Orthopedic Board Review MCQs: Arthroplasty & Trauma

About This Board Review Set

This is Part 192 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.
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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 192

This module focuses heavily on: Arthroplasty, Elbow, Knee, Ligament, Nerve, Revision, Trauma.

Sample Questions from This Set

Sample Question 1: The knee arthroplasty type associated with the highest 5-year revision rate is...

Sample Question 2: CLINICAL SITUATIONFigures 1 and 2 are the radiographs of a 35-year-old man who is brought into the emergency department after a motor vehicle collision. He is complaining of isolated knee pain. Examination reveals swelling, blood filled bli...

Sample Question 3: A professional pitcher reports pain localized to the medial aspect of his throwing elbow. History reveals that he was pitching in a playoff game and heard and felt a pop in his elbow. MRI reveals a complete ulnar-sided avulsion of the media...

Sample Question 4: A 10-year-old boy tripped as he was running down a hill, felt a painful pop in his right knee, and was unable to bear weight on the involved lower extremity. Examination reveals a tense effusion and an extensor lag of the right knee. Figure...

Sample Question 5: A 16-year-old boy has had thigh pain for the past several months. He denies any history of trauma. Examination reveals a large, deeply fixed, soft-tissue mass in the thigh. Laboratory results show an elevated erythrocyte sedimentation rate ...

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

The knee arthroplasty type associated with the highest 5-year revision rate is

Explanation

CLINICAL SITUATION QUESTIONS 167 THROUGH 169
Figures 167a and 167b are the radiographs of a middle-age man. He is a noncompliant patient who has severe insulin-dependent diabetes and a below-knee amputation on the right side. He is usually in a wheelchair, does not use a prosthesis, transfers using a walker, and resides in an institution. He had an infection in the left leg years ago, which was treated successfully with intravenous antibiotics (the details are unknown). His left knee is mildly painful, swollen but not warm, has limited range of motion (40-140 degrees), and is grossly unstable.

Question 2

CLINICAL SITUATION Figures 1 and 2 are the radiographs of a 35-year-old man who is brought into the emergency department after a motor vehicle collision. He is complaining of isolated knee pain. Examination reveals swelling, blood filled blisters, popliteal ecchymosis, joint line pain, and limited knee joint motion. His pulses and sensation are normal. Initial surgical management should consist of

Explanation

Discussion: Posterior partial articular tibial plateau fractures are rare. Failure to recognize this pattern can lead to poor patient outcomes secondary to poor surgical decision making. Pathognomonic findings on the lateral radiograph include maintenance of continuity between the anterior articular surface and tibial shaft along with subluxation of the knee joint with excessively anterior tibial station (the femoral condyles remain with the fractured posterior articular pieces while the remainder of the tibia subluxes anteriorly).
Initial management of axially unstable tibial plateau fractures with soft tissue swelling should consist of spanning external fixation and closed manipulative realignment. This allows for soft tissue recovery with the knee joint provisionally stabilized in reduced station. It also provides time for pre-operative planning, which is typically empowered via a CT scan with reconstructions. If the pattern was initially misdiagnosed as a more typically bicondylar tibial plateau fracture, the CT scan will clarify the misconception and allow for better surgical decision making.
Attempting to visualize, reduce, and stabilize a posterior partial articular pattern in the supine position from an anterior approach is fraught with difficulties. Prone positioning is preferred for definitive fixation. Surgical approaches vary, but
typically incorporate a posteromedial interval deep to the popliteus and soleus to provide buttress plating to the posterior column of the tibia.

Question 3

A professional pitcher reports pain localized to the medial aspect of his throwing elbow. History reveals that he was pitching in a playoff game and heard and felt a pop in his elbow. MRI reveals a complete ulnar-sided avulsion of the medial collateral ligament (MCL). Examination reveals valgus instability and ulnar nerve involvement. What recommendations should be made based on the patient’s desire to return to sport?

Explanation

DISCUSSION: Injuries to the MCL usually result from repetitive high valgus stress on the medial aspect of the elbow joint due to overhead throwing or racquet sports. Excessive stresses during the late cocking and acceleration phase of throwing can injure the anterior band of the MCL. Clinically, the injuries may present as chronic or acute, and a pop may be noted in the latter. Associated ulnar nerve involvement is common. Valgus instability is present in about 25% of patients. Patients typically are athletes who participate in throwing and have localized medial elbow pain and tenderness along the course of a ligament that extends from the medial epicondyle of the distal humerus to the sublime tubercle of the ulna. Surgical reconstruction is the procedure of choice in an athlete desiring a return to a high level of throwing.
REFERENCES: Miller MD, Cooper DE, Warner JJP (eds): Review of Sports Medicine and Arthroscopy. Philadelphia, PA, WB Saunders, 1995, p 230.
Arendt EA (ed): Orthopaedic Knowledge Update: Sports Medicine 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, p 227.
Altchek DW, Andrews JR (eds): The Athlete’s Elbow. Philadelphia, PA, Lippincott Williams
& Wilkins, 2001, p 91.

Question 4

A 10-year-old boy tripped as he was running down a hill, felt a painful pop in his right knee, and was unable to bear weight on the involved lower extremity. Examination reveals a tense effusion and an extensor lag of the right knee. Figures 36a and 36b show AP and lateral radiographs. Management should consist of

Explanation

DISCUSSION: The examination and radiographs are consistent with a sleeve fracture of the patella, which is an avulsion fracture of the distal pole of the patella with a disruption of the extensor mechanism. Treatment is open reduction and internal fixation of the patella, and repair of the extensor mechanism.
The distal fragment can be much larger than it appears on the radiographs because it consists largely of cartilage.
REFERENCES: Wu CD, Huang SC, Liu TK: Sleeve fracture of the patella in children: A report of five cases. Am J Sports Med 1991;19:525-528.
Grogan DP, Carey TP, Leffers D, et al: Avulsion fractures of the patella. J Pediatr Orthop 1990; 10:721 - 730. Question 37
When addressing a proximal intertrochanteric or subtrochanteric fracture in a juvenile with open growth plates, the arterial supply from what artery at the neck must be preserved?
Lateral femoral circumflex
Medial femoral circumflex
Superior gluteal
Inferior gluteal
Obturator
DISCUSSION: The medial femoral circumflex artery supplies blood to the femoral head. Its position along the posterior-superior femoral neck places this structure at risk with intramedullary nailing of the femur. Therefore, lateral entry through the greater trochanter is preferred when intramedullary fixation is performed.
REFERENCES: Gordon JE, Swenning TA, Burd TA, et al: Proximal femoral radiographic changes after lateral transtrochanteric intramedullary nail placement in children. J Bone Joint Surg Am 2003;85:1295- 1301.
Green NE, Swiontkowski MF: Skeletal Trauma in Children, ed 3. Philadelphia, PA, WB Saunders, 2003, pp 419-424.

Question 5

A 16-year-old boy has had thigh pain for the past several months. He denies any history of trauma. Examination reveals a large, deeply fixed, soft-tissue mass in the thigh. Laboratory results show an elevated erythrocyte sedimentation rate (ESR) and leukocytosis. A plain radiograph and MRI scan are shown in Figures 1a and 1b. Biopsy specimens are shown in Figures 1c and 1d. What is the most likely diagnosis?

Explanation

DISCUSSION: Ewing’s sarcoma typically can occur in the diaphysis of the long bones (50% to 55%). It is often accompanied by a large soft-tissue mass. Abnormal findings are common, including a low-grade fever, an elevated ESR, and leukocytosis. The histology is consistent with a small round blue cell tumor. The unique pathology and other findings exclude osteosarcoma. Giant cell tumor and chondrosarcoma have a different histologic appearance and typically are more metaphyseal in location. Chondrosarcoma typically is found in older age groups, has a different histologic pattern, and rarely occurs in the midshaft of the femur.
REFERENCE: Simon MA, Springfield DS, et al: Ewing’s Sarcoma: Surgery for Bone and Soft Tissue Tumors. Philadelphia, PA, Lippincott Raven, 1998, pp 287-297.

Question 6

A 22-year-old right hand-dominant man who fell off his motorcycle onto the tip of his right shoulder 2 weeks ago now reports pain and difficulty raising his right arm. Examination reveals tenderness and gross movement over the lateral scapular spine and severe weakness during resisted abduction. A radiograph and 3D-CT scan are shown in Figures 24a and 24b. What is the next most appropriate step in management?

Explanation

DISCUSSION: The patient has a displaced scapular spine fracture that has resulted in shoulder weakness from a poor deltoid lever arm. The downward tilt may lead to subacromial impingement and rotator cuff dysfunction. Open reduction and internal fixation would best allow normal deltoid and shoulder function. Bone stimulators and abduction bracing may lead to healing but in a malunited position. Arthroscopic acromioplasty and fragment excision should be avoided.
REFERENCES: Ogawa K, Naniwa T: Fractures of the acromion and the lateral scapular spine.

J Shoulder Elbow Surg 1997;6:544-548.
Ada Jr, Miller ME: Scapular fractures: Analysis of 113 cases. Clin Orthop Relat Res 1991;269:174-180.

Question 7

A 10-year-old girl sustained a Gartland type III supracondylar fracture after falling off a trampoline 1 hour ago. She has a well perfused hand but no palpable pulses. The remainder of her examination is otherwise normal. What is the next step in treatment? Review Topic

Explanation

Most supracondylar fractures are extension type and a Gartland type III is defined as a fracture that is completely displaced (ie, no posterior cortical hinge). Treatment consists of closed reduction and pinning. Controversy exists over the use of a medial and lateral pin versus multiple lateral pins. Although uncommonly needed, the surgeon should be prepared to open the fracture to achieve adequate reduction. A careful preoperative examination should be performed and documented. There is a growing body of evidence that patients with a normal neurovascular examination can be treated in a delayed fashion; nevertheless, the initial evaluation cannot be delayed.
If there is evidence of vascular compromise, the fracture should be reduced and pinned urgently and the limb reevaluated.

Question 8

Figure 31 shows the radiograph of an 8-year-old boy who has a swollen forearm after falling out of a tree. Examination reveals that all three nerves are functionally intact, and there is no evidence of circulatory embarrassment. Management should consist of

Explanation

DISCUSSION: The patient has a Bado type IV Monteggia lesion. It involves dislocation of the radial head and fractures of both the radial and ulnar shafts. These fractures are very difficult to manage by closed reduction alone. The radial and ulnar shafts first have to be stabilized surgically to give a lever arm to reduce the radial head. In this age group, intramedullary pins are easy to insert percutaneously and cause less tissue trauma than plates and screws. In these types of injuries, the focus is often on the forearm fracture; the radial head dislocation may not be appreciated as was the case with this patient.
REFERENCES: Gibson WK, Timperlake RW: Operative treatment of a type IV Monteggia fracture-dislocation in a child. J Bone Joint Surg Br 1992;74:780-781.
Stanley EA, DeLaGarza JF: Part IV: Monteggia fracture. Dislocations in children, in Rockwood CA Jr, Wilkins KE, Beaty JH (eds): Fractures in Children, ed 4. Philadelphia, PA, Lippincott-Raven, 1996, vol 3, pp 576-577.

Question 9

A 72-year-old man undergoes an uncomplicated cementless total hip arthroplasty for advanced osteoarthritis. At his 6-week postoperative follow-up, he has minimal pain and is progressing well with his mobility. Radiographs show early formation of Brooker grade III heterotopic bone around his hip. What is the best treatment of the heterotopic bone at this time?

Explanation

DISCUSSION: The development of heterotopic bone occurs early after hip arthroplasty. The process begins within days after surgery; therefore, prophylactic treatment must be in the early postoperative period (preoperative radiation given within 24 hours of surgery, or postoperative radiation given within 72 hours of surgery, or nonsteroidal antiinflammatory drugs (NSAIDs) given postoperatively for 7 to 21 days - longer duration has not been shown to be of any additional benefit). At 6 weeks, prophylactic treatment with NSAIDs or radiation is no longer effective. Surgery at 10 weeks would be premature because the patient is currently asymptomatic with regards to the heterotopic bone, and surgery prior to full maturation of the bone may increase the risk for more abundant recurrence of bone.
REFERENCES: Balboni TA, Gobezie R, Mamon HJ: Heterotopic ossification: Pathophysiology, clinical features, and the role of radiotherapy for prophylaxis. Int J Radiat Oncol Biol Phys 2006;65:1289-1299. Fransen M, Neal B: Non-steroidal anti-inflammatory drugs for preventing heterotopic bone formation after hip arthroplasty. Cochrane Database Syst Rev 2004;3:CD001160.
Neal BC, Rodgers A, Clark T, et al: A systematic survey of 13 randomized trials of non-steroidal antiinflammatory

drugs for the prevention of heterotopic bone formation after major hip surgery. Acta Orthop Scand 2000;71:122-128.

Question 10

8 (Normal ratio = 0.8 - 1.2). The most common symptoms associated with patella baja include anterior impingement, knee pain, and knee stiffness.

Explanation

osteotomy.

OrthoCash 2020
A 88-year-old female fell onto her right hip sustaining the fracture shown in Figure A. Past medical history is significant for mild dementia and moderate coronary artery disease. At baseline, she ambulates with a walker. There are concerns about her ability to maintain weight-bearing precautions following surgery. Which of the following is most appropriate for management of the femoral side?

Revision total hip replacement with a proximally coated femoral stem
Open reduction, internal fixation with plate and cerclage wires
Proximal femoral replacement with megaprosthesis
Impaction bone grafting
Cortical strut allograft with cerclage wiring Corrent answer: 3
The radiograph shows a Vancouver B3 periprosthetic fracture with poor proximal femoral bone stock. Given her age, co-morbidities, and dementia, the appropriate management of her condition would be a proximal femoral replacement with megaprosthesis. This can allow for immediate weightbearing in the post-operative period.
Vancouver B3 periprosthetic fractures are fractures around or just below the tip of a loose stem with poor proximal femoral bone stock. Options for management of this fracture include a fully coated stem, a fluted tapered stem, a proximal femoral replacement with megaprosthesis, allograft-prosthesis composite, and impaction bone grafting. In elderly patients with comorbidities and an inability to maintain the strict weight-bearing precautions that impaction bone grafting and allograft prosthetic replacements require, proximal femoral replacement with a megaprosthesis is the best option.
Duncan et al. were the originators of the Vancouver classification system for
periprosthetic fractures. Type A fractures are peritrochanteric, type B fracture are around the stem tip, and type C fractures are well below the stem tip.
Parvizi et al. review the indications for proximal femoral replacements with megaprostheses. They conclude it is a reasonable option for elderly patients with massive proximal femoral bone loss. The most frequent complications are aseptic loosening and dislocation.
Klein et al. identified 23 patients who underwent proximal femoral replacement for a Vancouver type-B3 periprosthetic fracture. At a follow-up of 3 years, 22 of 23 patients were walking with minimal pain. The most frequent complications were persistent drainage (2), dislocation (2), refracture (1) and acetabular cage failure (1).
Figure A shows a Vancouver B3 periprosthetic fracture with loose stem and poor proximal bone stock. Illustration A shows an example of a proximal femoral replacement. Illustration B shows a radiograph of a proximal femoral replacement used for a failed total hip replacement with massive bone loss. Illustration C shows the Vancouver classification (A, B1, B2, B3, C)
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A minimal-incision technique with an incision no more than 10 centimeters has which of the following advantages compared to a standard incision for a total hip replacement?
lower post-operative visual analogue pain score
less transfusion requirement
shorter length of stay
better cosmetic result
less pain medication requirement Corrent answer: 4
Ogonda et al randomized patients to standard (16cm) versus MIS incision (<10 cm). They found no significant difference with respect to postoperative hematocrit, blood transfusion requirements, pain scores, or analgesic use.
There were also no differences in early walking ability or length of hospital stay and no differences in component alignment.
OrthoCash 2020
What is an advantage of utilizing a 36-mm instead of a 28-mm femoral head in the setting of a revision total hip arthroplasty?
Compensating for abductor deficiency
Decreasing volumetric wear
Decreasing trunion stress
Delaying neck-socket impingement
Compensating for vertical cup placement Corrent answer: 4
Increasing femoral head size delays neck-socket impingement, enhancing stability by increasing the excursion distance prior to dislocation.
The optimal bearing in total hip arthroplasty (THA) should allow for the best stability and function while preserving implant longevity. Greater motion, stability, and patient satisfaction have been correlated with larger femoral head sizes. Stability is associated with an increased displacement distance in larger diameter heads prior to a dislocation event (increased jump distance) combined with a greater impingement-free range of motion. Although larger femoral head sizes are associated with greater volumetric wear and trunion stress (and possible taper corrosion), newer bearings such as ceramic-on-ceramic may help mitigate these factors.
Kung et al. examined the effect of femoral head size and abductor integrity on dislocation events after revision THA. They separated 230 patients who underwent revision THA into 4 groups: (1) intact abductors mechanism + 28-mm femoral head, (2) absent abductor mechanism + 28-mm femoral head,
(3) intact abductor mechanism + 36-mm femoral head, and (4) absent abductor mechanism + 36-mm femoral head. They found that in patients with intact abductor mechanisms, the 36-mm femoral head was associated with a lower dislocation rate with 6-month minimum follow-up; femoral head size did not reduce dislocation events in patients with deficient abductor mechanisms.
Burroughs et al. performed an in-vitro study evaluating the range of motion and stability in THA with 28-44-mm femoral head sizes. They found that
femoral heads >32-mm provided for greater ROM and decreased component impingement. For these reasons, the authors conclude that large femoral heads may be beneficial in revision THA.
Illustration 1 demonstrates the increased jump distance when utilizing a larger diameter femoral head. Illustration 2 demonstrates a greater impingement-free range of motion with a larger femoral head.
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A 65-year-old male is now 6 weeks status post an uncomplicated total knee arthroplasty. Figures A and B represent his x-rays at today's visit. His primary complaint is knee stiffness. His current passive range of motion is 0-80 degrees, compared to 120 degrees
preoperatively, and he has failed to improve with physical therapy. He is otherwise afebrile, has no incisional erythema or pain, and CRP is within normal limits. Manipulation under anesthesia (MUA) will provide the largest improvement in flexion if performed before which of the following:

Before 6 weeks
Before 12 weeks
Before 26 weeks
Before 34 weeks
Outcomes after MUA are equivalent if performed within 1 year of surgery Corrent answer: 2
Manipulation under anesthesia (MUA) yields the greatest gain in flexion and improvement in overall range of motion if performed within 12 weeks postoperatively.
Post-operative knee stiffness (flexion < 90 degrees) occurs in 1.3%-12% of patients who undergo TKA. The preoperative risk factors for stiffness include decreased preoperative range of motion, age, diabetes mellitus, and socioeconomic status. Surgical factors can also contribute, including
overstuffing the patellofemoral joint, tight flexion/extension gaps, and excessive tightening of the extensor mechanism. If left untreated, loss of flexion negatively impacts functional outcomes, patient satisfaction, and ability to perform activities of daily living. MUA is considered the initial management for patients with flexion less than 90 degrees.
Issa et al. studied the optimal timing of MUA. They found that patients undergoing MUA before 12 weeks had a significantly higher mean gain in flexion (36.5° versus 17°), higher final range of motion (119° versus 95°), and higher Knee Society objective (89 versus 84 points) and function scores (88 versus 83 points) than those who had late manipulation under anesthesia (after 12 weeks). There was no statistically significant difference between MUA before 6 weeks vs MUA before 12 weeks.
Desai et al. similarly demonstrated that maximum flexion gains were achieved when MUA was performed between 12-14 weeks post-operatively. They also demonstrated that there is no benefit to multiple manipulations, with no observed flexion gain after the initial intervention.
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A 51-year-old male presents with worsening left hip pain over the past 8 months. The patient reports hip surgery 5 years prior as seen in Figures A and B. His CRP level is within normal limits, ESR is at the upper limit of normal, and automated cell count following a hip aspiration yields a WBC of 15,000/µL (rr, 4500-11000µL) and 85% PMNs. Metal ion testing reveals elevated serum cobalt and chromium levels. What is the next best step?

Manual cell count of synovial fluid
stage revision arthroplasty
Acetabular cup revision with bone grafting
Femoral revision with cerclage wire placement
Hip arthrodesis
The patient has had a metal-on-metal (MoM) hip resurfacing with osteolysis. It is likely his WBC count is falsely elevated secondary to metal debris and corrosion. The next best step is a manual cell count to evaluate for metal debris, clots, fragmented cells, or other defects preventing accurate automated cell count.
Diagnosis of infection in the setting of MoM bearing surface can be difficult given very similar presentations. Typical workup includes CRP, ESR, synovial fluid WBC, and differential. Metal debris and corrosion reactions can confound the synovial fluid analysis leading to falsely elevated WBC counts in cases of aseptic failure. Prosthetic joint infection (PJI) and metallosis can occur concurrently so aggressive diagnostic testing is important for surgical decision making. Manual cell count of synovial fluid samples can identify metal debris and avoid false positives from automated cell testing. Supplementary tests, such as MARS MRI, metal ion levels, manual cell count, and repeat aspiration, can help guide appropriate management in these scenarios.
Yi et al. investigated ESR, CRP, synovial WBC and differential in diagnosing PJI in the setting of MoM hips or non-MoM hips undergoing revision for corrosion
or full thickness wear. They found that synovial fluid WBC count can be confounded by inaccurate automated cell counts secondary to foreign material and degenerating cells. They conclude that diagnosis of PJI in the setting of failed MoM bearings or corrosion is difficult due to falsely positive synovial fluid WBC.
Carrothers et al. evaluated the prevalence of complications of hip resurfacing arthroplasty. They found the most common complication was fracture of the femoral neck, followed by loosening of the acetabular component, femoral head collapse, loosening of a femoral component, infection, aseptic lymphocyte-dominated vasculitis-associated lesion (ALVAL), loosening of both components, and malposition of the acetabular component. They conclude that knowledge of complications following hip resurfacing is important to help select patients and counsel them on risks prior to surgery.
Figures A and B show a metal-on-metal hip resurfacing with supra-acetabular osteolysis.
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An 87-year-old female presents with longstanding knee pain. The structures identified in Figure A are formed through the pathologic activation of endochrondral ossification. The pathway involved in this process involves which of the following signaling molecules?

Indian hedgehog (Ihh)
Peroxisome proliferator-activated receptor gamma (PPARG)
Receptor activator of nuclear factor kappa-ligand (RANKL)
Osteoprotegerin (OPG)
Sclerostin
Osteoarthritis and formation of osteophytes are felt to be mediated by the differentiation of quiescent chondrocytes through the Indian hedgehog signaling pathway.
Indian hedgehog (Ihh) is an important mediator of chondrocyte and osteoblast differentiation in prenatal endochondral bone formation. Adult articular cartilage without osteoarthritis does not have active Ihh signaling. However, Ihh and its downstream signaling proteins have been found to be unregulated in osteoarthritic joints. Ihh may play an important role in activating endochondral ossification leading to some of the clinical features of osteoarthritis (osteophytes and subchondral cysts). Modulation of Ihh has therapeutic potential in the treatment of osteoarthritis.
Maeda et al. studied mice with Ihh genes ablated from postnatal chondrocytes.
They found a loss of columnar structure, premature vascular invasion, and formation of ectopic hypertrophic chondrocytes in the growth plate. They concluded that Ihh is essential for maintained trabecular bone, skeletal growth, and articular cartilage.
Wang et al. reviewed the molecular mechanisms associated with cartilage degeneration in osteoarthritis. The study found that upregulation of the Ihh signaling molecules leads to the development of osteoarthritis, similar to that found in injury-induced controls. Additionally, they found that inhibiting the Ihh pathway reduces the severity of injury-induced osteoarthritis in mouse models.
Figure A shows a knee with varus deformity and severe medial sided arthritis with femoral and tibial sided osteophytes(red arrows).
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Figure 1 is the AP pelvis radiograph of a 55-year-old male with known hip dysplasia and chronic right hip pain. He has no prior surgical history and is otherwise healthy. Your initial plan is to reconstruct his hip center at the site of his true acetabulum. Your preoperative template demonstrates that your acetabular component will have 40° of abduction, 15° of anteversion. However, there will be 25% uncoverage at the superolateral margin. What is the most appropriate next step to ensure adequate cup fixation?

Increase the abduction angle to 60 degrees for better coverage
Medialize the acetabular component beyond the medial wall for improved coverage
Elevate the hip center in search of better bone stock
Accept 25% uncoverage and proceed with total hip arthroplasty as templated
Use cement augments to improve superolateral coverage of the acetabular component
The most appropriate next step is to proceed with total hip arthroplasty (THA) as templated. Less than 30% of uncoverage is acceptable and has not been associated with increased rates of aseptic loosening.
Dysplasia of the hip broadly refers to abnormal development of the hip that leads to poor acetabular coverage of the femoral head. The characteristic pelvic deformities of dysplasia include a retroverted acetabulum with bone loss at the superolateral margin. As a result, there is often insufficient bone stock to provide complete coverage of the acetabular component when placed at the true hip center. Insufficient coverage (<60-70%) can lead to a lack of initial stability and early failure. If the pre-operative template suggests extreme superolateral bone loss, the surgeon must then consider alternative methods of achieving satisfactory fixation, including downsizing the acetabular component size, medializing or elevating the hip center, or use of trabecular metal augments or cement augmentation for better coverage.
Haddad et al. discuss pre-operative considerations when performing primary total hip arthroplasty on dysplastic hips. The literature review suggests that
less than 30% uncoverage does not increase the risk of aseptic loosening.
Paavilainen et al. studied the short-term outcomes on 100 cementless total hip replacements in severely dysplastic hips. They describe the importance of exposing the proximal aspect of the pubic and ischial bones since the pelvic wall is usually hypoplastic, and the use of augmentation when the superolateral rim was deficient. Overall, their outcomes with cementless total hip replacements were equivalent to cemented prostheses.
Figure A is an AP pelvis radiograph demonstrating a dysplastic right hip. Illustration A is a T1-weighted coronal MRI of a hip. Hip dysplasia can be assessed using the center-edge angle, the angle formed between a vertical line through the center of the femoral head and a line connecting the center of the femoral head with the lateral edge of the acetabulum. Less than 20° is one marker of hip dysplasia. Illustration B demonstrates the concept of joint reactive forces. Joint reactive force is minimized when the moment arm of body weight and abductor tensioning are balanced. Anatomic changes that reduce abductor tension such as elevating the hip center, decreasing femoral head size, and increased valgus neck angle increase the joint reactive force.
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OrthoCash 2020
A 65-year-old man presents to your clinic with chronic, progressive knee pain. Figure A is an x-ray of his right knee. He would like to pursue non-surgical treatment options. The AAOS clinical practice guidelines on the treatment of symptomatic knee arthritis support which of the following with "strong evidence"?

NSAIDs; tramadol
Weight loss; arthroscopic debridement
Weight loss; intra-articular steroid injections
Valgus-offloading brace; glucosamine chondroitin injections
Tramadol; acupuncture
The AAOS clinical practice guidelines (CPG) summary "strongly" recommends tramadol or NSAIDs for the treatment of symptomatic knee osteoarthritis.
Symptomatic knee osteoarthritis is widespread, with an incidence of 240 people per 100,000. Symptoms are often progressive, though addressing the modifiable risk factors of muscle weakness, large BMI, and repetitive loading can help with pain control. Definitive management is total knee arthroplasty, however, non-operative interventions are often successful in delaying surgery, particularly in younger patients.
The AAOS Clinical Practice Guideline Summary performed a systematic review of the available literature to propose evidence-based guidelines for the management of symptomatic knee osteoarthritis. The current guidelines show strong support for the engagement in physical activity (such as guided physical therapy), non-steroidal anti-inflammatory drugs, and Tramadol for the management of symptomatic osteoarthritis. The Clinical Guidelines provided “strong” evidence against acupuncture, glucosamine and chondroitin, hyaluronic acid, and arthroscopy with lavage or debridement.
Fishman et al. performed a double-blind, randomized study of 552 patients studying the efficacy of Tramadol vs placebo in the management of arthritic knee pain. Tramadol demonstrated a statistically significant improvement in knee pain over placebo as reported by the Patient Global Rating of Pain Relief Scale.
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OrthoCash 2020
An 82-year-old healthy male presents to the ED with right leg pain and inability to bear weight after a fall from standing. He has a history
of revision right total knee arthroplasty performed 5 years ago and was doing well until his fall this morning. On exam, he is able to actively extend his knee, though limited by pain, and is neurovascularly intact. Figures A-B are radiographs of his distal femur. What is the most appropriate treatment?

Retrograde intramedullary nail
Revision total knee arthroplasty with a stemmed femoral component
Nonoperative management with application of a long leg cast
Open reduction and internal fixation with a lateral plate
Antegrade intramedullary nail Corrent answer: 4
Open reduction and internal fixation with a lateral plate is the most appropriate treatment for this supracondylar periprosthetic femur fracture above a well-fixed total knee arthroplasty (TKA).
Supracondylar periprosthetic femur fractures are defined as fractures within 15cm of the joint line or within 5cm of the proximal end of the implant in the case of a stemmed component. Risk factors include rheumatoid arthritis, neurologic disorders, steroid use, anterior cortical notching of the femoral
component and revision TKA. Nonoperative management usually requires long-term immobilization, which can result in significant loss of knee range of motion (ROM). Therefore, surgical treatment is often preferred. An acceptable outcome is > 90° of knee ROM, fracture shortening < 2cm, varus/valgus malalignment < 5°, and flexion/extension malalignment < 10°.
Su et al. performed a literature review of the management of periprosthetic femur fractures above a TKA. First, it is crucial to determine the stability of the femoral component. An unstable femoral component requires either revision TKA or distal femoral replacement, depending on the quality of the distal femoral bone stock. A fracture with a stable femoral component can be well fixed with a buttress plate or retrograde intramedullary nail. In a series of 12 patients undergoing fracture fixation with lateral plate, all patients healed and returned to pre-fracture ambulatory status.
Zehntner et al. studied the surgical outcomes of buttress plating in 6 supracondylar femur fractures above TKA. There was no nonunion, loss of fixation or infection. Knee ROM averaged 97°, and all patients were ambulating postoperatively.
Figures A and B represent AP and lateral radiographs of a supracondylar periprosthetic femur fracture above a stemmed TKA. Illustrations C and D represent AP and lateral radiographs of a supracondylar periprosthetic femur fracture above a stemmed TKA status post repair with lateral plate.
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OrthoCash 2020
A 60-year-old woman presents for follow-up two weeks after right total knee arthroplasty. She complains of significant anterior knee pain after fall from standing onto a flexed knee. On physical exam, her passive range of motion is 0-120 degrees and she is stable to varus and valgus stress. She is able to achieve full extension with active range of motion, though she is experiencing severe pain. Lateral radiograph of the knee is provided in Figure A. What is the most appropriate next step?

Non-operative management with long leg cast
Closed treatment with immediate active range of motion
Removal of patellar component with early active range of motion
Open reduction and internal fixation of patella with wire or screw fixation
Extensor mechanism repair with Achilles allograft and revision of the patella Corrent answer: 1
The appropriate treatment for a transverse periprosthetic patella fracture with an intact extensor mechanism is closed treatment and immobilization in a long leg cast.
Periprosthetic patella fracture after total knee arthroplasty is rare (incidence of 0.68%-5.2%) and is overwhelmingly secondary to a traumatic mechanism.
Risk factors include excessive patella resection, use of cementless components, and elevated BMI. Broadly, the treatment algorithm for periprosthetic patella fracture depends on the stability of the implant and the involvement of the extensor mechanism. Ortiquerra and Berry classified periprosthetic patella fractures as intact extensor mechanism with well a fixed implant (Type I), extensor mechanism disruption with either a loose or stable implant (Type II), or intact extensor mechanism with a loose implant (Type III). Generally, fractures associated with component loosening or extensor mechanism injuries (Type II & Type III) require revision surgery and often yield poor results. Type I fractures are successfully managed non-operatively.
Nam et al. reviewed the management of extensor mechanism complications in
total knee arthroplasty. They report excellent results in Type I peri-prosthetic patella fractures managed non-operatively, with only 1 failure in 37 patients. They propose a treatment algorithm based upon fracture pattern (transverse vs vertical), component fixation, and extensor mechanism integrity. Type I injuries with transverse fractures should be immobilized in long leg casts, whereas Type I injuries with vertical fractures are more stable and can benefit from early active range of motion.
Cottino el al. similarly review the outcomes of peri-prosthetic patella fractures. They report a 50% complication rate and a 20-40% re-operation rate for type II and type III injuries, even with anatomic reductions.
Figure A is a lateral radiograph of the knee that demonstrates a transverse peri-prosthetic patella fracture without component loosening. There is no obvious extensor mechanism injury and the prompt indicates extension is intact. Illustration A represents the peri-prosthetic patella fracture treatment algorithm as proposed by Nam et al. Illustration B represents the Ortiquerra and Berry peri-prosthetic patella fracture classification.
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OrthoCash 2020
A 68-year-old healthy male with a history of a right total hip arthroplasty 8 years prior presents with one year of right hip pain and several months of inability to bear weight. An AP pelvis radiograph is shown in Figure A. ESR is 8 mm/hr and CRP is 1 mg/L. What is the best treatment option?

Cemented acetabular cup with morselized bone graft
Two stage revision with antibiotic spacer
Cup-cage construct with or without morselized bone graft
Definitive removal of hardware/Girdlestone procedure
Anterior and posterior column plates with hemispherical uncemented cup Corrent answer: 3
Cup-cage constructs have demonstrated excellent outcomes in patients with pelvic discontinuity and Gross type V acetabular defects.
When treating chronic pelvic discontinuities, four general principles need to be addressed: 1) restoration of the acetabulum by reconnecting the ischium to the ilium, 2) optimizing contact of bleeding bone to component surfaces with ingrowth potential, 3) grafting osseous deficiencies, 4) obtaining a mechanically stable reconstruction to protect components until ingrowth is achieved. There are several different classifications of acetabular bone loss, though the Gross classification is unique in that it not only grades the degree of bone loss but also provides reconstructive options that may be considered (Illustration A & B). Due to the segmental bone loss associated with Gross
Types IV and V defects, cup-cage constructs are used to bridge segmental defects or areas of discontinuity.
DeBoer et al. studied the long-term outcomes of 28 patients with pelvic discontinuity treated with custom triflange acetabular prostheses. They reported no instances of broken screws, implant migration, or component revision at 10 years. Complications included one partial sciatic nerve palsy and five patients with dislocation.
Makinen et al. reviewed the role of cages in revision arthroplasty. In Gross Type V defects, cages provide mechanical stability to protect the acetabular cup until ingrowth is achieved. They report two case series following cup-cage reconstructions for pelvic discontinuity, demonstrating 88% survival at 44.6 months and 87.2% survival at 82 months. The survivorship of cage only constructs was 49.9% at seven years.
Figure A demonstrates a failed right total hip arthroplasty with associated chronic pelvic discontinuity. Illustration A demonstrates the Gross classification for acetabular bone defects. Illustration B demonstrates the suggested reconstructive options for defects classified according to the Gross classification system.
Incorrect Answers:

OrthoCash 2020
A 60-year-old male presents with significant left knee pain and end-stage osteoarthritis. He failed non-operative management and is requesting a total knee arthroplasty (TKA). His past medical history is significant for a left distal femur fracture that occurred when he was struck by a car 30 years prior. A standing, full-length radiograph of his left lower extremity is shown in Figure A. His femoral coronal plane deformity measures 28 degrees. When proceeding with a TKA, what must be done to address this patient's coronal deformity?

Soft tissue balancing and intra-articular bone cuts
Distal femoral medial closing-wedge osteotomy
Distal femoral lateral closing-wedge osteotomy
High tibial osteotomy
Hinged TKA
Coronal plane deformities of the femur >20 degrees require an extra-articular femoral osteotomy to achieve proper mechanical alignment when performing a TKA.
Coronal and sagittal plane deformities of the femur less than 20 degrees can usually be addressed with intra-articular bone cuts and soft tissue balancing. Attempting to correct deformities greater than this without an extra-articular osteotomy can compromise ligamentous stability. This highlights the importance of careful pre-operative templating/planning and obtaining full-length, standing radiographs when clinically warranted. Although correcting severe deformities with staged or concomitant extra-articular osteotomies can be challenging, they are often successful when properly executed.
Lonner et al. provided a retrospective case series and review article addressing
severe extra-articular deformities with simultaneous femoral osteotomy and TKA in patients with osteoarthritis. In their 10-patient series, they were successful in restoring coronal alignment within two degrees of anatomic in all patients. They suggest securing the femoral osteotomy site with a plate or locked intramedullary nail, depending on the osteotomy site.
Rajgopal et al. presented a case series of TKA in 36 knees in the setting of extra-articular deformities. In this series, they treated all patients with intraarticular bone resection and soft-tissue balancing to address their deformities. Femoral-coronal, sagittal, and tibial-coronal deformities successfully treated included 11-18 degrees, 0-15 degrees, and 12-24 degrees, respectively.
Figure A is a standing, full-length radiograph of the left lower extremity demonstrating a significant coronal plane deformity resulting from a previous distal femur fracture malunion. Illustration A is a left knee radiograph demonstrating an extra-articular distal femoral osteotomy with placement of a fluted, press-fit stem. Illustration B is the same patient at 3-year follow-up demonstrating a fully healed osteotomy and maintained hardware alignment.
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OrthoCash 2020
A 76-year-old female presents with right hip pain 6 years after total hip arthroplasty. She denies constitutional symptoms at this time. On physical examination, her incision is well healed. Current radiographs are shown in Figures A and B. In addition to a complete blood count (CBC), C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR), an alpha-defensin immunoassay is ordered. What does the alpha-defensin immunoassay test for?

The presence of an intra-articular, antimicrobial peptide
The presence of an antimicrobial peptide within serum
The presence of an intra-articular, pro-inflammatory marker
The presence of an intra-articular, pro-inflammatory cytokine
The presence of intra-articular leukocytosis Corrent answer: 1
A synovial alpha-defensin immunoassay tests for the presence of an intraarticular, antimicrobial peptide.
When there is suspicion of a periprosthetic infection, laboratory workup should
include CRP and ESR. If suspicion remains after laboratory examination, an aspiration of the joint should be performed for cell count and culture. A fairly recent test developed to aid in the diagnosis of PJI is the synovial alpha-defensin immunoassay. Defensins are antimicrobial peptides that are active against many bacteria, fungi, and enveloped viruses. Alpha-defensin is an antimicrobial peptide which is abundant in neutrophils and macrophages. It is present in the natural local tissue response to infection. In the setting periprosthetic joint infection (PJI) the levels of intra-articular alpha-defensin increase substantially and may reach levels that can be detected by an immunoassay. Alpha-defensin may be more prone to false positive results in adverse local tissue reaction caused by a metal-on-metal arthroplasty.
Bonanzinga et al. performed a prospective study to determine the reliability of the alpha-defensin immunoassay for diagnosing PJI. They aspirated hips and knees in all patients presenting with pain in both primary and revision arthroplasties. They found the sensitivity of the alpha-defensin immunoassay was 97%, the specificity was 97%, the positive predictive value was 88%, and the negative predictive value was 99% (95% CI, 96%–99%). They conclude that alpha-defensin appears to be a reliable test.
Shinsky et al. performed a study to evaluate the utility of commonly available tests for determining the presence of PJI in patients undergoing revision total hip arthroplasty. 235 consecutive total hip arthroplasties undergoing revision were evaluated. They found that no hip in a patient with a preoperative ESR of
<30 mm/hr and a CRP of <10 mg/dL was infected. They also conclude that a synovial fluid cell count of >3000 white blood cells/mL was the most predictive perioperative testing modality when ESR and CRP were elevated as well.
Figures A and B are AP and lateral radiographs of the right hip, respectively, demonstrating a region of periarticular erosions around the proximal femoral stem.
Incorrect Answers:
OrthoCash 2020
A 72-year-old male presents to your clinic with a 6-month history of left groin pain without preceding trauma. He previously underwent an uneventful left total hip arthroplasty 15-years prior at an outside institution. He has been ambulating with a cane for the last month due to pain. A left hip radiograph is obtained and presented in Figure A. Less than 4 centimeters of intact diaphyseal bone remains distal to the isthmus. An infection work-up is negative. Of the choices provided, what is the most appropriate management option at this time?

Continued observation
Placement of a femoral cortical strut allograft and cerclage wires
Femoral revision with impaction grafting and a cementless femoral stem
Femoral revision with a metaphyseal-engaging tapered stem
Femoral revision with a modular fluted tapered stem Corrent answer: 5
This patient has a Paprosky type-IIIB femoral defect (less than 4cm diaphyseal bone available for distal fixation) that can be revised with a modular fluted tapered stem
Femoral revision with a modular fluted tapered stem is the preferred method
in the treatment of Paprosky type-IIIB femoral defects. Proximal femoral replacement, allograft prosthetic composite, resection arthroplasty, and impaction grafting may also be considered in the treatment of Paprosky type-IIIB and IV femoral defects. Impaction grafting involves creating a neomedullary canal by impacting cancellous bone chips into the femoral canal followed by cementation of the final femoral component.
Valle et al. present a review article describing the Paprosky classification of femoral defects as well as treatment options. They differentiate a type-IIIA and IIIB defect as having >4 and <4 centimeters of intact diaphyseal bone available for distal fixation, respectively.
Hartman et al. describe management strategies for femoral fixation in the setting of revision total hip arthroplasty. They review classification systems of femoral bone loss and provide an overview of various treatment options. The authors feel that type-II and IIIA defects can be effectively treated with cylindrical, extensively porous-coated implants, whereas IIIB defects can usually be treated with a modular fluted tapered stem.
Figure A show a total hip arthroplasty with less than 4cm of diaphyseal bone available for distal fixation with extensive metaphyseal and diaphyseal bone loss. Illustration A shows a diagram of the Paprosky classification for femoral bone loss.
Incorrect Answers:

OrthoCash 2020
An 85-year-old woman sustains a ground level fall. Her THA was done 25 years ago. She was previously ambulatory but with a significant limp. With regard to the femur specifically, what is the Vancouver classification and preferred treatment option?

Vancouver C, revision to proximal femoral replacement
Vancouver B1, ORIF with impaction grafting
Vancouver AG, ORIF
Vancouver B3, revision to proximal femoral replacement
Vancouver B2, ORIF with femoral strut allograft augmentation Corrent answer: 4
The periprosthetic femoral fracture should be classified as Vancouver B3 given the location around the femoral stem with very poor proximal femoral bone stock, thus making reconstruction of this bone unrealistic. The best treatment options for a B3 fracture would be revision of the stem to a proximal femoral replacement or proximal femoral allograft composite.
The Vancouver periprosthetic classification system is one of the most useful classifications in orthopaedics as it can reliably guide treatment. Vancouver B1 or C type fractures confer a well-fixed stem and so ORIF would be the
treatment of choice. B2 and B3 fractures signify a loose femoral stem and so revision is necessary while B3 fractures have very poor proximal bone quality making any reliance on metaphyseal proximal bone for fixation or reconstruction futile.
Klein et al. retrospectively reviewed 21 patients (mean age 79) with Vancouver B3 fractures treated with a proximal femoral replacement. At most recent follow-up, 20/21 patients were ambulatory with no or minimal pain.
They note a relatively high complication rate (2 recurrent dislocators, 1 repeat fracture, 1 acetabular complication, 2 infections treated with I&D). However, given the circumstances and morbidity of non-operative management, they still recommend a proximal femoral replacement for this complicated patient group.
Savvidou et al. offer a good review of proximal femoral replacement both for periprosthetic fracture and also revision THA with significant proximal bone loss. They emphasize the complications such as dislocation and aseptic loosening and offer recommendations for minimizing them such as a large femoral head, soft tissue repair, and preservation/repair of abductors.
Figure A demonstrates a cemented total hip arthroplasty with significant osteolytic changes about both the femoral and acetabular components with multiple fractures around the grossly loose femoral stem. Taken from Klein et. al.
Illustration A demonstrates an example of a proximal femoral replacement. Taken from Savvidou et al.
Incorrect Answers:

OrthoCash 2020
Which of the following liner types have been associated with early acetabular component loosening?

Figures B and C Corrent answer: 1
Figure A is an illustration of a lateralized or offset acetabular liner which has been shown to have a higher rate of loosening with primary and revision total hip arthroplasty (THA).
Extended offset polyethylene liners allow restoration of soft tissue tension by adding 4 to 10 mm of additional offset to the acetabular side. They translate the center of hip rotation laterally which will increase offset in the horizontal plane and add a few millimeters of additional limb lengthening in the vertical plane. The lateral translation of the center of rotation has been found to increase joint reaction forces and polyethylene wear. Additionally, this results
in an eccentric loading pattern and leads to increased torsional forces at the liner-shell interface and the bone-implant interface. This may cause motion at the interface resulting in failure of ingrowth and early loosening.
Glori performed a study to determine if torsion on an offset acetabular component may increase the risk of fixation failure. He found that a 70 kg person walking normally on a well-positioned 10-mm offset component will produce more torsion compared to a 4-mm offset component. Vertical cup placement was also found to increase torsion. He concludes that these torsional moments are comparable to moments shown to cause failure of the initial interference fit of cementless acetabular components in vitro. He suggests that after using an offset cementless acetabular component, one should initially limit weight bearing to minimize the risk of failure.
Archibeck et. al reviewed 1919 patients with primary THA and 346 with revision THA to evaluate acetabular component loosening. A 7-mm offset acetabular liner was used in 120 of the primary and 100 of the revision THAs. The aseptic loosening rate in the primary THA group was 0.12% in the standard offset and 4.2% in the extended offset groups at a minimum of 2 years follow-up. The aseptic loosening rate in the revision group was 1.7% in the standard and 7% in the extended offset groups at a mean of 4 years follow-up. They conclude that offset acetabular liners have a high failure rate in primary and revision THA.
Figure A is an illustration depicting an offset acetabular component. Figure B is an illustration depicting an oblique acetabular component or a face-changing liner. Figure C is an illustration depicting an elevated rim acetabular component or a lipped liner. Figure D is an illustration depicting a standard offset component.
Incorrect Answers:
OrthoCash 2020
During a revision hip surgery, which of the following muscles labeled in Figure 1 can be transferred in the setting of an abductor deficiency?

Question 11

An 82-year-old osteoporotic woman undergoes total hip arthroplasty for osteoarthritis. During implant trialing, a crack is heard. Intraoperative fluoroscopy reveals a long, spiral fracture of the distal femur. The fracture is reduced and fixed with an anatomic locking plate. The rest of the total hip arthroplasty proceeds uneventfully. Following surgery the surgeon has a meeting with the family and apologizes and provides full disclosure, accepts responsibility, provides a detailed explanation as to what happened, and gives reassurance that steps will be taken to prevent recurrences. This communication approach will most likely

Explanation

The surgeon has provided all the elements of good communication with the patient and family. His actions will lead to improved patient satisfaction, compared to nondisclosure and attempting to push or shirk responsibility.
In the event of a medical error or adverse event, effective communication with the patient and family is necessary. Effective communication should comprise: an apology, full disclosure (an explanation of what happened), accepting responsibility, and corrective steps that will be taken to prevent recurrence.While accepting responsibility is integral to the explanation process, it is different from accepting blame.
Mazor et al. found patients would more likely change physicians and seek legal advice in situations with a life-threatening outcome where physicians chose nondisclosure. They recommend full disclosure, acceptance of responsibility, an apology, detailed explanations, and assurances that steps will be taken to prevent recurrences will result in positive outcomes in terms of patient satisfaction, trust, and emotional response.
MacDonald et al. addressed medical errors in an editorial. Besides full disclosure, they feel that an apology is necessary. This includes an acknowledgement of the event and one’s role in the event, and a genuine expression of regret. Apology laws exist to to reduce concerns about legal implications of disclosure and apology.
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Question 12

A 9-year-old child has right groin pain after falling from a tree. Examination reveals that the right leg is held in external rotation, and there is significant pain with attempts at passive range of motion. Radiographs are shown in Figures 43a and 43b. Management should consist of

Explanation

DISCUSSION: The complications of femoral neck fractures in children include osteonecrosis, malunion, nonunion, and premature physeal closure. It is presumed that the risk of osteonecrosis is directly related to the amount of displacement at the time of injury and is not affected by the type of treatment. The risk of the other complications can be decreased depending on the type of treatment. Anatomic reduction by either closed or open methods can reduce the risk of malunion. The addition of internal fixation allows for maintenance of the reduction. In young children who cannot comply with a partial or non-weight-bearing status, the addition of a spica cast gives added protection.
REFERENCES: Canale ST: Fractures of the hip in children and adolescents. Orthop Clin North Am 1990;21:341-352.
Hughes LO, Beaty JH: Fractures of the head and neck of the femur in children. J Bone Joint Surg Am 1994;76:283-292.

Question 13

An orthopaedic surgeon frequently uses hip and knee prostheses from a specific manufacturer. The surgeon becomes acquainted with the manufacturer's representative who provides the support for these prostheses in the hospital. They develop a personal relationship outside of work through a common interest in sailing. Together they become interested in buying a sailboat. The manufacturer's representative suggests a partnership in a boat costing $200,000. The manufacturer's representative would purchase a 90% interest and the surgeon a 10% interest in the boat. There would be no restrictions on use of the boat by the surgeon. What should the orthopaedic surgeon do?

Explanation

Rejecting this proposal is the only appropriate course of action. Accepting it would, in essence, be receiving a huge gift from industry in the form of a sailboat. Physicians frequently assert that they are not influenced by gifts and relationships with industry representatives, but evidence is to the contrary. Such an arrangement constitutes a tremendous incentive to use the manufacturer's products. The fact that the boat partnership seems completely outside of the orthopaedic business relationship does not excuse it. Conflicts of interest should always be resolved and in the best interest of patient care, and in this case the best course clearly is to avoid the conflict of interest totally. An equal interest in the boat does not eliminate the conflict of interest.

Question 14

A 56-year-old man with poorly controlled diabetes mellitus has rapidly developing and advancing erythema, warmth and swelling with bullae formation on the left lower extremity. These findings appear to be advancing proximally several millimeters per hour. Culture results are most likely to reveal

Explanation

Discussion: Necrotizing fasciitis (NF) results in the death of the body's soft tissue. It is a severe disease of sudden onset that spreads rapidly. Symptoms include red or purple skin in the affected area, with severe pain, fever, and vomiting. The most commonly affected areas are the limbs and perineum. Early diagnosis is difficult as the disease often looks like a simple superficial skin infection in the early stages. While a number of laboratory and imaging modalities can raise the suspicion for necrotizing fasciitis, the gold standard for diagnosis is a surgical exploration in the setting of high suspicion. When in doubt, a small "keyhole" incision can be made into the affected tissue. If a finger easily separates the tissue along the fascial plane,
the diagnosis is confirmed and an extensive debridement should be performed. The Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score can be utilized to risk stratify people who have signs of cellulitis and determine the likelihood of necrotizing fasciitis being present. It uses six serologic measures, including C-reactive protein, total white blood cell count, hemoglobin, sodium, creatinine and glucose.
Polymicrobial synergistic infection was the most common cause of necrotizing fasciitis (48 patients; 53.9%) with streptococci and enterobacteriaceae being the most common isolates. Group-A streptococcus was the most common cause of monomicrobial necrotizing fasciitis. The most common associated comorbidity was diabetes mellitus (63 patients; 70.8%).

Question 15

A 26-year-old man was thrown from a car and sustained the injury seen in Figures 44a and 44b. Nonsurgical management of this injury is recommended. Which of the following factors increases the risk of nonunion?

Explanation

DISCUSSION: The patient has a displaced comminuted clavicle middle one third fracture from a high-energy mechanism. Recent literature on high-energy clavicular fractures suggests a higher rate of nonunion than previously reported. A nonunion rate of 30% has been reported by Hill and associates when the fracture fragments are displaced more than 1.5 cm. In addition, several patients had neurologic symptoms related to the injury. Robinson and associates reported an increased risk of nonunion in women, elderly patients, comminuted fractures, and injuries with a lack of cortical contact.
REFERENCES: Hill JM, McGuire MH, Crosby LA: Closed treatment of displaced middle-third fractures of the clavicle gives poor results. J Bone Joint Surg Br 1997;79:537-539.
Wick M, Muller EJ, Kollig E: Midshaft fractures of the clavicle with a shortening of more than

2 cm predispose to nonunion. Arch Orthop Trauma Surg 2001;121:207-211.
Robinson CM, Court-Brown CM, McQueen MM, et al: Estimating the risk of nonunion following nonoperative treatment of a clavicular fracture. J Bone Joint Surg Am

2004;86:1359-1365.

Question 16

A 20-year-old college pitcher reports medial elbow pain after 3 innings of hard throwing. He recalls no injury and reports no pain with light throwing. The examination shown in the clinical photograph in Figure 48 reproduces the elbow pain. What is the most likely diagnosis? Review Topic

Explanation

The milking test, as seen in the photograph, elicits pain when a tear is present in the medial collateral ligament. Complete rupture is possible but unlikely when there is no history of trauma and the patient is able to throw pain-free for several innings. Subluxation of the ulnar nerve and triceps tendon subluxation present as a painful snapping over the medial aspect of the elbow.

Question 17

A newborn has been referred for evaluation of a deformed foot. Prenatal and birth history are unremarkable. Examination reveals a rocker bottom appearance to the foot, and a longitudinal arch cannot be created. A palpable lump is appreciated on the plantar medial surface. What is the best course of action?

Explanation

DISCUSSION: The patient has congenital vertical talus. The navicular is irreducibly dorsally dislocated on the talus with the talar head prominent on the plantar medial aspect of the foot. Initial management involves corrective casting for 3 months to stretch the dorsal tendons, skin, and neurovascular structures. Surgical reconstruction is often needed and is indicated when the patient is age 6 to 12 months. Reconstruction requires both bony and soft-tissue procedures.
REFERENCES: Napiontek M: Congenital vertical talus: A retrospective and critical review of 32 feet operated on by peritalar reduction. J Pediatr Orthop 1995;4:179-187.
Oppenheim W, Smith C, Christie W: Congenital vertical talus. Foot Ankle 1985;5:198-204.

Question 18

When performing the exposure for an anterior approach to the cervical spine, the surgical dissection should not enter the plane between the trachea and the esophagus and excessive retraction should be avoided to prevent injury to the

Explanation

DISCUSSION: The recurrent laryngeal nerve lies between the trachea and the esophagus. The vagus nerve lies in the carotid sheath. The sympathetic trunk lies anterior to the longus colli muscles. The hypoglossal and superior laryngeal nerves are both at risk during the exposure but are not located between the trachea and the esophagus.
REFERENCES: Flynn TB: Neurologic complications of anterior cervical interbody fusion. Spine 1982;7:536-539.
Patel CK, Fischgrund JS: Complications of anterior cervical spine surgery. Instr Course Lect 2003;52:465-469.

Question 19

In patients with suspected hepatitis C, which of the following tests is commonly used to confirm the diagnosis after a positive ELISA screening test?

Explanation

DISCUSSION: The basic diagnostic test for hepatitis C (HCV) is detection of an antibody to epitopes on an enzyme-linked immunosorbent anti-HCV assay (ELISA). The currently used ELISA has high sensitivity (92%) and specificity (95%). False positives, however, still occur. The currently used supplemental test for HCV is strip immunoblot assay, which is based on detection of several HCV epitopes on nitrocellulose paper by antibody-capture techniques. Molecular amplification by PCR technology is very sensitive, but difficult to standardize and susceptible to contamination. Microarray and proteomics are relatively recent molecular techniques used for analysis of genes or proteins, respectively. A Northern blot is used to detect mRNA levels of specific genes but is not used in this situation.
REFERENCES: de Medina M, Schiff ER: Hepatitis C: Diagnostic assays. Semin Liver Dis 1995;15:33-40.
McGrory BJ, Kilby AE: Hepatitis C virus infection: Review and implications for the orthopedic surgeon. Am J Orthop 2000;29:261-266.

Question 20

The MRI findings shown in Figure 51 would most likely create which of the following signs and symptoms?

Explanation

DISCUSSION: The MRI scan shows a far lateral disk herniation. With the L4-5 disk, a far lateral herniation abuts the left L4 nerve root. The findings would be consistent with those of a left L4 radiculopathy and would include pain or a sensory deficit on the anteromedial aspect of the knee, diminished patellar tendon reflex, and quadriceps weakness, perhaps making it difficult to walk up and down stairs.
REFERENCES: Fardin DF, Garfin SR (eds): Orthopaedic Knowledge Update: Spine 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, p 329.
O’Hara LJ, Marshall RW: Far lateral lumbar disc herniation: The key to the intertransverse approach. J Bone Joint Surg Br 1997;79:943-947.

Question 21

A 40-year old man has limited, painful motion in dorsiflexion at the metatarsophalangeal (MTP) joint of the right great toe, despite nonsurgical treatment. Radiographs show dorsal and medial osteophytes and minimal narrowing of the articular space. Treatment should consist of

Explanation

Cheilectomy, the excision of an irregular osseous rim that interferes with motion of a joint was performed on the distal part of the metatarsal of patients who had hallux rigidus. In this study by Mann, published in JBJS 1988, they were able to conclude that cheilectomy is a better method of treatment for hallux rigidus than arthrodesis, resection arthroplasty, or arthroplasty with the use of a flexible implant. In older adults who present late, with more severe X-Ray changes, Keller procedure is indicated.

Question 22

A 40-year-old man with an acetabular chondrosarcoma has a small soft-tissue mass. Treatment should consist of

Explanation

DISCUSSION: The treatment of choice for pelvic chondrosarcoma is wide resection via an internal hemipelvectomy. Chondrosarcoma requires surgical resection for control and does not respond to traditional chemotherapy or external beam radiation. Hip arthroplasty with acetabular reconstruction and curettage and cementation of the lesion are intralesional procedures that result in a higher incidence of local recurrence of tumor.
REFERENCES: Pring M, Weber KL, Unni K, Sim FH: Chondrosarcoma of the pelvis: A review of sixty-four cases. J Bone Joint Surg Am 2001;83:1630-1642.
Sheth DS, Yasko AW, Johnson ME, Ayala AG, Murray JA, Romsdahl MM: Chondrosarcoma of the pelvis: Prognostic factors for 67 patients treated with definitive surgery. Cancer 1996;78:745-750.

Question 23

A 10-day-old girl has decreased active motion of the left upper extremity. The mother reports a difficult vaginal delivery with presumed shoulder dystocia. Examination shows full passive range of motion of the shoulder, elbow, and wrist but only active flexion of the fingers and wrist. Factors predictive of a good outcome include which of the following?

Explanation

Return of active biceps before 3 months and preservation of full passive shoulder range of motion are predictors of a good outcome. Breech delivery is usually associated with preganglionic injury. Preganglionic injury can result in a Horner's sign, which includes ptosis, myosis, and anhydrosis. Preganglionic injuries are unlikely to recover. The Moro reflex is elicited by dropping a baby's head a short distance and observing active elbow extension and fanning of the fingers, followed by elbow flexion and crying. Absence of the Moro reflex suggests a poor prognosis.

Question 24

The patient undergoes hip arthroscopy and the image of the right hip is shown in Figure 39. Repair of the injured structure would be expected to improve

Explanation

DISCUSSION
The radiographic studies reveal both acetabular dysplasia and cam-type femoroacetabular impingement. The MR image shows an acetabular labral tear. Structural abnormalities of the hip, including femoroacetabular impingement, have commonly been identified in association with labral tears. Disruption of the ligamentum teres is not associated with impingement conditions in the absence of trauma.
The patient has acetabular dysplasia with a decreased lateral center-edge angle and also has visible cam-type femoroacetabular impingement. The common pathway for joint degeneration in hips with cam-type femoral head anatomy includes the development of cartilage damage in the anterior or superolateral aspects of the acetabular cartilage. Paralabral cysts may be seen more commonly in association with acetabular dysplasia, although the patient’s radiographs did not demonstrate substantial cystic changes. Osteochondral loose bodies and ligamentum teres ruptures can be seen at arthroscopy in a small number of cases.
There are several proposed roles of the acetabular labrum. It can increase the depth of the acetabular socket by as much as 21% to 28%. Roles of the acetabular labrum include joint lubrication, shock absorption, and pressure distribution. Recent studies assessing the effects of loading on joint stability for both normal and dysplastic hips did not demonstrate a substantial role of the labrum in differences in loading. Although joint stability might be improved following surgical repair, acetabular dysplasia is not likely to be resolved with acetabular labral repair alone.
RECOMMENDED READINGS
Tibor LM, Leunig M. The pathoanatomy and arthroscopic management of femoroacetabular impingement. Bone Joint Res. 2012 Oct 1;1(10):245-57. doi: 10.1302/2046-3758.110.2000105.PubMed: 23610655. View Abstract at PubMed
Peelle MW, Della Rocca GJ, Maloney WJ, Curry MC, Clohisy JC. Acetabular and femoral radiographic abnormalities associated with labral tears. Clin Orthop Relat Res. 2005 Dec;441:327-33. PubMed PMID: 16331022. View Abstract at PubMed
Ross JR, Zaltz I, Nepple JJ, Schoenecker PL, Clohisy JC. Arthroscopic disease classification and interventions as an adjunct in the treatment of acetabular dysplasia. Am J Sports Med. 2011 Jul;39 Suppl:72S-8S. doi: 10.1177/0363546511412320.
PubMed PMID: 21709035. View Abstract at PubMed
James SL, Ali K, Malara F, Young D, O'Donnell J, Connell DA. MRI findings of 37
femoroacetabular impingement. AJR Am J Roentgenol. 2006 Dec;187(6):1412-9. PubMed PMID: 17114529. View Abstract at PubMed
Groh MM, Herrera J. A comprehensive review of hip labral tears. Curr Rev Musculoskelet Med. 2009 Jun;2(2):105-17. doi: 10.1007/s12178-009-9052-9. Epub 2009 Apr 7. PubMed PMID: 19468871. View Abstract at PubMed
Henak CR, Ellis BJ, Harris MD, Anderson AE, Peters CL, Weiss JA. Role of the acetabular labrum in load support across the hip joint. J Biomech. 2011 Aug 11;44(12):2201-6. doi: 10.1016/j.jbiomech.2011.06.011. Epub 2011 Jul 14. PubMed PMID: 21757198. View Abstract at PubMed

Question 25

A 14-year-old girl has idiopathic scoliosis with a 52-degree right thoracic curve and a 36-degree left lumbar curve. The rotation of the apical vertebra appears greater in the thoracic curve. A sagittal view radiograph shows the spine to be virtually straight. The iliac apophyses are Risser 2. Treatment should consist of

Explanation

The patient’s curve is beyond the limit for bracing to be effective (40 degrees). Therefore, surgical treatment should be utilized. King type II curves (predominant thoracic curve with secondary lumbar curve) historically has used selective posterior thoracic fusion with segmental hook systems and rotation maneuvers to correct the thoracic curve and compensatory lumbar curve. The patient’s primary curve is thoracic and lumbar fusion would be contraindicated.

Question 26

What structure is located immediately posterior to the capsule at the posterior cruciate ligament tibial insertion?

Explanation

DISCUSSION: The popliteal artery lies just posterior to the posterior cruciate ligament

tibial insertion, separated only by the posterior capsule of the knee. When performing

a posterior cruciate ligament reconstruction, this artery is at risk for injury during creation

of the tibial tunnel.
REFERENCES: Jackson DW, Proctor CS, Simon TM: Arthroscopic assisted PCL reconstruction: A technical note on potential neurovascular injury related to drill bit configuration. J Arthroscopy 1993;9:224-227.
Malek MM, Fanelli GC: Technique of arthroscopically assisted PCL reconstruction. Orthopedics 1993;16:961-966.

Question 27

..A lateral radiograph (Figure 131a), sagittal short tau inversion recovery MRI scan (Figure 131b), and an axial T1 contrast MRI scan (Figure 131c) were performed on a 15-year-old boy who has injured his right knee twice during the last 5 months. He has a reduced range of motion of the knee and posterior thigh tenderness. A biopsy showed bland spindle cells, giant cells, and blood-filled spaces without endothelial lining. What is the most appropriate treatment?

Explanation

CLINICAL SITUATION FOR QUESTIONS 132 THROUGH 134

Figure 132 is the bone scan of a 73-year-old man who is referred from his family doctor with diffuse bone pain, fatigue, and right knee pain. Examination is notable for pain with motion about the right knee and mild hyporeflexia.

Question 28

Which of the following anatomic structures are in contact with internal impingement in the throwing athlete? Review Topic

Explanation

Internal impingement occurs in the late cocking phase of throwing with humeral head abduction and maximal external rotation. It is a physiologic phenomenon occurring in 85% of patients undergoing arthroscopy for various indications in one study. Internal impingement is defined as impingement of the posterior-superior rotator cuff between the humerus and posterior-superior glenoid rim. Symptomatic internal impingement is felt to be due to the frequency and magnitude of the impingement in throwers.

Question 29

A 38-year-old man caught his index finger in a volleyball net. He noted an angular deformity of the finger that was reduced when a teammate pulled on his finger. Three weeks later, he now reports trouble extending his finger. A clinical photograph is shown in Figure 55. What anatomic structure is most likely injured?

Explanation

DISCUSSION: The clinical photograph shows a classic boutonniere deformity. It is likely that the patient sustained a volar dislocation of the proximal interphalangeal joint, with a concomitant rupture of the central slip insertion of the extensor tendon.
REFERENCES: Peimer CA, Sullivan DJ, Wild DR: Palmar dislocation of the proximal interphalangeal joint. J Hand Surg Am 1984;9:39-48.
Glickel SZ, Barron OA, Catalano LW: Dislocation and ligament injuries in the digits, in

Green DP, Hotchkiss RN, Pederson WC, et al (eds): Green’s Operative Hand Surgery, ed 5. Philadelphia, PA, Elsevier, 2005, p 355.

Question 30

A 75-year-old man who is right-hand dominant has had a painful right shoulder for the past 6 months, with no improvement with nonsurgical management. Examination reveals an active motion of 60 degrees of forward flexion and abduction, with severe crepitus and pain. Radiographs reveal a high-riding humeral head with severe glenohumeral arthritic changes. What is the most appropriate treatment? Review Topic

Explanation

In an older age group, the most predictable outcome is obtained with a reverse shoulder arthroplasty. Treatment with a standard hemiarthroplasty is more unpredictable in that the pain relief is typically good to excellent in 75% of patients, but the function is poor in most patients. A total shoulder arthroplasty is contraindicated as a result of the significant shearing forces that the glenoid would experience as a result of the rotator cuff deficiency. Arthroscopic lavage and debridement is ineffective in such advanced cases.

Question 31

The teardrop shape marked with an asterisk in Figure 61 represents what anatomic structure?

Explanation

DISCUSSION: The teardrop can be visualized on the obturator outlet view of the pelvis and represents a thick column of bone that runs from the AIIS to the PSIS. Half pins for eternal fixation frames or screws can be inserted into this column for fixation of fractures.
REFERENCES: Gardner MJ, Nork SE: Stabilization of unstable pelvic fractures with supra-acetabular compression external fixation. J Orthop Trauma 2007;21:269-273.
Haidukewych GJ, Kumar S, Prpa B: Placement of half-pins for supra-acetabular external fixation: An anatomic study. Clin Orthop Relat Res 2003;411:269-273.
Kim WY, Hearn TC, Seleem O, et al: Effect of pin location on stability of pelvic external fixation. Clin Orthop Relat Res 1999;361:237-244.

Question 32

Patients who have osteonecrosis of the humeral head and who have the best prognosis are those with which of the following conditions?

Explanation

DISCUSSION: The natural history of nontraumatic osteonecrosis varies greatly, so it is difficult to predict which patients will have severe arthrosis develop. Patients with sickle cell disease tend to have the most benign course. The most commonly reported cause of nontraumatic osteonecrosis is corticosteroid therapy. Fortunately, the incidence of osteonecrosis among patients treated with long-term systemic corticosteroids has fallen from more than 25% to less than 5% in recent years, owning to judicious steroid use and dosing. The interval between corticosteroid administration and the onset of shoulder symptoms is also variable, ranging from 6 to 18 months in one large series. This is comparable to the interval leading up to the onset of hip symptoms, which ranges from 6 months to 3 years or longer. The incidence of humeral head involvement has not been shown to vary with the underlying indication for steroid use.
REFERENCES: Hasan SS, Romeo AA: Nontraumatic osteonecrosis of the humeral head.

J Shoulder Elbow Surg 2002;11:281-298.
Mansat P, Huser L, Mansat M, et al: Shoulder arthroplasty for atraumatic avascular necrosis of the humeral head: Nineteen shoulders followed up for a mean of seven years. J Shoulder Elbow Surg 2005;14:114-120.

Question 33

A 46-year-old man sustains a calcaneal fracture in a fall off a scaffold. During surgical reconstruction using an extended lateral incision, the fracture is reduced and fixed with a plate and screws. One of the posterior facet screws is found to be 5 mm out of the bone on the Harris view. What structure is most likely at risk because of this finding?

Explanation

DISCUSSION: The abductor hallucis muscle is the most medial structure. The posterior tibial tendon and the flexor digitorum longus tendon lie more cephalad to the sustentaculum tali. There is a groove under the sustentaculum for the flexor hallucis longus tendon. Subchondral lag screws placed across the posterior facet exit the medial side of the calcaneus in this groove. Just medial to the flexor hallucis longus tendon is the neurovascular bundle. A screw that is out of the bone a short distance can cause triggering of the flexor hallucis longus tendon. Patients will report loss of great toe excursion in the early postoperative period. Accurate measurement of subchondral lag screw length avoids this complication.
REFERENCES: Hollinshead WH: Anatomy for Surgeons, ed 3. Philadelphia, PA, Harper and Row, 1982, pp 802-852.
Rosenberg AS, Cheung Y: Diagnostic imaging of the ankle and foot, in Jahss MH (ed): Disorders of the Foot and Ankle, ed 2. Philadelphia, PA, WB Saunders, 1991, pp 109-154.
Waggoner AM, Smith JW: Internal fixation of calcaneus fractures: An anatomical study of structures at risk. J Orthop Trauma 1995;9:107-112.

Question 34

Which of the following changes is seen with age and degeneration in the intervertebral disk? Review Topic

Explanation

The intervertebral disk consists of annulus fibrosus, nucleus pulposus, and endplate. Nucleus cells have a critical need for glucose because they obtain their energy primarily by glycolysis, even in the presence of oxygen. Disk cells do not require oxygen to remain alive, but they die at low glucose levels or acidic pH. Nutrients are supplied from the blood vessels at the margins of the disk and have to traverse the cartilaginous endplate and the fibrous annulus in order to reach the disk cells. The loss of the nutrient supply through the vertebral body will starve the cells in the disk center and may be a major factor in disk degeneration. The gross appearance of the nucleus pulposus is clear watery gelatinous matrix in the very young disk, but with age the nucleus pulposus becomes more opaque, and less hydrated and firm. The cellular composition of the young disk consists of many notochordal cells, but after 10 years of age, notochordal cells are not seen in the disk. Notochordal cells are the remnant of embryonal cells in the nucleus pulposus.

Question 35

Figure 1 is the radiograph of a 21-year-old college lacrosse player who has a 2-year history of progressive left groin pain that is exacerbated by activity. Pain is preventing him from participating with his team. Examination reveals a fit man without tenderness to palpation around the hip. No clicking or popping occurs with hip range of motion. Strength of all muscles about the hip is normal, but there is some mild pain with resisted hip flexion and hip adduction. While lying supine, progressive hip flexion with internal rotation and adduction reproduces his groin pain. Further workup confirms an anterosuperior tear of the acetabular labrum and prominence of the acetabulum. What is the most likely location of a chondral injury associated with these findings?

Explanation

This clinical scenario describes a patient with FAI attributable to pincer (acetabular) deformity. This form of FAI, which involves prominence of the anterosuperior acetabular lip, may be more common among women. Decreased range of motion and pain occur secondary to the abutment of the femoral head against the acetabular labrum and rim. Hip flexion, combined with adduction and internal rotation, recreates this contact and causes pain, but CAM or pincer etiology remains unknown. The differential diagnosis of hip pain in a young athlete includes femoral neck stress reaction/fracture, sacroiliac arthritis, intra-articular loose body, trochanteric bursitis, osteitis pubis, and hernia. No information presented in this scenario suggests any of these causes. Diagnosis of FAI is best performed via MR imaging, with an arthrogram increasing the sensitivity and specificity for labral pathology. Ultrasonography may be useful in the diagnosis of dysplasia or for dynamic assessment of a snapping hip, but ultrasonography is not commonly used to diagnose labral pathology. Although concomitant chondral lesions of the femoral head are uncommon, the forced leverage of the anterosuperior femoral neck upon the anterior acetabulum may result in a “contra-coup” chondral injury on the posteroinferior acetabulum. This is the most common location of chondral lesions in this scenario. Without bony resection to prevent further impingement, this patient will continue to experience symptoms. Because there is no evidence of femoral neck prominence (CAM lesion), there is no indication for osteoplasty of the femoral neck; resection of the pincer lesion is necessary. This will often require take-down of the labrum in this location. If possible, iatrogenic or traumatic labral tears should subsequently be repaired after pincer debridement because the labrum has important functions for hip stability and maintenance of the suction seal of the joint.

Question 36

Figures 1 through 4 are the radiographs and MR images of a healthy 21-year-old woman who has had persistent dorsal wrist pain despite immobilization and no history of trauma. The surgical procedure associated with the best prognosis in this scenario is

Explanation

EXPLANATION:
This patient has osteonecrosis of the capitate. The MR images show evidence of osteonecrosis with decreased signal on the T1-weighted image. The radiographs are unremarkable, with the exception of lunotriquetral coalition, which does not necessitate treatment. The etiology of osteonecrosis of the capitate may be related to trauma, abnormal Interosseous vascular supply, and hypermobility. Surgery is an option for patients with persistent symptoms despite immobilization. Vascularized bone graft should be considered in this scenario because there is no evidence of capitate collapse or arthritic change about the wrist. Free and local vascularized bone grafts have produced satisfactory results. Capitate excision with interposition arthroplasty is indicated for patients with proximal pole capitate collapse. Total wrist fusion is a salvage procedure and would be considered if there were evidence of collapse and arthritic change. PRC would leave the capitate articulating with the radius and is not indicated.

Question 37

A 32-year-old professional skydiver lands awkwardly during a jump. He presents to the emergency room with bilateral knee injuries. Following successful closed reduction of both extremities, both feet are warm and pulses are present. Bedside doppler assessment is performed and the results are seen in Figure A. What would be the most appropriate next step in treatment?

Explanation

The ankle-brachial index (ABI) of left and right limbs are 0.78 and 0.96 respectively. CT angiography (or conventional angiography) of the left lower extremity is indicated because of abnormal ABI <0.9. It is sufficient to observe the right lower extremity (ABI >0.9).
Injury to the popliteal artery is present in 10-40% of knee dislocations (KD). ABI
<0.9 has sensitivity of 87% and specificity of 97% for the diagnosis of arterial disruption. Delayed recognition of an occlusive injury (>8 hours) is likely to result in above knee amputation.
Stannard et al. examined the role of selective arteriography based on serial physical examination. They found arterial injury in 7% (9 out of 134 knees), and abnormal physical findings in 10 patients, with only 1 false positive. They recommend arteriography for patients with decreased pulses, color or temperature, expanding knee hematoma, or an abnormal physical examination prior to presentation in the emergency department.
Mills et al. reviewed the value of ABI for diagnosing arterial injury after knee dislocation. They found that of the 29% with ABI <0.9, all required surgery for arterial injury. Of the remaining patients with ABI >0.9, none had vascular injury. They concluded ABI >0.9 has negative predictive value of 100%.
Nicandri et al. reviewed an algorithm for selective angiography. They recommend the following: (1) Intact pulses and ABI >0.9, observation for 24 hours. (2) Asymmetric pulses or ABI <0.9, arteriogram. (3) Hard signs of vascular injury (absent distal pulses, distal ischemia, active hemorrhage, expanding pulsatile hematoma), surgical exploration.
Figure A is a table showing systolic pressure readings at different sites. To calculate the ABI, the highest measured arterial pressure in the ankle or foot is divided by the higher brachial arterial pressure from both upper extremities.
Incorrect Answers:

Question 38

An AP radiograph of the pelvis is shown in Figure 4. What muscle attaches to the avulsed fragment of bone identified by the arrow?

Explanation

DISCUSSION: The radiograph reveals an avulsion of the ischial apophysis, most likely the result of violent contraction of the attached hamstring tendons (semimembranosus, semitendinosus, and long head of the biceps femoris). The short head of the biceps femoris arises from the linea aspera on the posterior femur. The pectineus and adductor longus attach to the pubic portion of the pelvis. The piriformis runs from the sacrum to the femur.
REFERENCES: Woodburne RT (ed): Essentials of Human Anatomy. New York, NY, Oxford University Press, 1978, pp 542-545.
Metzmaker JN, Pappas AM: Avulsion fractures of the pelvis. Am J Sports Med 1985;13:349-358.

Question 39

Which of the following lesions is best suited for autologous chondrocyte implantation?

Explanation

DISCUSSION: Articular chondrocyte implantation is best performed for focal chondral defects of one area of the joint. It is not indicated for osteoarthritis.
REFERENCES: Mandelbaum BR, Brown JE, Fu F, et al: Articular cartilage lesions of the knee. Am J Sports Med 1998;26:853-861.
Minas T, Nehrer S: Current concepts in the treatment of articular cartilage defects. Orthopedics 1997;20:525-538.
Brittberg M, Lindahl A, Nilsson A, Ohlsson C, Isaksson O, Peterson L: Treatment of deep cartilage defects in the knee with autologous chondrocyte transplantation. N Engl J Med 1994;331:889-895.

Question 40

0 sustained a subcapital fracture of her hip. She is an avid tennis player, and history reveals no previous fractures. What is the most appropriate follow-up care? Review Topic

Explanation

A DEXA scan is most appropriately used to establish a baseline score. Even if the bone mineral density is not within the osteoporotic range (T-score less than -2.5), a prior fragility fracture is a strong risk factor for a second fracture as a result of factors other than bone density, such as worsening vision or balance, confusion, or other predispositions to falls. The guidelines of the National Osteoporosis Foundation indicate that, following a fragility hip fracture, active anti-osteoporotic medication should be initiated, whether or not a DEXA scan is performed. A recent study showed that antiresorptive therapy following a hip fracture reduces not only the risk of a second fracture but also overall mortality.

Question 41

What is a known risk factor for wound infection after spinal fusion for neuromuscular scoliosis? Review Topic

Explanation

The risk for wound infection after spinal fusion for neuromuscular scoliosis ranges from 4% to 14% and is higher than risk after spinal fusion in idiopathic scoliosis. A recent study of a database of 151 patients with neuromuscular scoliosis found the presence of ventriculoperitoneal shunt to be associated with an increased risk for wound infection. Age, preoperative major curve magnitude, number of vertebral levels fused, length of surgery, blood loss, and transfusion requirements were not associated with increased risk. A previous study found that poor nutritional status as measured by serum albumin <3.5 g/dL (reference range, 3.5-5.0 g/dL) or lymphocytes
<1500 cells/µL (reference range, 1000-4800/µL) has been associated with increased postoperative wound infections.

Question 42

A 22-year-old woman injured her ankle when she fell off a ladder. Radiographs reveal a displaced large posterior malleolus fracture of about 45% of the joint. What is the best definitive treatment?

Explanation

Basic understanding of fracture care requires a fundamental knowledge of the principles regarding absolute and relative stability. Compression plating and anatomic reduction of articular fractures are examples of absolute stability. Bridge plating, external fixation, casting, and intramedullary nailing are all examples of relative stability. Both bone forearm fractures have long been treated with open reduction and internal fixation even in the light of open wounds. Results have been excellent with plate fixation. Recently, intramedullary nails that are contoured and locked have been used in the treatment of both bone forearm fractures, but they are not reamed. It is well established that with restoring the proper radial bow, length, and alignment,
optimal function can be achieved. Open reduction and internal fixation allows this achievement. In cases where comminution exists, absolute stability may have to be sacrificed so as to not strip small comminuted bone fragments. Therefore, a bridging technique is worthwhile. External fixation can be used as a temporary technique until the soft tissues are more amenable to definitive fixation. Cast treatment is not indicated in adult forearm fractures. Locking nails for forearm use are not reamed. With regards to articular fractures, anatomic reduction and rigid stabilization are required to achieve the best results and allow for fracture healing. This environment also allows for the best chance of the cartilage repair process to form "hyaline-like" cartilage. Open reduction and internal fixation with absolute stability is the mainstay of treatment for partial articular fractures such as split depression tibial plateau fractures and posterior malleolus fractures involving greater than about 25% to 30% of the joint. The gold standard for the treatment of a closed femur fracture is a reamed intramedullary locked nail. Results are uniformly excellent. This can be done without stripping of the soft tissues such as in open reduction and internal fixation. External fixation can be used as a temporary device in patients in extremis for damage control reasons.Moed BR, Kellam JF, Foster RJ, Tile M, Hansen ST Jr. Immediate internal fixation of open fractures of the diaphysis of the forearm. J Bone Joint Surg Am. 1986 Sep;68(7):1008-17. http://www.ncbi.nlm.nih.gov/pubmed/3745238')">View Abstract at PubMedJones DB Jr, Kakar S. Adult diaphyseal forearm fractures: intramedullary nail versus plate fixation. J Hand Surg Am. 2011 Jul;36(7):1216-9. Epub 2011 May

Question 43

In which scenario is application of NPWT contraindicated?

Explanation

DISCUSSION
The most common complication associated with NPWT is a rash on the skin resulting from contact with a suction sponge. In a 2001 study by Webb and Schmidt, 2.2% of patients treated with NPWT had a rash that resolved within 48 hours. To minimize risk for this rash, care should be taken to avoid overlap of the sponge onto intact skin. If skin overlap is unavoidable, a lower-pressure setting should be used.
Acute bacterial infection is possible in this scenario, but there would likely be additional findings such as purulence in the wound itself. Similarly, an acute allergic reaction could be found within the wound and not just at the skin edge. Skin irritation from excessive adhesive plastic tension can result in blistering or shearing avulsion but not skin-edge erythema. Skin necrosis from the original trauma would result in skin-edge duskiness instead of erythema.
A study by Timmers and associates showed a statistically significant increase in microvascular blood flow to the skin under a sponge at subatmospheric pressures. Angiogenesis occurs in the area of the wound vacuum from the negative pressure and increased blood flow, not from the sponge material itself. There has been no indication that antibiotic concentration is increased in the setting of negative pressure therapy because antibiotics would be evacuated along with the fluid. NPWT does not result in increased temperatures that would kill pathogens.
NPWT is contraindicated in the setting of neoplasm because its effect on tumors is unknown. There is potential for increased angiogenesis in residual tumor cells, which could lead to recurrence or even metastasis. NPWT has been used safely and effectively for coverage of open fractures between initial debridement and definitive coverage. Fasciotomy wounds are frequently covered with NPWT dressings on a temporary basis with excellent results.
NPWT has been used to temporize wounds with exposed bone before flap coverage. Wounds with excessive tension frequently can be closed after short-term coverage with NPWT dressings.
RECOMMENDED READINGS
Webb LX, Schmidt U. [Wound management with vacuum therapy]. Unfallchirurg. 2001 Oct;104(10):918-26. German. PubMed PMID: 11699301.View Abstract at PubMed
Webb LX. New techniques in wound management: vacuum-assisted wound closure. J Am Acad Orthop Surg. 2002 Sep-Oct;10(5):303-11. PubMed PMID: 12374481. View Abstract at PubMed
Timmers MS, Le Cessie S, Banwell P, Jukema GN. The effects of varying degrees of pressure delivered bynegative-pressure wound therapy on skin perfusion. Ann Plast Surg. 2005 Dec;55(6):665-71. PubMed PMID: 16327472. View Abstract at PubMed
CLINICAL SITUATION FOR QUESTIONS 68 AND 69

Figure 68 is the radiograph of a 17-year-old girl who is treated with closed reduction and percutaneous screw fixation for her displaced femoral neck fracture. Capsulotomy of the hip is not performed. After surgery, the patient is instructed to maintain touch-down weight-bearing status for 3 months.

Question 44

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.

Question 45

below show the radiographs obtained from a year-old woman with a year history of progressive hip pain in the left groin with activity, which is unresponsive to activity modification and physical therapy. Examination reveals normal range of motion, with pain on anterior impingement testing. What treatment is associated with the best long-term results?

Explanation

DISCUSSION:
This patient has symptomatic femoroacetabular impingement as well as clinical and radiographic signs of acetabular retroversion, including a cross-over sign, ischial spine sign, and posterior wall sign bilaterally. Good midterm to long-term outcomes have been reported with reverse (anteverting) Bernese periacetabular osteotomy (PAO). In patients with less retroversion, open or arthroscopic rim trimming with labral refixation have shown good short-term results, but longer-term results have yet to be fully delineated. Isolated hip arthroscopy and labral repair would not be indicated without addressing the retroversion deformity. Femoral varus rotational osteotomy plays no role in the treatment of this pathology. Open surgical dislocation with rim trimming could be considered in patients with less deformity, but some studies have shown inferior long-term results compared with reverse PAO.

Question 46

Which of the following patients has the highest risk of developing recurrent instability after an arthroscopic Bankart procedure for anterior shoulder instability? Review Topic

Explanation

The 18-year old competitive tennis player with no ligamentous laxity and x-ray findings consistent with a Hill-Sachs lesion and loss of glenoid contour has an instability severity index score (ISIS) of 9, which is associated with a >70% chance of recurrent instability after a arthroscopic Bankart procedure.
The surgical management of anterior shoulder instability consists of both arthroscopic and open approaches. The guiding principles for treatment are the restoration of the normal glenoid labrum anatomy and retensioning of the inferior glenohumeral ligament which is achieved via soft-tissue reconstructions (repair of any labral detachment +/- capsular shift) or bony procedures (such as transfer of the coracoid process).
Ahmed et al. reviewed 302 patients who had undergone arthroscopic Bankart repair and capsular shift for the treatment of recurrent anterior glenohumeral instability. The prevalence of patient and injury-related risk factors for recurrence was assessed. The rate of recurrent glenohumeral instability after arthroscopic Bankart repair and capsular shift was 13.2%. The risk of recurrence was independently predicted by the patient’s age at surgery, the severity of glenoid bone loss, and the presence of an engaging Hill-Sachs lesion.
Balg et al. identified risk factors for recurrent instability after arthroscopic Bankart procedure in 131 consecutive patients. Age under 20 years at the time of surgery; involvement in competitive or contact sports or those involving forced overhead activity; shoulder hyperlaxity; a Hill-Sachs lesion present on an AP radiograph of the shoulder in external rotation and/or loss of the sclerotic inferior glenoid contour were all identified as risk factors. These factors were integrated into a 10-point preoperative instability severity index score (ISIS). Patients with a score over 6 points had an unacceptable recurrence risk of 70%.
Illustration A summarizes the components of the ISIS as developed by Balg and Boileau.
Incorrect Answers:

Question 47

A patient is scheduled to undergo total knee arthroplasty (TKA) following failure of nonsurgical management. History reveals that she underwent a patellectomy as a teenager as the result of a motor vehicle accident. Examination reveals normal ligamentous stability. For the most predictable outcome, which of the following implants should be used?

Explanation

DISCUSSION: Paletta and Laskins performed a retrospective study of the results of TKA with cement in 22 patients who had a previous patellectomy. Nine of the patients had insertion of a posterior cruciate ligament-substituting implant. Thirteen patients had insertion of a posterior cruciate ligament-sparing implant. The 5-year postoperative knee scores were 89 for the posterior cruciate ligament-substituting knee versus 67 for the posterior cruciate

ligament-sparing knee (P < 0.01). The patella functions to increase the lever arm of the extensor mechanism and to position the quadriceps tendon and the patellar ligament roughly parallel to the anterior cruciate ligament and posterior cruciate ligament, respectively. The patellar ligament thereby provides a strong reinforcing structure that functions to prevent excessive anterior translation of the femur during flexion of the knee. The absence of the patella results in the patellar ligament and the quadriceps tendon being relatively in line with one another. After a patellectomy, the resultant quadriceps force is no longer parallel to the posterior cruciate ligament. This results in loss of the reinforcing function of the patellar ligament. The authors believe this loss of reinforcing function may place increased stresses on the posterior cruciate ligament and posterior aspect of the capsule, which may result in stretching of these structures over time. They found a high rate of anteroposterior instability, a high prevalence of recurvatum, and a high rate of loss of full active extension compared with passive extension in the posterior cruciate ligament-sparing group, which supports their theory.
REFERENCES: Beaty JH (ed): Orthopaedic Knowledge Update 6. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 559-582.
Paletta GA Jr, Laskins RS: Total knee arthroplasty after a previous patellectomy. J Bone Joint Surg Am 1995;77:1708-1712.

Question 48

Scapular notching following reverse shoulder arthroplasty may be minimized by what technical modification? Review Topic

Explanation

Biomechanical studies have shown that a 10-degree inferior inclination may decrease scapular notching; whereas superior inclination may worsen notching. Scapular notching has been recognized as a complication following reverse shoulder arthroplasty. Mechanical abutment of the humeral component possibly leads to erosion of the anteroinferior scapular neck, with progressive vulnerability of the inferior baseplate screws. A horizontal humeral cut does not affect notching because the humeral component causes the notching, not the bone on the humerus. Glenosphere size has not been shown to correlate with scapular notching.

Question 49

Figures 1a through 1c show the radiograph and MRI scans of a 16-year-old patient who has a painful hip. Examination reveals a significant limp, limited abduction and internal rotation, and severe pain with internal rotation and adduction. A biopsy specimen is shown in Figure 1d. What is the deposited pigment observed in this condition?

Explanation

DISCUSSION: Pigmented villonodular synovitis (PVNS) is a synovial proliferative disorder that remains a diagnostic difficulty. The most common clinical features are mechanical pain and limited joint motion. On radiographs, the classic finding is often a large lesion, associated with multiple lucencies. Other findings may include a normal radiographic appearance, loss of joint space, osteonecrosis of the femoral head, or acetabular protrusion. MRI is the imaging modality of choice and will show the characteristic findings of a joint effusion, synovial proliferation, and bulging of the hip. The synovial lining has a low signal on T₁- and T₂-weighted images, secondary to hemosiderin deposition. Copper deposition occurs in patients with Wilson’s disease, which mainly affects the liver.
REFERENCES: Bhimani MA, Wenz JF, Frassica FJ: Pigmented villonodular synovitis: Keys to early diagnosis. Clin Orthop 2001;386:197-202.
Cotten A, Flipo RM, Chastanet P, et al: Pigmented villonodular synovitis of the hip: Review of radiographic features in 58 patients. Skeletal Radiol 1995;24:1-6.

Question 50

Increasing articular conformity of the tibial polyethylene insert of a fixed-bearing total knee arthroplasty (TKA) prosthesis will have which of the following biomechanical effects?

Explanation

DISCUSSION: Increasing articular conformity increases the surface area for contact between the polyethylene and the femoral component. Advantages of this include lower peak contact stress within the polyethylene and less risk of polyethylene fatigue failure. Patellofemoral tracking is unchanged by increasing conformity unless gross component apposition is present. A potential disadvantage of increasing conformity includes some restriction in tibial rollback. Modest changes in conformity have not been shown to alter the rate of mechanical loosening. If conformity was increased to the extent of significant constraint, a potential increased risk of loosening would be expected, not a decrease. Design of modern TKAs includes a compromise in achieving enough constraint to lower polyethylene stress, without providing so much constraint as to limit kinematics and stress the fixation interfaces.
REFERENCES: D’Lima DD, Chen PC, Colwell CW Jr: Polyethylene contact stresses, articular congruity, and knee alignment. Clin Orthop 2001;392:232-238.
Pellicci PM, Tria AJ Jr, Garvin KL (eds): Orthopaedic Knowledge Update: Hip and Knee Reconstruction 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000,

pp 265-274.

Question 51

A 35-year-old woman states that she stepped on a piece of glass 6 months ago and reports numbness and shooting pain along the plantar lateral forefoot. She had previously received steroid injections in the 3 to 4 webspace. Examination reveals mild tenderness along the plantar fascia; no Tinel’s sign is noted plantar medially and no Mulder’s click is noted distally. An MRI scan is shown in Figure 7. What is the most likely cause of the numbness?

Explanation

DISCUSSION: The MRI scan reveals a laceration through the abductor hallucis musculature and lateral plantar nerve, producing numbness along its distribution. There is no evidence of a foreign body on the MRI scan. Baxter’s nerve, or nerve to the abductor digiti quinti muscle, is the first branch off the lateral plantar nerve and impingement of this nerve typically produces a Tinel’s sign along the nerve branch deep to the abductor hallucis muscle. Interdigital neuroma would be suggested by the presence of a Mulder’s click. A digital nerve laceration would exhibit isolated numbness more distally.
REFERENCES: Baxter DE, Pfeffer GB: Treatment of chronic heel pain by surgical release of the first branch of the lateral plantar nerve. Clin Orthop Relat Res 1992;279:229-236.
Sarrafian SK: Anatomy of the Foot and Ankle: Descriptive, Topographic, Functional. Philadelphia, PA, JB Lippincott, 1983.

Question 52

An 8-year-old boy is diagnosed with acute onset cauda equina syndrome. A radiograph, MRI scans, and a biopsy specimen are shown in Figures 57a through 57d. What is the most appropriate treatment?

Explanation

DISCUSSION: The findings are consistent with an aneurysmal bone cyst. The MRI scan demonstrates a lesion involving the posterior elements of the vertebrae with fluid-fluid levels and neural compression. Fibrovascular tissue with multinucleated giant cells surrounding a vascular lake is seen on the histology. The most appropriate treatment is a marginal resection of the involved posterior elements. Although the recurrence rate can be as high as 25% to 30%, wide surgical resection could result in permanent neurologic injury and is not necessary. Aspiration and steroid injection have been advocated but would not relieve the nerve compression in this patient. Radiation therapy and chemotherapy are not indicated.
REFERENCES: Mankin HJ, Hornicek FJ, Ortiz-Cruz E, et al: Aneurysmal bone cyst: A review of 150 patients. J Clin Oncol 2005;23:6756-6762.
Garg S, Mehta S, Dormans JP: Modern surgical treatment of primary aneurysmal bone cyst of the spine in children and adolescents. J Ped Orthop 2005;25:387-392.

Question 53

Which of the following describes the correct proximal to distal progression of the annular and cruciform pulleys of the digits?

Explanation

DISCUSSION: The correct progression of the annular and cruciform pulley in the digits is A1, A2, C1, A3, C2, A4, C3. The two cruciform pulleys are collapsible elements adjacent to the more rigid annular pulleys of the flexor tendon sheath. This arrangement enables unrestricted flexion of the proximal interphalangeal joint.
REFERENCES: Hoppenfeld S, deBoer P: Surgical Exposures in Orthopaedics, ed 2. Philadelphia, PA, Lippincott-Raven, 1994, pp 176-186.
Strickland J: Flexor tendon-acute injuries, in Green D, Hotchkiss R, Pederson W (eds): Green’s Operative Hand Surgery, ed 4. New York, NY, Churchill Livingstone, 1999, pp 1853-1855.

Question 54

Patient-specific instrumentation (PSI) reliably demonstrates which benefit over conventional intramedullary guidance systems?

Explanation

DISCUSSION
Cost is usually increased with PSI because the theoretical decreased number of surgical trays and shortened surgical time do not offset cost of presurgical imaging and extra cost associated with the necessary jigs. Studies do not demonstrate a reliable improvement in functional outcomes or coronal alignment when PSI is compared to standard instrumentation. Evidence reveals that PSI necessitates fewer trays than standard instrumentation.

Question 55

Which factor should most influence a patient's decision to have surgery for adult scoliosis if he or she is younger than age 50?

Explanation

DISCUSSION
In a retrospective review of 137 patients treated surgically and 153 patients treated nonsurgically for adult scoliosis, Bess and associates found that surgical treatment for patients younger than 50 years of age was driven by increased coronal plane deformity, and surgical treatment for older patients was mandated by pain and disability. They also concluded that age, comorbidities, and sagittal balance did not influence treatment decisions.
RECOMMENDED READINGS
Bess S, Boachie-Adjei O, Burton D, Cunningham M, Shaffrey C, Shelokov A, Hostin R, Schwab F, Wood K, Akbarnia B; International Spine Study Group. Pain and disability determine treatment modality for older patients with adult scoliosis, while deformity guides treatment for younger patients. Spine (Phila Pa 1976). 2009 Sep 15;34(20):2186-90. PubMed PMID: 19752704.View Abstract at PubMed
Anderson DG, Albert T, Tannoury C. Adult scoliosis. In: Spivak JM, Connolly PJ, eds. Orthopaedic Knowledge Update: Spine 3. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2006:331-338.

Question 56

The radiographs shown in Figures 71a through 71c, and the CT scan shown in Figure 71d reveal an acetabular fracture that should be classified as

Explanation

The fracture shown represents a both column fracture described by Letournel and Judet. The fracture is a combination of a posterior column fracture and an anterior column fracture. T-type, transverse and hemitransverse all have a transverse element to them. The fracture shown involves more than just the anterior column.
Note the classic “Spur Sign” seen in these radiographs. This is pathognomonic of a both-column fracture of the acetabulum.
The other defining feature of the both column fx (as evident by these films) is that there is no intact acetabulum connected to the bone fragment which is connected to the ipsilateral SI joint.

Question 57

Which of the following nonunions is appropriately treated with exchange reamed nailing without bone graft augmentation?

Explanation

DISCUSSION: Exchange nailing is indicated for nonunions of diaphyseal femoral and tibia fractures in the absence of infection, comminution, or segmental bone loss. Hypertrophic nonunions need better stability (increased nail diameter) to acheive union. Where as atrophic nonunions often need better biology (bone graft, flap coverage, etc.) The referenced article by Brinker et al reviews the indications for exchange nailing. They argue, on the basis of the available literature, that exchange nailing is an excellent choice for aseptic nonunions of noncomminuted diaphyseal femoral and tibia fractures. Zelle et al. demonstrated 95% success with reamed exchange nailing for the treatment of aseptic tibial shaft nonunions that were initially treated with nonreamed intramedullary nailing.

Question 58

A 22-year-old female collegiate javelin thrower has shoulder pain. She notes that her pain is primarily located in the posterior aspect of her shoulder, is exacerbated with throwing, and she experiences maximal tenderness in the extreme cocking phase of the throwing cycle. On examination, she reports deep posterior shoulder pain when the arm is abducted 90 degrees and maximally externally rotated to 110 degrees. This reproduces her symptoms precisely. Shoulder radiographs are normal. What is the most likely diagnosis? Review Topic

Explanation

The patient has internal impingement. Internal impingement is commonly seen in overhead throwing athletes. When positioned in the extreme cocking phase of the throwing cycle, the posterior glenoid impacts the articular surface of the infraspinatus and posterior fibers of the supraspinatus tendon. This impact can cause partial-thickness rotator cuff tearing and posterosuperior labral lesions. She has no evidence of anterior shoulder instability, and her range of motion is excellent which rules out adhesive capsulitis. Subacromial impingement is identified with anterolateral shoulder pain with internal rotation in the abducted position. A full-thickness rotator cuff tear in a 22-year-old individual would require significant trauma and would likely result in pain at rest and with lifting.

Question 59

Figures 23a and 23b show the MRI scans of a 50-year-old woman who has increasing gait disturbance. She reports three falls in the past week. Examination reveals hyperreflexia, motor weakness in the biceps and triceps, and a positive Hoffman’s sign. What is the most appropriate treatment plan? Review Topic

Explanation

The patient has obvious signs of progressive myelopathy. Based on her significant physical examination findings, nonsurgical management will not significantly impact her outcome. Cervical decompression alone is contraindicated in patients with cervical kyphosis such as seen here. Anterior cervical fusion is the best option.
(SBQ12SP.77) A 68-year-old is undergoing lateral lumbar interbody fusion using the tranpsoas approach. Which of the following statements is true regarding the safe approach zone for this procedure as you move cranial to caudal in the lumbar spine? Review Topic
Safe approach zone increases due to vessels moving more ventral
Safe approach zone increases due to lumbar plexus moving more dorsal
Safe approach zone decreases due to vessels moving more dorsal
Safe approach zone decreases due to lumbar plexus moving more ventral
Safe approach zone remains the same throughout the lumbar spine
As you move cranial to caudal in the lumbar spine, the safe approach zone for the lateral transpsoas approach decreases due to the more ventral position of the lumbar plexus.
Lateral lumbar interbody fusion has become more common for degenerative spine disorders and adjacent segment degeneration. This transpsoas approach is typically useful for pathology from L1-L2 disc space to the L4-L5 disc space and places the lumbar plexus at risk. Working at the more caudal disc spaces is especially difficult given the more ventral position of the plexus, but the use of triggered EMG retractors and probes can help prevent nerve injuries. Surgical approach can be especially difficult in patients with rotational deformities.
Benglis et al. did a cadaver study with specimens placed lateral to trace the course of the lumbar plexus. They found that the plexus move more ventral with respect to the disc space moving more caudal in the lumbar spine.
Park et al. used 10 cadaver specimens to measure the distance of the lumbar nerve roots from the center of the disc space in the lateral approach. While disc space access was generally safe, there was less distance to the nerve root for more caudal disc levels.
Regev et al. did a MRI study to evaluate the safe working corridor for the lateral approach. The safe zone narrows considerably in the L4-L5 disc space due to more
ventral position of the nerve roots, and they recommend careful monitoring when addressing this level.
Incorrect

Question 60

A 10-year-old boy who plays baseball reports acute pain after throwing a softball from the outfield to second base. A radiograph is shown in Figure 26. Management should consist of

Explanation

DISCUSSION: The patient has a fracture through a unicameral bone cyst, as evidenced by the “falling leaf” sign on the radiograph. Following healing of the fracture, treatment should consist of corticosteroid injection or bone marrow injection. Some cysts heal with the fracture and do not require injections. Biopsy is unnecessary because the radiograph shows that the cyst is benign. Curettage and bone grafting are seldom necessary because these cysts regularly heal with injections. Corticosteroids are useful when injected into the cyst, but are not used systemically. Pulsed electromagnetic fields have not been used therapeutically in this condition.
REFERENCE: Yandow SM, Lundeen GA, Scott SM, Coffin C: Autogenic bone marrow injections as a treatment for simple bone cyst. J Pediatr Orthop 1998;18:616-620.

Question 61

When harvesting iliac crest bone graft during a posterior spinal decompression and fusion, injury to which of the following nerves may result in painful neuromas or numbness over the skin of the buttocks?

Explanation

DISCUSSION: The superior cluneal nerves (L1, L2, and L3) are at greatest risk when harvesting iliac crest bone graft during a posterior decompression and fusion. The nerves pierce the lumbodorsal fascia and cross the posterior iliac crest beginning at 8 cm lateral to the posterior superior iliac spine. The ilioinguinal and iliohypogastric nerves innervate anterior structures, and the lateral femoral cutaneous nerve lies in proximity to the anterior superior iliac spine and is at risk with anterior iliac crest bone graft harvesting. The superior gluteal nerve courses through the sciatic notch and supplies motor branches to the gluteus medius, minimus, and tensor fascia lata muscles.
REFERENCES: An HS: Principles and Techniques of Spine Surgery. Baltimore, MD,

Williams and Wilkins, 1998, pp 770-773.
Kurz LT, Garfin SR, Booth RE: Harvesting autogenous iliac bone grafts: A review of complications and techniques. Spine 1989;14:1324-1331.

Question 62

During the first 2 years of life, which of the following actions is most responsible for increasing structural stability of the physis?

Explanation

DISCUSSION: The zone of Ranvier provides the earliest increase in strength of the physis. During the first year of life, the zone spreads over the adjacent metaphysis to form a fibrous circumferential ring bridging from the epiphysis to the diaphysis. This ring increases the mechanical strength of the physis. The zone also helps the physis grow latitudinally. In turn, the increased width of the physis helps the physis further resist mechanical forces. The change in shape of the physis to its progressively more undulating form is also a factor in increasing physeal strength, but this occurs over a longer period of time, as the child’s activity level increases. The undulations of the physis seen in some growth plates also add to stability but to a lesser extent. The other changes contribute little toward increasing physeal strength.
REFERENCES: Burkus J, Ogden J: Development of the distal femoral epiphysis: A microscopic morphological investigation of the zone of Ranvier. J Pediatr Orthop 1984;4:661-668.
Shapiro F, Holtrop ME, Glimcher MJ: Organization and cellular biology of the perichondrial ossification groove of Ranvier: A morphological study in rabbits. J Bone Joint Surg Am 1977;59:703-723.

Question 63

What is the most common reason an individual with a malignant soft-tissue tumor in the extremities seeks medical attention?

Explanation

DISCUSSION: Unlike malignant bone tumors, malignant soft-tissue tumors usually are asymptomatic and present with the presence of a mass. Malignant soft-tissue tumors enlarge by centrifugal growth, creating a mass while compressing surrounding tissue. Symptoms may develop as the result of direct compression on neurovascular structures as the tumor enlarges. This is especially true in the pelvis where the tumor can enlarge appreciably without being noticed. However, in the extremities, the tumor is most often apparent before neurologic symptoms develop. An asymptomatic mass is not necessarily benign; therefore, biopsy should not be delayed. It is uncommon for a malignant soft-tissue mass to be discovered incidentally. Soft-tissue tumors are not typically apparent on radiographs; they are best identified with MRI.
REFERENCES: Brouns F, Stas M, De Wever I: Delay in diagnosis of soft tissue sarcomas. Eur J Surg Oncol 2003;29:440-445.
Rougraff B: The diagnosis and management of soft tissue sarcomas of the extremities in the adult. Curr Probl Cancer 1999;23:1-50.
Sim FH, Frassica FJ, Frassica DA: Soft-tissue tumors: Diagnosis, evaluation, and management. J Am Acad Orthop Surg 1994;2:202-211.

Question 64

Tension force in the anterior cruciate ligament during passive range of motion is highest at

Explanation

DISCUSSION: Tension forces in the healthy, as well as the reconstructed, anterior cruciate ligament were measured and found to be highest with the knee in full extension and decreased as the flexion increased.
REFERENCES: Markolf KL, Burchfield DM, Shapiro MM, et al: Biomechanical consequences of replacement of the anterior cruciate ligament with a patellar ligament allograft. Part II: Forces in the graft compared with forces in the intact ligament. J Bone Joint Surg Am 1996;78:1728-1734.
Beynnon BD, Johnson RJ, Fleming BC, et al: The measurement of elongation of anterior cruciate-ligament grafts in vivo. J Bone Joint Surg Am 1994;76:520-531.

Question 65

Type I collagen fibers in peripheral nerves are primarily responsible for which of the following?

Explanation

Type I collagen fibers are most responsible for the tensile strength of a peripheral nerve. Type I collagen is the most abundant collagen of the human body which forms large, eosinophilic fibers known as collagen fibers. It is present in scar tissue, the end product when tissue heals by repair, as well as tendons, ligaments, the endomysium of myofibrils, the organic part of bone, the dermis, the dentin and organ capsules.
The COL1A1 gene produces a component of type I collagen, called the pro-alpha1(I) chain. This chain combines with another pro-alpha1(I) chain and also with a pro-alpha2(I) chain (produced by the COL1A2 gene) to make a molecule of type I procollagen. These triple-stranded, rope-like procollagen molecules must be processed by enzymes outside the cell. Once these molecules are processed, they arrange themselves into long, thin fibrils that cross-link to one another in the spaces around cells. The cross-links result in the formation of very strong mature type I collagen fibers.
Wong et al. provide a review of the basic science behind nerve healing and the recovery after nerve repair. They note the importance of minimizing additional surgical insult and careful handling of nerve tissue during repair to optimize outcomes.
Pertici et al. noted that autologous nerve implantation to bridge a long nerve gap presents the greatest regenerative performance in spite of substantial drawbacks. They were able to show improved nerve guided regrowth with a type I collagen matrix conduit as compared to a conduit made of a mix of type I and type III collagen.
Illustration A shows a diagram of type I collagen, showing the rope-like characteristics behind the tensile strength.
Incorrect Answers:

Question 66

A toddler is brought in by his parents for evaluation of gait problems. Birth history and neurologic examination are unremarkable. After evaluating femoral torsion, tibial torsion, and foot contour, the diagnosis is excessive internal tibial torsion. The parents should be advised to expect which of the following outcomes? Review Topic

Explanation

Excessive internal tibial torsion is a common cause of intoeing in toddlers. In most children, this resolves spontaneously by 3 to 4 years of age. Intoeing in elementary age children is usually the result of excessive femoral anteversion. Studies have shown that active intervention (casting, splinting, and shoe modifications) has no demonstrable effect on the natural history or resolution of tibial torsion. Surgery is rarely indicated in adolescents with severe internal tibial torsion that has not resolved and is resulting in cosmetic and functional problems.

Question 67

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 68

A 38-year-old woman has a lesion on her left foot that has increased in size over the past 6 months. The clinical photograph is shown in Figure 17a, and a photomicrograph of the biopsy specimen is shown in Figure 17b. What is the most likely diagnosis?

Explanation

DISCUSSION: Melanoma comprises 25% of lower extremity lesions and is the most common malignant tumor of the foot. The preferred treatment is wide resection.
REFERENCES: Hughes LE, Horgan K, Taylor BA, Laidler P: Malignant melanoma of the hand and foot: Diagnosis and management. Br J Surg 1985;72:811-815.
Fortin PT, Freiberg AA: Malignant melanoma of the foot and ankle. J Bone Joint Surg Am 1995;77:1396-1403.

Question 69

A 25-year-old construction worker lands on his outstretched hand in a fall. The position of his wrist at the time of impact causes a force that leads to hyperextension, ulnar deviation, and intercarpal supination. Radiographs are shown in Figures 48a and 48b. What type of injury pattern is shown?

Explanation

DISCUSSION: The patient has a transscaphoid dorsal perilunate dislocation. The radiographs clearly define a dorsal dislocation of the capitolunate joint, and the scaphoid fracture component is easily visible on the AP view. A scaphoid fracture alone is an unlikely diagnosis because of the midcarpal dislocation component. The radiocarpal joint is not dislocated because the lunate is sitting in the lunate fossa of the radius. Isolated radiocarpal dislocations are not associated with a midcarpal disruption. While a midcarpal dislocation is a component of a dorsal perilunate dislocation, this diagnosis does not address the scaphoid fracture. A volar lunate dislocation is not seen because the lunate is reduced in the lunate fossa of the distal radius. Volar lunate dislocations are in the spectrum of injury of perilunate dislocations and fracture-dislocations; however, the radiographs show a transscaphoid dorsal perilunate dislocation.
REFERENCES: Mayfield JK, Johnson RP, Kilcoyne RK: Carpal dislocations: Pathomechanics and progressive perilunar instability. J Hand Surg Am 1980;5:226-241.
Herzberg G, Comtet JJ, Linscheid RL, Amadio PC, Cooney WP, Stalder J: Perilunate dislocations and fracture-dislocations: A multicenter study. J Hand Surg Am 1993;18:768-779.

Question 70

In patients with Crowe types III and IV developmental dysplasia of the hip with high hip centers, acetabular reconstruction often requires lowering the acetabular component into the native acetabulum. In doing so, considerable risk for limb lengthening beyond 4 cm exists, making the hip difficult to reduce and raising the risk for nerve injury. Which technique is used to overcome this problem?

Explanation

DISCUSSION:
When substantial lengthening of a dysplastic hip will occur because a high dislocation is relocated into a considerably lower acetabulum, a femoral shortening may be necessary to reduce the hip and avoid a stretch injury to the sciatic nerve. No other choice specifically addresses the need for femoral shortening, and high offset stems and lateralized liners may exacerbate the problem if used alone and without femoral shortening.

Question 71

What is the heaviest weight that can be safely applied to the adult cervical spine via Gardner-Wells tong traction?

Explanation

DISCUSSION: Cotler and associates reported on the use of awake skeletal traction to reduce facet fracture-dislocations in 24 patients. Seventeen patients required more than 50 pounds of traction (the “traditional” limit) to achieve reduction. More than 100 pounds of traction was safely used in one-third of the patients in this study. A cadaver study has supported the safe use of traction with weights in excess of 100 pounds.
REFERENCES: Cotler JM, Herbison GJ, Nasuti JF, et al: Closed reduction of traumatic cervical spine dislocation using traction weights up to 140 pounds. Spine 1993;18:386-390.
Anderson DG, Vacccaro AR, Gavin K: Cervical orthoses and cranioskeletal traction, in Clark CR (ed): The Cervical Spine, ed 4. Philadelphia, PA, Lippincott Williams & Wilkins, 2005,

pp 110-121.

Question 72

A 42-year-old athletic trainer has a persistent popping sensation about the lateral ankle associated with weakness and pain following a remote injury. Deficiency in what structure directly leads to this pathology?

Explanation

DISCUSSION: The patient has instability of the peroneal tendon. The superior peroneal retinaculum is the primary retaining structure preventing peroneal subluxation. It is a thickening of fascia that arises off the posterior margin of the distal 1 to 2 cm of the fibula and runs posteriorly to blend with the Achilles tendon sheath. The inferior peroneal retinaculum attaches to the peroneal tubercle of the calcaneus and is not involved in this pathology. A deficient groove in the posterior distal fibula may also be a contributing factor in the development of

the condition.
REFERENCE: Maffuli N, Ferran NA, Oliva F, et al: Recurrent subluxation of the peroneal tendons. Am J Sports Med 2006;34:986-992.

Question 73

A 34-year-old male presents with elbow pain after sustaining a ground level fall 2 weeks ago. An injury radiograph is shown in Figure

Explanation

positive finding and is seen in valgus posterolateral rotatory instability of the elbow.

OrthoCash 2020

Question 74

Which of the following statements regarding conus medullaris syndrome is most accurate?

Explanation

DISCUSSION: Conus medullaris syndrome most frequently occurs as a result of trauma or with a disk herniation at L1, resulting in a lower motor neuron syndrome but with a poor prognosis for recovery of bowel and bladder dysfunction. The conus region, as the termination of the spinal cord, contains the motor cell bodies of the sacral roots. The syndrome is usually a sacral level neural injury; therefore, lower extremity weakness is uncommon.
REFERENCES: Haher TR, Felmly WT, O’Brien M: Thoracic and lumbar fractures: Diagnosis and management, in Bridwell KH, Dewald RL, Hammerberg KW, et al (eds): The Textbook of Spinal Surgery, ed 2. New York, NY, Lippincott Williams & Wilkins, 1977, pp 1773-1778.
Reitman CA (ed): Management of Thoracolumbar Fractures. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004, pp 35-45.

Question 75

Which of the following is considered the preferred approach to resect a lesion in the posterior one third of the proximal humerus?

Explanation

DISCUSSION: At least 8 cm of the posterior aspect of the proximal region of the humeral diaphyseal cortex can be exposed through the interval between the lateral head of the triceps and the deltoid muscle. No nerves or blood vessels need to be exposed in the dissection. The deltoid muscle is innervated by the axillary nerve and the triceps muscle by the radial nerve. This is a true internervous plane.
REFERENCE: Berger RA, Buckwalter JA: A posterior surgical approach to the proximal part of the humerus. J Bone Joint Surg Am 1989;71:407-410.

Question 76

A 65-year-old woman with type II diabetes mellitus (most recent Hgb A1C was 8.2) has had 3 days of left knee pain. Physical examination of the left knee reveals erythema, warmth and a large effusion. Range of motion is painful and limited to 30 degrees of flexion. She is found to be hypotensive and not responding to volume resuscitation. She requires phenylephrine to maintain Mean Arterial Pressure (MAP) of 70. ESR and CRP are elevated and Lactate is 3.1 mmol/L. What is the next best intervention for this patient’s treatment?

Explanation

Discussion: The patient is demonstrating signs of septic shock. Administration of antibiotics should not be delayed. Aspirating the knee joint and obtaining blood cultures can be rapidly accomplished to obtain accurate specimens. This should be followed immediately by administration of broad spectrum IV antibiotics. Patients with septic shock can be identified with a clinical construct of sepsis with persisting hypotension requiring vasopressors to maintain mean arterial pressure (MAP) ≥ 65 mmHg and having a serum lactate level > 2mmol/L (18 mg/dL) despite adequate volume resuscitation. With these criteria, hospital mortality is in excess of 40%.

Question 77

Figures 45a and 45b show the radiographs of a 46-year-old man who reports the acute onset of right knee pain and is unable to bear weight on the extremity. His medical history is unremarkable. The next most appropriate step in management should consist of

Explanation

DISCUSSION: The patient has a pathologic fracture of the right distal femur; therefore, given the patient’s age, the most likely diagnosis is metastatic carcinoma. Staging studies should be obtained prior to surgical treatment. Immediate intramedullary fixation is contraindicated before a diagnosis is made by biopsy. Surgical stabilization should be performed prior to radiation therapy.
REFERENCE: Rougraff BT, Kneisl JS, Simon MA: Skeletal metastases of unknown origin: A prospective study of a diagnostic strategy. J Bone Joint Surg Am 1993;75:1276-1281.

Question 78

A 77-year-old woman who underwent total knee arthroplasty 16 years ago now reports pain, swelling, and notable crepitation with range of motion. AP, lateral, and Merchant radiographs are shown in Figures 54a through 54c. What is the most likely diagnosis?

Explanation

DISCUSSION: The Merchant radiograph shows a lateral patellar shift with total polyethylene failure, resulting in a metal-on-metal bearing. This problem is associated with metal-backed patellar components. Component fixation appears solid, and no osteolysis is evident.
REFERENCES: Poss R (ed): Orthopaedic Knowledge Update 3. Park Ridge, IL, American Academy of Orthopaedic Surgeons, 1990, pp 590-593.
Leopold SS, Berger RA, Patterson L, et al: Serum titanium level for diagnosis of a failed metal-backed patellar component. J Arthroplasty 2000;15:938-943.
Frymoyer JW (ed): Orthopaedic Knowledge Update 4. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1993, pp 613-614.

Question 79

During treatment of rupture of the subscapularis tendon with associated biceps instability, treatment of the biceps tendon should include which of the following?

Explanation

DISCUSSION: With subscapularis tendon ruptures that have biceps tendon pathology, treatment with tenodesis or tenotomy has improved clinical results. Subluxation or dislocation of the biceps tendon is common with subscapularis rupture. Dislocation of the biceps can occur either beneath the tendon, within the tendon, or extra-articularly. In all cases, the restraints to medial translations of the biceps have been disrupted. Attempts at recentering the biceps have not been successful, and clinical results appear to be improved when tenodesis or tenotomy is employed in the treatment of the unstable biceps associated with subscapularis tears.
REFERENCES: Edwards TB, Walch G, Sirvenaux F, et al: Repair of tears of the subscapularis: Surgical technique. J Bone Joint Surg Am 2006;88:1-10.
Deutsch A, Altchek DW, Veltri DM, et al: Traumatic tears of the subscapularis tendon: Clinical diagnosis, magnetic resonance imaging findings, and operative treatment. Am J Sports Med 1997;25:13-22.
Edwards TB, Walch G, Sirveaux F, et al: Repair of tears of the subscapularis. J Bone Joint Surg Am 2005;87:725-730.

Question 80

A 28-year-old cowgirl was injured while herding cattle 1 week ago. A radiograph and CT scans are shown in Figures 13a through 13c. What is the most appropriate management for this injury?

Explanation

DISCUSSION: The patient has an AP I pelvic ring disruption with minimal symphyseal widening. The best treatment is nonsurgical management and weight bearing as tolerated. This will help close the anterior pelvic ring during the healing process. Pelvic binders are excellent for acute treatment of widely displaced pelvic fractures but are not recommended for long-term use. Open reduction and internal fixation is not indicated for this injury and furthermore, the posterior ring is not injured.
REFERENCES: Matta JM: Indications for anterior fixation of pelvic fractures. Clin Orthop Relat Res 1996;329:88-96.
Templeman DC, Schmidt AH, Sems SA, et al: Diastasis of the symphysis pubis: Open reduction internal fixation, in Wiss D (ed): Masters Techniques in Orthopaedic Surgery-Fractures, ed 2. Philadelphia, PA, Lippincott Williams and Wilkins, 2006, pp 639-648.
Tile M: Management, in Tile M: Fractures of the Pelvis and Acetabulum, ed 2. Philadelphia, PA, Williams and Wilkins, 1995, pp 108-134.

Question 81

Figures 5a and 5b show the radiographs of a 21 -year-old wrestler who reports that his leg was rolled over while wrestling. The patient has decreased sensation and function in the distribution of the peroneal nerve, and he has absent pulses. What is the most appropriate initial management at this time?

Explanation

DISCUSSION: The patient has an acute traumatic anteromedial dislocation of the knee with occlusion of the popliteal artery with a possible tear. Treatment should include reduction and reevaluation of the vascular status. At this time, if pulses are symmetric, observation may be appropriate without surgical
intervention of the artery, but documentation with studies would be appropriate. Delayed reconstruction of injured structures is appropriate.
REFERENCES: Fanelli GC, Orcutt DR, Edson CJ: The multiple- ligament injured knee: Evaluation, treatment, and results. Arthroscopy 2005;21:471 -486.
McDonough EB Jr, Wojtys EM: Multiligamentous injuries of the knee and associated vascular injuries.
Am J Sports Med 2009;37:156-159.
Wascher DC: High-velocity knee dislocation with vascular injury: Treatment principles. Clin Sports Med 2000;19:457-477.

Question 82

An 11-year-old basketball player reports that he felt a painful pop in the left knee when he stumbled while running. He is unable to bear weight on the extremity and cannot actively extend the knee against gravity. Examination reveals a large knee effusion. A lateral radiograph is shown in Figure 7. Management should consist of

Explanation

DISCUSSION: The radiograph shows an avulsion fracture, or “sleeve fracture,” of the distal pole of the patella. The distal fragment is much larger than it appears on the radiograph because it largely consists of cartilage; therefore, excision of the fragment is contraindicated. The treatment of choice is open reduction and tension band fixation to correct patella alta and restore the extensor mechanism.
REFERENCES: Maguire JK, Canale ST: Fractures of the patella in children and adolescents.

J Pediatr Orthop 1993;13:567-571.
Grogan DP, Carey TP, Leffers D, et al: Avulsion fractures of the patella. J Pediatr Orthop 1990;10:721-730.

Question 83

A 35-year-old woman dislocated her right shoulder in a fall from a step stool several months ago. She now reports several painful recurrences. Examination reveals anterior and inferior apprehension that reproduces her symptoms. An MRI scan is shown in Figure 17. Management should consist of

Explanation

DISCUSSION: The MRI findings reveal a disruption of the humeral insertion of the glenohumeral ligaments and joint capsule (humeral avulsion of the glenohumeral ligament). This lesion has been reported to account for an 8% rate of recurrent dislocation in a subset of patients who are typically older than those with the more common lesions of the glenoid labrum (Bankart lesion). Open repairs have been reported to be successful in the prevention of recurrent instability. Since there is no Bankart lesion, open or arthroscopic labral repairs are not indicated. Nonsurgical management is possible if the patient does not want to undergo surgery; however, the recurrence rate is very high.
REFERENCES: Wolf EM, Cheng JC, Dickson K: Humeral avulsion of glenohumeral ligaments as a cause of anterior shoulder instability. Arthroscopy 1995;11:600-607.
Bokor DJ. Conboy VB. Olson C: Anterior instability of the glenohumeral joint with humeral avulsion of the glenohumeral ligament: A review of 41 cases. J Bone Joint Surg Br

1999;81:93-96.
Coates MH, Breidahl W: Humeral avulsion of the anterior band of the inferior glenohumeral ligament with associated subscapularis bony avulsion in skeletally immature patients. Skeletal Radiol 2001;30:661-666.

Question 84

Spontaneous entrapment of the posterior interosseous nerve most commonly occurs in which of the following locations?

Explanation

DISCUSSION: The extensor carpi radialis brevis, supinator muscle, arcade of Frohse, and leash of Henry are potential sites of compression for the posterior interosseous nerve. The most common location of spontaneous entrapment is the arcade of Frohse. The lateral intermuscular septum is a site of compression for the radial nerve.
REFERENCE: Spinner RJ, Spinner M: Nerve entrapment syndromes, in Morrey BF: The Elbow and Its Disorders, ed 3. Philadelphia, PA, WB Saunders, 2000, pp 839-862.

Question 85

A patient undergoes an arthroscopic debridement for lateral epicondylitis. Postoperatively she reports pain and a sense of clicking of the elbow. Examination reveals apprehension to supination, load, and extension. What structure has been injured resulting in the clinical presentation?

Explanation

DISCUSSION: The patient has an iatrogenic injury to the lateral ulnar collateral ligament following the arthroscopic procedure. Failure to adhere to known anatomic landmarks can lead to this devastating complication. The examination findings are classic for posterolateral elbow instability.
REFERENCES: Koval KJ (ed): Orthopaedic Knowledge Update 7. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, p 318.
O’ Driscoll SW, Bell DF, Morrey BF: Posterolateral rotatory instability of the elbow. J Bone Joint Surg Am 1991;73:440-446.

Question 86

What is the most common complication following metatarsal osteotomy for a bunion deformity in an adolescent?

Explanation

Hallux varus-The question does not specify proximal or distal osteotomies, however it is the most common complication with overcorrection of proximal 1st metatarsal osteotomies. Mann. Pg. 329. “Transfer” 2nd metatarsaglia-most significant, not most common, complication of the Mitchell Osteotomy.Mann pg. 319.
Physeal arrest of the first metatarsal-“While an open epiphysis cannot be considered an absolute contraindication to an osteotomy in either the proximal phalanx, or proximal first metatarsal, it is
important at surgery to determine the exact location of the metaphyseal epiphysis to avoid injury.” Pg. 307 Mann, Surgery of Foot and Ankle.
In studies performed by Blais et. Al. A females full foot growth is usually achieved by 14 years and at 12 years an average less than 1 cm of total foot growth remains with less than 50% of this growth at the proximal epiphysis. Males’ terminal growth expected at 16 years of age with 3cm left at 12 years and approximately 1.5 cm of metatarsal growth.
Most studies show recurrence of Hallux Valgus deformity after surgical correction in the juvenile as inordinately high.

Question 87

A 61-year-old man reports right hip pain and limited motion after undergoing total hip arthroplasty for posttraumatic arthritis 1 year ago. Figure 6 shows an AP radiograph of the pelvis. To improve motion and relieve pain, management should consist of

Explanation

DISCUSSION: The patient has symptomatic grade IV Brooker heterotopic ossification. Once the bone has matured, it can be excised. Surgical excision should be combined with postoperative irradiation to avoid recurrence. Pharmacologic and irradiation intervention are not successful beyond the perioperative period unless they are combined with surgical excision of mature heterotopic ossification.
REFERENCES: Koval KJ (ed): Orthopaedic Knowledge Update 7. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 417-451.
Iorio R, Healy WL: Heterotopic ossification after total hip and total knee arthroplasty: Risk factors, prevention, and treatment. J Am Acad Orthop Surg 2002;10:409-416.

Question 88

A 34-year-old woman reports constant midlateral arm pain after sustaining minimal trauma to the shoulder. Radiographs and a biopsy specimen are shown in Figures 29a and 29b. What is the most likely diagnosis?

Explanation

DISCUSSION: Eighty percent of giant cell tumors occur in patients older than age 20 years, with the peak incidence in the third decade of life. Most of these tumors are eccentrically located and epiphyseal in location. They are lytic in nature as in this patient. Although named for the hallmarked multinucleated giant cells seen in the lesion, the basic cell type is the spindle-shaped stromal cell. Chondroblastoma is highly cellular and contains large multinucleated giant cells with intercellular chondroid material, some of which is calcified. Chondromyxoid fibroma has chondroid tissue separated by strands of more cellular tissue with occasional multinucleated giant cells. Desmoplastic fibroma is characterized by poorly cellular fibrous tissue, and lymphoma is highly cellular with characteristic round cells.
REFERENCES: Campanacci M, Baldini N, Boriani S, et al: Giant cell tumor of bone. J Bone Joint Surg Am 1987;69:106-114.
Goldenberg RR, Campbell CJ, Bonfiglio M: Giant cell tumor of bone: An analysis of two hundred and eighteen cases. J Bone Joint Surg Am 1970;52:619-664.

Question 89

In infantile idiopathic scoliosis, which of the following factors suggests progression? Review Topic

Explanation

Infantile idiopathic scoliosis occurs more commonly in boys, with a 3 to 1 male to female ratio. Neural axis abnormalities, hip dysplasia, and congenital heart disease are all associated with the condition; spontaneous correction frequently occurs. Curve progression can be predicted by the rib vertebral angle difference or the phase of the rib head. Rib overlap of the apical vertebral body or a rib vertebral angle difference of greater than 20 degrees indicates that the curve is likely to progress. Gender, family history, and age at presentation have not been found to be risk factors for progression.

Question 90

below demonstrate the radiographs obtained from a year-old woman with end-stage debilitating osteoarthritis of the right hip. She is contemplating total hip arthroplasty (THA). She has a history of right hip dysplasia and underwent hip osteotomy as an adolescent. Over the years, nonsurgical treatment, including weight loss, activity modifications, and intra-articular injections, has failed. Her infection work-up reveals laboratory findings within defined limits. A further work-up reveals elevations in serum cobalt and chromium levels and fluid collections surrounding the hip on MRI with MARS. Revision THA is recommended. The most common complication following revision of a failed metal-on- metal hip arthroplasty is

Explanation

THA has proven durable and reliable for pain relief and improving function for patients with end-stage arthritis. Appropriate bearing selection is critical to minimize wear and hip complications. A metal-on- metal articulation is associated with excellent wear rates in vitro. With its capacity to offer a low wear rate with large femoral heads, it is an attractive bearing choice for THA. However, local soft-tissue reactions, pseudotumors, and potential systemic reactions including renal failure, cardiomyopathy, carcinogenesis, and potential teratogenesis with potential transfer of metal ions across the placental barrier make metal-on-metal bearings less desirable and relatively contraindicated for younger women of child- bearing age. The workup of a painful metal-on-metal hip arthroplasty necessitates a systematic approach. Several algorithms have been proposed. Routine laboratory studies including sedimentation rate, CRP, and serum cobalt and chromium ion levels should be obtained for all patients with pain. Advanced imaging including MARS MRI should be performed to evaluate for the presence of fluid collections, pseudotumors, and abductor mechanism destruction. Infection can coexist with metal-on-metal reactions, so, when indicated (if the CRP level is elevated), a hip arthrocentesis should be obtained. However, in this setting, a manual cell count and differential should be obtained because an automated cell counter may provide falsely elevated cellcounts. The results of revision surgery for a failed metal-on-metal hip prosthesis can be variable. The amount of local tissue destruction and the integrity of the hip abductor mechanism can greatly influence outcomes. Instability is the most common complication following revision of failed metal-on-metal hip replacements.

Question 91

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

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 92

A 16-year-old girl has had pain and swelling along the medial arch of her left foot for the past 3 months. She also reports pain from shoe wear and while running. Nonsteroidal anti-inflammatory drugs have failed to provide relief. Radiographs are shown in Figures 40a through 40c. What is the next most appropriate step in management?

Explanation

DISCUSSION: Nonsurgical management of a symptomatic accessory navicular should be attempted prior to surgery. Good relief is often obtained with a semi-rigid orthosis with a medial arch support.
REFERENCES: Myerson MS: Foot and Ankle Disorders. Philadelphia, PA, WB Saunders, 2000, p 655.
Bennett GL, Weiner DS, Leighley B: Surgical treatment of symptomatic accessory tarsal navicular. J Pediatr Orthop 1990;10:445-449.

Question 93

A 6-year-old boy with severe spastic quadriplegic cerebral palsy is nonambulatory. Examination reveals 10° of hip abduction on the left and 30° on the right with the hips and knees extended. The Thomas test shows 20° of flexion bilaterally, and Ely test results are 3+/4 bilaterally. Radiographs show a center edge angle of 0° on the left and -10° on the right. The neck shaft angles are 170° bilaterally. Which of the following procedures would offer the best results?

Explanation

DISCUSSION: The patient has bilateral subluxated hips, with nearly vertical neck shaft angles; therefore, the treatment of choice is varus derotation osteotomy. Shortening of the bone on one or both sides may be necessary to allow adequate range of motion postoperatively. In patients this age and with this degree of bony deformity, soft-tissue releases are not likely to lead to hip stability. Botulinum toxin has been shown to be effective in the treatment of ankle equinus, but its efficacy in other areas has not been demonstrated as yet. The indications for obturator neurectomy are unclear at present. Proximal femoral resection is a salvage procedure for long-standing hip dislocations that are symptomatic and not reconstructable.
REFERENCES: Tylkowski CM, Rosenthal RK, Simon SR: Proximal femoral osteotomy in cerebral palsy. Clin Orthop 1980;151:183-192.
Brunner R, Baumann JU: Long-term effects of intertrochanteric varus-derotation osteotomy on femur and acetabulum in spastic cerebral palsy: An 11- to 18-year follow-up study. J Pediatr Orthop 1997;17:585-591.
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Question 94

Figures 1 through 4 are the CT scans and intraoperative image of a 17-year-old boy who sustained a gunshot wound to his knee. What is the most appropriate definitive surgical management for his articular cartilage defect?

Explanation

The images show a full-thickness cartilage defect with significant bony involvement >4 cm2. Microfracture should be considered for lesions <2 cm2 without an underlying osseous defect. Autologous chondrocyte implantation, although used for lesions between 1 and 10 cm2, should be restricted for defects with minimal (<8 mm depth) bone loss. Osteochondral allograft transfer with the mosaicplasty technique (transfer of multiple plugs) would be well-suited for this large defect with significant osseous involvement. Dejour trochleoplasty is performed for patellar instability to correct trochlear dysplasia and would not be indicated in this case.

Question 95

A 46-year-old man has acute tenderness along the ulnar aspect of the wrist after falling on his outstretched hand while playing basketball. Examination reveals tenderness and mild swelling along the volar ulnar aspect of the wrist. Radiogaphs are shown in Figures 14a through 14c. Management should consist of

Explanation

DISCUSSION: The PA view of the wrist shows a pisiform fracture. Pisiform fractures constitute 1% to 3% of all carpal bone fractures. This fracture can be further evaluated with a carpal tunnel view or a supination oblique view of the wrist. Initial management should consist of immobilization with a short arm cast. If nonsurgical measures fail, bony excision is warranted.
REFERENCES: Failla JM, Amadio PC: Recognition and treatment of uncommon carpal fractures. Hand Clin 1988;4:469-476.
Botte MJ, Gelberman RH: Fractures of the carpus, excluding the scaphoid. Hand Clin 1987;3:149-161.

Question 96

What factor is most commonly associated with malignant transformation of a giant cell tumor?

Explanation

Most authors have agreed that radiation therapy should be avoided in the treatment of giant cell tumor, as there is a high prevalence of sarcomatous degeneration.

Question 97

A 29-year-old man sustained an injury when he was playing basketball, landing on his left knee while jumping for a rebound. He had vague pain in the anterior aspect of the knee for several weeks. The initial radiographs were negative with the exception of a large traumatic effusion. Examination reveals no apparent ligament instability but a significant extension lag of 30 degrees. There was a palpable defect above the superior pole of the patella. What is the most appropriate management? Review Topic

Explanation

This is the classic presentation of a tendon disruption in an active athlete that may represent chronic strain or weakening of the tendon insertion. The factors that lead to this condition are multitude, including biomechanic and cytologic, but there is little evidence that inflammation is an active factor. Surgical treatment is straightforward and logical. Suture anchors have been compared with simple holes made in the patella for suturing the tendon, with no apparent biomechanic advantage.

Question 98

What is the typical MRI signal intensity of bone marrow affected by acute osteomyelitis?

Explanation

DISCUSSION: The classic MRI findings of osteomyelitis are a decrease in the normally high signal intensity of marrow on T₁-weighted images and normal or increased signal intensity on T₂-weighted images. This is the result of replacement of marrow fat by inflammatory cells and edema, which causes lower signal intensity than fat on T₁-weighted images and higher signal intensity than fat on T₂-weighted images. The addition of gadolinium to a T₁-weighted sequence reveals increased signal intensity in the hyperemic marrow.
REFERENCES: Unger E, Moldofsky P, Gatenby R, et al: Diagnosis of osteomyelitis by MR imaging. Am J Roentgenol 1988;150:605-610.
Dormans JP, Drummond DS: Pediatric hematogenous osteomyelitis: New trends in presentation, diagnosis and treatment. J Am Acad Orthop Surg 1994;2:333-341.
Herring JA: Tachdjian’s Pediatric Orthopaedics, ed 3. Philadelphia, PA, WB Saunders, 2002, vol 1, pp 150-163.

Question 99

A 62-year-old woman with soft-tissue calcifications and telangiectasia has severe pain in the left index, middle, ring, and little fingers. History reveals that she does not smoke. The clinical history and arteriogram shown in Figure 6 are consistent with which of the following conditions?

Explanation

DISCUSSION: The arteriogram shows generalized disease of all vascular structures. Even though the image was obtained following an infusion of nitroglycerin, little flow is present to the fingers. Based on the history of soft-tissue calcifications and telangiectasia, the most likely diagnosis is CREST (chondrocalcinosis, Raynaud’s phenomenon, esophageal dysmotility, sclerodactyly and telangiectasias). The arteriogram reveals Raynaud’s phenomenon or the “R” component of CREST. Buerger’s disease, or thromboangiitis obliterans, is strongly associated with a history of smoking. Hypothenar hammer syndrome involves repetitive trauma to the ulnar artery at the wrist, resulting in well-defined filling defects in the superficial palmar arch of the hand. Although not well visualized in this patient, the superficial arch is narrowed, showing no evidence of aneurysmal dilation.
REFERENCES: Koman LA, Ruch DS, Patterson Smith B, et al: Vascular disorders, in Green DP, Hotchkiss RN, Pederson WC (eds): Green’s Operative Hand Surgery, ed 4. New York, NY, Churchill Livingstone, 1999, vol 2, pp 2254-2302.
Miller LM, Morgan RF: Vasospastic disorders: Etiology, recognition, and treatment. Hand Clin 1993;9:171-187.

Question 100

A 41-year-old right-hand-dominant man has been treated nonsurgically for right elbow arthritis. His radiographs reveal end-stage ulnohumeral arthritis with complete loss of the joint space. He reports pain during the mid-arc of elbow flexion and extension. During the last 8 years, he has attempted activity modification, medication, physical therapy, and multiple cortisone injections. His symptoms have progressed, resulting in constant pain, loss of a functional range of motion, and an inability to perform many activities of daily living. Secondary to his age and activity demands, he undergoes a soft-tissue interposition arthroplasty of his elbow with an Achilles allograft. Which presurgical finding correlates with elevated risk for postsurgical complications?

Explanation

End-stage posttraumatic or inflammatory elbow arthritis in active, high-demand patients remains difficult to treat. Traditional total elbow arthroplasty is discouraged in this demographic secondary to concerns about implant longevity. Soft-tissue interposition arthroplasty does not necessitate the same activity and weight
restrictions for patients after surgery and remains a reasonable salvage procedure. Larson and Morrey published their findings on 38 patients with a mean age of 39 years following soft-tissue interposition arthroplasty for posttraumatic and inflammatory end-stage elbow arthritis. These investigators reported a significant improvement in Mayo Elbow Performance Score in addition to improvement in the flexion- extension arc from 51° to 97° after surgery. They reported worse results and elevated incidence of complications for patients with presurgical elbow instability upon examination; retained hardware from prior
surgery was not deemed a contraindication.

Full Question & Answer Text (for Search Engines)

Question 1:

The knee arthroplasty type associated with the highest 5-year revision rate is

Options:

medial unicondylar arthroplasty.
mobile-bearing total knee arthroplasty (TKA).
patellofemoral arthroplasty.
lateral unicondylar knee arthroplasty (UKA).

Correct Answer: patellofemoral arthroplasty.

Explanation:

DISCUSSION
Revision rates for UKA at 10 years are lower than 5% at specialty centers. However, the 10-year revision rate associated with UKA in registries such as the National Joint Registry for England and Wales is 2 to 3 times that of TKA. Among partial knee replacements, patellofemoral arthroplasty is associated with the highest revision rate at every time interval.
CLINICAL SITUATION QUESTIONS 167 THROUGH 169
Figures 167a and 167b are the radiographs of a middle-age man. He is a noncompliant patient who has severe insulin-dependent diabetes and a below-knee amputation on the right side. He is usually in a wheelchair, does not use a prosthesis, transfers using a walker, and resides in an institution. He had an infection in the left leg years ago, which was treated successfully with intravenous antibiotics (the details are unknown). His left knee is mildly painful, swollen but not warm, has limited range of motion (40-140 degrees), and is grossly unstable.

Question 2:

Options:

closed reduction and percutaneous screw placement.
open reduction internal fixation through an anterior midline approach.
spanning external fixation and closed manipulative realignment.
ring fixation.

Correct Answer: spanning external fixation and closed manipulative realignment.

Explanation:

Discussion:
Posterior partial articular tibial plateau fractures are rare. Failure to recognize this pattern can lead to poor patient outcomes secondary to poor surgical decision making. Pathognomonic findings on the lateral radiograph include maintenance of continuity between the anterior articular surface and tibial shaft along with subluxation of the knee joint with excessively anterior tibial station (the femoral condyles remain with the fractured posterior articular pieces while the remainder of the tibia subluxes anteriorly).
Initial management of axially unstable tibial plateau fractures with soft tissue swelling should consist of spanning external fixation and closed manipulative realignment. This allows for soft tissue recovery with the knee joint provisionally stabilized in reduced station. It also provides time for pre-operative planning, which is typically empowered via a CT scan with reconstructions. If the pattern was initially misdiagnosed as a more typically bicondylar tibial plateau fracture, the CT scan will clarify the misconception and allow for better surgical decision making.
Attempting to visualize, reduce, and stabilize a posterior partial articular pattern in the supine position from an anterior approach is fraught with difficulties. Prone positioning is preferred for definitive fixation. Surgical approaches vary, but
typically incorporate a posteromedial interval deep to the popliteus and soleus to provide buttress plating to the posterior column of the tibia.

Question 3:

Options:

Surgical reconstruction
Rest, followed by physical therapy
Splinting in 15 degrees of flexion
Primary repair
Arthroscopic debridement, followed by bracing in full extension for 4 weeks

Correct Answer: Surgical reconstruction

Explanation:

Question 4:

Options:

long leg casting in 30 degrees of flexion for 6 weeks.
a long leg cast in full extension for 6 weeks.
knee arthroscopy to rule out internal derangement.
physical therapy for range of motion and quadriceps strengthening.
open reduction and internal fixation.

Correct Answer: a long leg cast in full extension for 6 weeks.

Explanation:

Question 5:

Options:

Ewing’s sarcoma
Osteomyelitis
Osteosarcoma
Chondrosarcoma
Giant cell tumor of bone

Correct Answer: Ewing’s sarcoma

Explanation:

Question 6:

Options:

Open reduction and internal fixation
External bone stimulator
Ninety-degree abduction splint
Arthroscopic acromioplasty
Fragment excision

Correct Answer: Open reduction and internal fixation

Explanation:

DISCUSSION: The patient has a displaced scapular spine fracture that has resulted in shoulder weakness from a poor deltoid lever arm. The downward tilt may lead to subacromial impingement and rotator cuff dysfunction. Open reduction and internal fixation would best allow normal deltoid and shoulder function. Bone stimulators and abduction bracing may lead to healing but in a malunited position. Arthroscopic acromioplasty and fragment excision should be avoided.
REFERENCES: Ogawa K, Naniwa T: Fractures of the acromion and the lateral scapular spine.
J Shoulder Elbow Surg 1997;6:544-548.
Ada Jr, Miller ME: Scapular fractures: Analysis of 113 cases. Clin Orthop Relat Res 1991;269:174-180.

Question 7:

Options:

Oblique radiographs
Arteriogram
Exploration of the brachial artery at the elbow
Closed reduction and pinning of the elbow
Open reduction and internal fixation of the elbow

Correct Answer: Closed reduction and pinning of the elbow

Explanation:

Question 8:

Options:

open reduction of both the radius and ulna with plate and screw fixation.
closed reduction and a long arm cast, with the elbow in 90 degrees of flexion and the forearm in neutral rotation.
closed reduction and a long arm cast, with the elbow in 120 degrees of flexion and the forearm in full supination.
closed reduction and a long arm cast, with the elbow extended and the forearm pronated.
closed reduction and intramedullary pin fixation of both the radius and ulna.

Correct Answer: closed reduction and intramedullary pin fixation of both the radius and ulna.

Explanation:

Question 9:

Options:

Observation, repeat radiographs, and reexamination in 6 weeks
A 14-day course of indomethacin
A 4-week course of indomethacin
Plan for a return to the operating room at 10 weeks for excision of the heterotopic bone
Arrange urgently for 800 centigrey of radiation to the soft tissues and areas of heterotopic bone around the hip, with shielding of the implants

Correct Answer: Observation, repeat radiographs, and reexamination in 6 weeks

Explanation:

DISCUSSION: The development of heterotopic bone occurs early after hip arthroplasty. The process begins within days after surgery; therefore, prophylactic treatment must be in the early postoperative period (preoperative radiation given within 24 hours of surgery, or postoperative radiation given within 72 hours of surgery, or nonsteroidal antiinflammatory drugs (NSAIDs) given postoperatively for 7 to 21 days - longer duration has not been shown to be of any additional benefit). At 6 weeks, prophylactic treatment with NS
AID
s or radiation is no longer effective. Surgery at 10 weeks would be premature because the patient is currently asymptomatic with regards to the heterotopic bone, and surgery prior to full maturation of the bone may increase the risk for more abundant recurrence of bone.
REFERENCES: Balboni TA, Gobezie R, Mamon HJ: Heterotopic ossification: Pathophysiology, clinical features, and the role of radiotherapy for prophylaxis. Int J Radiat Oncol Biol Phys 2006;65:1289-1299. Fransen M, Neal B: Non-steroidal anti-inflammatory drugs for preventing heterotopic bone formation after hip arthroplasty. Cochrane Database Syst Rev 2004;3:CD001160.
Neal BC, Rodgers A, Clark T, et al: A systematic survey of 13 randomized trials of non-steroidal antiinflammatory
drugs for the prevention of heterotopic bone formation after major hip surgery. Acta Orthop Scand 2000;71:122-128.

Question 10:

8 (Normal ratio = 0.8 - 1.2). The most common symptoms associated with patella baja include anterior impingement, knee pain, and knee stiffness.

Options:

Scuderi at al. evaluated the effect of proximal tibial osteotomy on patellar height in 66 patients. They found that patellar height decreased by 89%, as measured by the Insall-Salvati index, and 76.3%, as measured by the Blackburne-Peel index, post-operatively.
Wright et al. reviewed the complications associated lateral closing wedge and medial opening wedge high tibial osteotomy. They reported a 64% incidence of patella baja following these high tibial osteotomy techniques, with associated complaints of anterior knee pain.
Illustration A shows an X-Ray of patella baja after closed wedge high tibial osteotomy. The Insall-Salvati ratio is determined by measuring the ratio of patella tendon length (TL) to the length of the patella bone (PL) with the knee flexed at 30 deg.
Incorrect Answers:

Correct Answer: Scuderi at al. evaluated the effect of proximal tibial osteotomy on patellar height in 66 patients. They found that patellar height decreased by 89%, as measured by the Insall-Salvati index, and 76.3%, as measured by the Blackburne-Peel index, post-operatively.

Explanation:

osteotomy.
OrthoCash 2020
A 88-year-old female fell onto her right hip sustaining the fracture shown in Figure A. Past medical history is significant for mild dementia and moderate coronary artery disease. At baseline, she ambulates with a walker. There are concerns about her ability to maintain weight-bearing precautions following surgery. Which of the following is most appropriate for management of the femoral side?
Revision total hip replacement with a proximally coated femoral stem
Open reduction, internal fixation with plate and cerclage wires
Proximal femoral replacement with megaprosthesis
Impaction bone grafting
Cortical strut allograft with cerclage wiring
Corrent answer: 3
The radiograph shows a Vancouver B3 periprosthetic fracture with poor proximal femoral bone stock. Given her age, co-morbidities, and dementia, the appropriate management of her condition would be a proximal femoral replacement with megaprosthesis. This can allow for immediate weightbearing in the post-operative period.
Vancouver B3 periprosthetic fractures are fractures around or just below the tip of a loose stem with poor proximal femoral bone stock. Options for management of this fracture include a fully coated stem, a fluted tapered stem, a proximal femoral replacement with megaprosthesis, allograft-prosthesis composite, and impaction bone grafting. In elderly patients with comorbidities and an inability to maintain the strict weight-bearing precautions that impaction bone grafting and allograft prosthetic replacements require, proximal femoral replacement with a megaprosthesis is the best option.
Duncan et al. were the originators of the Vancouver classification system for
periprosthetic fractures. Type A fractures are peritrochanteric, type B fracture are around the stem tip, and type C fractures are well below the stem tip.
Parvizi et al. review the indications for proximal femoral replacements with megaprostheses. They conclude it is a reasonable option for elderly patients with massive proximal femoral bone loss. The most frequent complications are aseptic loosening and dislocation.
Klein et al. identified 23 patients who underwent proximal femoral replacement for a Vancouver type-B3 periprosthetic fracture. At a follow-up of 3 years, 22 of 23 patients were walking with minimal pain. The most frequent complications were persistent drainage (2), dislocation (2), refracture (1) and acetabular cage failure (1).
Figure A shows a Vancouver B3 periprosthetic fracture with loose stem and poor proximal bone stock. Illustration A shows an example of a proximal femoral replacement. Illustration B shows a radiograph of a proximal femoral replacement used for a failed total hip replacement with massive bone loss. Illustration C shows the Vancouver classification (A, B1, B2, B3, C)
Incorrect Answers:
OrthoCash 2020
A minimal-incision technique with an incision no more than 10 centimeters has which of the following advantages compared to a standard incision for a total hip replacement?
lower post-operative visual analogue pain score
less transfusion requirement
shorter length of stay
better cosmetic result
less pain medication requirement
Corrent answer: 4
Ogonda et al randomized patients to standard (16cm) versus MIS incision (<10 cm). They found no significant difference with respect to postoperative hematocrit, blood transfusion requirements, pain scores, or analgesic use.
There were also no differences in early walking ability or length of hospital stay and no differences in component alignment.
OrthoCash 2020
What is an advantage of utilizing a 36-mm instead of a 28-mm femoral head in the setting of a revision total hip arthroplasty?
Compensating for abductor deficiency
Decreasing volumetric wear
Decreasing trunion stress
Delaying neck-socket impingement
Compensating for vertical cup placement
Corrent answer: 4
Increasing femoral head size delays neck-socket impingement, enhancing stability by increasing the excursion distance prior to dislocation.
The optimal bearing in total hip arthroplasty (THA) should allow for the best stability and function while preserving implant longevity. Greater motion, stability, and patient satisfaction have been correlated with larger femoral head sizes. Stability is associated with an increased displacement distance in larger diameter heads prior to a dislocation event (increased jump distance) combined with a greater impingement-free range of motion. Although larger femoral head sizes are associated with greater volumetric wear and trunion stress (and possible taper corrosion), newer bearings such as ceramic-on-ceramic may help mitigate these factors.
Kung et al. examined the effect of femoral head size and abductor integrity on dislocation events after revision THA. They separated 230 patients who underwent revision THA into 4 groups: (1) intact abductors mechanism + 28-mm femoral head, (2) absent abductor mechanism + 28-mm femoral head,
(3) intact abductor mechanism + 36-mm femoral head, and (4) absent abductor mechanism + 36-mm femoral head. They found that in patients with intact abductor mechanisms, the 36-mm femoral head was associated with a lower dislocation rate with 6-month minimum follow-up; femoral head size did not reduce dislocation events in patients with deficient abductor mechanisms.
Burroughs et al. performed an in-vitro study evaluating the range of motion and stability in THA with 28-44-mm femoral head sizes. They found that
femoral heads >32-mm provided for greater ROM and decreased component impingement. For these reasons, the authors conclude that large femoral heads may be beneficial in revision THA.
Illustration 1 demonstrates the increased jump distance when utilizing a larger diameter femoral head. Illustration 2 demonstrates a greater impingement-free range of motion with a larger femoral head.
Incorrect Answers:
OrthoCash 2020
A 65-year-old male is now 6 weeks status post an uncomplicated total knee arthroplasty. Figures A and B represent his x-rays at today's visit. His primary complaint is knee stiffness. His current passive range of motion is 0-80 degrees, compared to 120 degrees
preoperatively, and he has failed to improve with physical therapy. He is otherwise afebrile, has no incisional erythema or pain, and CRP is within normal limits. Manipulation under anesthesia (MUA) will provide the largest improvement in flexion if performed before which of the following:
Before 6 weeks
Before 12 weeks
Before 26 weeks
Before 34 weeks
Outcomes after MUA are equivalent if performed within 1 year of surgery
Corrent answer: 2
Manipulation under anesthesia (MUA) yields the greatest gain in flexion and improvement in overall range of motion if performed within 12 weeks postoperatively.
Post-operative knee stiffness (flexion < 90 degrees) occurs in 1.3%-12% of patients who undergo TKA. The preoperative risk factors for stiffness include decreased preoperative range of motion, age, diabetes mellitus, and socioeconomic status. Surgical factors can also contribute, including
overstuffing the patellofemoral joint, tight flexion/extension gaps, and excessive tightening of the extensor mechanism. If left untreated, loss of flexion negatively impacts functional outcomes, patient satisfaction, and ability to perform activities of daily living. MUA is considered the initial management for patients with flexion less than 90 degrees.
Issa et al. studied the optimal timing of MUA. They found that patients undergoing MUA before 12 weeks had a significantly higher mean gain in flexion (36.5° versus 17°), higher final range of motion (119° versus 95°), and higher Knee Society objective (89 versus 84 points) and function scores (88 versus 83 points) than those who had late manipulation under anesthesia (after 12 weeks). There was no statistically significant difference between MUA before 6 weeks vs MUA before 12 weeks.
Desai et al. similarly demonstrated that maximum flexion gains were achieved when MUA was performed between 12-14 weeks post-operatively. They also demonstrated that there is no benefit to multiple manipulations, with no observed flexion gain after the initial intervention.
Incorrect Answers:
OrthoCash 2020
A 51-year-old male presents with worsening left hip pain over the past 8 months. The patient reports hip surgery 5 years prior as seen in Figures A and B. His CRP level is within normal limits, ESR is at the upper limit of normal, and automated cell count following a hip aspiration yields a WBC of 15,000/µL (rr, 4500-11000µL) and 85% PMNs. Metal ion testing reveals elevated serum cobalt and chromium levels. What is the next best step?
Manual cell count of synovial fluid
stage revision arthroplasty
Acetabular cup revision with bone grafting
Femoral revision with cerclage wire placement
Hip arthrodesis
The patient has had a metal-on-metal (MoM) hip resurfacing with osteolysis. It is likely his WBC count is falsely elevated secondary to metal debris and corrosion. The next best step is a manual cell count to evaluate for metal debris, clots, fragmented cells, or other defects preventing accurate automated cell count.
Diagnosis of infection in the setting of MoM bearing surface can be difficult given very similar presentations. Typical workup includes CRP, ESR, synovial fluid WBC, and differential. Metal debris and corrosion reactions can confound the synovial fluid analysis leading to falsely elevated WBC counts in cases of aseptic failure. Prosthetic joint infection (PJI) and metallosis can occur concurrently so aggressive diagnostic testing is important for surgical decision making. Manual cell count of synovial fluid samples can identify metal debris and avoid false positives from automated cell testing. Supplementary tests, such as MARS MRI, metal ion levels, manual cell count, and repeat aspiration, can help guide appropriate management in these scenarios.
Yi et al. investigated ESR, CRP, synovial WBC and differential in diagnosing PJI in the setting of MoM hips or non-MoM hips undergoing revision for corrosion
or full thickness wear. They found that synovial fluid WBC count can be confounded by inaccurate automated cell counts secondary to foreign material and degenerating cells. They conclude that diagnosis of PJI in the setting of failed MoM bearings or corrosion is difficult due to falsely positive synovial fluid WBC.
Carrothers et al. evaluated the prevalence of complications of hip resurfacing arthroplasty. They found the most common complication was fracture of the femoral neck, followed by loosening of the acetabular component, femoral head collapse, loosening of a femoral component, infection, aseptic lymphocyte-dominated vasculitis-associated lesion (ALVAL), loosening of both components, and malposition of the acetabular component. They conclude that knowledge of complications following hip resurfacing is important to help select patients and counsel them on risks prior to surgery.
Figures A and B show a metal-on-metal hip resurfacing with supra-acetabular osteolysis.
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OrthoCash 2020
An 87-year-old female presents with longstanding knee pain. The structures identified in Figure A are formed through the pathologic activation of endochrondral ossification. The pathway involved in this process involves which of the following signaling molecules?
Indian hedgehog (Ihh)
Peroxisome proliferator-activated receptor gamma (PPARG)
Receptor activator of nuclear factor kappa-ligand (RANKL)
Osteoprotegerin (OPG)
Sclerostin
Osteoarthritis and formation of osteophytes are felt to be mediated by the differentiation of quiescent chondrocytes through the Indian hedgehog signaling pathway.
Indian hedgehog (Ihh) is an important mediator of chondrocyte and osteoblast differentiation in prenatal endochondral bone formation. Adult articular cartilage without osteoarthritis does not have active Ihh signaling. However, Ihh and its downstream signaling proteins have been found to be unregulated in osteoarthritic joints. Ihh may play an important role in activating endochondral ossification leading to some of the clinical features of osteoarthritis (osteophytes and subchondral cysts). Modulation of Ihh has therapeutic potential in the treatment of osteoarthritis.
Maeda et al. studied mice with Ihh genes ablated from postnatal chondrocytes.
They found a loss of columnar structure, premature vascular invasion, and formation of ectopic hypertrophic chondrocytes in the growth plate. They concluded that Ihh is essential for maintained trabecular bone, skeletal growth, and articular cartilage.
Wang et al. reviewed the molecular mechanisms associated with cartilage degeneration in osteoarthritis. The study found that upregulation of the Ihh signaling molecules leads to the development of osteoarthritis, similar to that found in injury-induced controls. Additionally, they found that inhibiting the Ihh pathway reduces the severity of injury-induced osteoarthritis in mouse models.
Figure A shows a knee with varus deformity and severe medial sided arthritis with femoral and tibial sided osteophytes(red arrows).
Incorrect Answers:
OrthoCash 2020
Figure 1 is the AP pelvis radiograph of a 55-year-old male with known hip dysplasia and chronic right hip pain. He has no prior surgical history and is otherwise healthy. Your initial plan is to reconstruct his hip center at the site of his true acetabulum. Your preoperative template demonstrates that your acetabular component will have 40° of abduction, 15° of anteversion. However, there will be 25% uncoverage at the superolateral margin. What is the most appropriate next step to ensure adequate cup fixation?
Increase the abduction angle to 60 degrees for better coverage
Medialize the acetabular component beyond the medial wall for improved coverage
Elevate the hip center in search of better bone stock
Accept 25% uncoverage and proceed with total hip arthroplasty as templated
Use cement augments to improve superolateral coverage of the acetabular component
The most appropriate next step is to proceed with total hip arthroplasty (THA) as templated. Less than 30% of uncoverage is acceptable and has not been associated with increased rates of aseptic loosening.
Dysplasia of the hip broadly refers to abnormal development of the hip that leads to poor acetabular coverage of the femoral head. The characteristic pelvic deformities of dysplasia include a retroverted acetabulum with bone loss at the superolateral margin. As a result, there is often insufficient bone stock to provide complete coverage of the acetabular component when placed at the true hip center. Insufficient coverage (<60-70%) can lead to a lack of initial stability and early failure. If the pre-operative template suggests extreme superolateral bone loss, the surgeon must then consider alternative methods of achieving satisfactory fixation, including downsizing the acetabular component size, medializing or elevating the hip center, or use of trabecular metal augments or cement augmentation for better coverage.
Haddad et al. discuss pre-operative considerations when performing primary total hip arthroplasty on dysplastic hips. The literature review suggests that
less than 30% uncoverage does not increase the risk of aseptic loosening.
Paavilainen et al. studied the short-term outcomes on 100 cementless total hip replacements in severely dysplastic hips. They describe the importance of exposing the proximal aspect of the pubic and ischial bones since the pelvic wall is usually hypoplastic, and the use of augmentation when the superolateral rim was deficient. Overall, their outcomes with cementless total hip replacements were equivalent to cemented prostheses.
Figure A is an AP pelvis radiograph demonstrating a dysplastic right hip. Illustration A is a T1-weighted coronal MRI of a hip. Hip dysplasia can be assessed using the center-edge angle, the angle formed between a vertical line through the center of the femoral head and a line connecting the center of the femoral head with the lateral edge of the acetabulum. Less than 20° is one marker of hip dysplasia. Illustration B demonstrates the concept of joint reactive forces. Joint reactive force is minimized when the moment arm of body weight and abductor tensioning are balanced. Anatomic changes that reduce abductor tension such as elevating the hip center, decreasing femoral head size, and increased valgus neck angle increase the joint reactive force.
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OrthoCash 2020
A 65-year-old man presents to your clinic with chronic, progressive knee pain. Figure A is an x-ray of his right knee. He would like to pursue non-surgical treatment options. The AAOS clinical practice guidelines on the treatment of symptomatic knee arthritis support which of the following with "strong evidence"?
NSAIDs; tramadol
Weight loss; arthroscopic debridement
Weight loss; intra-articular steroid injections
Valgus-offloading brace; glucosamine chondroitin injections
Tramadol; acupuncture
The AAOS clinical practice guidelines (CPG) summary "strongly" recommends tramadol or NSAIDs for the treatment of symptomatic knee osteoarthritis.
Symptomatic knee osteoarthritis is widespread, with an incidence of 240 people per 100,000. Symptoms are often progressive, though addressing the modifiable risk factors of muscle weakness, large BMI, and repetitive loading can help with pain control. Definitive management is total knee arthroplasty, however, non-operative interventions are often successful in delaying surgery, particularly in younger patients.
The AAOS Clinical Practice Guideline Summary performed a systematic review of the available literature to propose evidence-based guidelines for the management of symptomatic knee osteoarthritis. The current guidelines show strong support for the engagement in physical activity (such as guided physical therapy), non-steroidal anti-inflammatory drugs, and Tramadol for the management of symptomatic osteoarthritis. The Clinical Guidelines provided “strong” evidence against acupuncture, glucosamine and chondroitin, hyaluronic acid, and arthroscopy with lavage or debridement.
Fishman et al. performed a double-blind, randomized study of 552 patients studying the efficacy of Tramadol vs placebo in the management of arthritic knee pain. Tramadol demonstrated a statistically significant improvement in knee pain over placebo as reported by the Patient Global Rating of Pain Relief Scale.
Incorrect Answers:
OrthoCash 2020
An 82-year-old healthy male presents to the ED with right leg pain and inability to bear weight after a fall from standing. He has a history
of revision right total knee arthroplasty performed 5 years ago and was doing well until his fall this morning. On exam, he is able to actively extend his knee, though limited by pain, and is neurovascularly intact. Figures A-B are radiographs of his distal femur. What is the most appropriate treatment?
Retrograde intramedullary nail
Revision total knee arthroplasty with a stemmed femoral component
Nonoperative management with application of a long leg cast
Open reduction and internal fixation with a lateral plate
Antegrade intramedullary nail
Corrent answer: 4
Open reduction and internal fixation with a lateral plate is the most appropriate treatment for this supracondylar periprosthetic femur fracture above a well-fixed total knee arthroplasty (TKA).
Supracondylar periprosthetic femur fractures are defined as fractures within 15cm of the joint line or within 5cm of the proximal end of the implant in the case of a stemmed component. Risk factors include rheumatoid arthritis, neurologic disorders, steroid use, anterior cortical notching of the femoral
component and revision TKA. Nonoperative management usually requires long-term immobilization, which can result in significant loss of knee range of motion (ROM). Therefore, surgical treatment is often preferred. An acceptable outcome is > 90° of knee ROM, fracture shortening < 2cm, varus/valgus malalignment < 5°, and flexion/extension malalignment < 10°.
Su et al. performed a literature review of the management of periprosthetic femur fractures above a TKA. First, it is crucial to determine the stability of the femoral component. An unstable femoral component requires either revision TKA or distal femoral replacement, depending on the quality of the distal femoral bone stock. A fracture with a stable femoral component can be well fixed with a buttress plate or retrograde intramedullary nail. In a series of 12 patients undergoing fracture fixation with lateral plate, all patients healed and returned to pre-fracture ambulatory status.
Zehntner et al. studied the surgical outcomes of buttress plating in 6 supracondylar femur fractures above TKA. There was no nonunion, loss of fixation or infection. Knee ROM averaged 97°, and all patients were ambulating postoperatively.
Figures A and B represent AP and lateral radiographs of a supracondylar periprosthetic femur fracture above a stemmed TKA. Illustrations C and D represent AP and lateral radiographs of a supracondylar periprosthetic femur fracture above a stemmed TKA status post repair with lateral plate.
Incorrect Answers:
OrthoCash 2020
A 60-year-old woman presents for follow-up two weeks after right total knee arthroplasty. She complains of significant anterior knee pain after fall from standing onto a flexed knee. On physical exam, her passive range of motion is 0-120 degrees and she is stable to varus and valgus stress. She is able to achieve full extension with active range of motion, though she is experiencing severe pain. Lateral radiograph of the knee is provided in Figure A. What is the most appropriate next step?
Non-operative management with long leg cast
Closed treatment with immediate active range of motion
Removal of patellar component with early active range of motion
Open reduction and internal fixation of patella with wire or screw fixation
Extensor mechanism repair with Achilles allograft and revision of the patella
Corrent answer: 1
The appropriate treatment for a transverse periprosthetic patella fracture with an intact extensor mechanism is closed treatment and immobilization in a long leg cast.
Periprosthetic patella fracture after total knee arthroplasty is rare (incidence of 0.68%-5.2%) and is overwhelmingly secondary to a traumatic mechanism.
Risk factors include excessive patella resection, use of cementless components, and elevated BMI. Broadly, the treatment algorithm for periprosthetic patella fracture depends on the stability of the implant and the involvement of the extensor mechanism. Ortiquerra and Berry classified periprosthetic patella fractures as intact extensor mechanism with well a fixed implant (Type I), extensor mechanism disruption with either a loose or stable implant (Type II), or intact extensor mechanism with a loose implant (Type III). Generally, fractures associated with component loosening or extensor mechanism injuries (Type II & Type III) require revision surgery and often yield poor results. Type I fractures are successfully managed non-operatively.
Nam et al. reviewed the management of extensor mechanism complications in
total knee arthroplasty. They report excellent results in Type I peri-prosthetic patella fractures managed non-operatively, with only 1 failure in 37 patients. They propose a treatment algorithm based upon fracture pattern (transverse vs vertical), component fixation, and extensor mechanism integrity. Type I injuries with transverse fractures should be immobilized in long leg casts, whereas Type I injuries with vertical fractures are more stable and can benefit from early active range of motion.
Cottino el al. similarly review the outcomes of peri-prosthetic patella fractures. They report a 50% complication rate and a 20-40% re-operation rate for type II and type III injuries, even with anatomic reductions.
Figure A is a lateral radiograph of the knee that demonstrates a transverse peri-prosthetic patella fracture without component loosening. There is no obvious extensor mechanism injury and the prompt indicates extension is intact. Illustration A represents the peri-prosthetic patella fracture treatment algorithm as proposed by Nam et al. Illustration B represents the Ortiquerra and Berry peri-prosthetic patella fracture classification.
Incorrect Answers:
OrthoCash 2020
A 68-year-old healthy male with a history of a right total hip arthroplasty 8 years prior presents with one year of right hip pain and several months of inability to bear weight. An AP pelvis radiograph is shown in Figure A. ESR is 8 mm/hr and CRP is 1 mg/L. What is the best treatment option?
Cemented acetabular cup with morselized bone graft
Two stage revision with antibiotic spacer
Cup-cage construct with or without morselized bone graft
Definitive removal of hardware/Girdlestone procedure
Anterior and posterior column plates with hemispherical uncemented cup
Corrent answer: 3
Cup-cage constructs have demonstrated excellent outcomes in patients with pelvic discontinuity and Gross type V acetabular defects.
When treating chronic pelvic discontinuities, four general principles need to be addressed: 1) restoration of the acetabulum by reconnecting the ischium to the ilium, 2) optimizing contact of bleeding bone to component surfaces with ingrowth potential, 3) grafting osseous deficiencies, 4) obtaining a mechanically stable reconstruction to protect components until ingrowth is achieved. There are several different classifications of acetabular bone loss, though the Gross classification is unique in that it not only grades the degree of bone loss but also provides reconstructive options that may be considered (Illustration A & B). Due to the segmental bone loss associated with Gross
Types IV and V defects, cup-cage constructs are used to bridge segmental defects or areas of discontinuity.
DeBoer et al. studied the long-term outcomes of 28 patients with pelvic discontinuity treated with custom triflange acetabular prostheses. They reported no instances of broken screws, implant migration, or component revision at 10 years. Complications included one partial sciatic nerve palsy and five patients with dislocation.
Makinen et al. reviewed the role of cages in revision arthroplasty. In Gross Type V defects, cages provide mechanical stability to protect the acetabular cup until ingrowth is achieved. They report two case series following cup-cage reconstructions for pelvic discontinuity, demonstrating 88% survival at 44.6 months and 87.2% survival at 82 months. The survivorship of cage only constructs was 49.9% at seven years.
Figure A demonstrates a failed right total hip arthroplasty with associated chronic pelvic discontinuity. Illustration A demonstrates the Gross classification for acetabular bone defects. Illustration B demonstrates the suggested reconstructive options for defects classified according to the Gross classification system.
Incorrect Answers:
OrthoCash 2020
A 60-year-old male presents with significant left knee pain and end-stage osteoarthritis. He failed non-operative management and is requesting a total knee arthroplasty (TKA). His past medical history is significant for a left distal femur fracture that occurred when he was struck by a car 30 years prior. A standing, full-length radiograph of his left lower extremity is shown in Figure A. His femoral coronal plane deformity measures 28 degrees. When proceeding with a TKA, what must be done to address this patient's coronal deformity?
Soft tissue balancing and intra-articular bone cuts
Distal femoral medial closing-wedge osteotomy
Distal femoral lateral closing-wedge osteotomy
High tibial osteotomy
Hinged TKA
Coronal plane deformities of the femur >20 degrees require an extra-articular femoral osteotomy to achieve proper mechanical alignment when performing a TKA.
Coronal and sagittal plane deformities of the femur less than 20 degrees can usually be addressed with intra-articular bone cuts and soft tissue balancing. Attempting to correct deformities greater than this without an extra-articular osteotomy can compromise ligamentous stability. This highlights the importance of careful pre-operative templating/planning and obtaining full-length, standing radiographs when clinically warranted. Although correcting severe deformities with staged or concomitant extra-articular osteotomies can be challenging, they are often successful when properly executed.
Lonner et al. provided a retrospective case series and review article addressing
severe extra-articular deformities with simultaneous femoral osteotomy and TKA in patients with osteoarthritis. In their 10-patient series, they were successful in restoring coronal alignment within two degrees of anatomic in all patients. They suggest securing the femoral osteotomy site with a plate or locked intramedullary nail, depending on the osteotomy site.
Rajgopal et al. presented a case series of TKA in 36 knees in the setting of extra-articular deformities. In this series, they treated all patients with intraarticular bone resection and soft-tissue balancing to address their deformities. Femoral-coronal, sagittal, and tibial-coronal deformities successfully treated included 11-18 degrees, 0-15 degrees, and 12-24 degrees, respectively.
Figure A is a standing, full-length radiograph of the left lower extremity demonstrating a significant coronal plane deformity resulting from a previous distal femur fracture malunion. Illustration A is a left knee radiograph demonstrating an extra-articular distal femoral osteotomy with placement of a fluted, press-fit stem. Illustration B is the same patient at 3-year follow-up demonstrating a fully healed osteotomy and maintained hardware alignment.
Incorrect Answers:
OrthoCash 2020
A 76-year-old female presents with right hip pain 6 years after total hip arthroplasty. She denies constitutional symptoms at this time. On physical examination, her incision is well healed. Current radiographs are shown in Figures A and B. In addition to a complete blood count (CBC), C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR), an alpha-defensin immunoassay is ordered. What does the alpha-defensin immunoassay test for?
The presence of an intra-articular, antimicrobial peptide
The presence of an antimicrobial peptide within serum
The presence of an intra-articular, pro-inflammatory marker
The presence of an intra-articular, pro-inflammatory cytokine
The presence of intra-articular leukocytosis
Corrent answer: 1
A synovial alpha-defensin immunoassay tests for the presence of an intraarticular, antimicrobial peptide.
When there is suspicion of a periprosthetic infection, laboratory workup should
include CRP and ESR. If suspicion remains after laboratory examination, an aspiration of the joint should be performed for cell count and culture. A fairly recent test developed to aid in the diagnosis of PJI is the synovial alpha-defensin immunoassay. Defensins are antimicrobial peptides that are active against many bacteria, fungi, and enveloped viruses. Alpha-defensin is an antimicrobial peptide which is abundant in neutrophils and macrophages. It is present in the natural local tissue response to infection. In the setting periprosthetic joint infection (PJI) the levels of intra-articular alpha-defensin increase substantially and may reach levels that can be detected by an immunoassay. Alpha-defensin may be more prone to false positive results in adverse local tissue reaction caused by a metal-on-metal arthroplasty.
Bonanzinga et al. performed a prospective study to determine the reliability of the alpha-defensin immunoassay for diagnosing PJI. They aspirated hips and knees in all patients presenting with pain in both primary and revision arthroplasties. They found the sensitivity of the alpha-defensin immunoassay was 97%, the specificity was 97%, the positive predictive value was 88%, and the negative predictive value was 99% (95% CI, 96%–99%). They conclude that alpha-defensin appears to be a reliable test.
Shinsky et al. performed a study to evaluate the utility of commonly available tests for determining the presence of PJI in patients undergoing revision total hip arthroplasty. 235 consecutive total hip arthroplasties undergoing revision were evaluated. They found that no hip in a patient with a preoperative ESR of
<30 mm/hr and a CRP of <10 mg/dL was infected. They also conclude that a synovial fluid cell count of >3000 white blood cells/mL was the most predictive perioperative testing modality when ESR and CRP were elevated as well.
Figures A and B are AP and lateral radiographs of the right hip, respectively, demonstrating a region of periarticular erosions around the proximal femoral stem.
Incorrect Answers:
OrthoCash 2020
A 72-year-old male presents to your clinic with a 6-month history of left groin pain without preceding trauma. He previously underwent an uneventful left total hip arthroplasty 15-years prior at an outside institution. He has been ambulating with a cane for the last month due to pain. A left hip radiograph is obtained and presented in Figure A. Less than 4 centimeters of intact diaphyseal bone remains distal to the isthmus. An infection work-up is negative. Of the choices provided, what is the most appropriate management option at this time?
Continued observation
Placement of a femoral cortical strut allograft and cerclage wires
Femoral revision with impaction grafting and a cementless femoral stem
Femoral revision with a metaphyseal-engaging tapered stem
Femoral revision with a modular fluted tapered stem
Corrent answer: 5
This patient has a Paprosky type-IIIB femoral defect (less than 4cm diaphyseal bone available for distal fixation) that can be revised with a modular fluted tapered stem
Femoral revision with a modular fluted tapered stem is the preferred method
in the treatment of Paprosky type-IIIB femoral defects. Proximal femoral replacement, allograft prosthetic composite, resection arthroplasty, and impaction grafting may also be considered in the treatment of Paprosky type-IIIB and IV femoral defects. Impaction grafting involves creating a neomedullary canal by impacting cancellous bone chips into the femoral canal followed by cementation of the final femoral component.
Valle et al. present a review article describing the Paprosky classification of femoral defects as well as treatment options. They differentiate a type-IIIA and IIIB defect as having >4 and <4 centimeters of intact diaphyseal bone available for distal fixation, respectively.
Hartman et al. describe management strategies for femoral fixation in the setting of revision total hip arthroplasty. They review classification systems of femoral bone loss and provide an overview of various treatment options. The authors feel that type-II and IIIA defects can be effectively treated with cylindrical, extensively porous-coated implants, whereas IIIB defects can usually be treated with a modular fluted tapered stem.
Figure A show a total hip arthroplasty with less than 4cm of diaphyseal bone available for distal fixation with extensive metaphyseal and diaphyseal bone loss. Illustration A shows a diagram of the Paprosky classification for femoral bone loss.
Incorrect Answers:
OrthoCash 2020
An 85-year-old woman sustains a ground level fall. Her THA was done 25 years ago. She was previously ambulatory but with a significant limp. With regard to the femur specifically, what is the Vancouver classification and preferred treatment option?
Vancouver C, revision to proximal femoral replacement
Vancouver B1, ORIF with impaction grafting
Vancouver AG, ORIF
Vancouver B3, revision to proximal femoral replacement
Vancouver B2, ORIF with femoral strut allograft augmentation
Corrent answer: 4
The periprosthetic femoral fracture should be classified as Vancouver B3 given the location around the femoral stem with very poor proximal femoral bone stock, thus making reconstruction of this bone unrealistic. The best treatment options for a B3 fracture would be revision of the stem to a proximal femoral replacement or proximal femoral allograft composite.
The Vancouver periprosthetic classification system is one of the most useful classifications in orthopaedics as it can reliably guide treatment. Vancouver B1 or C type fractures confer a well-fixed stem and so ORIF would be the
treatment of choice. B2 and B3 fractures signify a loose femoral stem and so revision is necessary while B3 fractures have very poor proximal bone quality making any reliance on metaphyseal proximal bone for fixation or reconstruction futile.
Klein et al. retrospectively reviewed 21 patients (mean age 79) with Vancouver B3 fractures treated with a proximal femoral replacement. At most recent follow-up, 20/21 patients were ambulatory with no or minimal pain.
They note a relatively high complication rate (2 recurrent dislocators, 1 repeat fracture, 1 acetabular complication, 2 infections treated with I&D). However, given the circumstances and morbidity of non-operative management, they still recommend a proximal femoral replacement for this complicated patient group.
Savvidou et al. offer a good review of proximal femoral replacement both for periprosthetic fracture and also revision THA with significant proximal bone loss. They emphasize the complications such as dislocation and aseptic loosening and offer recommendations for minimizing them such as a large femoral head, soft tissue repair, and preservation/repair of abductors.
Figure A demonstrates a cemented total hip arthroplasty with significant osteolytic changes about both the femoral and acetabular components with multiple fractures around the grossly loose femoral stem. Taken from Klein et. al.
Illustration A demonstrates an example of a proximal femoral replacement. Taken from Savvidou et al.
Incorrect Answers:
OrthoCash 2020
Which of the following liner types have been associated with early acetabular component loosening?
Figures B and C
Corrent answer: 1
Figure A is an illustration of a lateralized or offset acetabular liner which has been shown to have a higher rate of loosening with primary and revision total hip arthroplasty (THA).
Extended offset polyethylene liners allow restoration of soft tissue tension by adding 4 to 10 mm of additional offset to the acetabular side. They translate the center of hip rotation laterally which will increase offset in the horizontal plane and add a few millimeters of additional limb lengthening in the vertical plane. The lateral translation of the center of rotation has been found to increase joint reaction forces and polyethylene wear. Additionally, this results
in an eccentric loading pattern and leads to increased torsional forces at the liner-shell interface and the bone-implant interface. This may cause motion at the interface resulting in failure of ingrowth and early loosening.
Glori performed a study to determine if torsion on an offset acetabular component may increase the risk of fixation failure. He found that a 70 kg person walking normally on a well-positioned 10-mm offset component will produce more torsion compared to a 4-mm offset component. Vertical cup placement was also found to increase torsion. He concludes that these torsional moments are comparable to moments shown to cause failure of the initial interference fit of cementless acetabular components in vitro. He suggests that after using an offset cementless acetabular component, one should initially limit weight bearing to minimize the risk of failure.
Archibeck et. al reviewed 1919 patients with primary THA and 346 with revision THA to evaluate acetabular component loosening. A 7-mm offset acetabular liner was used in 120 of the primary and 100 of the revision THAs. The aseptic loosening rate in the primary THA group was 0.12% in the standard offset and 4.2% in the extended offset groups at a minimum of 2 years follow-up. The aseptic loosening rate in the revision group was 1.7% in the standard and 7% in the extended offset groups at a mean of 4 years follow-up. They conclude that offset acetabular liners have a high failure rate in primary and revision THA.
Figure A is an illustration depicting an offset acetabular component. Figure B is an illustration depicting an oblique acetabular component or a face-changing liner. Figure C is an illustration depicting an elevated rim acetabular component or a lipped liner. Figure D is an illustration depicting a standard offset component.
Incorrect Answers:
OrthoCash 2020
During a revision hip surgery, which of the following muscles labeled in Figure 1 can be transferred in the setting of an abductor deficiency?

Question 11:

Options:

Lead to lower patient satisfaction rates
Lead to higher patient satisfaction rates
Lead to higher likelihood the patient will take legal action against surgeon
Lead to higher likelihood the patient will change physicians
Prevent any legal action

Correct Answer: Lead to lower patient satisfaction rates

Explanation:

Question 12:

Options:

closed reduction and a double spica cast.
skeletal traction for 3 weeks, followed by a double spica cast.
reduction and internal fixation crossing the physis if necessary.
reduction and internal fixation with primary bone grafting.
skin traction.

Correct Answer: reduction and internal fixation crossing the physis if necessary.

Explanation:

Question 13:

Options:

Accept the offer because it would allow the physician to have a boat and enjoy a hobby of sailing with a minimal financial outlay.
Accept the offer because it would have nothing to do with the orthopaedic practice and because the physician feels strongly that it would have no influence on practice decisions.
Reject the offer because it represents an unacceptable conflict of interest.
Accept the offer but disclose the relationship to patients when using the representative's products.
Accept the offer but only with an equal interest arrangement in the purchase and use of the boat.

Correct Answer: Reject the offer because it represents an unacceptable conflict of interest.

Explanation:

Question 14:

Options:

group A Streptococcus.
Methicillin-resistant staphylococcus aureus.
Clostridium.
polymicrobial infection.

Correct Answer: polymicrobial infection.

Explanation:

Question 15:

Options:

Male gender
Diaphyseal location
Comminuted displaced fracture
Young age
Associated injuries

Correct Answer: Comminuted displaced fracture

Explanation:

DISCUSSION: The patient has a displaced comminuted clavicle middle one third fracture from a high-energy mechanism. Recent literature on high-energy clavicular fractures suggests a higher rate of nonunion than previously reported. A nonunion rate of 30% has been reported by Hill and associates when the fracture fragments are displaced more than 1.5 cm. In addition, several patients had neurologic symptoms related to the injury. Robinson and associates reported an increased risk of nonunion in women, elderly patients, comminuted fractures, and injuries with a lack of cortical contact.
REFERENCES: Hill JM, McGuire MH, Crosby LA: Closed treatment of displaced middle-third fractures of the clavicle gives poor results. J Bone Joint Surg Br 1997;79:537-539.
Wick M, Muller EJ, Kollig E: Midshaft fractures of the clavicle with a shortening of more than
2 cm predispose to nonunion. Arch Orthop Trauma Surg 2001;121:207-211.
Robinson CM, Court-Brown CM, McQueen MM, et al: Estimating the risk of nonunion following nonoperative treatment of a clavicular fracture. J Bone Joint Surg Am
2004;86:1359-1365.

Question 16:

Options:

Flexor-pronator avulsion
Ulnar nerve subluxation
Medial collateral ligament injury
Lateral ulnar collateral ligament rupture
Triceps tendon subluxation

Correct Answer: Medial collateral ligament injury

Explanation:

Question 17:

Options:

Parental education and reassurance
Serial casting of the forefoot
Complete peritalar release
Lengthening of the Achilles tendon and soft-tissue balancing
Reverse last shoes

Correct Answer: Serial casting of the forefoot

Explanation:

Question 18:

Options:

vagus nerve.
recurrent laryngeal nerve.
superior laryngeal nerve.
hypoglossal nerve.
sympathetic trunk.

Correct Answer: recurrent laryngeal nerve.

Explanation:

Question 19:

In patients with suspected hepatitis C, which of the following tests is commonly used to confirm the diagnosis after a positive ELISA screening test?

Options:

Polymerase chain reaction (PCR)
Northern blot
Immunoblot assay
Microarray
Proteomics

Correct Answer: Immunoblot assay

Explanation:

Question 20:

The MRI findings shown in Figure 51 would most likely create which of the following signs and symptoms?

Options:

Weakness of the left extensor hallucis longus and a sensory deficit in the first dorsal web space
Diminished right Achilles tendon reflex and weakness of the gastrocnemius-soleus complex
Pain radiating into the anteromedial aspect of the left knee, diminished patellar tendon reflex, and difficulty climbing stairs
Numbness in the right first dorsal web space and a slap foot gait
Urinary retention and right quadriceps weakness with diminished patellar tendon reflex

Correct Answer: Pain radiating into the anteromedial aspect of the left knee, diminished patellar tendon reflex, and difficulty climbing stairs

Explanation:

Question 21:

- A 40-year old man has limited, painful motion in dorsiflexion at the metatarsophalangeal (MTP) joint of the right great toe, despite nonsurgical treatment. Radiographs show dorsal and medial osteophytes and minimal narrowing of the articular space. Treatment should consist of

Options:

Arthrodesis of the MTP joint
A Silastic implant of the MTP joint
Resection arthroplasty of the MTP joint
Cheilctomy of the MTP joint
Osteotomy of the base of the proximal phalanx

Correct Answer: Cheilctomy of the MTP joint

Explanation:

Question 22:

A 40-year-old man with an acetabular chondrosarcoma has a small soft-tissue mass. Treatment should consist of

Options:

chemotherapy with ifosfamide and doxorubicin hydrochloride.
external beam radiation.
wide resection.
curettage and cementation of the pelvic lesion.
cemented total hip arthroplasty with acetabular reconstruction.

Correct Answer: wide resection.

Explanation:

Question 23:

Options:

Breech delivery
Absence of an ipsilateral clavicle fracture
Horner's sign and an APGAR score of 10 at 1 minute
Return of active biceps before 3 months and preservation of full passive shoulder range of motion
Absent Moro and Babinski reflexes

Correct Answer: Return of active biceps before 3 months and preservation of full passive shoulder range of motion

Explanation:

Question 24:

The patient undergoes hip arthroscopy and the image of the right hip is shown in Figure 39. Repair of the injured structure would be expected to improve

Options:

hip joint survival.
hip joint lubrication.
hip joint motion. 36
hip joint stability.

Correct Answer: hip joint lubrication.

Explanation:

DISCUSSION
The radiographic studies reveal both acetabular dysplasia and cam-type femoroacetabular impingement. The MR image shows an acetabular labral tear. Structural abnormalities of the hip, including femoroacetabular impingement, have commonly been identified in association with labral tears. Disruption of the ligamentum teres is not associated with impingement conditions in the absence of trauma.
The patient has acetabular dysplasia with a decreased lateral center-edge angle and also has visible cam-type femoroacetabular impingement. The common pathway for joint degeneration in hips with cam-type femoral head anatomy includes the development of cartilage damage in the anterior or superolateral aspects of the acetabular cartilage. Paralabral cysts may be seen more commonly in association with acetabular dysplasia, although the patient’s radiographs did not demonstrate substantial cystic changes. Osteochondral loose bodies and ligamentum teres ruptures can be seen at arthroscopy in a small number of cases.
There are several proposed roles of the acetabular labrum. It can increase the depth of the acetabular socket by as much as 21% to 28%. Roles of the acetabular labrum include joint lubrication, shock absorption, and pressure distribution. Recent studies assessing the effects of loading on joint stability for both normal and dysplastic hips did not demonstrate a substantial role of the labrum in differences in loading. Although joint stability might be improved following surgical repair, acetabular dysplasia is not likely to be resolved with acetabular labral repair alone.
RECOMMENDED READINGS
Tibor LM, Leunig M. The pathoanatomy and arthroscopic management of femoroacetabular impingement. Bone Joint Res. 2012 Oct 1;1(10):245-57. doi: 10.1302/2046-3758.110.2000105.PubMed: 23610655.
View Abstract at PubMed
Peelle MW, Della Rocca GJ, Maloney WJ, Curry MC, Clohisy JC. Acetabular and femoral radiographic abnormalities associated with labral tears. Clin Orthop Relat Res. 2005 Dec;441:327-33. PubMed PMID: 16331022.
View Abstract at PubMed
Ross JR, Zaltz I, Nepple JJ, Schoenecker PL, Clohisy JC. Arthroscopic disease classification and interventions as an adjunct in the treatment of acetabular dysplasia. Am J Sports Med. 2011 Jul;39 Suppl:72S-8S. doi: 10.1177/0363546511412320.
PubMed PMID: 21709035.
View Abstract at PubMed
James SL, Ali K, Malara F, Young D, O'Donnell J, Connell DA. MRI findings of
37
femoroacetabular impingement. AJR Am J Roentgenol. 2006 Dec;187(6):1412-9. PubMed PMID: 17114529.
View Abstract at PubMed
Groh MM, Herrera J. A comprehensive review of hip labral tears. Curr Rev Musculoskelet Med. 2009 Jun;2(2):105-17. doi: 10.1007/s12178-009-9052-9. Epub 2009 Apr 7. PubMed PMID: 19468871.
View Abstract at PubMed
Henak CR, Ellis BJ, Harris MD, Anderson AE, Peters CL, Weiss JA. Role of the acetabular labrum in load support across the hip joint. J Biomech. 2011 Aug 11;44(12):2201-6. doi: 10.1016/j.jbiomech.2011.06.011. Epub 2011 Jul 14. PubMed PMID: 21757198.
View Abstract at PubMed

Question 25:

- A 14-year-old girl has idiopathic scoliosis with a 52-degree right thoracic curve and a 36-degree left lumbar curve. The rotation of the apical vertebra appears greater in the thoracic curve. A sagittal view radiograph shows the spine to be virtually straight. The iliac apophyses are Risser 2. Treatment should consist of

Options:

Anterior fusion of the lumbar curve
Anterior and posterior fusion of the thoracic curve
Posterior fusion of the thoracic curve
Posterior fusion of the thoracic and lumbar curves
Application of a brace until the iliac apophyses are Risser 4 or 5, followed by surgical correction

Correct Answer: Posterior fusion of the thoracic curve

Explanation:

Question 26:

What structure is located immediately posterior to the capsule at the posterior cruciate ligament tibial insertion?

Options:

Popliteal artery
Popliteal vein
Tibial nerve
Peroneal nerve
Medial head gastrocnemius tendon

Correct Answer: Popliteal artery

Explanation:

DISCUSSION: The popliteal artery lies just posterior to the posterior cruciate ligament
tibial insertion, separated only by the posterior capsule of the knee. When performing
a posterior cruciate ligament reconstruction, this artery is at risk for injury during creation
of the tibial tunnel.
REFERENCES: Jackson DW, Proctor CS, Simon TM: Arthroscopic assisted PCL reconstruction: A technical note on potential neurovascular injury related to drill bit configuration. J Arthroscopy 1993;9:224-227.
Malek MM, Fanelli GC: Technique of arthroscopically assisted PCL reconstruction. Orthopedics 1993;16:961-966.

Question 27:

Options:

Chemotherapy and wide local excision
Chemotherapy and radiotherapy
Marginal excision
Extended intralesional curettage DISCUSSION.. The imaging shows an aneurysmal bone cyst with a destructive, eccentric metaphyseal lesion with fluid-fluid levels on MR imaging. The described histology confirms this. The differential diagnosis would include telangiectactic osteosarcoma, although there is no associated soft-tissue mass on imaging and no malignant stroma described on histology. Treatment is extended intralesional curettage. Serial embolization is used in surgically inaccessible spaces. Chemotherapy and/or radiotherapy are not indicated for this benign lesion. Intralesional treatment rather than excision is the appropriate surgical option.

Correct Answer: Extended intralesional curettage DISCUSSION.. The imaging shows an aneurysmal bone cyst with a destructive, eccentric metaphyseal lesion with fluid-fluid levels on MR imaging. The described histology confirms this. The differential diagnosis would include telangiectactic osteosarcoma, although there is no associated soft-tissue mass on imaging and no malignant stroma described on histology. Treatment is extended intralesional curettage. Serial embolization is used in surgically inaccessible spaces. Chemotherapy and/or radiotherapy are not indicated for this benign lesion. Intralesional treatment rather than excision is the appropriate surgical option.

Explanation:

CLINICAL SITUATION FOR QUESTIONS 132 THROUGH 134
Figure 132 is the bone scan of a 73-year-old man who is referred from his family doctor with diffuse bone pain, fatigue, and right knee pain. Examination is notable for pain with motion about the right knee and mild hyporeflexia.

Question 28:

Which of the following anatomic structures are in contact with internal impingement in the throwing athlete? Review Topic

Options:

Humerus and posterior-superior glenoid
Humerus and anterior inferior glenoid
Humerus and acromion
Biceps and acromion
Rotator cuff and acromion

Correct Answer: Humerus and posterior-superior glenoid

Explanation:

Question 29:

Options:

Spiral oblique retinacular ligament
Sagittal bands
Volar plate
Central slip of the extensor tendon
Terminal extensor tendon

Correct Answer: Central slip of the extensor tendon

Explanation:

DISCUSSION: The clinical photograph shows a classic boutonniere deformity. It is likely that the patient sustained a volar dislocation of the proximal interphalangeal joint, with a concomitant rupture of the central slip insertion of the extensor tendon.
REFERENCES: Peimer CA, Sullivan DJ, Wild DR: Palmar dislocation of the proximal interphalangeal joint. J Hand Surg Am 1984;9:39-48.
Glickel SZ, Barron OA, Catalano LW: Dislocation and ligament injuries in the digits, in
Green DP, Hotchkiss RN, Pederson WC, et al (eds): Green’s Operative Hand Surgery, ed 5. Philadelphia, PA, Elsevier, 2005, p 355.

Question 30:

Options:

Humeral head resurfacing
Humeral head arthroplasty
Reverse shoulder arthroplasty
Total shoulder arthroplasty
Arthroscopic shoulder debridement

Correct Answer: Reverse shoulder arthroplasty

Explanation:

Question 31:

The teardrop shape marked with an asterisk in Figure 61 represents what anatomic structure?

Options:

Anterior superior iliac spine
Sciatic buttress
A column of bone running from the anterior inferior iliac spine (AIIS) to the posterior superior iliac spine (PSIS)
The most superior portion of the roof of the acetabulum
Iliopectineal line

Correct Answer: A column of bone running from the anterior inferior iliac spine (AIIS) to the posterior superior iliac spine (PSIS)

Explanation:

DISCUSSION: The teardrop can be visualized on the obturator outlet view of the pelvis and represents a thick column of bone that runs from the AIIS to the PSIS. Half pins for eternal fixation frames or screws can be inserted into this column for fixation of fractures.
REFERENCES: Gardner MJ, Nork SE: Stabilization of unstable pelvic fractures with supra-acetabular compression external fixation. J Orthop Trauma 2007;21:269-273.
Haidukewych GJ, Kumar S, Prpa B: Placement of half-pins for supra-acetabular external fixation: An anatomic study. Clin Orthop Relat Res 2003;411:269-273.
Kim WY, Hearn TC, Seleem O, et al: Effect of pin location on stability of pelvic external fixation. Clin Orthop Relat Res 1999;361:237-244.

Question 32:

Patients who have osteonecrosis of the humeral head and who have the best prognosis are those with which of the following conditions?

Options:

Sickle cell disease
Associated malunion
Alcoholic-induced disease
Previously received high-dose steroids
Postradiation necrosis

Correct Answer: Sickle cell disease

Explanation:

DISCUSSION: The natural history of nontraumatic osteonecrosis varies greatly, so it is difficult to predict which patients will have severe arthrosis develop. Patients with sickle cell disease tend to have the most benign course. The most commonly reported cause of nontraumatic osteonecrosis is corticosteroid therapy. Fortunately, the incidence of osteonecrosis among patients treated with long-term systemic corticosteroids has fallen from more than 25% to less than 5% in recent years, owning to judicious steroid use and dosing. The interval between corticosteroid administration and the onset of shoulder symptoms is also variable, ranging from 6 to 18 months in one large series. This is comparable to the interval leading up to the onset of hip symptoms, which ranges from 6 months to 3 years or longer. The incidence of humeral head involvement has not been shown to vary with the underlying indication for steroid use.
REFERENCES: Hasan SS, Romeo AA: Nontraumatic osteonecrosis of the humeral head.
J Shoulder Elbow Surg 2002;11:281-298.
Mansat P, Huser L, Mansat M, et al: Shoulder arthroplasty for atraumatic avascular necrosis of the humeral head: Nineteen shoulders followed up for a mean of seven years. J Shoulder Elbow Surg 2005;14:114-120.

Question 33:

Options:

Posterior tibial tendon
Flexor digitorum longus tendon
Flexor hallucis longus tendon
Posterior tibial neurovascular bundle
Abductor hallucis muscle

Correct Answer: Flexor hallucis longus tendon

Explanation:

Question 34:

Which of the following changes is seen with age and degeneration in the intervertebral disk? Review Topic

Options:

Increased number of blood vessels in the outer annulus fibrosus
Increased number of notochordal cells in the nucleus pulposus
Increase of diffusion gradient between the annulus fibrosus and the nucleus pulposus
Decreased type 1 collagen
Decreased water content of the nucleus pulposus

Correct Answer: Decreased water content of the nucleus pulposus

Explanation:

Question 35:

Options:

Posterosuperior acetabulum
Posteroinferior acetabulum
Femoral head above the fovea
Femoral head below the fovea

Correct Answer: Posteroinferior acetabulum

Explanation:

This clinical scenario describes a patient with FAI attributable to pincer (acetabular) deformity. This form of FAI, which involves prominence of the anterosuperior acetabular lip, may be more common among women. Decreased range of motion and pain occur secondary to the abutment of the femoral head against the acetabular labrum and rim. Hip flexion, combined with adduction and internal rotation, recreates this contact and causes pain, but CAM or pincer etiology remains unknown. The differential diagnosis of hip pain in a young athlete includes femoral neck stress reaction/fracture, sacroiliac arthritis, intra-articular loose body, trochanteric bursitis, osteitis pubis, and hernia. No information presented in this scenario suggests any of these causes. Diagnosis of FAI is best performed via MR imaging, with an arthrogram increasing the sensitivity and specificity for labral pathology. Ultrasonography may be useful in the diagnosis of dysplasia or for dynamic assessment of a snapping hip, but ultrasonography is not commonly used to diagnose labral pathology. Although concomitant chondral lesions of the femoral head are uncommon, the forced leverage of the anterosuperior femoral neck upon the anterior acetabulum may result in a “contra-coup” chondral injury on the posteroinferior acetabulum. This is the most common location of chondral lesions in this scenario. Without bony resection to prevent further impingement, this patient will continue to experience symptoms. Because there is no evidence of femoral neck prominence (CAM lesion), there is no indication for osteoplasty of the femoral neck; resection of the pincer lesion is necessary. This will often require take-down of the labrum in this location. If possible, iatrogenic or traumatic labral tears should subsequently be repaired after pincer debridement because the labrum has
important functions for hip stability and maintenance of the suction seal of the joint.

Question 36:

Options:

capitate excision with interposition arthroplasty.
capitate proximal pole excision and drilling.
proximal row carpectomy (PRC).
vascularized bone graft.

Correct Answer: vascularized bone graft.

Explanation:

EXPLANATION:
This patient has osteonecrosis of the capitate. The MR images show evidence of osteonecrosis with decreased signal on the T1-weighted image. The radiographs are unremarkable, with the exception of lunotriquetral coalition, which does not necessitate treatment. The etiology of osteonecrosis of the capitate may be related to trauma, abnormal Interosseous vascular supply, and hypermobility. Surgery is an option for patients with persistent symptoms despite immobilization. Vascularized bone graft should be considered in this scenario because there is no evidence of capitate collapse or arthritic change about the wrist. Free and local vascularized bone grafts have produced satisfactory results. Capitate excision with interposition arthroplasty is indicated for patients with proximal pole capitate collapse. Total wrist fusion is a salvage procedure and would be considered if there were evidence of collapse and arthritic change.
PRC would leave the capitate articulating with the radius and is not indicated.

Question 37:

Options:

Long-leg splinting of bilateral lower extremities, monitoring of bilateral pedal pulses for 48 hours
Intravenous dextran administration, repeat doppler evaluation at 6 hourly intervals
Perform CT angiography for bilateral lower extremities
Perform CT angiography for the left lower extremity, monitor right pedal pulses for 48 hours
Surgical exploration of bilateral lower extremities

Correct Answer: Intravenous dextran administration, repeat doppler evaluation at 6 hourly intervals

Explanation:

Question 38:

An AP radiograph of the pelvis is shown in Figure 4. What muscle attaches to the avulsed fragment of bone identified by the arrow?

Options:

Short head of the biceps femoris
Adductor longus
Pectineus
Piriformis
Semitendinosus

Correct Answer: Semitendinosus

Explanation:

Question 39:

Which of the following lesions is best suited for autologous chondrocyte implantation?

Options:

Patellofemoral arthritis
Lateral femoral condylar arthritis
Medial femoral condylar arthritis
Medial femoral chondral defect
Medial femoral and tibial articular chondral matching defects

Correct Answer: Medial femoral chondral defect

Explanation:

Question 40:

0 sustained a subcapital fracture of her hip. She is an avid tennis player, and history reveals no previous fractures. What is the most appropriate follow-up care? Review Topic

Options:

Antiresorptive bisphosphonate medication
A repeat dual-energy x-ray absorptiometry scan (DEXA) and treatment if the T-score is less than -2.5
A repeat DEXA scan and treatment if the T-score is greater than -1.5
No treatment since the BMD is not in osteoporotic range
(PTH) taraparatide hormone followed by surgery

Correct Answer: Antiresorptive bisphosphonate medication

Explanation:

Question 41:

What is a known risk factor for wound infection after spinal fusion for neuromuscular scoliosis? Review Topic

Options:

Number of levels fused
Blood loss
Serum albumin level <3.5 g/dL
Preoperative curve magnitude

Correct Answer: Serum albumin level <3.5 g/dL

Explanation:

Question 42:

A 22-year-old woman injured her ankle when she fell off a ladder. Radiographs reveal a displaced large posterior malleolus fracture of about 45% of the joint. What is the best definitive treatment?

Options:

Open reduction and internal fixation with absolute stability
Open reduction and internal fixation with relative stability
Closed reduction with casting
Reamed locked intramedullary nailing
External fixation

Correct Answer: Open reduction and internal fixation with absolute stability

Explanation:

Basic understanding of fracture care requires a fundamental knowledge of the principles regarding absolute and relative stability. Compression plating and anatomic reduction of articular fractures are examples of absolute stability. Bridge plating, external fixation, casting, and intramedullary nailing are all examples of relative stability. Both bone forearm fractures have long been treated with open reduction and internal fixation even in the light of open wounds. Results have been excellent with plate fixation. Recently, intramedullary nails that are contoured and locked have been used in the treatment of both bone forearm fractures, but they are not reamed. It is well established that with restoring the proper radial bow, length, and alignment,
optimal function can be achieved. Open reduction and internal fixation allows this achievement. In cases where comminution exists, absolute stability may have to be sacrificed so as to not strip small comminuted bone fragments. Therefore, a bridging technique is worthwhile. External fixation can be used as a temporary technique until the soft tissues are more amenable to definitive fixation. Cast treatment is not indicated in adult forearm fractures. Locking nails for forearm use are not reamed. With regards to articular fractures, anatomic reduction and rigid stabilization are required to achieve the best results and allow for fracture healing. This environment also allows for the best chance of the cartilage repair process to form "hyaline-like" cartilage. Open reduction and internal fixation with absolute stability is the mainstay of treatment for partial articular fractures such as split depression tibial plateau fractures and posterior malleolus fractures involving greater than about 25% to 30% of the joint. The gold standard for the treatment of a closed femur fracture is a reamed intramedullary locked nail. Results are uniformly excellent. This can be done without stripping of the soft tissues such as in open reduction and internal fixation. External fixation can be used as a temporary device in patients in extremis for damage control reasons.Moed BR, Kellam JF, Foster RJ, Tile M, Hansen ST Jr. Immediate internal fixation of open fractures of the diaphysis of the forearm. J Bone Joint Surg Am. 1986 Sep;68(7):1008-17.
http://www.ncbi.nlm.nih.gov/pubmed/3745238')">View Abstract at PubMedJones DB Jr, Kakar S. Adult diaphyseal forearm fractures: intramedullary nail versus plate fixation. J Hand Surg Am. 2011 Jul;36(7):1216-9. Epub 2011 May

Question 43:

In which scenario is application of NPWT contraindicated?

Options:

- Fasciotomy wound after compartment syndrome
- Exposed bone after debridement
- Surgical wound that cannot be closed because of tension
- Surgical tumor bed after excision while awaiting final pathology and definitive closure

Correct Answer: - Surgical tumor bed after excision while awaiting final pathology and definitive closure

Explanation:

DISCUSSION
The most common complication associated with NPWT is a rash on the skin resulting from contact with a suction sponge. In a 2001 study by Webb and Schmidt, 2.2% of patients treated with NPWT had a rash that resolved within 48 hours. To minimize risk for this rash, care should be taken to avoid overlap of the sponge onto intact skin. If skin overlap is unavoidable, a lower-pressure setting should be used.
Acute bacterial infection is possible in this scenario, but there would likely be additional findings such as purulence in the wound itself. Similarly, an acute allergic reaction could be found within the wound and not just at the skin edge. Skin irritation from excessive adhesive plastic tension can result in blistering or shearing avulsion but not skin-edge erythema. Skin necrosis from the original trauma would result in skin-edge duskiness instead of erythema.
A study by Timmers and associates showed a statistically significant increase in microvascular blood flow to the skin under a sponge at subatmospheric pressures. Angiogenesis occurs in the area of the wound vacuum from the negative pressure and increased blood flow, not from the sponge material itself. There has been no indication that antibiotic concentration is increased in the setting of negative pressure therapy because antibiotics would be evacuated along with the fluid. NPWT does not result in increased temperatures that would kill pathogens.
NPWT is contraindicated in the setting of neoplasm because its effect on tumors is unknown. There is potential for increased angiogenesis in residual tumor cells, which could lead to recurrence or even metastasis. NPWT has been used safely and effectively for coverage of open fractures between initial debridement and definitive coverage. Fasciotomy wounds are frequently covered with NPWT dressings on a temporary basis with excellent results.
NPWT has been used to temporize wounds with exposed bone before flap coverage. Wounds with excessive tension frequently can be closed after short-term coverage with NPWT dressings.
RECOMMENDED READINGS
Webb LX, Schmidt U. [Wound management with vacuum therapy]. Unfallchirurg. 2001 Oct;104(10):918-26. German. PubMed PMID: 11699301.
View Abstract at PubMed
Webb LX. New techniques in wound management: vacuum-assisted wound closure. J Am Acad Orthop Surg. 2002 Sep-Oct;10(5):303-11. PubMed PMID: 12374481.
View Abstract at
PubMed
Timmers MS, Le Cessie S, Banwell P, Jukema GN. The effects of varying degrees of pressure delivered bynegative-pressure wound therapy on skin perfusion. Ann Plast Surg. 2005 Dec;55(6):665-71. PubMed PMID: 16327472.
View Abstract at PubMed
CLINICAL SITUATION FOR QUESTIONS 68 AND 69
Figure 68 is the radiograph of a 17-year-old girl who is treated with closed reduction and percutaneous screw fixation for her displaced femoral neck fracture. Capsulotomy of the hip is not performed. After surgery, the patient is instructed to maintain touch-down weight-bearing status for 3 months.

Question 44:

Which of the following studies is considered most sensitive in monitoring a therapeutic response in acute hematogenous osteomyelitis?

Options:

Blood culture
WBC count
Erythrocyte sedimentation rate (ESR)
C-reactive protein
Radiography

Correct Answer: C-reactive protein

Explanation:

Question 45:

Options:

Hip arthroscopy with labral repair B. Reverse periacetabular osteotomy C. Varus rotational osteotomy
Open surgical dislocation with rim trimming

Correct Answer: Open surgical dislocation with rim trimming

Explanation:

Question 46:

Which of the following patients has the highest risk of developing recurrent instability after an arthroscopic Bankart procedure for anterior shoulder instability? Review Topic

Options:

year old female, recreational soccer player with ligamentous laxity and an x-ray showing a Hill-Sachs lesion and loss of glenoid contour
year old male, who plays hockey recreationally with no laxity and an x-ray showing a loss of glenoid contour
year old female, competitive tennis player with no laxity and x-ray findings of a Hill-Sachs lesion and loss of glenoid contour
year old male, recreational basketball player with ligamentous laxity and x-ray findings of a Hill-Sachs lesion
year old male, competitive football player with no laxity and no abnormal x-ray findings.

Correct Answer: year old female, recreational soccer player with ligamentous laxity and an x-ray showing a Hill-Sachs lesion and loss of glenoid contour

Explanation:

Question 47:

Options:

Mobile-bearing knee
Posterior cruciate ligament-sparing knee
Posterior cruciate ligament-substituting knee
Semiconstrained-style knee
Triaxial hinged knee

Correct Answer: Posterior cruciate ligament-substituting knee

Explanation:

DISCUSSION: Paletta and Laskins performed a retrospective study of the results of TKA with cement in 22 patients who had a previous patellectomy. Nine of the patients had insertion of a posterior cruciate ligament-substituting implant. Thirteen patients had insertion of a posterior cruciate ligament-sparing implant. The 5-year postoperative knee scores were 89 for the posterior cruciate ligament-substituting knee versus 67 for the posterior cruciate
ligament-sparing knee (P < 0.01). The patella functions to increase the lever arm of the extensor mechanism and to position the quadriceps tendon and the patellar ligament roughly parallel to the anterior cruciate ligament and posterior cruciate ligament, respectively. The patellar ligament thereby provides a strong reinforcing structure that functions to prevent excessive anterior translation of the femur during flexion of the knee. The absence of the patella results in the patellar ligament and the quadriceps tendon being relatively in line with one another. After a patellectomy, the resultant quadriceps force is no longer parallel to the posterior cruciate ligament. This results in loss of the reinforcing function of the patellar ligament. The authors believe this loss of reinforcing function may place increased stresses on the posterior cruciate ligament and posterior aspect of the capsule, which may result in stretching of these structures over time. They found a high rate of anteroposterior instability, a high prevalence of recurvatum, and a high rate of loss of full active extension compared with passive extension in the posterior cruciate ligament-sparing group, which supports their theory.
REFERENCES: Beaty JH (ed): Orthopaedic Knowledge Update 6. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 559-582.
Paletta GA Jr, Laskins RS: Total knee arthroplasty after a previous patellectomy. J Bone Joint Surg Am 1995;77:1708-1712.

Question 48:

Scapular notching following reverse shoulder arthroplasty may be minimized by what technical modification? Review Topic

Options:

Horizontal humeral cut
Superior inclination of the baseplate
Inferior inclination of the baseplate
Use of a 36-mm glenosphere
Use of a retentive polyethylene liner

Correct Answer: Inferior inclination of the baseplate

Explanation:

Question 49:

Options:

Hemoglobin
Myoglobin
Melanin
Copper
Hemosiderin

Correct Answer: Hemosiderin

Explanation:

DISCUSSION: Pigmented villonodular synovitis (PVNS) is a synovial proliferative disorder that remains a diagnostic difficulty. The most common clinical features are mechanical pain and limited joint motion. On radiographs, the classic finding is often a large lesion, associated with multiple lucencies. Other findings may include a normal radiographic appearance, loss of joint space, osteonecrosis of the femoral head, or acetabular protrusion. MRI is the imaging modality of choice and will show the characteristic findings of a joint effusion, synovial proliferation, and bulging of the hip. The synovial lining has a low signal on T
1
- and T
2
-weighted images, secondary to hemosiderin deposition. Copper deposition occurs in patients with Wilson’s disease, which mainly affects the liver.
REFERENCES: Bhimani MA, Wenz JF, Frassica FJ: Pigmented villonodular synovitis: Keys to early diagnosis. Clin Orthop 2001;386:197-202.
Cotten A, Flipo RM, Chastanet P, et al: Pigmented villonodular synovitis of the hip: Review of radiographic features in 58 patients. Skeletal Radiol 1995;24:1-6.

Question 50:

Increasing articular conformity of the tibial polyethylene insert of a fixed-bearing total knee arthroplasty (TKA) prosthesis will have which of the following biomechanical effects?

Options:

Decreased contact stress within the polyethylene
Decreased risk of patellofemoral instability
Decreased risk of mechanical loosening
Increased risk of subsurface polyethylene cracking
Increased tibial rollback during flexion

Correct Answer: Decreased contact stress within the polyethylene

Explanation:

DISCUSSION: Increasing articular conformity increases the surface area for contact between the polyethylene and the femoral component. Advantages of this include lower peak contact stress within the polyethylene and less risk of polyethylene fatigue failure. Patellofemoral tracking is unchanged by increasing conformity unless gross component apposition is present. A potential disadvantage of increasing conformity includes some restriction in tibial rollback. Modest changes in conformity have not been shown to alter the rate of mechanical loosening. If conformity was increased to the extent of significant constraint, a potential increased risk of loosening would be expected, not a decrease. Design of modern TKAs includes a compromise in achieving enough constraint to lower polyethylene stress, without providing so much constraint as to limit kinematics and stress the fixation interfaces.
REFERENCES: D’Lima DD, Chen PC, Colwell CW Jr: Polyethylene contact stresses, articular congruity, and knee alignment. Clin Orthop 2001;392:232-238.
Pellicci PM, Tria AJ Jr, Garvin KL (eds): Orthopaedic Knowledge Update: Hip and Knee Reconstruction 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000,
pp 265-274.

Question 51:

Options:

Residual foreign body
Lateral plantar nerve laceration
Impingement of Baxter’s nerve
Interdigital neuroma
Digital nerve laceration

Correct Answer: Lateral plantar nerve laceration

Explanation:

DISCUSSION: The MRI scan reveals a laceration through the abductor hallucis musculature and lateral plantar nerve, producing numbness along its distribution. There is no evidence of a foreign body on the MRI scan. Baxter’s nerve, or nerve to the abductor digiti quinti muscle, is the first branch off the lateral plantar nerve and impingement of this nerve typically produces a Tinel’s sign along the nerve branch deep to the abductor hallucis muscle. Interdigital neuroma would be suggested by the presence of a Mulder’s click. A digital nerve laceration would exhibit isolated numbness more distally.
REFERENCES: Baxter DE, Pfeffer GB: Treatment of chronic heel pain by surgical release of the first branch of the lateral plantar nerve. Clin Orthop Relat Res 1992;279:229-236.
Sarrafian SK: Anatomy of the Foot and Ankle: Descriptive, Topographic, Functional. Philadelphia, PA, JB Lippincott, 1983.

Question 52:

An 8-year-old boy is diagnosed with acute onset cauda equina syndrome. A radiograph, MRI scans, and a biopsy specimen are shown in Figures 57a through 57d. What is the most appropriate treatment?

Options:

Radiation therapy
Chemotherapy
Wide surgical resection
Marginal surgical resection
Aspiration and steroid injection

Correct Answer: Marginal surgical resection

Explanation:

DISCUSSION: The findings are consistent with an aneurysmal bone cyst. The MRI scan demonstrates a lesion involving the posterior elements of the vertebrae with fluid-fluid levels and neural compression. Fibrovascular tissue with multinucleated giant cells surrounding a vascular lake is seen on the histology. The most appropriate treatment is a marginal resection of the involved posterior elements. Although the recurrence rate can be as high as 25% to 30%, wide surgical resection could result in permanent neurologic injury and is not necessary. Aspiration and steroid injection have been advocated but would not relieve the nerve compression in this patient. Radiation therapy and chemotherapy are not indicated.
REFERENCES: Mankin HJ, Hornicek FJ, Ortiz-Cruz E, et al: Aneurysmal bone cyst: A review of 150 patients. J Clin Oncol 2005;23:6756-6762.
Garg S, Mehta S, Dormans JP: Modern surgical treatment of primary aneurysmal bone cyst of the spine in children and adolescents. J Ped Orthop 2005;25:387-392.

Question 53:

Which of the following describes the correct proximal to distal progression of the annular and cruciform pulleys of the digits?

Options:

A1, C1, A2, C2, A3, A4, C3
A1, A2, A3, C1, C2, C3, A4
A1, C1, C2, A2, A3, A4, C3
A1, A2, C1, A3, C2, A4, C3
A1, A2, A3, A4, C1, C2, C3

Correct Answer: A1, A2, C1, A3, C2, A4, C3

Explanation:

DISCUSSION: The correct progression of the annular and cruciform pulley in the digits is A1, A2, C1, A3, C2, A4, C3. The two cruciform pulleys are collapsible elements adjacent to the more rigid annular pulleys of the flexor tendon sheath. This arrangement enables unrestricted flexion of the proximal interphalangeal joint.
REFERENCES: Hoppenfeld S, deBoer P: Surgical Exposures in Orthopaedics, ed 2. Philadelphia, PA, Lippincott-Raven, 1994, pp 176-186.
Strickland J: Flexor tendon-acute injuries, in Green D, Hotchkiss R, Pederson W (eds): Green’s Operative Hand Surgery, ed 4. New York, NY, Churchill Livingstone, 1999, pp 1853-1855.

Question 54:

Patient-specific instrumentation (PSI) reliably demonstrates which benefit over conventional intramedullary guidance systems?

Options:

Lower cost
Improved functional outcomes
Better coronal alignment
Fewer trays

Correct Answer: Fewer trays

Explanation:

Question 55:

Which factor should most influence a patient's decision to have surgery for adult scoliosis if he or she is younger than age 50?

Options:

Increasing coronal plane deformity
Increasing pain
Increasing sagittal balance
Invasiveness of the surgical procedure

Correct Answer: Increasing coronal plane deformity

Explanation:

DISCUSSION
In a retrospective review of 137 patients treated surgically and 153 patients treated nonsurgically for adult scoliosis, Bess and associates found that surgical treatment for patients younger than 50 years of age was driven by increased coronal plane deformity, and surgical treatment for older patients was mandated by pain and disability. They also concluded that age, comorbidities, and sagittal balance did not influence treatment decisions.
RECOMMENDED READINGS
Bess S, Boachie-Adjei O, Burton D, Cunningham M, Shaffrey C, Shelokov A, Hostin R, Schwab F, Wood K, Akbarnia B; International Spine Study Group. Pain and disability determine treatment modality for older patients with adult scoliosis, while deformity guides treatment for younger patients. Spine (Phila Pa 1976). 2009 Sep 15;34(20):2186-90. PubMed PMID: 19752704.
View
Abstract at PubMed
Anderson DG, Albert T, Tannoury C. Adult scoliosis. In: Spivak JM, Connolly PJ, eds. Orthopaedic Knowledge Update: Spine 3. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2006:331-338.

Question 56:

- The radiographs shown in Figures 71a through 71c, and the CT scan shown in Figure 71d reveal an acetabular fracture that should be classified as

Options:

t-type
both column
transverse
anterior column
anterior column posterior hemitransverse

Correct Answer: both column

Explanation:

Question 57:

Which of the following nonunions is appropriately treated with exchange reamed nailing without bone graft augmentation?

Options:

Infected tibial shaft nonunion 6 months status post intramedullary nail fixation
Oligotrophic humeral shaft nonunion 7 months status post non-operative management
Hypertrophic tibial shaft nonunion 7 months status post intramedullary nail fixation
Comminuted open tibial shaft nonunion with segmental bone loss 8 months status post intramedullary nail fixation
Supracondylar femoral shaft nonunion 6 months status post intramedullary nail fixation with 4 distal locking screws

Correct Answer: Infected tibial shaft nonunion 6 months status post intramedullary nail fixation

Explanation:

Question 58:

Options:

Anterior shoulder instability
Early adhesive capsulitis
Internal impingement
Subacromial impingement
Full-thickness rotator cuff tear

Correct Answer: Internal impingement

Explanation:

Question 59:

Options:

Observation
Physical therapy
Epidural steroid injections
Cervical laminectomy
Anterior cervical diskectomy and fusion

Correct Answer: Observation

Explanation:

The patient has obvious signs of progressive myelopathy. Based on her significant physical examination findings, nonsurgical management will not significantly impact her outcome. Cervical decompression alone is contraindicated in patients with cervical kyphosis such as seen here. Anterior cervical fusion is the best option.
(SBQ12SP.77) A 68-year-old is undergoing lateral lumbar interbody fusion using the tranpsoas approach. Which of the following statements is true regarding the safe approach zone for this procedure as you move cranial to caudal in the lumbar spine?
Review Topic
Safe approach zone increases due to vessels moving more ventral
Safe approach zone increases due to lumbar plexus moving more dorsal
Safe approach zone decreases due to vessels moving more dorsal
Safe approach zone decreases due to lumbar plexus moving more ventral
Safe approach zone remains the same throughout the lumbar spine
As you move cranial to caudal in the lumbar spine, the safe approach zone for the lateral transpsoas approach decreases due to the more ventral position of the lumbar plexus.
Lateral lumbar interbody fusion has become more common for degenerative spine disorders and adjacent segment degeneration. This transpsoas approach is typically useful for pathology from L1-L2 disc space to the L4-L5 disc space and places the lumbar plexus at risk. Working at the more caudal disc spaces is especially difficult given the more ventral position of the plexus, but the use of triggered EMG retractors and probes can help prevent nerve injuries. Surgical approach can be especially difficult in patients with rotational deformities.
Benglis et al. did a cadaver study with specimens placed lateral to trace the course of the lumbar plexus. They found that the plexus move more ventral with respect to the disc space moving more caudal in the lumbar spine.
Park et al. used 10 cadaver specimens to measure the distance of the lumbar nerve roots from the center of the disc space in the lateral approach. While disc space access was generally safe, there was less distance to the nerve root for more caudal disc levels.
Regev et al. did a MRI study to evaluate the safe working corridor for the lateral approach. The safe zone narrows considerably in the L4-L5 disc space due to more
ventral position of the nerve roots, and they recommend careful monitoring when addressing this level.
Incorrect

Question 60:

A 10-year-old boy who plays baseball reports acute pain after throwing a softball from the outfield to second base. A radiograph is shown in Figure 26. Management should consist of

Options:

observation during healing of the fracture, followed by bone marrow or corticosteroid injection.
biopsy and appropriate chemotherapy.
curettage and bone grafting.
high-dose systemic corticosteroids.
pulsed electromagnetic fields.

Correct Answer: observation during healing of the fracture, followed by bone marrow or corticosteroid injection.

Explanation:

Question 61:

Options:

Ilioinguinal
Superior gluteal
Superior cluneal
Iliohypogastric
Lateral femoral cutaneous

Correct Answer: Superior cluneal

Explanation:

DISCUSSION: The superior cluneal nerves (L1, L2, and L3) are at greatest risk when harvesting iliac crest bone graft during a posterior decompression and fusion. The nerves pierce the lumbodorsal fascia and cross the posterior iliac crest beginning at 8 cm lateral to the posterior superior iliac spine. The ilioinguinal and iliohypogastric nerves innervate anterior structures, and the lateral femoral cutaneous nerve lies in proximity to the anterior superior iliac spine and is at risk with anterior iliac crest bone graft harvesting. The superior gluteal nerve courses through the sciatic notch and supplies motor branches to the gluteus medius, minimus, and tensor fascia lata muscles.
REFERENCES: An HS: Principles and Techniques of Spine Surgery. Baltimore, MD,
Williams and Wilkins, 1998, pp 770-773.
Kurz LT, Garfin SR, Booth RE: Harvesting autogenous iliac bone grafts: A review of complications and techniques. Spine 1989;14:1324-1331.

Question 62:

During the first 2 years of life, which of the following actions is most responsible for increasing structural stability of the physis?

Options:

The change from a flat to an undulating physis
The growth of the zone of Ranvier
Increased strength of the points of insertion of muscles onto bone
Increased penetration of proprioceptive nerve endings about the physis
Increased capillary penetration about the physis

Correct Answer: The growth of the zone of Ranvier

Explanation:

Question 63:

What is the most common reason an individual with a malignant soft-tissue tumor in the extremities seeks medical attention?

Options:

Incidental finding on imaging tests
Pain
Presence of a mass
Deformity
Neurologic symptoms

Correct Answer: Presence of a mass

Explanation:

Question 64:

Tension force in the anterior cruciate ligament during passive range of motion is highest at

Options:

full extension.
30 degrees of flexion.
60 degrees of flexion.
90 degrees of flexion.
120 degrees of flexion.

Correct Answer: full extension.

Explanation:

Question 65:

Type I collagen fibers in peripheral nerves are primarily responsible for which of the following?

Options:

Conduction strength
Tensile strength
Conduction velocity
Compressive strength
Cross-linkage

Correct Answer: Conduction velocity

Explanation:

Question 66:

Options:

Resolution by age 3 or 4 years without active treatment in most patients
Resolution by age 8 or 9 years without active treatment in most patients
Resolution with casting as the most effective treatment
Resolution with bracing and shoe modification as the most effective treatment
Resolution with surgery as the most effective treatment

Correct Answer: Resolution by age 3 or 4 years without active treatment in most patients

Explanation:

Question 67:

repair of the rotator cuff

Options:

closed reduction and immobilization
open reduction and immobilization
open reduction and early passive motion

Correct Answer: closed reduction and immobilization

Explanation:

Question 68:

Options:

Kaposi sarcoma
Squamous cell carcinoma
Pigmented basal cell carcinoma
Melanoma
Basillary angiomatosis

Correct Answer: Melanoma

Explanation:

Question 69:

Options:

Scaphoid fracture
Radiocarpal dislocation
Midcarpal dislocation
Transscaphoid dorsal perilunate dislocation
Volar lunate dislocation

Correct Answer: Transscaphoid dorsal perilunate dislocation

Explanation:

Question 70:

Options:

Subtrochanteric osteotomy with femoral shortening
An offset femoral component
A lateralized liner
Extended trochanteric osteotomy

Correct Answer: Subtrochanteric osteotomy with femoral shortening

Explanation:

Question 71:

What is the heaviest weight that can be safely applied to the adult cervical spine via Gardner-Wells tong traction?

Options:

40 pounds
50 pounds
75 pounds
100 pounds
Greater than 100 pounds

Correct Answer: Greater than 100 pounds

Explanation:

DISCUSSION: Cotler and associates reported on the use of awake skeletal traction to reduce facet fracture-dislocations in 24 patients. Seventeen patients required more than 50 pounds of traction (the “traditional” limit) to achieve reduction. More than 100 pounds of traction was safely used in one-third of the patients in this study. A cadaver study has supported the safe use of traction with weights in excess of 100 pounds.
REFERENCES: Cotler JM, Herbison GJ, Nasuti JF, et al: Closed reduction of traumatic cervical spine dislocation using traction weights up to 140 pounds. Spine 1993;18:386-390.
Anderson DG, Vacccaro AR, Gavin K: Cervical orthoses and cranioskeletal traction, in Clark CR (ed): The Cervical Spine, ed 4. Philadelphia, PA, Lippincott Williams & Wilkins, 2005,
pp 110-121.

Question 72:

Options:

Lateral talar process
Superior peroneal retinaculum
Inferior peroneal retinaculum
Extensor retinaculum
Crural fascia

Correct Answer: Superior peroneal retinaculum

Explanation:

DISCUSSION: The patient has instability of the peroneal tendon. The superior peroneal retinaculum is the primary retaining structure preventing peroneal subluxation. It is a thickening of fascia that arises off the posterior margin of the distal 1 to 2 cm of the fibula and runs posteriorly to blend with the Achilles tendon sheath. The inferior peroneal retinaculum attaches to the peroneal tubercle of the calcaneus and is not involved in this pathology. A deficient groove in the posterior distal fibula may also be a contributing factor in the development of
the condition.
REFERENCE: Maffuli N, Ferran NA, Oliva F, et al: Recurrent subluxation of the peroneal tendons. Am J Sports Med 2006;34:986-992.

Question 73:

A 34-year-old male presents with elbow pain after sustaining a ground level fall 2 weeks ago. An injury radiograph is shown in Figure

Options:

Which of the following provocative maneuvers will most likely be positive?
Lateral pivot shift test
Milking maneuver
Chair rise test
Posterior drawer test
Gravity-assisted varus stress test Corrent answer: 5 Figure A demonstrates a fracture of the anteromedial coronoid. Patients with this injury pattern will have feelings of instability with the gravity-assisted varus stress test. Varus posteromedial rotatory instability (VPMRI) of the elbow is caused by a varus and posteromedial rotation force, resulting in rupture of the lateral collateral ligament (LCL) from its humeral origin. The medial coronoid process is subsequently forced against the medial trochlea, which results in fracture of the anteromedial portion. The most sensitive test is the gravity-assisted varus stress test. The arm is abducted to 90° and the patient is asked to flex and extend the elbow. The test is positive for pain, grinding, or instability during range of motion, as the ulnohumeral joint is closed medially by the lack of the buttress from the anteromedial coronoid. Treatment involves surgically addressing the anteromedial facet of the coronoid and repairing the LCL. Steinmann performed a review of coronoid process fractures. He reports that with an anteromedial coronoid fracture, the anteroposterior (AP) radiograph of the elbow will demonstrate progressive narrowing of the joint space from lateral to medial. They conclude that an important determinant of stability is the involvement of the sublime tubercle (insertion point of the MCL). When the sublime tubercle is involved, medial elbow instability is likely. Doornberg et al. performed a retrospective review of coronoid fracture patterns. They found that large fractures of the coronoid were involved with anterior and posterior olecranon fracture/dislocations, small transverse fractures were involved with terrible triad injuries, and anteromedial facet fractures were associated with VPMRI. Doornberg et al. performed a retrospective review of patients with fracture of the anteromedial facet of the coronoid. They report that if the fracture is not specifically treated, patients ultimately developed arthrosis. They report that the coronoid fracture may be secured with a plate, screw, or sutures. They conclude that secure fixation of the coronoid usually restores good elbow function. Figure A is an AP radiograph of the elbow demonstrating a fracture of the anteromedial facet of the coronoid. Illustration A is a fluoroscopic stress view demonstrating ulnohumeral instability due to an associated LCL injury. Illustration B is an AP radiograph demonstrating plate and screw fixation of the coronoid and suture anchor repair of the LCL. Incorrect Answers:

Correct Answer: Chair rise test

Explanation:

positive finding and is seen in valgus posterolateral rotatory instability of the elbow.
OrthoCash 2020

Question 74:

Which of the following statements regarding conus medullaris syndrome is most accurate?

Options:

Conus medullaris syndrome most commonly accompanies injuries at the T12-L2 region.
Conus medullaris injury is a lower motor neuron injury, resulting in an excellent prognosis for recovery of bowel and bladder dysfunction.
The conus medullaris houses the motor cell bodies for the lumbar roots.
Lower extremity weakness is a common sign of conus medullaris syndrome.
Autonomic dysreflexia is common.

Correct Answer: Conus medullaris syndrome most commonly accompanies injuries at the T12-L2 region.

Explanation:

DISCUSSION: Conus medullaris syndrome most frequently occurs as a result of trauma or with a disk herniation at L1, resulting in a lower motor neuron syndrome but with a poor prognosis for recovery of bowel and bladder dysfunction. The conus region, as the termination of the spinal cord, contains the motor cell bodies of the sacral roots. The syndrome is usually a sacral level neural injury; therefore, lower extremity weakness is uncommon.
REFERENCES: Haher TR, Felmly WT, O’Brien M: Thoracic and lumbar fractures: Diagnosis and management, in Bridwell KH, Dewald RL, Hammerberg KW, et al (eds): The Textbook of Spinal Surgery, ed 2. New York, NY, Lippincott Williams & Wilkins, 1977, pp 1773-1778.
Reitman
CA
(ed): Management of Thoracolumbar Fractures. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004, pp 35-45.

Question 75:

Which of the following is considered the preferred approach to resect a lesion in the posterior one third of the proximal humerus?

Options:

Triceps splitting
Deltoid splitting
Between the lateral head of the triceps and the deltoid muscle
Between the long head of triceps and the deltoid muscle
Between the long head of triceps and the teres major

Correct Answer: Between the lateral head of the triceps and the deltoid muscle

Explanation:

Question 76:

Options:

Administration of broad spectrum IV antibiotics
Irrigation and debridement in OR followed by broad spectrum IV antibiotics
NSAIDS and observation with repeat ESR and CRP in 24 hours
Joint aspiration and blood cultures

Correct Answer: Joint aspiration and blood cultures

Explanation:

Question 77:

Options:

intramedullary rod fixation.
arterial embolization.
skeletal traction and radiation therapy for 2 weeks.
CT of the chest, abdomen, and pelvis, and serum protein electrophoresis.
a skeletal survey and serum protein electrophoresis.

Correct Answer: CT of the chest, abdomen, and pelvis, and serum protein electrophoresis.

Explanation:

Question 78:

Options:

Failure of patellar polyethylene
Loosening of the femoral component
Loosening of the tibial component
Loosening of the patellar component
Wear-induced osteolysis

Correct Answer: Failure of patellar polyethylene

Explanation:

Question 79:

During treatment of rupture of the subscapularis tendon with associated biceps instability, treatment of the biceps tendon should include which of the following?

Options:

Tenosynovectomy
Recentering
Deepening of the bicipital groove
Tenodesis or tenotomy
Lysis of sheath adhesion

Correct Answer: Tenodesis or tenotomy

Explanation:

DISCUSSION: With subscapularis tendon ruptures that have biceps tendon pathology, treatment with tenodesis or tenotomy has improved clinical results. Subluxation or dislocation of the biceps tendon is common with subscapularis rupture. Dislocation of the biceps can occur either beneath the tendon, within the tendon, or extra-articularly. In all cases, the restraints to medial translations of the biceps have been disrupted. Attempts at recentering the biceps have not been successful, and clinical results appear to be improved when tenodesis or tenotomy is employed in the treatment of the unstable biceps associated with subscapularis tears.
REFERENCES: Edwards TB, Walch G, Sirvenaux F, et al: Repair of tears of the subscapularis: Surgical technique. J Bone Joint Surg Am 2006;88:1-10.
Deutsch A, Altchek DW, Veltri DM, et al: Traumatic tears of the subscapularis tendon: Clinical diagnosis, magnetic resonance imaging findings, and operative treatment. Am J Sports Med 1997;25:13-22.
Edwards TB, Walch G, Sirveaux F, et al: Repair of tears of the subscapularis. J Bone Joint Surg Am 2005;87:725-730.

Question 80:

A 28-year-old cowgirl was injured while herding cattle 1 week ago. A radiograph and CT scans are shown in Figures 13a through 13c. What is the most appropriate management for this injury?

Options:

Nonsurgical management and gradual weight bearing as tolerated
Nonsurgical management and restricted weight bearing
Placement of a pelvic binder
Open reduction and internal fixation of the symphysis
Open reduction and internal fixation of the symphysis and iliosacral screws

Correct Answer: Nonsurgical management and gradual weight bearing as tolerated

Explanation:

DISCUSSION: The patient has an AP I pelvic ring disruption with minimal symphyseal widening. The best treatment is nonsurgical management and weight bearing as tolerated. This will help close the anterior pelvic ring during the healing process. Pelvic binders are excellent for acute treatment of widely displaced pelvic fractures but are not recommended for long-term use. Open reduction and internal fixation is not indicated for this injury and furthermore, the posterior ring is not injured.
REFERENCES: Matta JM: Indications for anterior fixation of pelvic fractures. Clin Orthop Relat Res 1996;329:88-96.
Templeman DC, Schmidt AH, Sems SA, et al: Diastasis of the symphysis pubis: Open reduction internal fixation, in Wiss D (ed): Masters Techniques in Orthopaedic Surgery-Fractures, ed 2. Philadelphia, PA, Lippincott Williams and Wilkins, 2006, pp 639-648.
Tile M: Management, in Tile M: Fractures of the Pelvis and Acetabulum, ed 2. Philadelphia, PA, Williams and Wilkins, 1995, pp 108-134.

Question 81:

Options:

Acute reconstruction of all ligamentous structures
Emergency MRI and reconstruction of all ligamentous structures
Emergency arteriogram followed by MRI
Emergency surgery with open reduction and repair of all tom structures with vascular surgery available
Closed reduction in the emergency room and reevaluation of the vascular status

Correct Answer: Closed reduction in the emergency room and reevaluation of the vascular status

Explanation:

Question 82:

Options:

physical therapy for quadriceps strengthening exercises.
a long leg cast with the knee fully extended.
excision of the fragment.
suture reattachment of the patellar tendon to the tibial tuberosity.
open reduction and tension band fixation.

Correct Answer: open reduction and tension band fixation.

Explanation:

DISCUSSION: The radiograph shows an avulsion fracture, or “sleeve fracture,” of the distal pole of the patella. The distal fragment is much larger than it appears on the radiograph because it largely consists of cartilage; therefore, excision of the fragment is contraindicated. The treatment of choice is open reduction and tension band fixation to correct patella alta and restore the extensor mechanism.
REFERENCES: Maguire JK, Canale ST: Fractures of the patella in children and adolescents.
J Pediatr Orthop 1993;13:567-571.
Grogan DP, Carey TP, Leffers D, et al: Avulsion fractures of the patella. J Pediatr Orthop 1990;10:721-730.

Question 83:

Options:

open repair of the lateral joint capsule disruption.
open Bankart-type repair of the labral-glenoid tear.
arthroscopic repair of the Bankart lesion.
physical therapy for rotator cuff strengthening.
immobilization for 6 weeks, followed by rehabilitation.

Correct Answer: open repair of the lateral joint capsule disruption.

Explanation:

DISCUSSION: The MRI findings reveal a disruption of the humeral insertion of the glenohumeral ligaments and joint capsule (humeral avulsion of the glenohumeral ligament). This lesion has been reported to account for an 8% rate of recurrent dislocation in a subset of patients who are typically older than those with the more common lesions of the glenoid labrum (Bankart lesion). Open repairs have been reported to be successful in the prevention of recurrent instability. Since there is no Bankart lesion, open or arthroscopic labral repairs are not indicated. Nonsurgical management is possible if the patient does not want to undergo surgery; however, the recurrence rate is very high.
REFERENCES: Wolf EM, Cheng JC, Dickson K: Humeral avulsion of glenohumeral ligaments as a cause of anterior shoulder instability. Arthroscopy 1995;11:600-607.
Bokor DJ. Conboy VB. Olson C: Anterior instability of the glenohumeral joint with humeral avulsion of the glenohumeral ligament: A review of 41 cases. J Bone Joint Surg Br
1999;81:93-96.
Coates MH, Breidahl W: Humeral avulsion of the anterior band of the inferior glenohumeral ligament with associated subscapularis bony avulsion in skeletally immature patients. Skeletal Radiol 2001;30:661-666.

Question 84:

Spontaneous entrapment of the posterior interosseous nerve most commonly occurs in which of the following locations?

Options:

Lateral intermuscular septum
Extensor carpi radialis brevis
Arcade of Frohse
Midsubstance of the supinator
Leash of Henry

Correct Answer: Arcade of Frohse

Explanation:

DISCUSSION: The extensor carpi radialis brevis, supinator muscle, arcade of Frohse, and leash of Henry are potential sites of compression for the posterior interosseous nerve. The most common location of spontaneous entrapment is the arcade of Frohse. The lateral intermuscular septum is a site of compression for the radial nerve.
REFERENCE: Spinner RJ, Spinner M: Nerve entrapment syndromes, in Morrey BF: The Elbow and Its Disorders, ed 3. Philadelphia, PA, WB Saunders, 2000, pp 839-862.

Question 85:

Options:

Medial collateral ligament
Annular ligament
Lateral ulnar collateral ligament
Extensor carpi radialis brevis
Extensor carpi radialis longus

Correct Answer: Lateral ulnar collateral ligament

Explanation:

DISCUSSION: The patient has an iatrogenic injury to the lateral ulnar collateral ligament following the arthroscopic procedure. Failure to adhere to known anatomic landmarks can lead to this devastating complication. The examination findings are classic for posterolateral elbow instability.
REFERENCES: Koval KJ (ed): Orthopaedic Knowledge Update 7. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, p 318.
O’ Driscoll SW, Bell DF, Morrey BF: Posterolateral rotatory instability of the elbow. J Bone Joint Surg Am 1991;73:440-446.

Question 86:

What is the most common complication following metatarsal osteotomy for a bunion deformity in an adolescent?

Options:

Hallux varus
Osteonecrosis
Recurrence of the hallux valgus
“Transfer” second metatarsalgia
Physeal arrest of the first metatarsal

Correct Answer: Recurrence of the hallux valgus

Explanation:

Question 87:

Options:

surgical excision of heterotopic ossification and ethyl hydroxydiphosphonate at a dose of 20 mg/kg of body weight for 3 months.
surgical excision of heterotopic ossification and irradiation of the right hip in a single dose of 400 Gy postoperatively.
surgical excision of heterotopic ossification and irradiation of the right hip in a single dose of 700 Gy postoperatively.
ethyl hydroxydiphosphonate at a dose of 20 mg/kg of body weight for 3 months.
25 mg of oral indomethacin administered three times a day for 10 days.

Correct Answer: surgical excision of heterotopic ossification and irradiation of the right hip in a single dose of 700 Gy postoperatively.

Explanation:

Question 88:

Options:

Chondroblastoma
Lymphoma
Giant cell tumor
Chondromyxoid fibroma
Desmoplastic fibroma

Correct Answer: Giant cell tumor

Explanation:

Question 89:

In infantile idiopathic scoliosis, which of the following factors suggests progression? Review Topic

Options:

Age at presentation
Rib overlap of the apical vertebra
Rib vertebral angle difference of greater then 10 degrees
Male gender
Family history

Correct Answer: Rib overlap of the apical vertebra

Explanation:

Question 90:

Options:

infection. B. instability. C. loosening.
periprosthetic fracture.

Correct Answer: periprosthetic fracture.

Explanation:

Question 91:

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?

Options:

Numbness in the anterior aspect of his shoulder
Recurrent instability
Difficulty raising his arm
Biceps muscle deformity

Correct Answer: Difficulty raising his arm

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.

Question 92:

Options:

Resection of the tarsal coalition
Open reduction and internal fixation of the navicular fracture
Surgical resection of the accessory navicular
Corticosteroid injection
Custom-molded orthosis

Correct Answer: Custom-molded orthosis

Explanation:

Question 93:

Options:

Proximal femoral resections
Bilateral adducter, iliopsoas, and hamstring lengthenings
Bilateral varus derotation shortening osteotomies
Injection of botulinum toxin into the adducters bilaterally
Posterior branch obturator neurectomies bilaterally

Correct Answer: Bilateral varus derotation shortening osteotomies

Explanation:

Question 94:

Options:

Microfracture
Autologous chondrocyte implantation
Osteochondral allograft transfer
Dejour trochleoplasty

Correct Answer: Osteochondral allograft transfer

Explanation:

The images show a full-thickness cartilage defect with significant bony involvement >4 cm
2
. Microfracture should be considered for lesions <2 cm
2
without an underlying osseous defect. Autologous chondrocyte implantation, although used for lesions between 1 and 10 cm
2
, should be restricted for defects with minimal (<8 mm depth) bone loss. Osteochondral allograft transfer with the mosaicplasty technique (transfer of multiple plugs) would be well-suited for this large defect with significant osseous involvement. Dejour trochleoplasty is performed for patellar instability to correct trochlear dysplasia and
would not be indicated in this case.

Question 95:

Options:

immobilization.
closed reduction.
open reduction and internal fixation.
early range of motion.
excision.

Correct Answer: immobilization.

Explanation:

Question 96:

- What factor is most commonly associated with malignant transformation of a giant cell tumor?

Options:

high-grade histology of the initial tumor
multiple local recurrences after curettage
previous treatment of the tumor with cryotherapy
previous treatment of the tumor with radiation therapy
extraosseous extension into two or more adjacent compartments

Correct Answer: previous treatment of the tumor with radiation therapy

Explanation:

Most authors have agreed that radiation therapy should be avoided in the treatment of giant cell tumor, as there is a high prevalence of sarcomatous degeneration.

Question 97:

Options:

MRI scan
Diagnostic arthroscopy
Surgical repair of a ruptured quadriceps tendon
Knee immobilizer for 6 weeks, followed by a sport brace
Limited weight bearing for 3 weeks, followed by physical therapy

Correct Answer: Surgical repair of a ruptured quadriceps tendon

Explanation:

Question 98:

What is the typical MRI signal intensity of bone marrow affected by acute osteomyelitis?

Options:

Decreased on T 1 -weighted imaging, increased on T 1 -weighted imaging with gadolinium enhancement, increased on T 2 -weighted imaging
Decreased on T 1 -weighted imaging, increased on T 1 -weighted imaging with gadolinium enhancement, decreased on T2-weighted imaging
Increased on T 1 -weighted imaging, increased on T 1 -weighted imaging with gadolinium enhancement, increased on T 2 -weighted imaging
Increased on T 1 -weighted imaging, increased on T 1 -weighted imaging with gadolinium enhancement, decreased on T 2 -weighted imaging
Increased on T 1 -weighted imaging, decreased on T 1 -weighted imaging with gadolinium enhancement, decreased on T 2 -weighted imaging

Correct Answer: Decreased on T 1 -weighted imaging, increased on T 1 -weighted imaging with gadolinium enhancement, increased on T 2 -weighted imaging

Explanation:

DISCUSSION: The classic MRI findings of osteomyelitis are a decrease in the normally high signal intensity of marrow on T
1
-weighted images and normal or increased signal intensity on T
2
-weighted images. This is the result of replacement of marrow fat by inflammatory cells and edema, which causes lower signal intensity than fat on T
1
-weighted images and higher signal intensity than fat on T
2
-weighted images. The addition of gadolinium to a T
1
-weighted sequence reveals increased signal intensity in the hyperemic marrow.
REFERENCES: Unger E, Moldofsky P, Gatenby R, et al: Diagnosis of osteomyelitis by MR imaging. Am J Roentgenol 1988;150:605-610.
Dormans JP, Drummond DS: Pediatric hematogenous osteomyelitis: New trends in presentation, diagnosis and treatment. J Am Acad Orthop Surg 1994;2:333-341.
Herring JA: Tachdjian’s Pediatric Orthopaedics, ed 3. Philadelphia, PA, WB Saunders, 2002, vol 1, pp 150-163.

Question 99:

Options:

Buerger’s disease
Hypothenar hammer syndrome
Superficial palmar arch aneurysm
Raynaud’s phenomenon
Diabetic vasculopathy

Correct Answer: Raynaud’s phenomenon

Explanation:

Question 100:

Options:

Inflammatory elbow arthritis
A presurgical flexion-extension elbow arc of approximately 50°
Retained distal humerus hardware on presurgical radiographs
Evidence of presurgical elbow instability

Correct Answer: Evidence of presurgical elbow instability

Orthopedic Surgery Board Review MCQs: Arthroplasty, Trauma & Spine Part 255

Orthopedic Board Exam MCQs: Arthroplasty, Sports Medicine & Trauma | Part 192

Key Takeaway

About This Board Review Set

How to Use the Interactive Quiz

Topics Covered in Part 192

Sample Questions from This Set

Why Active MCQ Practice Works

Chapter Index