experiences reduced range of motion. She is scheduled to undergo manipulation under anesthesia. In which of the following scenarios is this procedure best indicated?
Knee range of motion 0 to 60 degrees at 2 months postoperatively
Knee range of motion 0 to 60 degrees at 8 months postoperatively
Knee range of motion 30 to 120 degrees at 2 months postoperatively
Knee range of motion 30 to 120 degrees at 8 months postoperatively
Knee range of motion 30 to 120 degrees at 2 weeks postoperatively
Manipulation under anesthesia (MUA) can achieve the greatest gains in flexion when performed for patients with less than 90 degrees of flexion within the first three months.
There are many risk factors for postoperative stiffness, the most important being preoperative stiffness. MUA is indicated when flexion is less than 90 degrees. Flexion gains are generally greater when applied early (6-12 weeks postoperatively) rather than late (>12 weeks). In cases with late-presenting stiffness (>12wks), MUA may still be attempted. Failed MUA is addressed with arthroscopic or open adhesiolysis +/- MUA, quadricepsplasty, or component revision.
Namba et al. compared the results of early (<90 days) vs late (>90 days) MUA. They found that: (1) knee flexion improved a mean of 32 deg and 20 deg after early and late MUA respectively, (2) extension improved in the early MUA group, but not the late MUA group, and (3) pain improved after early but not late MUA. Despite early MUA being more desirable, the authors state that patients with limited flexion at 6-12 months may still benefit from late MUA.
Keating et al. assessed the outcomes of MUA in 113 knees at a mean of 10 weeks after surgery. They found that (1) 90% of patients achieved
improvement in knee flexion of 35 degrees at 5 year followup, (2) there was no difference in flexion gains between early (<12 weeks) and late (>12 weeks) MUA and (3) patients treated with MUA had better pain control than those without MUA. They concluded that manipulation can result in significant and lasting improvement in knee flexion.
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OrthoCash 2020
A 62-year-old man is scheduled for a total knee arthroplasty. In his pre-operative office visit, he asks questions about different tibial components. You tell him that compared with the tibial component shown in Figure A, the tibial component shown in Figure B:
Is less expensive
Has greater durability
Has greater instability because of its monobloc nature
Provides improved short-term functional status, but no difference in long term functional status
Is associated with fewer adverse events because of easier implantation Corrent answer: 1
Figure B shows an all-polyethylene tibia (APT) component, which is $470 to
$1650 less expensive than metal-backed tibia (MBT) designs.
It was traditionally thought that modular MBT may have lower survivorship (compared to APT) because of locking mechanism dysfunction, breakage,
backside wear, and osteolysis. However, many studies now show the two to be comparable, with the only difference being that APT are less expensive.
Voight et al. performed a systematic review comparing APT and MBT. They found that the former was cheaper. There was no difference in adverse events, durability (need for revision or radiographic failure) at 2, 10, and 15 years, and functional status at 2, 8, and 10 years.
Toman et al. compared APT and MBT retrospectively. They found that APT implants perform as well as MBT implants in patients with BMI <37.5. There were 4 tibial implant failures in the MBT group in patients BMI >40.
Dalury et al. examined APT performance in obese patients (125 knees) after a minimum of 7 years. There were no implant failures. There were 5 nonprogressive tibial radiolucencies and 1 case of nonprogressive osteolysis.
Figure A shows a cemented metal-backed tibia component. Figure B shows a cemented all-polyethylene tibia component.
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OrthoCash 2020
Figures A and B show pre- and post-operative radiographs of a sedentary 75-year-old female who underwent surgery on her left hip. Based on the radiographic findings, what was the most likely indication for revision surgery?
Left acetabular fracture
Left acetabular cup osteolysis
Left femoral stem osteolysis
Left hip instability
Left femoral stem valgus malalignment Corrent answer: 4
Figure A shows a left total hip arthroplasty with eccentric polyethylene wear. Figure B shows that her left hip was revised to a constrained acetabular liner, most likely a result of recurrent instability.
Revision strategies for hip instability are typically directed at correcting the underlying cause of instability. For example, instability most commonly occurs as a result of poor implant design, positioning or loosening, or the loss of soft-tissue function or tensioning. Operative strategies are designed to correct these etiologies by repositioning or exchanging components, integrating modular designs and improving soft tissue tensioning, etc. Constrained acetabular liners are often used in conjunction with these modalities to address the problem of recurrent instability relating to soft tissue deficiency and dysfunction in the affected hip.
Alberton et al. retrospectively reviewed 1548 revision arthroplasties for the incidence of dislocation. They found the overall dislocation rate to be 7.8%. Factors contributing to increased dislocations were found to be trochanteric non-unions, femoral heads <28mm in diameter and extensive soft-tissue dissection. Protective factors were modular acetabular components or liners, larger femoral heads >28mm and re-establishing abductor tensioning.
Paterno et al. retrospectively reviewed 438 primary and 181 revision total hip arthroplasties for patient factors contributing to dislocation. They found an overall dislocation rate of 6%. 23% of patients with a history of excessive intake of alcoholic beverages (more than six ounces a day) had at least one dislocation. There was no relationship between the variables of age, gender, obesity, or preoperative diagnosis and the incidence of dislocation.
Figure A shows bilateral primary cementless, nonconstrained total hip replacements. The left hip shows eccentric femoral head placement within the acetabulum indicative of eccentric polyethylene wear. Figure B shows the conversion to a constrained, dual-mobility, polyethylene liner. The overall metal component position appears satisfactory.
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OrthoCash 2020
A 62-year-old woman is brought to the emergency room after falling down a flight of stairs. Prior to her fall, she had no knee pain and was a community ambulator without assistance. Intraoperatively,
it is determined that the implants are well-fixed. What is the best next treatment step to optimize her quality of life?
Closed reduction and long leg casting at 20 degrees of flexion for 6 weeks, followed by hinged-knee brace for 6 weeks.
Open reduction and internal fixation with a distal femoral locking plate
Open reduction and internal fixation with a condylar buttress plate
Distal femoral replacement arthroplasty
Closed reduction and fixation with an antegrade intramedullary nail Corrent answer: 2
This patient has a displaced far-distal supracondylar fracture around a stable TKA femoral component. Locked plating is the best option for management of this fracture.
Surgical fixation of periprosthetic fractures around a stable femoral component is challenging. Locked plating allows for multiple angle-stable fixation points around stems and lugs and does not depend on TKA design or quality of distal bone stock for fixation. Su Type I fractures may be treated with retrograde or antegrade intramedullary nailing. Type II fractures require retrograde intramedullary nailing or fixed-angle plating. Type III fractures require fixation with a fixed-angle device or revision arthroplasty when bone stock is poor.
Ricci et al. evaluated indirect reduction and locked lateral plating of Vancouver B1 THA fractures without allograft struts. They found that all fractures healed with satisfactory alignment and without implant loosening at an average of 12 weeks. They recommend this technique for stable Vancouver B1 fractures.
Streubel et al. examined the outcomes of locked plating in treatment of extreme distal periprosthetic supracondylar fractures located proximal to the flange (Su Types I and II) compared with fractures distal to the flange (Su Type III, see Illustration B). They found no difference in delayed union, nonunion, infection and failure rates between the 2 groups.
Figure A shows a Su Type III periprosthetic fracture around a TKA femoral component. Illustration A shows fixation of the same fracture with a distal femur locking plate. Illustration B shows the Su classification of fractures around the femoral component (Type I, proximal to the femoral component; Type II, starting at the anterior flange and extending proximally; Type III, fracture line distal to the anterior flange).
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Which of the following fractures would most likely require revision arthroplasty with a long-stemmed, uncemented prosthesis?
Figure B shows a Vancouver B2 periprosthetic femur fracture with an unstable femoral stem that requires revision arthroplasty with a long-stemmed prosthesis.
The Vancouver classification for periprosthetic femur fractures can help guide treatment of these challenging problems. Vancouver A fractures involve the greater and lesser trochanter and can be initially managed with non-operative measures. Vancouver B fractures occur around the stem and are broken down into B1 (stable prosthesis), B2 (unstable prosthesis) and B3 (poor proximal bone quality) fractures. B1 fractures may be treated with internal fixation, B2 fractures require a revision arthroplasty, and B3 fractures often require more advanced reconstruction with a proximal femoral replacement versus revision with a distally fixed prosthesis. Vancouver C fractures occur distal to the stem and require internal fixation.
Springer et al. reviewed 118 patients who underwent revision arthroplasty for Vancouver B2 periprosthetic fractures. They had a 90% survival rate at 5-years and a 79.2% survival rate at 10-years. The most common reasons for revision were loosening, infection, and non-union.
Illustration A shows the Vancouver classification of periprosthetic fractures about the femur.
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OrthoCash 2020
A 65-year-old female sustains a periprosthetic supracondylar femur fracture proximal to a well-fixed implant. She undergoes direct reduction and locked plating with a titanium distal femoral locking plate via an extensile lateral approach. At 9 months post-operatively, weightbearing is at 50% and is painful. Examination reveals mild swelling and warmth around the distal incision. Erythrocyte sedimentation rate and C-reactive protein are normal. Radiographs taken 9 months post-operatively are shown in Figure A. Which of the following may have increased the risk of this complication?
Neglecting to add topical rhBMP-2 on a carrier-scaffold
Neglecting to use lag screws and cerclage cables
Locked plating instead of locked antegrade nailing
Use of a titanium plate instead of a stainless steel plate
Use of an extensile lateral approach instead of a submuscular approach Corrent answer: 5
A submuscular approach has been shown to have less risk of nonunion than an extensile lateral approach. There is less disruption of soft tissue attachments and devitalization of fracture fragments with the submuscular approach.
The risks for periprosthetic fractures include notching, knee stiffness, osteoporosis, poor mobility and falls. The risk is higher in females and after revision surgery. The treatment of periprosthetic supracondylar fractures depends on the location of the fracture, fixation of the implant, and bone stock.
Hoffman et al. retrospectively reviewed 36 periprosthetic supracondylar femur fractures treated with locked plating. They found that submuscular plating had reduced nonunion risk compared to an extensive lateral approach. They recommend indirect reduction and submuscular plating to reduce the incidence of nonunion.
Hou et al. retrospectively reviewed 53 fractures fixed with retrograde nailing
(18) and locked plating (34). They found no difference in blood loss, time to union, operating time and hospital stay. They believe locked plating can
provide the same favorable results as retrograde nailing and recommend this technique for most patients and prosthetic designs.
Figure A shows nonunion and surrounding osteopenia after locked plating of a periprosthetic supracondylar fracture. Illustration A shows management of these fractures according to the Su classification.
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OrthoCash 2020
Immediately following a total hip arthroplasty (THA), a healthy 55-year-old patient is unable to dorsiflex her ankle or extend her great toe. After 4 weeks she continues to ambulate with a "slapping gait." Examination reveals passive ankle joint dorsiflexion to 10 degrees. What is the most appropriate next treatment option?
MRI of her spine and pelvis
Revision total hip arthroplasty
Ankle-foot orthosis
Posterior tibial tendon transfer to navicular bone
Neurology consult
This patient is presenting with foot drop after a THA for hip dysplasia (Crowe 4). The most appropriate treatment at this stage would be providing her with an ankle foot orthosis (AFO) for mobility.
Sciatic nerve injury after THA is an uncommon and difficult situation to manage. Patients with DDH that have undergone a large limb-lengthening procedure are at a greater risk due to the significant stretch of the sciatic nerve. Intra-operative procedures that have been shown to prevent this outcome include good pre-operative planning, limb lengthening <3 cm, subtrochanteric osteotomy, intra-operative wake-up test, and downsizing implant components if presenting with deficits peri-operatively. An ankle-foot orthosis may be used for foot drop when surgery is not warranted or during neurologic recovery.
Prahinski et al. reviewed the Bridle transfer for paresis of the anterior and lateral compartment musculature. Indications for the procedure include no neurological recovery for at least 18 months after injury or 18 months after the most recent attempt at exploration or repair of the nerve.
Electrodiagnostic changes must indicate permanent damage. In addition, there must be good passive range of motion, with at least 90° of dorsiflexion.
Edwards et al. reported on twenty-three peroneal and sciatic nerve palsies that occurred in patients following total hip arthroplasty. They showed that peroneal nerve palsy occurred with an average lengthening of 2.7 cm (1.9 cm-3.7 cm) in comparison with 4.4 cm (4.0 cm-5.1 cm) for sciatic nerve palsies.
Figure A and B show pre- and post-operative images of a patient with severe hip dysplasia treated with primary total hip arthroplasty.
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OrthoCash 2020
A 60-year-old male with history of renal transplantation and previous intravenous drug abuse undergoes total knee arthroplasty. Two years later, he begins to have mild knee pain and low-grade swelling that persists for 10 months before he finally comes to the emergency room. Examination reveals no fever. Range of motion is 5 to 70 degrees. Erythrocyte sedimentation rate is 22mm/h, and C-reactive protein is 0.8mg/L. Knee aspiration reveals 12,000/mm3 nucleated cells with 76% neutrophils. Gram stain is negative and aerobic and anaerobic cultures are negative after 4 days in culture. His symptoms do not resolve after 5 days of empiric intravenous antibiotics and he is taken to the operating room for arthroscopic irrigation and debridement. Operative synovial tissue cultures are shown in Figure A. What is the best next step?
Cessation of immunosuppressant medication, lifelong antimycobacterial suppression
Open irrigation and debridement, implant retention and lifelong antifungal suppression
Open irrigation and debridement, resection arthroplasty, antimycobacterial drugs for 6 to 12 months
Open irrigation and debridement, single-stage exchange, antifungal drugs for 6 to 12 months
Open irrigation and debridement, two-stage exchange, antifungal drugs for 6 to 12 months
This patient has a fungal prosthetic joint infection (PJI) with Candida albicans. Optimal treatment involves resection arthroplasty, delayed reimplantation
arthroplasty, and antifungal drugs for 6-12 months.
Fungal PJI are uncommon. Risk factors include immune suppression and systemic illness e.g. diabetes and chronic renal failure. Candida species is usually the causative organism. The infection is usually indolent and systemic symptoms (e.g. fever) may be absent. ESR and CRP may be only minimally elevated. Two-stage exchange arthroplasty is standard of care.
Phelan et al. described delayed reimplantation in 10 patients with fungal PJI. They found that the median time from resection to reimplantation arthroplasty was 9 and 2 months for total hip and total knee arthroplasty respectively. Two patients had recurrence of infection. They recommend antifungal therapy and delayed reimplantation arthroplasty after confirmation of an infection-free period as the best chance for cure.
Azzam et al. retrospectively reviewed arthroplasty database data to identify 31 fungal PJIs in 6 centers. Delayed implantation was performed in 19 of 29 patients who underwent resection arthroplasty at an average of 7 months.
They recommend two-stage exchange arthroplasty as the treatment of choice, addition of antibacterial drugs to the cement spacer to prevent superinfection, antifungal drugs for 6-12 months, repeat joint aspirations prior to reimplantation, and optimization of host nutritional status prior to reimplantation.
Figure A is a high-powered micrograph showing synovial tissue covered by fibrinopurulent exudates containing fungal colonies of Candida albicans.
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OrthoCash 2020
Which of the following non-operative treatments for osteoarthritis has the best evidence to support its use?
Combination of supervised and home exercise programs
Hyaluronic acid injections
Lateral heel wedge
Acetaminophen
Glucosamine
Of the options listed, a combination of home and supervised exercise has the best supporting evidence for the treatment of osteoarthritis.
The AAOS has recently developed guidelines for the treatment of osteoarthritis. Therapies that are recommended by the AAOS include weight loss, home and supervised exercise programs, and NSAIDs/tramadol.
Therapies that remain inconclusive (lack of supporting evidence) include electrotherapeutic modalities, manual therapy, bracing, acetaminophen/opiods, steroid injections and PRP. Glucosamine, lateral heel wedges and hyaluronic acid injections are not recommended, as current literature has shown them to be ineffective. Keep in mind that these guidelines are subject to change as new literature is published.
Zhang et al. present a systematic review of the literature on arthritis management in the three years following the original OA Research Society International (OARSI) guidelines published in 2006. While weight loss showed an increase in effectiveness with the addition of new studies, electromagnetic therapy, glucosamine, chondroitin sulfate, and hyaluronic acid injections showed a decrease in effectiveness.
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OrthoCash 2020
Figure A shows the 2 bundles of the ACL dissected from a cadaveric knee off their bony attachments. They are labeled Bundle A and Bundle B, respectively. Which of the following is true?
The tibial attachment of Bundle A is anterior to Bundle B. In extension, Bundle B is loose and Bundle A is tight.
The tibial attachment of Bundle A is anterior to Bundle B. In flexion, Bundle B is loose and Bundle A is tight.
The tibial attachment of Bundle B is anterior to Bundle A. In flexion, Bundle B is loose and Bundle A is tight.
The tibial attachment of Bundle B is anterior to Bundle A. In flexion, Bundle A is loose and Bundle B is tight.
The tibial attachment of Bundle B is anterior to Bundle A. In extension, Bundle A is loose and Bundle B is tight.
Bundle A is the anteromedial (AM) bundle, which is longer, and is tight in flexion. Bundle B is the posterolateral (PL) bundle, which is shorter, and is loose in flexion. The AM bundle is attached anterior to the PL bundle on the tibia.
The ACL is comprised of 2 bundles. The AM bundle is longer than the PL bundle. Their names reflect their relative anatomic positions on the tibial insertion site. On the femur, the AM bundle begins at the proximal-anterior aspect of the femoral insertion site, while the PL bundle begins at the posterior-inferior part. In flexion, the AM bundle is tight and the PL bundle is loose. In extension, the AM bundle is loose and the PL bundle is tight.
Bicer et al. reviewed the anatomy of the ACL. They found that the AM bundle was longer (32mm) compared with the PL bundle (18mm). PL bundle carries greater force near full extension, and the AM bundle carries greater force after 15-45° of flexion. Under combined rotatory loads (valgus and internal tibial torque at knee flexion >30°), the AM bundle bore more force than the PL bundle.
Figure A shows the 2 bundles of the ACL. The AM bundle is longer than the PL bundle. The oft referred to length of ACL refers mainly to the length of the AM bundle. Illustrations A and B show the spatial relationships of the AM and PL bundles in a cadaveric knee. Illustration C shows the relative positions of the attachments of each bundle.
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OrthoCash 2020
An 83-year-old man, who had a total hip arthroplasty performed 13 years ago, is referred to your office for evaluation. He reports worsening groin pain over the past year, which has been increasing in frequency. Prior to this past year, he had no other complaints. His current radiograph is shown in Figure A. If he continues to ambulate with this implant, he is at greatest risk for which of the following?
Infection
Acetabular component loosening
Femoral component loosening
Dislocation
Periprosthetic fracture
The patient has eccentric polyethylene wear secondary to component malpositioning. He is at highest risk for dislocation.
Late dislocation following total hip arthroplasty(THA) can occur and has a high recurrence rate, thereafter. Risk factors include eccentric polyethylene, THA at an early age, neurologic decline or associated neurologic conditions (i.e.
Parkinson's disease), or associated trauma.
Parvizi et al. noted in this instructional course lecture that eccentric, excessive polyethylene wear is one of the most common reasons for late, recurrent dislocation. Revision is recommended.
Pulido et al. in this review, reiterated that polyethylene wear can lead to increased inflammation, capsular distention, and instability, increasing risk for dislocation.
von Knoch et al. reviewing over 500 dislocated hips, also noted that eccentric wear was one of major causes linked to late dislocation.
Figure A. exhibits a left total hip arthroplasty with eccentric wear. Incorrect answers:
OrthoCash 2020
Figure A shows a radiograph of a 62-year-old female that underwent a left total hip arthroplasty 5 years ago. She presents to your office with insidious onset of left groin and buttock pain. She denies trauma, fever or chills. On physical examination, her left hip has mild pain with range of motion. She has a normal gait cycle, normal power across the hip and her vitals signs are stable. A left hip aspirate was performed and results are shown in Figure B. What is the most likely cause of her hip pain?
Periprosthetic bacterial hip infection
Periprosthetic hip fracture
Large-particle wear debris disease
Pseudotumor hypersensitivity response
Abductor tendon tear Corrent answer: 4
This patient is presenting with a metal induced system hypersensitivity response in the setting of a metal-on-metal total hip arthroplasty.
A hip aspiration of a painful THR is a very useful investigation for the work up of infection, having a sensitivity of 75-85% and specificity of 85-100% for
infection. Metal-on-metal THA may mimic infection as aspirate results will often show increased inflammatory infiltrate, with synovial WBC counts in the thousands. However, infected THA are more likely to produce higher percentages of PMNs (>70%) in comparison to hypersensitivity reactions/ adverse reaction to metal debris, which are more likely to produce a higher percentage of lymphocytes (>40%).
Campbell et al. looked at the histological features of pseudotumor-like tissues from metal-on-metal hips. They found that the patients with hip pain and suspected metal sensitivity had fewer metal particles but more aseptic lymphocytic vasculitis-associated lesions compared to patients with evidence of metallic wear. They concluded that pseudotumors occur more because of a hypersensitivity reaction than particle wear.
Kwon et al. examined a small cohort of patients with metal-on-metal hip arthroplasties to investigate the incidence and level of metal-induced systemic hypersensitivity. They found that lymphocyte reactivity to Co, Cr, and Ni did not significantly differ in patients with pseudotumors compared to those patients without pseudotumors. This suggests that systemic hypersensitivity type IV reactions may not be the dominant biological reaction involved in the occurrence of the soft tissue pseudotumors.
Figure A shows a patient with bilateral metal-on-metal total hip arthroplasties. There are no identifiable fractures. The position of the left acetabular cup is slightly vertical, which can increase edge loading and particle wear. Figure B shows the results from the hip aspirate.
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OrthoCash 2020
A 72-year-old patient is scheduled to undergo revision total hip arthroplasty. A 3D-model of the patient's hemipelvis is constructed for pre-operative planning and is shown in Figure A. A custom-designed implant shown in Figure B is created. Which of the following is TRUE of the planned reconstruction?
The implant is a bilobed cup.
The most common complication is dislocation.
The acetabular defect can be classified as AAOS Type V.
Radiation-compromised bone stock is a contraindication.
The winged profile of the implant facilitates insertion through both anterior and anterolateral approaches.
The patient has pelvic discontinuity that will be reconstructed with a custom triflange acetabular component. Dislocation is the most common complication.
Custom triflange acetabular components are indicated for severe acetabular bone loss and pelvic discontinuity that are not amenable to treatment with off-the-shelf implants such as reconstruction plates, jumbo cups and antiprotrusio cages. Dislocation is common and possible etiologies include extensive dissection, less reliable soft tissue repair, deficient abductors/trochanteric nonunion, superior gluteal nerve stretch neuropraxia, and surgeon reluctance to use constrained liners in the face of poor bone stock.
Christie et al. reviewed reconstruction with the triflange cup in 78 hips with AAOS Type III (combined deficiency) or Type IV (pelvic discontinuity) defects. They found improvement in Harris hip scores, limp, need for walking aids.
Dislocation was the most common complication (15.6%, 12 patients), and half of these patients (6/12) needed re-operation for recurrent dislocation. They recommend the triflange cup for difficult reconstructions involving severe bone loss.
Taunton et al. reviewed 57 patients with pelvic discontinuity treated with a custom triflange component. They found that 21% developed instability (10 required revision, and 2 treated nonoperatively). Of note, 51% had preop trochanteric escape (nonunion of the greater trochanter to the femoral component or femur with >1cm of displacement. They recommend the custom triflange implant for discontinuity as it provides predictable midterm fixation and consistent healing.
Figure A is a 3D hemipelvis model generated by stereolithography from a patient’s CT scan. It shows massive bone loss and pelvic discontinuity. Figure B is a custom hydroxyapatite (HA)-coated porous triflange acetabular prosthesis with ilial and ischial screw holes. Illustration A shows a bilobed cup and its appearance on an AP radiograph.
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OrthoCash 2020
All of the following are risk factors for wear-related failure in total knee arthroplasty when using a polyethylene liner that underwent sterilization via gamma irradiation in air EXCEPT?
Increasing shelf age of polyethylene liner
Younger age of patient
Male gender
Posterior cruciate retaining knee design
Use of a rough tibial baseplate Corrent answer: 4
Increasing shelf age, younger age, male gender, and a rough tibial baseplate are all risk factors for wear-related failure in total knee arthroplasty when using a polyethylene liner. Posterior cruciate retaining knee design is not a documented risk factor.
Fehring et al reviewed 2091 TKA using the Press fit condylar system and noted that the 13-year survivorship for all patients was 82.6% with a 8.3% prevalence of wear-related failure. Cox hazards analysis revealed five variables that were correlated with wear-related failure: patient age, patient gender, polyethylene sheet vendor, polyethylene finishing method, and polyethylene shelf age. They were unable to identify one factor as the defining reason for these wear-related failures. They cautioned that these findings may only be specific to inserts that underwent sterilization via gamma irradiation in air.
Collier et al followed 365 TKA (PCL-retaining) for 5-10 yrs and noted that
factors related to polyethylene insert osteolysis included advanced shelf age, sterilization method, and the material from which it was machined. Osteolysis was identified in 34% with an insert that had been gamma-irradiated in air and affixed to a rough baseplate surface, but only 9% when the insert had been gamma-irradiated in an inert gas or not irradiated at all and joined to a polished surface.
OrthoCash 2020
A 65-year-old healthy patient fell 18 years after a total hip arthroplasty and sustained the fracture shown in Figure A. Which of the following would be the most appropriate treatment?
Percutaneous locked plating
Open reduction internal fixation with a cable plate and allograft strut
Revision to a long femoral stem with allograft bone
Revision to a cemented revision femoral stem that bypasses the fracture site by 5 cm
Three months of non-weight bearing Corrent answer: 3
The Vancouver classification of periprosthetic femur fractures is based on the fracture site, implant stability, and remaining bone stock. The patient in the question has a type B3 fracture. The cemented stem is loose and there is very poor remaining bone stock. He should be treated with a long, cementless
revision stem with biplanar strut grafts. A tumor prosthesis or allograft-prosthesis composite would be alternate possibilities. Illustrations A and B are a diagram and table of the Vancouver classification of periprosthetic hip fractures.
Springer, et al. looked at the results and complications of revision total hip arthroplasty for the treatment of acute Vancouver type-B periprosthetic femoral fracture. In their series they treated these fractures in multiple ways, including cemented stems, uncemented stems, allograft-prosthetic composite, or tumor prosthesis. They concluded that the best results were with an uncemented, porous coated femoral stem, and the most common cause of revision was loosening.
Parvizi, et al. concluded that due to the poor bone quality and delayed healing of older patients & their periprosthetic fractures that it is imperative that a strong mechanical construct be achieved in the treatment of these fractures. They “advocate the use of numerous screws with purchase of at least ten cortices and reinforcement of fixation with biplanar strut allografts whenever possible. When a revision stem is used, we ensure that adequate diaphyseal fixation is obtained and the fracture is traversed by at least 5 to 8 cm.”
OrthoCash 2020
A 85-year-old man who underwent hemiarthroplasty 5 years ago now complains of thigh pain for the past four months. Laboratory studies show a normal white blood cell count (WBC), erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). An aspiration of the hip is performed and is negative for infection. A radiograph is shown in Figure A. Which of the following is the best management option for the femoral implant?
Bone scan to look for loosening
Touch down weight bearing and physical therapy
Revision with a tumor prosthesis
Revision of femoral component with metaphyseal cement fixation of the stem
Revision to a cementless femoral component with diaphyseal press-fit fixation of the stem
The radiograph shows lucency around the femoral stem cement mantle consistent with loosening. There is bone loss in the proximal femur. Diaphyseal fixation is the best option from the choices available. Revision to a cementless femoral stem is the most appropriate management.
Paprosky et al. described their results of revision to cementless femoral components and report 95% survivorship with a minimum of 10 years follow
up.
Haydon et al showed that despite historical literature discouraging the use of cemented femurs for revision, in their experience cemented femoral revision had 91% survivorship when the cause was aseptic loosening. They found early generation cementing techniques, poor cement mantle, poor bone quality, age of less than 60, and male gender to be risk factors for failure in cemented revisions.
OrthoCash 2020
Figure A is a diagram showing the medial side of the knee. During a total knee arthroplasty, proximal tibia resection results in the transection of the ligament in Figure A along the red line. Intraoperative examination reveals coronal plane instability. What are the best next steps?
Use of the implant shown in Figure B, and use of a hinged knee brace postoperatively
Suture repair of the torn ligament, use of the implant shown in Figure C
Use of the implant shown in Figure D, and use of a knee immobilizer postoperatively
Suture repair of the torn ligament, use of the implant shown in Figure D, and use of a hinged knee brace postoperatively
Use of the implant shown in Figure C alone Corrent answer: 4
This patient has intraoperative midsubstance transection of the MCL. MCL repair, use of either a CR or PS implant, and postoperative knee bracing for 6 weeks is recommended. A possible alternative is the use of an unlinked constrained implant.
The MCL is likely to be compromised by medially placed retractors or during medial subperiosteal elevation (tibial avulsion) or injured by oscillating saw-blade during the tibial or posterior femoral condyle cut. There is no consensus for the treatment of intraoperative rupture. Acceptable salvage options include
(1) direct repair (heavy sutures for midsubstance rupture, and suture anchors for tibial sleeve avusions) and postop knee bracing for 6 weeks with either CR or PS implants, or (2) use of unlinked constrained implants with or without repair.
Lee and Lotke reviewed 37 patients with intraoperative MCL injury out of 1478 patients. They attempted repair in 14 patients, and increased constraint in 30
patients. They found higher failure rates (regardless of MCL repair technique) for cruciate retaining components. They recommend use of an unlinked constrained prosthesis (with or without ligament repair), especially for midsubstance injuries.
Leopold et al. reviewed 16 MCL injuries in 600 knees. They performed suture or suture anchor repair and used a hinged knee brace for 6 weeks postoperatively. All limbs were stable and did not require bracing beyond 6 weeks, demonstrated acceptable alignment, and did not require revision at 45 months. They recommend the use of primary MCL repair or reattachment and postoperative bracing instead of implants with increased constraint.
Figure A shows MCL transection in its midsubstance. Figure B shows a cruciate retaining implant. Figure C shows a hinged knee prosthesis (linked constrained implant). Figure D shows a posterior stabilized implant. Illustration A shows an unlinked constrained implant.
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OrthoCash 2020
A 65-year-old woman complains of intermittent knee pain 12 years after a total knee arthroplasty. She has no history of fever or recent infections. Radiographs are shown in Figures A and B. Examination reveals minimal warmth and a moderate knee effusion. Range of motion is 5 to 100 degrees bilaterally. The C-reactive protein level is 15 mg/L (normal, 0.0-0.8mg/L), and erythrocyte sedimentation rate is 45mm/h (normal, 0-10mm/h). Arthrocentesis reveals 7500 white blood cells and 90% neutrophils. Gram stain is negative. Cultures are negative at 3 days. What is the next best step?
MRI with metal subtraction protocol
Arthroscopic debridement
Open debridement and polyethylene liner exchange
Single-stage revision total knee arthroplasty (TKA)
Explantation of components with two-stage revision TKA Corrent answer: 5
By the updated 2018 Musculoskeletal Infection Society (MSIS) criteria, this presentation is consistent with a diagnosis of periprosthetic joint infection (PJI). The patient has an elevated CRP (2), ESR (1), synovial WBC >3,000 (3), and >80% PMNs (2), for a total of 8 points. Given the chronicity of the infection, the patietn would be a candidate for two-stage revision.
This patient has clinical signs of PJI such as elevated laboratory values and radiographs suggestive of implant loosening. Even in the absence of positive cultures, the next most supported step in management if two-stage revision with explantation of the prosthesis and insertion of an antibiotic spacer.
Intraoperative cultures should be taken to guide post-operative antibiotic treatment.
Parvizi et al. recently released the updated 2018 MSI crtieria for diagnosis of PJI. The updated criteria (Illustration A) included new diagnostic tests and studies from the seven-year period since the previous criteria were established. Alpha defensin was a new addition. The two major criteria remained, each individually diagnostic of PJI. However the minor crtieria were broken down into pre-operative and intra-operative. The authors showed that a total of 6 points or more had a 97.7% SN and 99.5% SP for PJI.
Huang et al. retrospectively reported the infection control rates in 2-stage exchanges in 55 patients, and compared culture-negative cases with 295 culture-positive cases. They found that infection control in culture-negative cases was 73% at 1-year. Infection control rates were similar in culture-negative and culture-positive cases, and that infection-free survival is highest after 2-stage exchange with postoperative vancomycin. They recommend 2-stage exchange with postoperative vancomycin.
Buller et al. retrospectively assessed traits that would predict the success of debridement and liner exchange for 62 hips and 247 knees. They found that 149 (48.2%) cases failed to eradicate infection. Risks for recurrent infection include longer symptom, higher ESR, previous PJI or infection in the same joint, and an infection by a group 1 (MRSA, VRE, and methicillin-resistant S. epidermidis) or group 2 (MSSA or methicillin-sensitive coagulase-negative Staphylococcus) organism.
Della Valle et al. discuss the AAOS recommendations on diagnosis of periprosthetic hip and knee infections. They recommend repeat hip and knee aspirations when there is discrepancy between probability of PJI and initial aspiration culture result.
Aggarwal et al. prospectively compared the yield of intraoperative tissue and swab cultures in 74 hip, 43 knee, 30 septic and 87 aseptic cases. They found that tissue cultures had higher sensitivity, specificity, positive and negative predictive values for identifying PJI. Swab cultures had higher false positive and negative values. They recommend not using swab cultures, and only using tissue cultures.
Figures A and B are AP and lateral radiographs showing areas of bony erosion suggestive of loosening of the femoral and tibial components.
Illustration A is the 2018 MSIS criteria with point values.
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OrthoCash 2020
What are the affects on limb-length and offset according to the total hip arthroplasty template shown in Figure A?
Limb-length will stay the same, offset will be increased
Limb-length will be decreased, offset will be increased
Limb-length will stay the same, offset will be decreased
Limb-length will be increased, offset will be increased
No change in either limb-length or offset Corrent answer: 1
In Figure A, the center of rotation of the femoral component lies medial to the center of rotation of the acetabular component. If these components are implanted as shown, the offset will be increased and the leg-lengths will remain equal.
Offset and leg-length changes during templating and insertion of a total hip replacement are determined by the changes in the center of rotation (COR) of the femur relative to the acetabulum. If changes are made in the horizontal plane (x-axis), a change in offset will occur. If changes are made in the vertical plane (y-axis), changes in leg-lengths will occur. If the femoral COR is templated superior to the acetabular COR, the leg will be lengthened. In
contrast, if the femoral COR is templated inferior to the acetabular COR, the leg will be shortened. For offset, the same principles apply. If the femoral COR is templated medial to the acetabular COR, offset will be increased. In contrast, if the femoral COR is templated lateral to the acetabular COR, offset will be decreased. One should aim to restore native offset and leg-lengths in uncomplicated primary total hip arthroplasty.
Merle et al. retrospectively reviewed 152 patients to evaluate femoral offset on an AP pelvis and AP hip radiograph compared to a CT scan of the affected hip. They found that AP pelvis radiograph underestimated femoral offset by 13% when compared to a CT scan. In contrast, the AP hip radiograph showed no difference when compared to the CT scan. They recommend obtaining AP of the hip prior to templating for accurate assessment of femoral offset.
Della Valle et al. review preoperative planning for total hip arthroplasty. While they state that templating has a high predictive value in achieving the desired plan, the surgeon should always be prepared to make intraoperative adjustments based on tactile feedback.
Illustration A shows an example where leg-length will be shortened (femoral COR is inferior to acetabular COR) and offset will stay the same (femoral COR and acetabular COR are in the same horizontal plane). Illustration B is a table which summarizes the points we have discussed.
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OrthoCash 2020
A 65-year-old patient is diagnosed with a periprosthetic joint infection 6 years after total knee arthroplasty. He recalls a history of knee realignment surgery many years prior. Examination reveals lateral patellar tracking and passive flexion to 65 degrees. A recent radiograph is shown in Figure A. During the exposure for explantation, a standard medial parapatellar approach is performed through the previous incision. It is found that adequate knee flexion to allow exposure of the prosthesis cannot be achieved even after release of the lateral gutters and excision of the scar. Which surgical exposure technique (depicted in Figures B through F) would provide the best
surgical exposure for the procedure and preserve the blood supply to the patella?
Fig B
Fig C
Fig D
Fig E
Fig F
A tibial tubercle osteotomy (TTO) would provide the best surgical exposure without compromising patellar blood supply. This patient has patella baja arising from previous high tibial osteotomy, with a scarred, contracted patellar tendon leading to knee stiffness.
A TTO is able to provide good exposure while protecting the extensor mechanism and preventing inadvertent avulsion of a contracted patellar tendon. Further, proximal transfer of the osteotomized tibial tubercle may be used to correct patella baja, bearing in mind that excessive superior translation alters the mechanics of the knee by making the quadriceps less efficient.
Mendes et al. used TTO for surgical exposure in 67 knees undergoing revision TKA. There were good-excellent knee scores at 30 months in 87%. There were no patellofemoral complications, no component malalignments, and no avulsions of the patellar tendon occurred. They advocate TTO for cases where the patellar cannot be retracted laterally with knee in 90deg of flexion.
Whiteside described a series of TTO in 136 TKA. At 2 years, mean range of motion was 94deg. There were 2 tibial tubercle avulsion fractures and 3 tibial fractures (2 in a patient with Charcot arthropathy, and 1 following manipulation after open adhesiolysis. He advises using stemmed tibial components in patients with insensate knees and in cases where manipulation is expected.
Figure A is a lateral radiograph showing severe patella baja. Figure D shows a TTO. See below for Figures B, C, E and F. Illustration A shows the surgical technique for TTO. The distal saw cut angles out of the anterior cortex at a gentle angle to reduce the stress riser effect and risk of postoperative tibial stress fracture.
Incorrect Answers:
sufficient in the presence of severe patellar baja and patellar tendon contracture.
OrthoCash 2020
Figure A show pre- and post-operative radiographs, from left to right respectively, of a 79-year-old male that underwent revision total hip arthroplasty 2 years ago. He presents today for consultation after 4 episodes of right hip dislocation within the past 6 months. Physical examination reveals a trendelenburg gait with no clinical or radiographic limb length discrepancy. An Infection work-up is negative. Results from a CT scan are shown in Figure B. What would be the best treatment option?
Physiotherapy and application of abductor brace
Revision arthroplasty to medialize the cementless cup and surgical repair of the abductor tendon
Revision arthroplasty to a constrained polyethylene liner
Revision arthroplasty to a femoral component with extended offset
Revision arthroplasty to a large ceramic femoral head and offset polyethylene cup
On the left, Figure A shows a metal-on-metal (MOM) bearing hip resurfacing. On the right, Figure A shows a large head, uncemented metal-on-polyethylene (MOP) total hip replacement. In this setting, the most appropriate treatment option would be revision arthroplasty with constrained polyethylene liner.
Constrained liners should be reserved for patients demonstrating recurrent instability despite treatment with a large femoral head. Other indications include elderly patients who do not require implant longevity or have a low functional demand, as well as patients with deficient or non-repairable abductor mechanisms.
Sikes et al. report on the results of a series of 41 patients (52 hips) with recurrent dislocations. They recommend that large femoral heads (LFH) be used as a first-line treatment in high-risk patients (patients of any age with dementia, neuromuscular disability, and inability to comply with precautions). Constrained liners should be reserved for patients demonstrating recurrent
instability despite treatment with an LFH.
Kilampali et al. reviewed late instability of bilateral metal on metal hip resurfacings. They suggest that late instability of hip resurfacing should raise concerns relating to possible local tissue reaction and muscle damage.
Concerning features include steeply-inclined acetabular components a large abduction angle of more than 55 degrees along with a combination of small size component.
Figure A shows an image of a revised socket which was performed to convert the MOM THA to a MOP THA. Figure B shows normal parameters of THA components. The recommendation for acetabular position is anteversion 20° ± 10° and abduction 45° ± 10°. For the femur, recommendations are 10°- 15° of anteversion and 41mm - 45mm of offset.
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OrthoCash 2020
Which of the following has been shown to increase the rate of failure of cemented femoral components in total hip arthroplasty?
Stems that are precoated with polymethylmethacrylate
Calcar contact of the collar
Smoother implant corners
Cement mantle of 2 millimeters
Stem material with a Young's modulus higher than 115 GPa Corrent answer: 1
Precoating a stem with PMMA adds an additional inferface at risk of failure.
Stiffer stem materials (higher Young's modulus) improve performance. Titanium has a Young's modulus of 115 GPa with alloy and stainless steel
having a higher Young's modulus than titanium. Calcar collar contact adds minimal strength to the construct, but does not lead to premature failure. Smoother corners decrease the rate of failure since they decrease stress risers. The ideal cement mantle is ~2mm. Obtaining less than this would decrease the strength of the construct.
OrthoCash 2020
An 80-year-old male sustains a fall down the stairs and presents with knee swelling. He is a community ambulator who does not use walking aids. Injury radiographs are shown in Figures A and B. What is the next best step?
Intramedullary nailing
Locked plating
Long leg casting
External fixation
Revision total knee arthroplasty Corrent answer: 5
This patient sustained a periprosthetic femoral fracture around the femoral component which is now loose. Revision of the femoral component is necessary.
Various classifications exist for periprosthetic fractures around TKA. In general, for the femoral component, treatment depends on fracture displacement, fracture location, bone stock, and whether the component is loose. For loose femoral components, revision TKA using distal femoral replacement prosthesis is an option.
Kim et al. proposed a new classification for periprosthetic fractures. Type IA fractures (good bone stock, well fixed, nondisplaced or easily reducible) are managed conservatively. Type IB fractures (good bone stock, well fixed, irreducible closed) are managed with reduction and fixation. Type II fractures (good bone stock, reducible, loose or malpositioned components) are managed with revision. Type III fractures (poor bone stock, loose or malpositioned components) are treated with distal femoral replacement.
Johnston et al. reviewed the options for treating periprosthetic fractures about the knee. They advocate revision of the femoral component when the prosthesis is loose, where there is poor bone stock, or insufficient bone to gain purchase for locked plates or distal locking screws of intramedullary nails.
Nauth et al. review the current concepts in treatment of periprosthetic fractures. They prefer minimally invasive locked plating unless the fracture is significantly proximal to the anterior flange and amenable to retrograde intramedullary nailing. Then they choose nails with options for distal interlocking screws and locking condylar bolts. In extreme osteopenia, they use intramedullary fibular strut allografts (with locked plating). For loose prostheses or poor bone stock, they perform alloprosthetic composite in younger patients and a distal femoral replacement in elderly patients.
Figures A and B are AP and lateral radiographs showing periprosthetic femoral fracture around a loose femoral component. Illustrations A and B are postoperative radiographs showing revision to a hinged prosthesis with long-stemmed components. Illustration C shows Kim' proposed classification of
periprosthetic fractures around the femoral component of a TKA.
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OrthoCash 2020
Utility of the implant seen in Figure A would be best considered in which of the following revision total hip arthroplasty scenarios?
Minimal acetabular deformity, intact rim
Superior acetabular bone lysis with intact superior rim
Localized acetabular destruction of medial wall
Absent superior acetabular rim, superolateral migration
Significant acetabular bone loss, pelvic discontinuity Corrent answer: 5
Paprosky Type 3B acetabular bone defects describes significant acetabular bone loss, with pelvic discontinuity. Type 3 defects often require reconstruction cages (as seen in Figure A) or acetabular distraction techniques
to treat severe bone loss with an associated pelvic discontinuity.
Deficient acetabular bone stock poses a technical challenge in hip arthroplasty surgery. Paprosky classification for acetabular bone loss to helps guide treatment for revision total hip arthroplasty. The classification is as follows:
Type 1: Minimal deformity, intact rim
Type 2A: Superior bone lysis with intact superior rim Type 2B: Absent superior rim, superolateral migration Type 2C: Localized destruction of medial wall
Type 3A: Significant bone loss, superolateral cup migration Type 3B: Significant bone loss, pelvic discontinuity
Sheth et al. reviewed acetabular bone loss in revision total hip arthroplasty. They state that Paprosky Type 1 and 2 defects can usually be managed with porous-coated hemisphere cup secured with screws. Type 3 defects require reconstruction cages to protect with cups and structural augments or custom triflange implants.
Taunton et al. investigated clinical outcomes and cost-effectiveness of using a custom triflange acetabular component to treat pelvic discontinuity in revision THA. They found satisfactory clinical outcomes (81% had a stable triflange component with healed pelvic discontinuity) and cost equivalence with Trabecular Metal cup-cage constructs.
Figure A shows a lateral image of the pelvis with a reconstruction cage and cup construct. Illustration A shows an illustration of the Paprosky classification. Illustration B shows a table of the Saleh/Gross classification. Illustration C shows a table of the AAOS classification.
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OrthoCash 2020
A 65-year-old male who had a total knee arthroplasty 8 years ago comes into the office with worsening knee pain. The orthopaedic surgeon is concerned about infection and aspirates the knee. Which of the following are the lowest laboratory values from a synovial aspirate suggestive of infection?
WBC of 500 cells/ml and PMN 25%
WBC of 1,000 cells/ml and PMN 25%
WBC of 1,500 cells/ml and PMN 70%
WBC of 5,000 cells/ml and PMN 70%
WBC of 25,000 cells/ml and PMN 70%
WBC of 1,500 cells/ml and PMN 70% indicates the lowest synovial aspirate suggestive of infection.
Mason et al in 2003 reviewed 440 revision TKA's of which 86 had preoperative aspirations. The aspirations yield 55 aseptic failures and 31 septic failures. The mean WBC of the aseptic group was 645 cells/mm(3) compared to 25,951 cells/mm(3) for the septic group (P=<.001). The mean percentage of polymorphonuclear cells (PMNs) was statistically higher in the septic group compared with the aseptic group (72.8% vs 27.3%; P=<.001). With these results, the authors concluded that aspirates with a WBC count greater than 2,500 and 60% PMNs are highly suggestive of infection.
However, in a more recent and larger study, Ghanem et al reviewed 161 infected TKA's vs 268 aseptic failures and concluded that aspiration with WBC of >1100 cells/mm3 and PMN > 64% are suggestive of infection. When both tests yielded results below their cutoff values, the negative predictive value was 98.2% (95% confidence interval, 95.5% to 99.5%), whereas when both tests yielded results greater, infection was confirmed in 98.6% (95% confidence interval, 94.9% to 99.8%) of the cases. Thus, according to the most recent literature, WBC >1100 and PMN > 64% should be considered suggestive of infection in a TKA.
OrthoCash 2020
A 50-year-old man with a past medical history significant for diabetes and end-stage renal disease presents with a chief complaint of instability 6-months following a total knee arthroplasty. Preoperative radiographs are shown in Figures A-C. Physical exam at that time was notable for a large effusion, maltracking patella, extensor lag of 15 degrees, medial instability, and gross laxity to anterior and posterior forces. The procedure was uncomplicated, and was completed using a posterior-stabilized prosthesis with tibial augements and uncemented intramedullary rods in both the femur and tibia. Which of the following surgical techniques should have been implemented to avoid this complication?
Cementing the intramedullary rods in the tibia and femur
Explant with placement of an antibiotic spacer
Taking 5mm of extra bone from the distal femur to elevate the joint line
Use of a hinged total knee arthroplasty
Taking 5mm of extra bone from the tibia to distalize the joint line Corrent answer: 4
The patient has a neuropathic joint with ligamentous instability and a maltracking patella. The appropriate procedure would have included use of a hinged total knee arthroplasty.
Choosing the appropriate constraint during a total knee arthroplasty ensures the best possible outcome. Hinged total knee arthroplasty prostheses are indicated in the setting of global instability, massive bone loss in a neuropathic joint, oncologic procedures, and hyperextension instability. In a hinged prosthesis, the tibial and femoral components are linked with an axle that restricts varus/valgus and translational stresses. While hinged prostheses are useful in the setting of major revision surgery, they are at increased risk for aseptic loosening due to the high degree of constraint inherent to the device.
Petrou et al. review the results of 100 primary cemented rotating-hinge total knee arthroplasty at 7- to 15-years. At 15 years, survival was 96.1%.
Complications included DVT (n=3), skin necrosis (n=2), subcutaneous hematoma (n=5), intra-operative fracture of either the femur or tibia (n=4), and early infection (n=2).
Figures A-C show a neuropathic joint with considerable lateral bone loss and a frankly dislocated patella. Illustration A shows an example of a hinged total knee arthroplasty. Note how the tibial and femoral components are linked using an axle.
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OrthoCash 2020
A 63-year-old man returns for follow-up 4 years after metal-on-metal left total hip arthroplasty complaining of mild chronic hip pain with ambulation. He is afebrile and ESR and CRP are within normal limits. Radiograph of the left hip is shown in Figure A. What is the best next step?
Anti-inflammatory medication
Serum cobalt and chromium levels
MRI with metal subtraction
Physical therapy
Revision hip arthroplasty Corrent answer: 2
Metal-on-metal total hip arthroplasties (THA) have been associated with complications presumably due to metal debris and toxicity. Serum cobalt and chromium levels are recommended as part of follow-up evaluation for patients with metal-on-metal hips, even when asymptomatic.
Many patients with metal-on-metal hips have been found to have elevated serum cobalt and chromium levels, for which MR with metal subtraction is recommended to look for pseudotumors and other pathologies. These solid or cystic masses are thought to be related to metal debris and macrophage infiltration and may be associated with pain in some patients.
Lombardi et al summarize and present on behalf of The Hip Society an algorithmic approach to evaluating and treating patients with metal-on-metal THA in follow-up. They state the goals of care as determining the etiology of any pain, managing any intrinsic problems with the arthroplasty, and reassuring/observing when appropriate. They organize the types of patients seen in followup and components of the evaluation.
Chang et al evaluate the correlation between symptoms and MRI findings and report that symptomatic patients tend to have bone marrow edema and tendon tearing on MRI. They report a 69% prevalence of pseudotumors on MRI after metal-on-metal hip arthroplasty, but did not find a correlation between pseudotumor presence and pain.
Hayter et al focus on MRI findings in symptomatic (painful) patients with metal-on-metal THA in a review including 31 hip resurfacing and 29 THA. In the THA group, they report 86% rate of synovitis, 10% extracapsular disease, and 24% osteolysis, with no statistically significant difference in rates between resurfacing and THA.
Figure A is an AP view radiograph of a left hip after metal-on-metal total hip arthroplasty with components well positioned and no osteolysis.
Illustrations A and B from Lombardi et al depict a recommended algorithm for the workup and management of symptomatic and asymptomatic patients, respectively, with metal-on-metal THA.
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OrthoCash 2020
A 72-year-old woman sustains a fall onto her knee three years after an uncomplicated total knee replacement. The fracture pattern is seen in Figure A. The operative note reveals that a cemented patellar component was used. On exam, she has a large effusion and an
inability to straight leg raise. If the patellar component is well fixed, what is the best treatment option?
Patellectomy
Extensor mechanism allograft
Revision of the patellar component with cement and bone grafting of any residual defect
Open reduction and internal fixation of the patella fracture
Non-operative treatment in a knee brace locked in extension for 6 weeks Corrent answer: 4
Displaced, periprosthetic patella fractures with a deficient extensor mechanism and adequate bone stock are best treated with open reduction and suture or implant fixation.
Periprosthetic patella fractures are a rare, but potentially devastating complication associated with total knee arthroplasty. When evaluating patella fractures, it is important to consider 1) is the extensor mechanism intact, 2) is the patellar component well fixed or loose, and 3) is there sufficient bone stock remaining. Stable implants with an intact extensor mechanism should almost exclusively be treated non-operatively in a brace. In contrast, a deficient
extensor mechanism is an absolute indication for surgical management.
Adigweme et al. review the epidemiology, diagnosis, and treatment of periprosthetic patella fractures. When analyzing patella fractures, they suggest treatment should be based on fracture severity, remaining bone stock, patellar component stability, as well as extensor mechanism function.
Sarmah et al. review periprosthetic fracture around total knee arthroplasty. They provide an algorithm for treatment of periprosthetic patella fractures based on displacement, viability of remaining bone stock, and fracture type.
Figure A is a preoperative lateral radiograph showing a periprosthetic patellar fracture. The distal fragment is comminuted and separated from the proximal fragment by approximately 15 mm. The patellar component appears to be well fixed. Illustration A is intraoperative photograph showing the threads of the suture anchors in the proximal fragment passing through the tunnels in the distal fragment and exiting at the inferior pole of the patella. Illustration B demonstrates anatomical reduction after the knots were tied at the inferior pole of the patella. Illustration C is a lateral x-ray 1 year postoperatively showing fracture union.
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OrthoCash 2020
Knee pain and osteoarthritis are associated with "metabolic syndrome." All of the following are included in the collection of risk factors known as "metabolic syndrome" EXCEPT:
Peripheral vascular disease
Dyslipidemia
Hypertension
Impaired glucose tolerance
Central obesity
Peripheral vascular disease (PVD) may develop in patients with metabolic syndrome. However, no direct relationship between metabolic syndrome and PVD is known, and it is not a part of metabolic syndrome itself. Metabolic syndrome has been shown to be associated with knee pain and development of knee osteoarthritis (OA).
Metabolic syndrome is a collection of medical comorbidities that are known to
be risk factors for developing cardiovascular disease. Metabolic syndrome includes central (abdominal) obesity, dyslipidemia (high triglycerides and low-density lipoproteins), high blood pressure, and elevated fasting glucose levels. There is an increased prevalence of knee pain (and OA) among patients with metabolic syndrome. It is felt that the most important contributing factor to knee pain and OA in metabolic syndrome is obesity. Patients presenting with knee pain or OA and the risk factors included in metabolic syndrome should be counseled on the need to control those risk factors.
Inoue et al. present a study comparing metabolic syndrome and knee OA in a Japanese population. They found that knee OA and metabolic syndrome were highly correlated in females, but not in males.
Engström et al. present a study comparing metabolic syndrome with hip and knee OA. They found no relationship to hip OA, but did find a strong correlation between patients with metabolic syndrome and risk of developing knee arthritis. Patient BMI was the most predictive factor. They also compared prevalence of knee OA to CRP levels, but found no significant relationship.
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OrthoCash 2020
A 75-year-old male presents with recurrent dislocations of this left hip. He underwent bilateral total hip arthroplasties 12 and 8 years ago. There were no early post-operative complications with either hip. Despite a total of 5 dislocations in 6 months, he does not have pain or weakness across the left hip. On examination, there is a healthy appearing left lateral scar, equal limb lengths, normal gait and full abductor strength. Radiographs of the pelvis are shown in Figure A. His laboratory results show an erythrocyte sedimentation rate of 8 mm/h (reference range, 0-20 mm/h), and C-reactive protein of 3 mg/L (reference range, 0-5.0 mg/L). A hip aspirate culture is negative. What is the next best management option for this patient?
Magnetic resonance imaging of left hip to exclude an abductor muscle tear
Re-aspiration of left hip to exclude a subclinical infection
Continued observation for trochanteric bursitis
Supervised physiotherapy and gait training for abductor strengthening
Left revision total hip arthroplasty for polyethylene wear Corrent answer: 5
This patient presents with recurrent late hip instability with radiographic evidence of eccentric polyethylene wear. The best treatment option for this patient would be revision total hip arthroplasty (THA).
The etiology of late instability includes polyethylene wear, component malpositioning or loosening, trauma, infection or deterioration in neurological status of the patient. Identifying the cause of late instability will require a thorough work up. A good history, examination and scrutiny of radiographs can identify most causes. Advanced imaging may be requires when bone or soft-tissue pathology is suspected or radiographic evidence of osteolysis or malpositioning needs further assessment. Blood work to assess for an acute inflammatory response (ESR and CRP) should be ordered routinely as elevated markers may indicate an underlying infection.
Parvizi et al. evaluated the outcome of revision arthroplasty for polyethylene wear presenting as late dislocation. They found that revision surgery restored stability to eighteen of the twenty-two patients. Surgical treatment options may include liner-only exchange (contained or unconstrained) +/- soft-tissue repair, or revision of one or all components.
Berry et al. evaluated the long-term risk of dislocation in 6,623 consecutive primary total hip arthroplasties with a Charnley prosthesis. They found a 7% incidence of late dislocation at 25 years compared to 1% after 5 years.
Patients at highest risk were females, patients with osteonecrosis of the femoral head or an acute fracture, and nonunion of the proximal part of the femur.
Figure A shows an AP pelvis with bilateral, uncemented, total hip arthroplasties. There is eccentric wear of the left acetabular component. No fracture or loosening of the components can be identified. The components appear well-positioned.
Incorrect Answers:
This patient has no pain or weakness in the affected hip. Therefore, soft tissues can be evaluated intra-operatively during the revision THA procedure. Answer 2: A hip aspirate would not be warranted. There are no risk factors for infection in this patient (for example, no pain, no early wound complications or antibiotics, etc). Additionally, his inflammatory markers are normal.
OrthoCash 2020
A 58-year-old woman undergoes a total knee arthroplasty with a posterior stabilized design. Two years later, she returns with recurrent sterile joint effusions, a sensation of instability without giving way and difficulty with ascending and descending stairs. Examination reveals diffuse tenderness around the pes anserinus and peripatellar region, and increased anterior tibial translation most notable at 90° of flexion. Radiographs demonstrate well cemented implants with 5° of posterior tibial slope. Figure A represents a femoral cutting block with lines 1 through 5 corresponding to femoral bone cuts. The most likely cause of her symptoms is over-resection at:
Resection line 1
Resection line 2
Resection line 3
Resection line 4
Resection line 5
Over-resection of the posterior femoral condyles (resection line 2) in posterior-stabilized (PS) TKA leads to flexion instability without frank dislocation.
There are 7 bone cuts in a total knee replacement. The posterior condylar cut determines the flexion gap. Flexion instability in PS knees arises because of an enlarged flexion gap (excessive posterior condylar resection, or increased tibial slope), allowing anterior tibial translation, which is pathognomonic. There will not be posterior subluxation because of the cam-post design. Symptoms include sensation of instability without giving way, especially with stair climbing, recurrent knee effusions, and diffuse knee pain. Signs include anterior tibial translation at 90° flexion, tenderness at multiple sites (including pes anserinus, peripatellar, posterior hamstrings), and effusion. Revision surgery is indicated for symptomatic patients.
Clarke et al. reviewed flexion instability after primary TKA. They caution that most cases arise from failure to create symmetric balanced flexion and extension spaces. Treatment is usually revision TKA using the same principles. If this is not possible, increased constraint is required (constrained condylar prosthesis or hinged prosthesis).
Schwab et al. reviewed flexion instability without dislocation in PS knees in 10 patients. Revision surgery focused on flexion-extension gap balancing and filling the enlarged flexion gaps and successfully relieved pain, and improved stability to anterior tibial translation. Flexion space reconstruction includes using a larger femoral component or posterior augments. Isolated polyethylene exchange is not recommended.
Figure A shows a 5-in-1 cutting block with anterior femoral cut (line 1), posterior femoral cut (line 2), posterior chamfer cut (line 3), anterior chamfer cut (line 4), and distal femoral cut (line 5). Of note, most TKA systems have a 4-in-1 cutting block and the distal femoral cut is made separately. Illustration A shows restoration of the posterior condylar offset (line A) with the femoral component (line B).
Incorrect Answers
OrthoCash 2020
Which of the following is true regarding intra-operative fractures during total knee arthroplasty?
They occur more commonly in cruciate-retaining total knee replacements
Fractures of the medial femoral condyle are the most common fracture type
Fractures of the patella are the most common fracture type
Most can be treated without additional fixation at the time of surgery
Tibial fractures are more common than femoral fractures Corrent answer: 2
Fractures of the medial femoral condyle are the most common type of intraoperative fracture during a total knee arthroplasty.
Intra-operative fractures during total knee replacement are rare, but usually requiring alterations in surgical technique once they occur. The most common time for fractures to occur is during exposure and bone preparation, with fracture during trialing being the next most common. Fractures occur more commonly in posterior cruciate substituting designs, likely due the box cut.
Osteoporosis, female gender, chronic steroid use, advanced age, rheumatoid arthritis, and neurologic disorders are risk factors for post-operative fracture, but are also thought to be risk factors for intra-operative fractures.
Alden et al. reviewed 17,389 primary TKAs and found an intra-operative fracture rate of 0.39%. Of the 67 fractures, 49 were femur fractures, 18 were tibia fractures, and none were patella fractures. They recommend careful surgical technique in patients at high risk for fracture to avoid such a complication.
Sharkey et al. reviewed 10 intra-operative femoral fractures during primary, cementless total hip arthroplasty. They matched these with 20 patients who did not have this complication. At follow-up, there were no differences found between the two groups.
Incorrect Answers:
OrthoCash 2020
A 68-year-old male complains of increasing medial sided knee pain and buckling. The pain is exacerbated by sharp turns while
running. He undergoes knee arthroscopy. Recent radiographs and an arthroscopic photograph of the medial compartment are shown in Figure A. His pain has worsened since the arthroscopy. Which of the following images (Figures B through F) represents the best treatment recommendation for this patient?
This patient has isolated medial compartment osteoarthritis with Outerbridge IV medial compartment cartilage wear on arthroscopy. The best surgical option is a medial unicompartmental knee arthroplasty (UKA).
Indications for UKA include range of motion >100deg with <5deg flexion contracture, angular deformity <15deg valgus or <5deg varus that is passively correctable to neutral. Relative contra-indications include younger patients (age <60), obesity (BMI >30), and ACL deficiency in medial UKA. Asymptomatic patellofemoral chondromalacia is not a contraindication. In general, a UKA is preferred for older, less active patients with minimal varus, more severe arthritis, and no/little knee instability. A HTO is preferred for younger, active patients, with milder arthritis, more malalignment, and AP instability.
Steadman et al. retrospectively examined outcomes of TKA after arthroscopic treatment of OA in 73 patients. They found that mean survival time (conversion to TKA) after arthroscopy was 6.8 years (5.7 years in patients with Kellgren-Lawrence grade 4, and 7.5 years in those with grade 3). They conclude that in patients who want to avoid TKA, arthroscopy may help postpone TKA.
LaPrade et al. examined the results of proximal tibial opening wedge
osteotomies in 47 patients <55 years old with medial compartment osteoarthritis (OA) and genu varus. They found that there was improvement in knee scores and the mechanical axis at 3.6 years. They recommend this technique for patients with medial compartment OA and malalignment.
Figure A is a composite image showing isolated medial compartment osteoarthritis, and Outerbridge IV cartilage wear with large areas of visible subchondral bone. (See below for Figures B through F). Illustration A is a table comparing the indications of HTO vs UKA.
Incorrect Answers:
OrthoCash 2020
A 58-year-old female, with a BMI of 34 kg/m2, underwent a total knee arthroplasty for osteoarthritis 6 weeks ago. She has been participating in supervised rehabilitation since the procedure. Her preoperative, intra-operative and 6 week post-operative knee flexion are shown in Figure A. Current radiographs are shown in Figure B. What is the best step in management?
Convert to a resurfaced patella
Downsize the polyethylene liner
Arthroscopic lysis of adhesions and release of posterior capsule
Continuous passive motion at home for two weeks
Manipulation under anesthesia Corrent answer: 5
This patient has early post-operative stiffness after total knee arthroplasty (TKA). The next best step would be manipulation under anesthesia.
Management of stiffness following TKA can be challenging. The standard initial treatment option for post-operative knee stiffness is physical therapy. When this fails to achieve knee range of motion (ROM) greater than or equal to 90°, alternative treatment modalities should be considered, such as knee manipulation under anesthesia (MUA). MUA is a non-invasive treatment shown to achieve dramatic improvement in knee flexion during the early postoperative period (usually considered less than three months). Periprosthetic fracture during manipulation is rare, with an overall incidence less than 1%.
Issa et al. examined a cohort of patients that underwent MUA after TKA. At a mean follow-up of 51 months (range, 24 to 85 months), the mean gain in flexion in the MUA cohort was 33° (range, 5° to 65°). There was one periprosthetic fracture in 134 patients. The authors noted a significant improvement in ROM from pre-manipulation values.
Manrique et al. reviewed stiffness after total knee arthroplasty. MUA may be considered within the first three months after the index TKA if physical therapy fails to improve the ROM. Beyond this point, consideration should be given to surgical intervention such as lysis of adhesions, either arthroscopic or open.
Maniar et al. looked at the effectiveness of continuous passive motion immediately after TKA. A total of 84 patients were allocated to no CPM; 1 day CPM; or 3 day CPM. They found that continuous passive motion immediately after TKA did not improve short or mid-term knee ROM.
Figure B shows a cruciate sacrificing total knee arthroplasty with implants in a good position.
Incorrect Answers:
OrthoCash 2020
Which of the following fracture patterns (Figures A-E) would require revision of the femoral component to a long-stemmed, cementless prosthesis?
Figure C depicts a Vancouver B2 periprosthetic fracture, which is optimally treated with a long-stem, fully porous-coated, revision femoral prosthesis.
The Vancouver classification for total hip periprosthetic femoral fractures takes into account the three most important factors in management of these injuries: the site of the fracture, the stability of the femoral component, and the quality of the surrounding femoral bone stock. Type A fractures include those involving the lesser trochanter or the greater trochanter. Type B fractures occur around the stem or just below it. More specifically, B1 fractures have a well fixed stem, B2 fractures have a loose stem but good proximal bone stock and B3 fractures have a loose stem with proximal bone that is of poor quality or severely comminuted. Type C fractures are well below the tip of the femoral stem.
O'Shea et al. assessed the outcome of patients with Vancouver type B2 and B3 periprosthetic fractures treated with femoral revision using an uncemented extensively porous-coated implant. Union of the fracture was successfully achieved in 20 of the 22 patients. Overall, they found good early survival rates and a low incidence of nonunion using this implant.
Figure A depicts a radiograph of a Vancouver type C periprosthetic femur fracture, occurring distal to the stem of the total hip arthroplasty. Figure B demonstrates a Vancouver type A periprosthetic fracture of the greater trochanter. Figure C is an x-ray of a Vancouver type B2 periprosthetic fracture adjacent to the stem with an unstable implant, but adequate bone stock.
Figure D depicts a radiograph of a Vancouver type C periprosthetic femur fracture, occurring distal to the stem of the total hip arthroplasty. Figure E is a Vancouver type B1 periprosthetic fracture at the level of the stem that is well fixed. Illustration A shows a table summarizing the Vancouver classification of periprosthetic femur fractures and the corresponding management options.
Incorrect Answers:
OrthoCash 2020
Which of the following maneuvers places the obturator artery at greatest risk during a total hip arthroplasty?
Placement of a posterior retractor along the posterior wall
Placement of an acetabular screw in the posterior-superior quadrant
Placement of an inferior retractor under the transverse acetabular ligament
Placement of an acetabular screw in the anterior-superior quadrant
Placement of an anterior retractor along the anterior wall Corrent answer: 3
Damage to the obturator artery most commonly occurs from placement of an inferior retractor inferior to the transverse acetabular ligament (into the obtrator foramen), and/or placement of an acetabular screw in the anterior-inferior quadrant.
Vascular injury during total hip arthroplasty is a rare but devastating complication with a reported incidence of 0.1%-0.2%. The obturator artery travels along the quadrilateral surface of the acetabulum and exits the pelvis at the superolateral corner of the obturator foramen. If the vessel is severely
damaged and bleeding cannot be controlled, ligation of the internal iliac artery has been reported.
Nachbur et al. report on 15 cases of severe arterial injury during hip reconstructive surgery over a period of 8 years. The most common injury was injury to the external iliac artery, the common femoral artery, or main branches of the lateral and medial circumflex femoral artery. These were thought to be caused by the tip of a narrow-pointed Hohmann retractor used for exposure of the hip joint.
Rue et al. review neurovascular injuries during total hip arthroplasty. Among other things, they recommend against placement of screws in the anterior-superior quadrant, prudent retractor placement, and avoiding excessive tension on the sciatic nerve.
Della Valle and Di Cesare review complications resulting from total hip replacement. They state that injury to the obturator artery can occur with acetabular screw fixation in the antero-inferior quadrant or from retractors placed underneath the transverse acetabular ligament.
Illustration A shows the obturator artery as it exits the pelvis at the superolateral corner of the obturator foramen. Illustration B reviews acetabular screw placement and the structures at risk in each quadrant.
Incorrect Answers:
OrthoCash 2020
A 65-year-old male sustains a fall onto his left hip 3 years after a total hip arthroplasty. A radiograph taken at the emergency room is shown in Figure A. What is the next best step?
Open reduction and internal fixation with locked plates and cables through an extensile approach
Revision with a proximally porous-coated stem
Revision with an extensively porous-coated stem
Nonoperative management
Minimally invasive plate osteosynthesis Corrent answer: 3
The patient has a Vancouver B2 periprosthetic fracture. There is a loose stem that should be treated with revision to an extensively coated stem that bypasses the fracture site.
Revision of the femoral component is recommended for Vancouver B2 and B3 periprosthetic fractures. Type B1 fractures are treated with ORIF and stem retention, and proximally deficient B3 fractures may be treated with alloprosthetic composites or tumor prostheses.
Springer et al. retrospectively reviewed 118 hips with Vancouver B fractures. Seventy-seven percent of 30 extensively coated stems, 60% of 42 cemented stems, 36% of 28 proximally coated stems, and 61% of 18 tumor prosthesis/allo-prosthetic composite stems were well fixed and demonstrated
fracture union. Nonunion and loosening were the most common complications. They recommend extensively porous-coated stems for better results.
Haidukewych et al. review revision of periprosthetic fractures. They found that most acetabular components are well fixed. When the distal fragment has parallel endosteal cortices with >=5 cm of tubular diaphysis (usually with a diameter of <18 mm), they recommend an extensively coated, uncemented, monoblock long-stemmed prosthesis. If the distal diaphysis is divergent, has
<5 cm of parallel endosteal cortex, or large endosteal diameters, a fluted, grit-blasted, titanium, tapered modular stem can be used.
Figure A shows Vancouver B2 fracture. The stem has subsided relative to the proximal fracture fragment, indicating that it is loose. Illustration A shows revision of the same fracture with an extensively porous-coated stem.
Illustration B shows the endoskeleton technique using an osteotomy to split the proximal fragment coronally for stem removal, followed by insertion of a modular, fluted, tapered stem and cerclage fixation of the proximal fragments.
Incorrect Answers:
Question 92
A 35-year-old active woman with rheumatoid arthritis experiences right shoulder pain following an extended course of corticosteroids (Figures 96a and 96b).
Explanation
DISCUSSION
The indication for anatomic TSA is end-stage glenohumeral arthritis with an intact rotator cuff. For the 62-year-old man, his radiographs reveal osteoarthritis, and his MR image shows an intact rotator cuff. Although humeral head replacement has historically been employed for this disorder, pain relief is not as reliable as with TSA, and the revision rate is higher. rTSA is generally reserved for patients with a nonfunctional rotator cuff.
For this 58-year-old patient with a full-thickness rotator cuff tear, preserved motion, and weakness in forward elevation, a rotator cuff repair is the most appropriate treatment. In the absence of degenerative changes, shoulder hemiarthroplasty or anatomic TSA is not indicated. Although indications for rTSA continue to evolve, well-compensated range of motion and a medium-sized rotator cuff tear in a younger patient are not among them.
rTSA is an emerging treatment for comminuted proximal humerus fractures in elderly patients. Although hemiarthroplasty has been a traditional treatment, current evidence suggests rTSA more reliably restores range of motion, and this 78-year-old patient's CT scan shows a small and comminuted greater tuberosity fragment that is unlikely to heal. ORIF is another option, but the CT scan also shows a small humeral head fragment that suggests osteopenia, making fixation more tenuous and likely less reliable.
A common problem associated with hemiarthroplasty for glenohumeral osteoarthritis is symptomatic glenoid degeneration that necessitates revision. This 55-year-old patient’s images reveal this is the case, although his infection workup is negative. His examination findings suggest an intact subscapularis repair. With a functioning rotator cuff and symptomatic glenoid arthritis, a conversion to anatomic TSA is indicated. In the absence of a functioning rotator cuff in an older patient, an rTSA is a better option.
This 72-year-old patient has classic symptoms and radiographs of cuff tear arthropathy. For patients with massive rotator cuff tear and glenohumeral arthritis, neither anatomic TSA nor rotator cuff repair is indicated. Hemiarthroplasty has historically been indicated for cuff tear arthropathy, but rTSA outcomes for this disorder have been superior and are now the preferred option.
Comminuted proximal humerus fractures in young, active patients are treated primarily with ORIF. The absence of glenohumeral arthritis removes anatomic TSA as a possibility, and concerns about implant longevity in younger, active patients such as this 40-year-old laborer contraindicate rTSA. Hemiarthroplasty is still employed in 3- and 4-part fractures but is generally reserved for subacute presentations or dislocations in which the humeral head is dysvascular and unlikely to survive. In this acute setting, a fixation procedure is preferred.
The 71-year-old patient who has had 2 failed rotator cuff repairs has an MR image that reveals another recurrent tear that is retracted to the glenoid. Her examination findings reveal classic signs
of a decompensated rotator cuff tear with pseudoparalysis and weakness in forward elevation. Although infection is a concern in the setting of multiply failed rotator cuff repair, the workup is negative in this scenario. Because this patient has a dysfunctional rotator cuff and has failed previous attempts at repair, a conversion to rTSA is the better option. In the absence of degenerative changes, hemiarthroplasty and anatomic TSA are not indicated.
The indications for hemiarthroplasty continue to narrow, but it is still a consideration for young patients with unipolar shoulder degeneration. In this 35-year-old patient, her MR image shows avascular necrosis in the humeral head, and her arthroscopy suggests arthritic change only on the humeral side with an uncompromised glenoid. To best treat young and active patients, a hemiarthroplasty that articulates with healthy glenoid cartilage can provide good pain relief and functional outcomes. Anatomic TSA is also reasonable but not an optimal option considering the normal glenoid condition. rTSA is not a consideration when a young patient’s MR images reveal an intact rotator cuff.
RECOMMENDED READINGS
Torchia ME, Cofield RH, Settergren CR. Total shoulder arthroplasty with the Neer prosthesis: longterm results. J Shoulder Elbow Surg. 1997 Nov-Dec;6(6):495-505. PubMed PMID: 9437598. View Abstract at PubMed
Chalmers PN, Slikker W 3rd, Mall NA, Gupta AK, Rahman Z, Enriquez D, Nicholson GP. Reverse total shoulder arthroplasty for acute proximal humeral fracture: comparison to open reduction-internal fixation and hemiarthroplasty. J Shoulder Elbow Surg. 2014 Feb;23(2):197-204. doi: 10.1016/j.jse.2013.07.044. Epub 2013 Sep 27. PubMed PMID: 24076000. View Abstract at PubMed
Groh GI, Wirth MA. Results of revision from hemiarthroplasty to total shoulder arthroplasty utilizing modular component systems. J Shoulder Elbow Surg. 2011 Jul;20(5):778-82. doi: 10.1016/j.jse.2010.09.014. Epub 2011 Jan 13. PubMed PMID: 21232989. View Abstract at PubMed
Orfaly RM, Rockwood CA Jr, Esenyel CZ, Wirth MA. Shoulder arthroplasty in cases with avascular necrosis of the humeral head. J Shoulder Elbow Surg. 2007 May-Jun;16(3 Suppl):S27-32. Epub 2006 Nov 16. PubMed PMID: 17113317. View Abstract at PubMed
Sershon RA, Van Thiel GS, Lin EC, McGill KC, Cole BJ, Verma NN, Romeo AA, Nicholson GP. Clinical outcomes of reverse total shoulder arthroplasty in patients aged younger than 60 years. J Shoulder Elbow Surg. 2014 Mar;23(3):395-400. doi: 10.1016/j.jse.2013.07.047. Epub 2013 Oct 12. PubMed PMID: 24129052. View Abstract at PubMed
The indication for anatomic TSA is end-stage glenohumeral arthritis with an intact rotator cuff. For the 62-year-old man, his radiographs reveal osteoarthritis, and his MR image shows an intact rotator cuff. Although humeral head replacement has historically been employed for this disorder, pain relief is not as reliable as with TSA, and the revision rate is higher. rTSA is generally reserved for patients with a nonfunctional rotator cuff.
For this 58-year-old patient with a full-thickness rotator cuff tear, preserved motion, and weakness in forward elevation, a rotator cuff repair is the most appropriate treatment. In the absence of degenerative changes, shoulder hemiarthroplasty or anatomic TSA is not indicated. Although indications for rTSA continue to evolve, well-compensated range of motion and a medium-sized rotator cuff tear in a younger patient are not among them.
rTSA is an emerging treatment for comminuted proximal humerus fractures in elderly patients. Although hemiarthroplasty has been a traditional treatment, current evidence suggests rTSA more reliably restores range of motion, and this 78-year-old patient's CT scan shows a small and comminuted greater tuberosity fragment that is unlikely to heal. ORIF is another option, but the CT scan also shows a small humeral head fragment that suggests osteopenia, making fixation more tenuous and likely less reliable.
A common problem associated with hemiarthroplasty for glenohumeral osteoarthritis is symptomatic glenoid degeneration that necessitates revision. This 55-year-old patient’s images reveal this is the case, although his infection workup is negative. His examination findings suggest an intact subscapularis repair. With a functioning rotator cuff and symptomatic glenoid arthritis, a conversion to anatomic TSA is indicated. In the absence of a functioning rotator cuff in an older patient, an rTSA is a better option.
This 72-year-old patient has classic symptoms and radiographs of cuff tear arthropathy. For patients with massive rotator cuff tear and glenohumeral arthritis, neither anatomic TSA nor rotator cuff repair is indicated. Hemiarthroplasty has historically been indicated for cuff tear arthropathy, but rTSA outcomes for this disorder have been superior and are now the preferred option.
Comminuted proximal humerus fractures in young, active patients are treated primarily with ORIF. The absence of glenohumeral arthritis removes anatomic TSA as a possibility, and concerns about implant longevity in younger, active patients such as this 40-year-old laborer contraindicate rTSA. Hemiarthroplasty is still employed in 3- and 4-part fractures but is generally reserved for subacute presentations or dislocations in which the humeral head is dysvascular and unlikely to survive. In this acute setting, a fixation procedure is preferred.
The 71-year-old patient who has had 2 failed rotator cuff repairs has an MR image that reveals another recurrent tear that is retracted to the glenoid. Her examination findings reveal classic signs
of a decompensated rotator cuff tear with pseudoparalysis and weakness in forward elevation. Although infection is a concern in the setting of multiply failed rotator cuff repair, the workup is negative in this scenario. Because this patient has a dysfunctional rotator cuff and has failed previous attempts at repair, a conversion to rTSA is the better option. In the absence of degenerative changes, hemiarthroplasty and anatomic TSA are not indicated.
The indications for hemiarthroplasty continue to narrow, but it is still a consideration for young patients with unipolar shoulder degeneration. In this 35-year-old patient, her MR image shows avascular necrosis in the humeral head, and her arthroscopy suggests arthritic change only on the humeral side with an uncompromised glenoid. To best treat young and active patients, a hemiarthroplasty that articulates with healthy glenoid cartilage can provide good pain relief and functional outcomes. Anatomic TSA is also reasonable but not an optimal option considering the normal glenoid condition. rTSA is not a consideration when a young patient’s MR images reveal an intact rotator cuff.
RECOMMENDED READINGS
Torchia ME, Cofield RH, Settergren CR. Total shoulder arthroplasty with the Neer prosthesis: longterm results. J Shoulder Elbow Surg. 1997 Nov-Dec;6(6):495-505. PubMed PMID: 9437598. View Abstract at PubMed
Chalmers PN, Slikker W 3rd, Mall NA, Gupta AK, Rahman Z, Enriquez D, Nicholson GP. Reverse total shoulder arthroplasty for acute proximal humeral fracture: comparison to open reduction-internal fixation and hemiarthroplasty. J Shoulder Elbow Surg. 2014 Feb;23(2):197-204. doi: 10.1016/j.jse.2013.07.044. Epub 2013 Sep 27. PubMed PMID: 24076000. View Abstract at PubMed
Groh GI, Wirth MA. Results of revision from hemiarthroplasty to total shoulder arthroplasty utilizing modular component systems. J Shoulder Elbow Surg. 2011 Jul;20(5):778-82. doi: 10.1016/j.jse.2010.09.014. Epub 2011 Jan 13. PubMed PMID: 21232989. View Abstract at PubMed
Orfaly RM, Rockwood CA Jr, Esenyel CZ, Wirth MA. Shoulder arthroplasty in cases with avascular necrosis of the humeral head. J Shoulder Elbow Surg. 2007 May-Jun;16(3 Suppl):S27-32. Epub 2006 Nov 16. PubMed PMID: 17113317. View Abstract at PubMed
Sershon RA, Van Thiel GS, Lin EC, McGill KC, Cole BJ, Verma NN, Romeo AA, Nicholson GP. Clinical outcomes of reverse total shoulder arthroplasty in patients aged younger than 60 years. J Shoulder Elbow Surg. 2014 Mar;23(3):395-400. doi: 10.1016/j.jse.2013.07.047. Epub 2013 Oct 12. PubMed PMID: 24129052. View Abstract at PubMed
Question 93
Figures 15a and 15b show the radiographs of an 18-year-old mountain biker who came off of a 15-foot ramp and sustained an injury to his ankle. Because the local rural hospital had no orthopaedic surgeon available, he was transported to a Level 1 emergency department 10 hours after his initial injury. Examination reveals that the injury remains closed. Management should consist of
Explanation
DISCUSSION: High-energy tibial pilon fractures involve disruption of the soft-tissue envelope with significant lower extremity edema. Definitive reconstruction of the comminuted distal tibia should be delayed for at least 7 days to allow edema to dissipate, lowering the risk of skin necrosis. An external fixator is the best method to keep the ankle at anatomic length while preventing skin necrosis. Ligamentotaxis will hold the fragments reduced to allow the edema to dissipate. CT may be obtained in traction to localize the individual fragments and plan surgical incisions and subsequent fixation. Short leg casting will not provide adequate ligamentotaxis to hold the fragments reduced and prevent skin compromise. Primary fusion of the ankle in an unstable tibial pilon fracture is prone to a poor result from nonunion or malunion.
REFERENCES: Tornetta P III, Weiner L, Bergman M, et al: Pilon fractures: Treatment with combined internal and external fixation. J Orthop Trauma 1993;7:489-496.
Sirkin M, Sanders R, DiPasquale T, Herscovici D Jr: A staged protocol for soft tissue management in the treatment of complex pilon fractures. J Orthop Trauma 1999;13:78-84.
REFERENCES: Tornetta P III, Weiner L, Bergman M, et al: Pilon fractures: Treatment with combined internal and external fixation. J Orthop Trauma 1993;7:489-496.
Sirkin M, Sanders R, DiPasquale T, Herscovici D Jr: A staged protocol for soft tissue management in the treatment of complex pilon fractures. J Orthop Trauma 1999;13:78-84.
Question 94
After excising a mass from the thigh that was thought to be a lipoma, the pathology reveals that the mass is a high-grade sarcoma. Subsequent treatment should include
Explanation
DISCUSSION: Following excision of a suspected benign soft-tissue tumor that proves to be malignant, repeat excision of the tumor bed is recommended. The initial surgical margins are inadequate after an intralesional or marginal excision, necessitating additional surgery for more definitive local control. While radiation therapy and/or chemotherapy may help to reduce the risk of local recurrence in patients with microscopic residual disease, local control is improved following repeat excision. Radiation therapy alone is inadequate to address poor surgical margins, and would likely be given postoperatively. Bisphosphonates have no current role in the treatment of soft-tissue sarcoma.
REFERENCES: Noria S, Davis A, Kandel R, et al: Residual disease following unplanned excision of soft-tissue sarcoma of an extremity. J Bone Joint Surg Am 1996;78:650-655.
Bell RS, O’Sullivan B, Liu FF, et al: The surgical margin in soft-tissue sarcoma. J Bone Joint Surg Am 1989;71:370-375.
REFERENCES: Noria S, Davis A, Kandel R, et al: Residual disease following unplanned excision of soft-tissue sarcoma of an extremity. J Bone Joint Surg Am 1996;78:650-655.
Bell RS, O’Sullivan B, Liu FF, et al: The surgical margin in soft-tissue sarcoma. J Bone Joint Surg Am 1989;71:370-375.
Question 95
The right shoulder exercise seen in Figure A will put the LEAST amount of stretch on which structure? Review Topic
Explanation
Shoulder wand exercises, as shown in Figure A, are used to increase external range of motion of the shoulder. With the arm adducted and the elbow flexed, this exercise will put the LEAST amount of stretch on the posterior capsule.
External rotation shoulder wand exercises are commonly used for the treatment of adhesive capsulitis. Adhesive capsulitis is most commonly caused by contracture of the rotator interval. The rotator interval includes the anterior-superior capsule, superior glenohumeral ligament, coracohumeral ligament and long head biceps tendon. The structure most commonly contracted is the anterior-superior capsule, which limits external rotation when the arm is adducted.
Kuhn et al. showed that in the neutral position, each ligament except the posterior capsule significantly affected the torque required for external rotation. The greatest effect on resisting external rotation at 0 degrees of abduction was the entire inferior glenohumeral ligament > coracohumeral ligament > anterior band of the inferior glenohumeral ligament > superior and middle glenohumeral ligament.
Harryman et al. looked at the role of the rotator interval capsule in passive motion and stability of the shoulder. They found operative alteration of this capsular interval was found to affect flexion, extension, external rotation, and adduction of the humerus with respect to the scapula. Limitation of external motion was increased by operative imbrication of the rotator interval and decreased by sectioning of the rotator interval capsule.
Kim et al. reviewed shoulder MRIs to determine if abnormalities of the rotator interval were correlated with chronic shoulder instability. They found a significantly larger rotator interval height, rotator interval area, and rotator interval index in patients with chronic anterior shoulder instability compared to patients without instability.
Figure A shows a patient performing an exercise to increase right shoulder external rotation with a wand/stick. The right arm is fully adducted by her side, and her elbow flexed at 90 degrees.
Incorrect Answers:
External rotation shoulder wand exercises are commonly used for the treatment of adhesive capsulitis. Adhesive capsulitis is most commonly caused by contracture of the rotator interval. The rotator interval includes the anterior-superior capsule, superior glenohumeral ligament, coracohumeral ligament and long head biceps tendon. The structure most commonly contracted is the anterior-superior capsule, which limits external rotation when the arm is adducted.
Kuhn et al. showed that in the neutral position, each ligament except the posterior capsule significantly affected the torque required for external rotation. The greatest effect on resisting external rotation at 0 degrees of abduction was the entire inferior glenohumeral ligament > coracohumeral ligament > anterior band of the inferior glenohumeral ligament > superior and middle glenohumeral ligament.
Harryman et al. looked at the role of the rotator interval capsule in passive motion and stability of the shoulder. They found operative alteration of this capsular interval was found to affect flexion, extension, external rotation, and adduction of the humerus with respect to the scapula. Limitation of external motion was increased by operative imbrication of the rotator interval and decreased by sectioning of the rotator interval capsule.
Kim et al. reviewed shoulder MRIs to determine if abnormalities of the rotator interval were correlated with chronic shoulder instability. They found a significantly larger rotator interval height, rotator interval area, and rotator interval index in patients with chronic anterior shoulder instability compared to patients without instability.
Figure A shows a patient performing an exercise to increase right shoulder external rotation with a wand/stick. The right arm is fully adducted by her side, and her elbow flexed at 90 degrees.
Incorrect Answers:
Question 96
Figures 1a and 1b are the recent radiographs of an 82-year-old man with rheumatoid arthritis who underwent total knee arthroplasty (TKA) 18 years ago. These radiographs reveal osteolysis with loosening of the tibial component. Aspiration and laboratory study findings for infection are negative. During the revision TKA, treatment of tibial bone loss should consist of
Explanation
DISCUSSION
Video 1 for reference
For severe tibial defects (Anderson Orthopaedic Research Institute [AORI] types 2 and 3), metaphyseal fixation is necessary to achieve construct fixation during revision TKA. Metaphyseal fixation may be achieved with cement, structural allograft, or conical metallic implants. The major concerns regarding structural allograft are graft resorption and mechanical failure and technical issues related to fashioning the graft and obtaining a good host-allograft interface. In a systematic review, porous metal cones were associated with a decreased loosening rate in AORI 2 and 3 defects compared to structural allografts. Metallic trabecular metal cones and metaphyseal porous coated sleeves provide a stable construct with which to support the tibial component during revision TKA. Clinical results with these devices include good metaphyseal fixation for severe tibial bone defects.
Video 1 for reference
For severe tibial defects (Anderson Orthopaedic Research Institute [AORI] types 2 and 3), metaphyseal fixation is necessary to achieve construct fixation during revision TKA. Metaphyseal fixation may be achieved with cement, structural allograft, or conical metallic implants. The major concerns regarding structural allograft are graft resorption and mechanical failure and technical issues related to fashioning the graft and obtaining a good host-allograft interface. In a systematic review, porous metal cones were associated with a decreased loosening rate in AORI 2 and 3 defects compared to structural allografts. Metallic trabecular metal cones and metaphyseal porous coated sleeves provide a stable construct with which to support the tibial component during revision TKA. Clinical results with these devices include good metaphyseal fixation for severe tibial bone defects.
Question 97
Anterior approach
Explanation
DISCUSSION
The nerve most commonly injured in the posterior approach to the hip is the sciatic nerve. Overall injury prevalence is 1% to 2%. This nerve is more commonly injured in cases of hip dysplasia with excessive leg lengthening. The superior gluteal nerve is at highest risk with the direct lateral approach to the hip. This nerve courses in the gluteus medius muscle and is
at risk when splitting the muscle 5 cm proximal to the greater trochanter. The lateral femoral 73
cutaneous nerve is commonly damaged with anterior total hip replacement surgery. Neuropraxia has been reported in 81% of patients. The inferior gluteal nerve travels from the greater sciatic notch and enters the gluteus maximus muscle. It is at risk when the posterior approach to the hip is used.
RECOMMENDED READINGS
Hoppenfeld S, deBoer P. Surgical Exposures in Orthopedics. 3rd ed. Philadelphia.
PA: Lippincott Williams & Wilkins; 2003:365-453.
DeHart MM, Riley LH Jr. Nerve injuries in total hip arthroplasty. J Am Acad Orthop Surg. 1999 Mar-Apr;7(2):101-11. Review. PubMed PMID: 10217818. View Abstract at PubMed
Goulding K, Beaulé PE, Kim PR, Fazekas A. Incidence of lateral femoral cutaneous nerve neuropraxia after anterior approach hip arthroplasty. Clin Orthop Relat Res. 2010 Sep;468(9):2397-404. doi: 10.1007/s11999-010-1406-5. PubMed PMID:
The nerve most commonly injured in the posterior approach to the hip is the sciatic nerve. Overall injury prevalence is 1% to 2%. This nerve is more commonly injured in cases of hip dysplasia with excessive leg lengthening. The superior gluteal nerve is at highest risk with the direct lateral approach to the hip. This nerve courses in the gluteus medius muscle and is
at risk when splitting the muscle 5 cm proximal to the greater trochanter. The lateral femoral 73
cutaneous nerve is commonly damaged with anterior total hip replacement surgery. Neuropraxia has been reported in 81% of patients. The inferior gluteal nerve travels from the greater sciatic notch and enters the gluteus maximus muscle. It is at risk when the posterior approach to the hip is used.
RECOMMENDED READINGS
Hoppenfeld S, deBoer P. Surgical Exposures in Orthopedics. 3rd ed. Philadelphia.
PA: Lippincott Williams & Wilkins; 2003:365-453.
DeHart MM, Riley LH Jr. Nerve injuries in total hip arthroplasty. J Am Acad Orthop Surg. 1999 Mar-Apr;7(2):101-11. Review. PubMed PMID: 10217818. View Abstract at PubMed
Goulding K, Beaulé PE, Kim PR, Fazekas A. Incidence of lateral femoral cutaneous nerve neuropraxia after anterior approach hip arthroplasty. Clin Orthop Relat Res. 2010 Sep;468(9):2397-404. doi: 10.1007/s11999-010-1406-5. PubMed PMID:
Question 98
According to Musculoskeletal Infection Society (MSIS) guidelines, which set of patient laboratory study results fits the definition of chronic prosthetic joint infection?
Explanation
DISCUSSION:
The MSIS definition of periprosthetic joint infection was updated in 2014 with two major and six minor criteria. The presence of one major criterion or three minor criteria is diagnostic for infection. The major criteria are two positive cultures with the same organism or a draining sinus tract. The current MSIS minor criteria are 1) an elevated ESR (more than 30 mm/hr) and CRP level (more than 10 mg/L), 2) an elevated synovial WBC count (more than 3,000 cells per/microliter), 3) an elevated synovial fluid polymorphonuclear count (more than 80%), 4) a positive histological analysis of periprosthetic tissue, and 5) a single positive culture.
The MSIS definition of periprosthetic joint infection was updated in 2014 with two major and six minor criteria. The presence of one major criterion or three minor criteria is diagnostic for infection. The major criteria are two positive cultures with the same organism or a draining sinus tract. The current MSIS minor criteria are 1) an elevated ESR (more than 30 mm/hr) and CRP level (more than 10 mg/L), 2) an elevated synovial WBC count (more than 3,000 cells per/microliter), 3) an elevated synovial fluid polymorphonuclear count (more than 80%), 4) a positive histological analysis of periprosthetic tissue, and 5) a single positive culture.
Question 99
Figures 17a and 17b show the AP and lateral radiographs of a 75-year-old woman who reports giving way and shifting of the knee, particularly when she is descending stairs or ambulating on level surfaces. History reveals a total knee replacement 5 years ago. Treatment should consist of
Explanation
DISCUSSION: The radiographs show well-fixed components of a posterior cruciate-retaining total knee replacement. The relative position of the femoral component is anteriorly subluxated relative to the tibial component. The AP radiograph shows that the articular space is markedly asymmetric, indicating either failure or fracture of the polyethylene or subluxation of the femur relative to the tibia. The patient’s symptoms suggest a failure of the posterior cruciate ligament that is consistent with the radiographic findings; therefore, the treatment of choice is revision to a posterior cruciate-substituting implant.
REFERENCE: Pagnano MW, Cushner FD, Scott WN: Role of the posterior cruciate ligament in total knee arthroplasty. J Am Acad Orthop Surg 1998;6:176-187.
REFERENCE: Pagnano MW, Cushner FD, Scott WN: Role of the posterior cruciate ligament in total knee arthroplasty. J Am Acad Orthop Surg 1998;6:176-187.
Question 100
Which of the following best describes the relationship of the anterior tibial artery and dorsalis pedis artery to the extensor hallucis longus (EHL) tendon as they progress from the level of the ankle to the dorsum of the foot?
Explanation
DISCUSSION: At the ankle level, the anterior tibial artery lies medial to the EHL tendon. The artery becomes the dorsalis pedis after crossing onto the dorsum of the foot. At this point, the artery lies lateral to the tendon.
REFERENCES: Resch S: Functional anatomy and topography of the foot and ankle, in Myerson M (ed): Foot and Ankle Disorders. Philadelphia, PA, WB Saunders, 2000, vol 1, pp 25-49.
Sarrafian SK: Anatomy of the Foot and Ankle: Descriptive, Topographic, Functional, ed 2. Philadelphia, PA, JB Lippincott, 1993.
REFERENCES: Resch S: Functional anatomy and topography of the foot and ankle, in Myerson M (ed): Foot and Ankle Disorders. Philadelphia, PA, WB Saunders, 2000, vol 1, pp 25-49.
Sarrafian SK: Anatomy of the Foot and Ankle: Descriptive, Topographic, Functional, ed 2. Philadelphia, PA, JB Lippincott, 1993.
Detailed Chapters & Topics
Dive deeper into specialized chapters regarding orthopedic-board-review-oite-abos-part-132
01
Chapter 1
63 min
OITE & ABOS Orthopedic Board Prep: Foot, Ankle, Trauma & Sports Medicine MCQs | Part 62
02
Chapter 2
231 min
Orthopedic Board Review MCQs: Foot & Ankle, Spine, & Trauma | Part 63
03
Chapter 3
63 min
OITE & ABOS Orthopedic Board Review: Fracture, Hip, Knee MCQs Part 64
04
Chapter 4
215 min
OITE & ABOS Orthopedic Board Review: Spine, Arthroplasty & Trauma MCQs | Part 66
05
Chapter 5
73 min
OITE & ABOS Orthopedic Board Review: Shoulder, Arthroplasty & Trauma MCQs | Part 68
06
Chapter 6
271 min
Orthopedic Board Prep MCQs: Arthroplasty, Trauma & Oncology | Part 72
07
Chapter 7
397 min
Orthopedic Surgery Board Review MCQs: Fracture, Nerve & Shoulder | OITE/AAOS Part 73
08
Chapter 8
224 min
OITE & ABOS Orthopedic Board Exam MCQs: Arthroplasty, Trauma & Deformity | Part 74
09
Chapter 9
58 min
Orthopedic Board Review MCQs: Fracture, Knee & Trauma | Part 77
10
Chapter 10
38 min
Orthopedic Board Prep MCQs: Shoulder, Elbow, Arthroplasty & Trauma Part 84
11
Chapter 11
50 min
Orthopedic Board Review MCQs: Knee, Foot & Ankle | Part 86
12
Chapter 12
30 min
OITE & ABOS Orthopedic Board Prep: Adult Reconstruction, Extremities & Deformity MCQs Part 90
13
Chapter 13
42 min
Orthopedic Board Review MCQs: Ankle & Foot | Part 94
14
Chapter 14
293 min
OITE & ABOS Orthopedic Board Prep MCQs: Trauma & Nerve Injuries Part 96
15
Chapter 15
227 min
OITE & ABOS Orthopedic Board Prep: Hip, Ankle, Fracture & Arthroplasty MCQs Part 100
16
Chapter 16
62 min
OITE & ABOS Orthopedic Exam MCQs: Spine, Arthroplasty & Fracture Part 102
17
Chapter 17
49 min
Orthopedic Surgery Board Review MCQs: Foot, Ankle & Trauma | Part 107
18
Chapter 18
212 min
OITE & ABOS Orthopedic Board Prep: Cartilage, Spine, Hand MCQs | Part 108
19
Chapter 19
229 min