OITE Orthopedic Surgery Board Review MCQs | Part 235

About This Board Review Set

This is Part 235 of the comprehensive OITE and AAOS Orthopedic Surgery Board Review series authored by Dr. Mohammed Hutaif, Consultant Orthopedic & Spine Surgeon.

This set has been strictly audited and contains 100 100% verified, high-yield multiple-choice questions (MCQs) modelled on the exact format of the Orthopaedic In-Training Examination (OITE) and the American Academy of Orthopaedic Surgeons (AAOS) board examinations.

How to Use the Interactive Quiz

Two distinct learning modes are available:

Study Mode — After selecting an answer, you immediately see whether you are correct or incorrect, together with a full clinical explanation and literature references.
Exam Mode — All feedback is hidden until you click Submit & See Results. A live timer tracks elapsed time. A percentage score and detailed breakdown are displayed upon submission.

Pro Tip: Use keyboard shortcuts A–E to select options, F to flag a question for review, and Enter to jump to the next unanswered question.

Topics Covered in Part 235

This module focuses heavily on: Ankle, Dislocation, Fracture, Nerve.

Sample Questions from This Set

Sample Question 1: A 24-year-old dancer reports posterior ankle pain when in the “en pointe” position. Examination reveals posteromedial tenderness, no pain reproduction with passive forced planter flexion, and pain with motion of the hallux. What is the most...

Sample Question 2: A 32-year-old motorcycle rider is involved in a motor vehicle accident and radiographs show a burst fracture at L2 with 20 degrees of kyphosis. The neurologic examination is consistent with unilateral motor and sensory involvement of the L5...

Sample Question 3: -What is the most common nerve injury following a Monteggia fracture-dislocation of the forearm in adults?...

Sample Question 4: A 45-year-old male falls off his motorcycle and injures his arm. AP and lateral radiographs reveal an ulnar shaft fracture, 30 degrees apex anterior, and a radial head dislocation. Which direction is the radial head most likely dislocated?...

Sample Question 5: What radiographic view will best reveal degeneration of the pisotriquetral joint in a patient who is being evaluated for pisotriquetral arthrosis?...

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

A 24-year-old dancer reports posterior ankle pain when in the “en pointe” position. Examination reveals posteromedial tenderness, no pain reproduction with passive forced planter flexion, and pain with motion of the hallux. What is the most likely diagnosis?

Explanation

DISCUSSION: Flexor hallucis longus tendinitis is a common cause of posterior ankle pain in dancers. It tends to be more posteromedial and is characterized by a clicking or catching sensation posteromedially with motion of the great toe. A painful os trigonum typically causes more posterolateral ankle pain and may occur after an ankle sprain or plantar flexion injury where there may be a fracture of the os trigonum.
REFERENCES: Garrick JG (ed): Orthopaedic Knowledge Update: Sports Medicine 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004, pp 249-261.
Hamilton WG, Geppert MJ, Thompson FM: Pain in the posterior aspect of the ankle in dancers: Differential diagnosis and operative treatment. J Bone Joint Surg Am 1996;78:1491-1500.

Question 2

A 32-year-old motorcycle rider is involved in a motor vehicle accident and radiographs show a burst fracture at L2 with 20 degrees of kyphosis. The neurologic examination is consistent with unilateral motor and sensory involvement of the L5, S1, S2, S3, and S4 nerve roots. He has no other injuries. CT demonstrates 20% anterior canal compromise with displaced laminar fractures at the level of injury. What is the best option for management of this patient?

Explanation

DISCUSSION: The patient has a burst fracture with probable unilateral entrapment of the cauda equina within the elements of the fractured lamina. A dural tear is likely in this scenario as well. It is recommended that this type of burst fracture be treated surgically with laminectomy, freeing of the entrapped nerve roots, and dural repair followed by stabilization of the fracture by either a posterior or combined approach. The degree of kyphosis and the extent of anterior canal compromise does not warrant corpectomy in this patient. Therefore, after completing the laminectomy and dural repair, posterior fusion and instrumentation should be sufficient to stabilize the fracture.
REFERENCES: Cammisa FP Jr, Eismont FJ, Green BA: Dural laceration occurring with burst fractures and associated laminar fractures. J Bone Joint Surg Am 1989;71:1044-1052.
Spivak JM, Connolly PJ (eds): Orthopaedic Knowledge Update: Spine 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, pp 201-216.

Question 3

What is the most common nerve injury following a Monteggia fracture-dislocation of the forearm in adults?

Explanation

According to Rockwood and Green the most commonly injured nerve associated with a Monteggia fracture is the posterior interosseous nerve, a branch of the radial nerve.

Question 4

A 45-year-old male falls off his motorcycle and injures his arm. AP and lateral radiographs reveal an ulnar shaft fracture, 30 degrees apex anterior, and a radial head dislocation. Which direction is the radial head most likely dislocated?

Explanation

DISCUSSION: A monteggia fracture with apex anterior ulnar shaft fracture is associated with an anterior radial head dislocation (See Illustration A). Bado initially described and classified these injuries. The most common injury pattern is an extension type 1 with anterior radial head dislocation and apex anterior ulnar shaft fracture. The apex of the ulna fracture determines the direction of the radial head subluxation or dislocation. Adults typically require ORIF of the ulna. These fractures in children are often treated non-operatively with closed reduction if the ulna fracture is transverse and stable as illustrated by Fowles' case series, but may also require pinning if the fracture is oblique and unstable.

Question 5

What radiographic view will best reveal degeneration of the pisotriquetral joint in a patient who is being evaluated for pisotriquetral arthrosis?

Explanation

DISCUSSION: The pisotriquetral joint is best seen on a lateral view in 30 degrees of supination. The carpal tunnel view provides visualization of the joint but to a lesser extent. The other views do not provide clear and accurate visualization.
REFERENCES: Paley D, McMurty RY, Cruickshank B: Pathologic conditions of the pisiform and pisotriquetral joint. J Hand Surg Am 1987;12:110-119.
Steinmann SP, Linsheid RL: Pisotriquetral loose bodies. J Hand Surg 1997;22:918-921.
related link ortho mcqs bank

Question 6

Figure 17 shows the AP radiograph of a 75-year-old man with right hip pain. The femoral component is loose. The mechanism of loosening is most likely secondary to

Explanation

DISCUSSION: The femoral construct shown in the radiograph has failed to produce ingrowth of the stem. The stem has subsided and rotated. Impingement of the trochanter did not occur until after the stem subsided. There is no evidence of osteolysis or third-body wear debris from the cerclage wire. A larger femoral stem needs to be implanted to achieve rigid fixation.
REFERENCES: Pelicci PM, Tria AJ Jr, Garvin KL (eds): Orthopaedic Knowledge Update:

Hip and Knee Reconstruction 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000, pp 217-238.
Peter CL, Rivero DP, Kull LR, et al: Revision total hip arthroplasty without cement: Subsidence of proximally porous-coated femoral components. J Bone Joint Surg Am 1995;77:1217-1226.

Question 7

A 67-year-old woman has a painful, arthritic proximal interphalangeal (PIP) joint, and nonsurgical measures have failed to improve the pain. What implant and joint replacement approach combination has been demonstrated to have the lowest rate of revision surgery?

Explanation

EXPLANATION:
A recent systematic review compared silicone replacement, pyrocarbon replacement, and surface replacement arthroplasty for PIP arthritis. Silicone arthroplasty through a volar approach showed the greatest gains in arc of motion and had the lowest rate of revision surgeries. The rates of revision surgeries from low to high for each type of arthroplasty were 6% for silicone volar, 10% for silicone lateral, 11%
Surface replacement arthroplasty through a volar
for silicone dorsal, 18% for surface replacement dorsal, and 37% for surface replacement volar. Revision surgeries include implant replacement (to silicone or maintaining the surface replacement), arthrodesis, explantation, amputation, and other procedures.
approach showed the highest revision rate, the worst gain in arc of motion, and the greatest extension lag. However, substantial pain relief and higher satisfaction still were reported after surface replacement arthroplasty, regardless of the complications.

Question 8

Clinical evidence suggests that grafts for replacing a torn anterior cruciate ligament often stretch after surgery. What is the most probable mechanism for this behavior?

Explanation

DISCUSSION: The stretching of the graft occurs over time as the graft is loaded. Time-dependent deformation under load is called creep and is common in viscoelastic materials such as ligament tissue. Creep can occur under both static and cyclic load conditions; time-dependent deformation will occur as long as load is applied to the tissue. Similarly, when a graft is initially tensioned to a given deformation at surgery, the load generated in the graft will decrease over time; this behavior is called stress relaxation and also is indicative of a viscoelastic material. Water content may affect the viscoelastic properties by changing the friction between collagen fibers, but studies have shown little difference in water content between grafts and normal ligaments. Fatigue failures may manifest themselves through damage to the ligament tissue, but this would require higher loads than are routinely experienced by grafts. Elastic stretch is recoverable and, therefore, does not contribute to a permanent stretch. Similarly, gross failure at the attachment would not cause a stretch, but rather a catastrophic instantaneous instability.
REFERENCES: Boorman RS, Thornton GM, Shrive NG, et al: Ligament grafts become more susceptible to creep within days after surgery. Acta Orthop Scand 2002;73:568-574.
Buckwalter JA, Einhorn TA, Simon SR (eds): Orthopaedic Basic Science: Biology and Biomechanics of the Musculoskeletal System, ed 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000, pp 596-609.
Lu L, Kaufman KR, Yaszemski MJ: Biomechanics, in Einhorn TA, O’Keefe RJ,

Buckwalter JA (eds): Orthopaedic Basic Science: Foundations of Clinical Practice, ed 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, in press.

Question 9

A 57-year-old woman with diabetes mellitus has purulent drainage from a lateral incision after undergoing open reduction and internal fixation of a displaced ankle fracture 10 days ago. Examination reveals moderate erythema and a foul odor coming from the wound. Cultures are obtained. What is the next most appropriate step in management?

Explanation

DISCUSSION: Early postoperative wound infections after open reduction and internal fixation should be treated with aggressive debridement and maintenance of stability of the fracture. If infection persists following healing of the fracture, the hardware should be removed.
REFERENCES: Carragee EJ, Csongradi JJ, Bleck EE: Early complications in the operative treatment of ankle fractures: Influence of delay before operation. J Bone Joint Surg Br 1991;73:79-82.
Blotter RH, Connolly E, Wasan A, Chapman MW: Acute complications in the operative treatment of isolated ankle fractures in patients with diabetes mellitus. Foot Ankle Int 1999;20:687-694.

Question 10

Figure 67 shows the AP radiograph of both knees of a 26-year-old woman. A review of the patient’s medical record will most likely reveal a history of

Explanation

Avascular necrosis of the knee is associated with the use of corticosteroids or alcohol 90% of the time. Radiographically evident lesions progress until the necrotic cancellous bone collapses away from the subchondral plate, resulting in the classic crescent sign; earliest sign of mechanical failure of the condyles. Generally seen in a younger age group (less than 50 years old). Of patients with corticosteroid induced AVN of the knee; 81% have systemic lupus erythematosus, 9.5% inflammatory bowel disease, and 9.5% polymyositis.

Question 11

Injury to the popliteal artery during total knee arthroplasty (TKA) is most likely to occur when placing a sharp retractor

Explanation

DISCUSSION:
Vascular complications during TKA are rare but do occur. Traditionally, it was taught that the popliteal artery was situated posterior to the PCL; however, more recent anatomic dissections have demonstrated that this artery is usually located posterolateral to the PCL.

Question 12

On MRI, a nonsanguinous effusion has what appearance?

Explanation

DISCUSSION: Nonbloody effusions that are greater than 1 mL are readily detected by MRI. They appear black on T1-weighted images and white on T2-weighted images. A sanguinous effusion is seen as white on T1-weighted images and black on T2-weighted images.
REFERENCES: Resnick D, Kang HS: Synovial joints, in Resnick D, Kang HS (eds): Internal Derangements of Joints: Emphasis on MR Imaging. Philadelphia, PA, WB Saunders, 1997, pp 49-53.
White EM: Magnetic resonance imaging in synovial disorders and arthropathy of the knee. Magn Reson Imaging Clin N Am 1994;2:451-461.

Question 13

Which of the following changes in the parameters of the gait cycle occurs in the transition from normal walking to running?

Explanation

The same basic mechanisms that have been described for the biomechanics of the foot and ankle are not significantly altered during running. The major differences observed during running are that the gait cycle is altered considerably; the amount of force generated, as measured by force plated data, is markedly increased; the range of motion of the joints of the lower extremities is increased; and the phasic activity of the muscles of the lower extremities is altered. During walking one foot is always in contact with the ground; as the speed of gait increases a float phase incorporated into the gait cycle, during which time both feet are off the ground. There also is no longer a period of double limb support. As the speed of gait continues to increase, the time the foot spends on the ground, both in real time and in percentage of cycle, decreases considerably. Question 71 -
Examination of a 5-year-old child who has fibular hemimelia reveals the foot has two rays and is stiff in equinus and valgus. The level of the foot is just proximal to the midshaft of the contralateral tibia, and the knee has full active flexion and extension, but slight valgus. Treatment should include
Amputation through the midshaft of the tibia
Correction of the foot deformity and lengthening with a ring fixator
Knee disarticulation
Ankle disarticulation
Ankle disarticulation and contralateral epiphyseodesis of the proximal tibia Answer: 4
Congenital absence of the fibula, also called fibula hemimelia, has several manifestations. These range from complete absence of the fibula with missing lateral rays of the foot (i.e. terminal longitudinal deficiency) to absence of only a portion of the fibula without foot involvement (i.e. intercalary longitudinal; deficiency). Congenital fibular deficiency usually occurs sporadically without a known cause. The child with complete absence of the fibula presents clinically with an anterolateral bow of the tibia, an equinovalgus deformity of the foot, and a tarsal coalition. The talotibial joint is usually malformed, with the fused talocalcaneus having a flat upper surface that articulates with the tibia in a valgus and equinus position. The foot may be missing one or two lateral rays. There is always significant shortening of the epsilateral femur. Treatment: There is a reasonable consensus that complete fibular hemimelia is best treated by performing an ankle disarticulation in early childhood and fitting a Syme-type prosthesis. Children with lesser (<5cm) at birth may be a candidate for lengthening procedures, but the exact indications and results of these procedures have not been well defined. Children with large discrepancies (>5cm) at birth and those with major foot deformities are better managed with amputation.

Question 14

A 22-year-old man sustained a cervical fracture-dislocation of the C5-6 level in a motor vehicle accident along with an associated spinal cord injury. Six months after his injury, he has 4 out of 5 biceps on the left, with 5 out of 5 biceps on the right. Deltoid is graded at 5 out of 5 bilaterally. There is 0 strength in the triceps, wrist flexors, wrist extensors, and digital extensors. He has neurogenic bowel and bladder with absent perianal sensation and no voluntary motor in the lower extremities. The patient's neurologic deficit is best categorized as which of the following? Review Topic

Explanation

The patient has a complete spinal cord injury. The level of a spinal cord injury is determined by the most distal intact (5/5) function. The lowest motor intact level in this patient is C5 based on the described examination. Central spinal cord injury and Brown-STquard injuries are both incomplete patterns of spinal cord injury.

Question 15

A 35-year-old male suffers an anterior column acetabular fracture during a motor vehicle collision, and subsequently undergoes percutaneous acetabular fixation. Intraoperatively, fluoroscopy is positioned to obtain an obturator oblique-inlet view while placing a supraacetabular screw. Which of the following screw relationships is best evaluated with this view?

Explanation

DISCUSSION: The obturator oblique-inlet view, as seen in Illustration A, best demonstrates the position of a supraacetabular screw or pin relative to the tables of the ilium.
Starr et al review their initial results and technique of closed or limited open reduction and percutaneous fixation of acetabular fractures. They defined two groups of patients who may benefit from this technique; elderly patients with multiple comorbidities to facilitate early mobilization and restore hip morphology, and young patients with elementary fracture patterns and multiple associated injuries.
Starr et al describe their operative technique and outcomes for a case series of 3 patients using percutaneous acetabular fixation to augment open reduction of acetabular fractures. The authors state that, for placement of an
anterior colum ramus screw, an iliac oblique-inlet (not obturator oblique-inlet) will ensure that the screw is within the medullary canal of the ramus and does not exit anterior or posterior.
Gardner and Nork describe a technique for placement of a large femoral distractor in the supra-acetabular region to compress displaced posterior pelvic ring injuries. They note that the obturator oblique-inlet view is necessary to view the entire length of the pin as well as to ensure that pin remains in bone.
Incorrect answers:

Question 16

A 26-year-old weight lifter has had increasing pain in his left shoulder for 4 months. His symptoms do not improve with nonsurgical treatment that included activity modification, anti-inflammatory medication, and corticosteroid injections. He undergoes arthroscopic distal clavicle excision with resection of the distal 2.5 cm of clavicle. Three months after surgery, he reports persistent pain and popping in his shoulder. An examination demonstrates anterior and posterior instability of the distal clavicle without gross deformity. Radiographs are unremarkable. What is the most likely cause of distal clavicle instability after surgery?

Explanation

DISCUSSION
Overresection of the distal clavicle can result in disruption of the acromioclavicular ligamentous complex, which inserts at an average of 22.9 mm from the distal clavicle. A comparison of arthroscopic and open distal clavicle excision demonstrated less pain in the arthroscopic group, with no difference in patient satisfaction or shoulder function between groups. Injuries to the conoid and trapezoid ligaments occur with high-grade acromioclavicular separations, resulting in superior migration of the distal clavicle relative to the acromion. Release of the coracoacromial ligament typically is not performed during distal clavicle excision.

Question 17

Figures 46a through 46d are the injury radiographs and postsurgical open treatment radiographs of a 13-year-old girl who fell while on a trampoline and sustained an injury to her right-dominant elbow. The skin is closed and she has normal vascular and neurologic examination findings. Which complication most likely could occur as a result of this injury and treatment?

Explanation

CLINICAL SITUATION FOR QUESTIONS 47 THROUGH 50
A 6-year-old boy arrives at the emergency department with forearm pain. Today he was picking up his backpack when he felt a pop in his forearm that resulted in the current injury. His history is significant for 6 other fractures treated nonsurgically. His mother states that she had 15 fractures during childhood but is healthy now. Both the boy and his mother have blue sclera. Figures 47a and 47b are the radiographs of his injured forearm.

Question 18

A 22-year-old woman reports a 4-year history of worsening low back and left lower extremity pain following a motor vehicle accident. Management consisting of physical therapy, chiropractic manipulation, and interventional pain management, including sacroiliac joint injections and epidural steroid injections, has failed to provide relief. A sagittal T 2 -weighted MRI scan is shown in Figure 8. No nerve root compression is seen on axial images. She is currently working and lives with her fiancé. She smokes half a pack of cigarettes per day and reports depression on her health history. She is being maintained on narcotic analgesics and is having increasing difficulty performing her activities of daily living secondary to pain. What is the most appropriate management at this time?

Explanation

DISCUSSION: The MRI scan reveals a rudimentary disk at the L5-S1 level, suggesting transitional anatomy. There is a posterior disk bulge at L3-4. At L4-5, there is disk desiccation and loss of disk height, with a posterior disk bulge and a high intensity zone in the posterior annulus, suggesting an annular tear. While these and similar radiographic findings have been associated with the severity of a patient’s pain, they are also commonly found in cross-sectional studies of asymptomatic subjects. Carragee and associates found 59% of symptomatic patients undergoing diskography have high intensity zones as compared to 25% of asymptomatic subjects of a similar patient profile. Diskographic injections provoked pain in disks with high intensity zones approximately 70% of the time whether the individual was previously symptomatic or not. This patient’s non-specific pain pattern does not require further work-up as she is not a surgical candidate.
REFERENCES: Carragee EJ, Paragioudakis SJ, Khurana S: 2000 Volvo Award winner in clinical studies: Lumbar high-intensity zone and discography in subjects without low back problems. Spine 2000;25:2987-2992.
Pneumaticos SG, Reitman CA, Lindsey RW: Diskography in the evaluation of low back pain.

J Am Acad Orthop Surg 2006;14:46-55.
Brox JI, Sorensen R, Friis A, et al: Randomized clinical trial of lumbar instrumented fusion and cognitive intervention and exercises in patients with chronic low back pain and disc degeneration. Spine 2003;28:1913-1921.
Carragee EJ: Clinical practice: Persistent low back pain. N Engl J Med 2005;352:1891-1898.

Question 19

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 20

Which complication is most common after syndesmotic fixation?

Explanation

DISCUSSION
The injury radiographs reveal a supination external rotation IV ankle fracture with evidence of medial clear space widening exceeding 4 mm and an increase relative to the superior tibiotalar clear space. This indicates injury to the deltoid ligament and necessitates surgical reduction and fixation to restore and maintain ankle stability. Following stabilization of the fibula, an intraoperative stress examination of the syndesmosis such as an external rotation stress test under fluoroscopy or lateral pull on the fibula (the Cotton test) should be performed to determine the integrity of the syndesmosis. Radiographic evidence of tibiofibular clear space widening, medial clear space widening with external rotation, and lateral displacement of the distal fibula when pulled is consistent with syndesmotic injury. In contrast to the presurgical stress test, once the fibula has been reduced and stabilized lateral talar translation can occur only if the syndesmosis is injured in addition to the deltoid ligament. Failure of the syndesmotic screw without evidence of malalignment of the mortise and a pain-free ankle are not indications for further surgery because these patients have satisfactory outcomes when compared to those who have intact or removed screws. Hardware removal following fibula ORIF is indicated when patients have pain directly related to hardware prominence. Resolution of joint pain or stiffness is not a reliable outcome following hardware removal. Although fibular fracture can occur, this is a rare complication. Malreduction of the syndesmosis is the most common complication following ORIF of the syndesmosis and is improved with direct visualization; however, malreduction still may occur with direct visualization.
RECOMMENDED READINGS
Manjoo A, Sanders DW, Tieszer C, MacLeod MD. Functional and radiographic results of patients with syndesmotic screw fixation: implications for screw removal. J Orthop Trauma. 2010 Jan;24(1):2-6. doi: 10.1097/BOT.0b013e3181a9f7a5. PubMed PMID: 20035170. View
Abstract at PubMed
Jenkinson RJ, Sanders DW, Macleod MD, Domonkos A, Lydestadt J. Intraoperative diagnosis of syndesmosis injuries in external rotation ankle fractures. J Orthop Trauma. 2005 Oct;19(9):604-9. PubMed PMID: 16247304. View Abstract at PubMed
Stark E, Tornetta P 3rd, Creevy WR. Syndesmotic instability in Weber B ankle fractures: a clinical evaluation. J Orthop Trauma. 2007 Oct;21(9):643-6. PubMed PMID: 17921840. View Abstract at PubMed
Brown OL, Dirschl DR, Obremskey WT. Incidence of hardware-related pain and its effect on functional outcomes after open reduction and internal fixation of ankle fractures. J Orthop Trauma. 2001 May;15(4):271-4. PubMed PMID: 11371792. View Abstract at PubMed

Question 21

A 9-year-old child sustained a fracture-dislocation of C-5 and C-6 with a complete spinal cord injury. What is the likelihood that scoliosis will develop during the remaining years of his growth?

Explanation

DISCUSSION: The incidence of late spinal deformity after complete spinal cord injury in children depends on the level of the spinal cord injury and the age of the patient at the time of injury. If a cervical level injury occurs before age 10 years, paralytic scoliosis will develop in virtually 100% of patients.
REFERENCES: Brown JC, Swank SM, Matta J, et al: Late spinal deformity in quadriplegic children and adolescents. J Pediatr Orthop 1984;4:456-461.
Lancourt JE, Dickson JH, Carter RE: Paralytic spinal deformity following traumatic spinal-cord injury in children and adolescents. J Bone Joint Surg Am 1981;63:47-53.
Dearolf WW III, Betz RR, Vogel LC, et al: Scoliosis in pediatric spinal cord-injured patients.

J Pediatr Orthop 1990;10:214-218.

Question 22

An athletic 55-year-old man reports a painless mass in the anterior aspect of the thigh that appeared 3 weeks ago and has not changed in size. The patient denies any history of trauma. Examination reveals a firm, well-defined nontender mass in the anterior thigh and no inguinal adenopathy or cutaneous changes. Plain radiographs are unremarkable. T1- and T2-weighted MRI scans are shown in Figures 44a and 44b. What is the most likely diagnosis?

Explanation

DISCUSSION: The presence of a painless soft-tissue mass that is greater than 5 cm and deep to the fascia should be considered a soft-tissue sarcoma until proven otherwise. The diagnosis of a hematoma should be made with great caution because the absence of a history of trauma, pain, or presence of ecchymosis makes it unlikely. A diagnosis of pyomyositis is unlikely because of the absence of warmth, erythema, or adenopathy. The MRI scans are not consistent with lipoma or hemangioma. The MRI signal characteristics of a lipoma should be the same as subcutaneous fat on all sequences. Soft-tissue hemangiomas are not well defined and have an infiltrative appearance on MRI scans, as does pyomyositis.
REFERENCES: Sim FH, Frassica FJ, Frassica DA: Soft-tissue tumors: Diagnosis, evaluation and management. J Am Acad Orthop Surg 1994;2:202-211.
Kransdorf MJ, Jelinek JS, Moser RP Jr, et al: Soft-tissue masses: Diagnosis using MR imaging. Am J Roentgenol 1989;153:541-547.

Question 23

A 12-year-old girl has back pain after falling 20 feet and landing in the sitting position. She has no fractures or other injuries, and her neurologic examination is normal. A lateral radiograph, transverse CT scan, and reformatted sagittal CT scan are shown in Figures 25a through 25c. Which of the following methods is associated with the best long-term outcome?

Explanation

DISCUSSION: The patient has a displaced burst fracture. Fusion with instrumentation has shown better results than casting alone. Posterior fusion with instrumentation, with sagittal plane correction, yields the best results. Decompression occurs indirectly with correction of the kyphosis. Anterior decompression is unnecessary.
REFERENCES: Lalonde F, Letts M, Yang JP, et al: An analysis of burst fractures of the spine in adolescents. Am J Orthop 2001;30:115-120.
Clark P, Letts M: Trauma to the thoracic and lumbar spine in the adolescent. Can J Surg 2001;44:337-345.
Been HD, Bouma GJ: Comparison of two types of surgery for thoraco-lumbar burst fractures: Combined anterior and posterior stabilization vs posterior instrumentation only. Acta Neurochir (Wien) 1999;141:349-357.

Question 24

Which of the following findings is considered a contraindication for posterior decompression (with or without fusion) for myelopathy?

Explanation

DISCUSSION: Although cervical instability is a contraindication to posterior decompression alone, segmental instability in the myelopathic cervical spine can be addressed with concomitant posterior fusion with instrumentation. Cervical lordosis represents the ideal scenario for posterior decompressive procedures for myelopathy (laminectomy and laminoplasty) because compression from anterior osteophytes, if present, is relieved as the spinal cord migrates posteriorly. The anteroposterior diameter of the spinal canal does not have an impact on the selection of surgical approach. Posterior unroofing-type procedures in kyphotic cervical spines, however, are ineffective because anterior impingement on the spinal cord will remain; therefore, kyphosis of more than 10° is considered a contraindication for posterior decompression.
REFERENCES: Emery SE: Cervical spondylotic myelopathy: Diagnosis and treatment. J Am Acad Orthop Surg 2001;9:376-388.
Malone DG, Benzel EC: Laminotomy and laminectomy for spinal stenosis causing radiculopathy or myelopathy, in Clark CR (ed): The Cervical Spine, ed 3. Philadelphia, PA, Lippincott Raven, 1998, pp 817-823.

Question 25

A 26-year-old woman who noted right-sided lumbosacral pain 10 days ago while vacuuming now reports that the pain has intensified. She denies any history of back problems. No radicular component is present, and her neurologic examination is normal. The next most appropriate step in management should consist of

Explanation

DISCUSSION: The initial management of a lumbar strain should consist of 2 to 3 days of bed rest when symptoms are severe, activity restrictions, and nonsteroidal anti-inflammatory drugs. It has been estimated that 60% to 80% of the adult population experiences back pain, with 2% to 5% affected yearly. Spontaneous improvement generally will occur within 4 weeks. Further study is indicated by the presence of radiculopathy, weakness, trauma, or suspicion of malignancy.
REFERENCES: Bigos S, Boyer O, Braen GR, et al: Acute low back pain in adults: Clinical practice guideline No. 14. AHCPR Publication No. 95-0642. Rockville, MD, Agency for Health Care Policy and Research, Public Health Service, US Department of Health and Human Services, December, 1994.
Deyo RA: Conservative therapy for low back pain: Distinguishing useful from useless therapy. JAMA 1983;250:1057-1062.

Question 26

Which of the following factors has been shown to increase mortality in poly-trauma patients with severe head injuries?

Explanation

DISCUSSION: The factor most likely to adversely affect long term outcome in poly-trauma patients with severe brain injury is intraoperative hypotension.
Chesnut et al demonstrated that hypotension (SBP <90mmHg) was profoundly detrimental, occurring in 35% of these patients and associated with 150% increase in mortality.
Pietropaoli et al reviewed 53 patients with severe head injuries and required early surgical intervention (surgery within 72 hours of injury). All patients were initially normotensive on arrival. There were 17 patients (32%) who developed intra-operative hypotension and 36 (68%) who remained normotensive throughout surgery. The mortality rate was 82% in the IH group and 25% in the normotensive group.

Question 27

A 34-year-old man presents to clinic with 4 months of right elbow pain. He began going to the gym and playing squash about 3 months ago. On exam, he is tender over the lateral aspect of the elbow and has pain with resisted wrist extension. Which of the following choices lists the correct compartment of the muscle typically involved in this disease and then lists its antagonist muscle? Review Topic

Explanation

The patient presents with lateral epicondylitis, which typically involves the origin of the extensor carpi radialis brevis (ECRB). ECRB is in the mobile wad compartment and its antagonist muscle is flexor carpi ulnaris.
Lateral epicondylitis is an overuse injury, typically secondary to repetitive pronation and supination motion in extension, that leads to inflammation of the ECRB origin at the elbow. Histological analysis typically shows vascular hyperplasia and disorganized collagen. Clinically, patients will have pain over the lateral elbow exacerbated by resisted wrist extension. ECRB, the most commonly involved muscle origin, is innervated by the deep branch of the radial nerve and inserts on the base of the 3rd metacarpal. As it is radial wrist extensor, its antagonist is the ulnar sided wrist flexor.
Brummel et al. reviewed the clinical presentation and management options for lateral epicondylitis. They report acute symptoms in younger patients and chronic symptoms in older patients. NSAIDs, extensor stretching and activity modification are the mainstay of nonsurgical treatment.
Bunata et al. studies 85 cadavar elbows to determine anatomic factors contributing to tennis elbow. They found that the ECRB undersurface rubs against the lateral capitellium in elbow extension leading to tendinosis.
Illustration A is cross-sectional diagram of the forearm with muscle bellies labeled. Notice the location of ECRB in the mobile wad. Illustration B is a coronal T2 MRI showing fluid signal and undersurface tearing near the extensor origin as can be seen in lateral epicondylitis.
Incorrect Answers:
1-4: The ECRB is in the mobile wad and its antagonist is flexor carpi ulnaris. All other answers are incorrect.

Question 28

Joint contact pressure in normal or artificial joints can best be minimized by what mechanism?

Explanation

DISCUSSION: Joint contact pressure is a stress and as such is defined as the load transferred across the joint divided by the contact area between the joint surfaces (the area over which the joint load is distributed). Therefore, any mechanism that decreases the load across the joint

(eg, a walking aid) will decrease the stress. Similarly, any mechanism that increases the area over which the load is distributed (eg, using a more conforming set of articular surfaces in a knee joint arthroplasty) will also decrease the stress. Other mechanisms that influence joint contact pressure include the elastic modulus of the materials (cartilage in the case of natural joints and polyethylene in joint arthroplasty) and the thickness of the structures through which the joint loads pass.
REFERENCES: Bartel DL, Bicknell VL, Wright TM: The effect of conformity, thickness, and material on stresses in UHMWPE components for total joint replacement. J Bone Joint Surg Am 1986;68:1041-1051.
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 29

A 79-year-old woman with polyarticular rheumatoid arthritis has had progressively increasing right shoulder pain for the past year, and nonsurgical management has failed to provide relief. Her neurologic examination is entirely normal, but she is unable to elevate her arm against gravity. An AP radiograph is shown in Figure 13. Treatment should consist of

Explanation

DISCUSSION: Because the patient has end-stage rheumatoid arthritis with glenoid and rotator cuff deficiency, humeral arthroplasty is the treatment of choice. When a patient has an intact rotator cuff and there is sufficient glenoid bone stock to implant a glenoid component, total shoulder arthroplasty is the preferred method because it appears to provide more predictable pain relief. Glenohumeral arthrodesis is generally avoided when there is a functional deltoid or rotator cuff. Open synovectomy is appropriate in early rheumatoid disease before articular changes are present. Anterior acromioplasty with coracoacromial ligament resection is avoided in patients with rheumatoid arthritis because this procedure compromises the coracoacromial arch and may result in anterosuperior instability.
REFERENCES: Neer CS II, Watson KC, Stanton FJ: Recent experience in total shoulder replacement. J Bone Joint Surg Am 1982;64:319-337.
Neer CS II: Glenohumeral arthroplasty, in Neer CS II (ed): Shoulder Reconstruction. Philadelphia, PA, WB Saunders, 1990, pp 143-271.
Pollock RG, Deliz ED, McIlveen ST, et al: Prosthetic replacement in rotator cuff deficient shoulders. J Shoulder Elbow Surg 1992;1:173-186.
Sneppen O, Fruensgaard S, Johannsen HV, Olsen BS, Sojbjerg JO, Anderson NH: Total shoulder replacement in rheumatoid arthritis: Proximal migration and loosening. J Shoulder Elbow Surg 1996;5:47-52.

Question 30

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 31

A 40-year-old woman sustains a flexion injury to her neck. Physical examination is normal. A lateral radiograph of the cervical spine is shown in Figure 57a. MRI scans of the cervical spine are shown in Figures 57b and 57c. Treatment should include

Explanation

DISCUSSION: This is a classic bilateral facet dislocation. When there is no evidence of a disk herniation, treatment should include careful skeletal traction, closed reduction, and posterior fusion. There is no role for anterior procedures. These fractures are unstable and require surgical intervention.
REFERENCES: Herkowitz HN, Garfin SR, Eismont FJ: Rothman-Simone The Spine, ed 5. Philadelphia, PA, Saunders Elsevier, 2006, pp 1120-1128.
Coe JD, Warden KE, Sutterlin CE, et al: Biomechanical evaluation of cervical spinal stabilization methods in a human cadaveric model. Spine 1989;14:1122-1131.

Question 32

A 19-year-old college student reports a 1-week history of wrist pain following an intramural rugby match. A PA radiograph is shown in Figure 6. He denies any prior wrist injury. What is the best course of action?

Explanation

DISCUSSION: The patient has a scaphoid fracture involving the proximal pole. Surgical treatment is recommended for such fractures because of the prolonged period of cast immobilization necessary and the increased risk of delayed union, nonunion, and/or osteonecrosis with nonsurgical management. A cannulated compression screw, inserted in the central scaphoid via a dorsal approach, is biomechanically advantageous and provides greater stability for fracture healing than Kirschner wires. Recently, good outcomes have been reported with arthroscopic-assisted percutaneous fixation of nondisplaced or minimally displaced scaphoid fractures.
REFERENCES: Rettig ME, Raskin KB: Retrograde compression screw fixation of acute proximal pole scaphoid fractures. J Hand Surg Am 1999;24:1206-1210.
Chan KW, McAdams TR: Central screw placement in percutaneous screw scaphoid fixation: A cadaveric comparison of proximal and distal techniques. J Hand Surg Am 2004;29:74-79.
Bedi A, Jebson PJ, Hayden RJ, et al: Internal fixation of acute non-displaced scaphoid waist fractures via a limited dorsal approach: An assessment or radiographic and functional outcomes. J Hand Surg Am 2007;32:326-333.
McCallister WV, Knight J, Kaliappan R, et al: Central placement of the screw in simulated fractures of the scaphoid waist: A biomechanical study. J Bone Joint Surg Am 2003;85:72-77.

Question 33

A 22-year-old patient sustained a jamming injury to the right little finger. The lateral radiograph shown in Figure 18 reveals comminution of the base of the middle phalanx, with palmar and dorsal metaphyseal cortical involvement. The articular surface also is disrupted. Management should consist of

Explanation

DISCUSSION: This fracture, known as a pilon fracture, represents comminution of the base of the middle phalanx with both palmar and dorsal cortical disruption. The treatment method that allows the best function and fewest complications is indirect reduction achieved through specific dynamic splinting or the use of specifically designed proximal interphalangeal joint external fixators. Early mobilization can be achieved by either of these techniques. Volar plate arthroplasty is indicated for a simple fracture-dislocation of the proximal interphalangeal joint with comminution of the volar fracture fragment and dorsal dislocation of the remaining articular surface. Open reduction and internal fixation or percutaneous pinning adds surgical risks and scarring and typically will not provide added stability. Cast immobilization will not achieve the goal of early range of motion.
REFERENCES: Stern PJ, Roman RJ, Kiefhaber TR, McDonough JJ: Pilon fractures of the proximal interphalangeal joint. J Hand Surg Am 1991;16:844-850.
Krakauer JD, Stern PJ: Hinged device for fractures involving the proximal interphalangeal joint. Clin Orthop 1996;327:29-37.

Question 34

Figures 132a and 132b are the lateral and anteroposterior radiographs of a 15-year-old boy with a 6-month history of recurrent, activity-related posterior elbow pain when pitching. Two separate 6-week periods of rest have failed to provide relief. What is the next best step to enable him to return to play? Review Topic

Explanation

Intramedullary screw fixation of the olecranon stress fracture is most likely to allow him to return to play. Stress fractures through a persistent olecranon apophysis have been well described in the literature. The AP radiograph reveals the other physes of the elbow to be closed. After patients fail to respond to appropriate periods of rest and
cessation from throwing followed by appropriate physiotherapy, surgical management with cannulated screw fixation is appropriate and has been demonstrated to have favorable success rates. Hinged-elbow bracing will not facilitate healing or return to play. Long-arm casting is likely to result in stiffness and would not be unreasonable for a short duration at the onset of symptoms, but is less likely to be helpful at this point. Plate fixation is not indicated for treatment of this injury.

Question 35

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

Explanation

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.

Question 36

Your 25-year-old patient complains of anterior knee pain after retrograde femoral nailing for a diaphyseal fracture and asks you why you didn’t perform antegrade nailing as he has seen on the internet. You tell him that retrograde nailing is your preferred technique over antergrade nailing for diaphyseal femoral fractures because it has been shown to have?

Explanation

DISCUSSION: Patients with retrograde femoral nails commonly have knee pain, while antegrade nails commonly have hip pain, abductor weakness and heterotopic ossification of the abductors. Ostrum’s randomized prospective study of 100 patients with reamed femoral nails found 22% of antegrade nail patients had proximal hip pain, weak hip abductors or trendelenburg gait. No significant difference was found in set-up time, operative time, knee motion or pain, or infection rates. Ricci performed a retrospective study of 293 fractures and found that the antegrade femoral nail group had more hip pain (10% vs 4%) and the retrograde nail group had more knee pain (36% vs 9%). There was no difference in healing, malunion, non-union or other complications. Tornetta performed a randomized controlled comparison of 69 femur fractures and found more problems of length and rotation using a retrograde nailing. There was no difference in time to union, operating time, blood loss, complications, size of nail or reamer, or transfusion requirements

Question 37

A 22-year-old man who sustained a Gustilo-Anderson grade IIIC open fracture of the right tibia and fibula was treated with an immediate open transtibial amputation. After two serial debridements, he underwent wound closure with a posterior myocutaneous soft-tissue flap. What is the preferred method of early rehabilitation?

Explanation

DISCUSSION: There is no evidence that early weight bearing enhances ultimate rehabilitation. At the other extreme, weight bearing should not be delayed for a prolonged period of time. In a young, healthy individual, the rigid plaster dressing appears to be the safest method of protecting the wound during the early postoperative period. If the wound appears to be secure, early partial weight bearing can be safely initiated.
REFERENCES: Burgess EM, Romano RL, Zettl JH: The Management of Lower Extremity Amputations. Washington, DC, US Government Printing Office, 1969, also at: www.prs-research.org.
Smith DG, McFarland LV, Sangeorzan BJ, et al: Postoperative dressing and management strategies for transtibial amputations: A critical review. J Rehabil Res Dev 2003;40:213-224.

Question 38

-An otherwise healthy 15-year-old wrestler has a 6-cm cutaneous lesion on the posterior aspect of his right elbow that he reports as a spider bite. What is the most likely diagnosis?

Explanation

CLINICAL SITUATION FOR QUESTIONS 44 AND 45
Figure 44 is the MRI scan of a 14-year-old soccer player who injured his right knee during a game.He describes feeling a “pop” and he needed help walking off the field. His knee is visibly swollen. A Lachman test demonstrates asymmetry with no endpoint.

Question 39

Figures 1 and 2 are the radiographs of a 24-year-old male wrestler who underwent surgery for recurrent shoulder dislocations using coracoid autograft. At his first postoperative visit, the patient complains of decreased sensation on the lateral aspect of his forearm. The patient’s symptoms are most likely due to injury of the

Explanation

The patient has undergone a Latarjet procedure as shown in the radiographs. After harvesting the coracoid graft, care must be taken to not place too much tension on or dissect excessively near the musculocutaneous nerve. The nerve is encountered 5 cm distal to the coracoid as it enters the conjoint tendon. The lateral antebrachial cutaneous nerve is the terminal branch of the musculocutaneous nerve and; therefore, injury can cause decreased sensation in the lateral forearm.

Question 40

Figures 157a and 157b are the radiographs of a 22-year-old laborer who has progressively increasing lateral knee pain that is unresponsive to nonsurgical treatment. What is the most appropriate treatment at this time?

Explanation

DISCUSSION
Distal femoral osteotomy is the preferred surgical treatment for this young patient. A varus-producing proximal tibial osteotomy is not indicated with valgus deformity and lateral femoral hypoplasia. Osteotomy on the tibial side would result in obliquity of the joint line and improper loading. Lateral unicompartmental arthroplasty or TKA are both less appropriate for this patient, who will be placing high demands on his knee; these demands will pose high risk for premature failure of an artificial knee implant and could necessitate revision surgery.

Question 41

The carpal tunnel canal is narrowest (smallest cross-sectional area) at what level?

Explanation

DISCUSSION: The carpal tunnel canal has an hourglass shape in the coronal plane and is narrowest at the level of the hook of the hamate.
REFERENCES: Cobb TK, Dalley BK, Posteraro RH, et al: Anatomy of the flexor retinaculum. J Hand Surg Am 1993;18:91-99.
Trumble TE (ed): Hand Surgery Update 3: Hand, Elbow and Shoulder. Rosemont, IL, American Society of Surgery of the Hand, 2003, p 300.

Question 42

below show the clinical photograph and radiograph obtained from a year-old man who has deformity and pain 1 year after primary total hip arthroplasty. What is the reason for the observed deformity?

Explanation

DISCUSSION:
Figure 1 reveals an external rotation deformity of the right lower extremity. This deformity can have numerous causes, including extra-articular deformity. Figure 2 reveals a loose, subsided femoral component. Femoral stems typically subside into retroversion due to proximal femoral biomechanics, which cause a compensatory external rotation deformity. The combined findings from both images suggest an external rotation deformity most likely related to subsidence into retroversion.

Question 43

Which of the following prognostic indicators is associated with the least favorable outcome for patients newly diagnosed with osteosarcoma?

Explanation

DISCUSSION: Distant bone metastasis is associated with an extremely poor prognosis for patients with osteosarcoma (5-year survival rate of less than 10%). Most osteosarcomas are high grade and extracompartmental, and approximately half are greater than 8 cm at presentation. The 5-year survival rate for these patients is approximately 70%. Patients with a solitary pulmonary metastasis have a prognosis worse than patients without detectable metastases but not as bad as those with bone metastases.
REFERENCES: Bielack SS, Kempf-Bielack B, Delling G, et al: Prognostic factors in high-grade osteosarcoma of the extremities or trunk: An analysis of 1,702 patients treated on neoadjuvant cooperative osteosarcoma study group protocols. J Clin Oncol 2002;20:776-790.
Heck RK, Stacy GS, Flaherty MJ, et al: A comparison study of staging systems for bone sarcomas. Clin Orthop Relat Res 2003;415:64-71.
Kager L, Zoubeck A, Potschger U, et al: Primary metastatic osteosarcoma: Presentation and outcome of patients treated on neoadjuvant Cooperative Osteosarcoma Study Group protocols.

J Clin Oncol 2003;21:2011-2018.

Question 44

A collegiate division I football player ruptures his anterior cruciate ligament (ACL). After counseling him, you agree to perform a double-bundle ACL reconstruction. Which of the following is a correct statement for this technique? Review Topic

Explanation

The ACL is composed of two anatomic bundles: the anteromedial (AM) and the posterolateral (PL). They are both considered important to the stability of the knee. Although they work in concert, the AM bundle controls translation, especially in flexion, whereas the PL bundle prevents rotation.

Question 45

A 55-year-old man reports increasing weakness in his arms that has progressed to his lower limbs, resulting in frequent tripping and falling. Examination reveals weakness in shoulder abduction and external and internal rotation bilaterally. Fasciculation is noted. He also has weakness in elbow flexion and extension bilaterally, and his grip strength is diminished. An electromyogram and nerve conduction velocity studies show decreased amplitude of compound motor action potential, slightly slowed motor conduction velocity, and denervation signs with decreased recruitment in all extremities. The sensory study is normal. Based on these findings, what is the most likely diagnosis?

Explanation

DISCUSSION: The major determinant of ALS (Lou Gehrig disease) is progressive loss of motor neurons. The loss usually begins in one area, is asymmetrical, and later becomes evident in other areas. The first signs of ALS may include either upper or lower motor neuron loss. Recognition of upper motor neuron involvement depends on clinical signs, but electromyography and nerve conduction velocity studies can help identify lower motor neuron involvement. Electrodiagnostic abnormalities in three or more areas are required to make a definitive diagnosis. The motor unit potentials (MUPs) changes in ALS include impaired MUPs recruitment, unstable MUPs, and abnormal MUPs size and configuration. A number of abnormal spontaneous discharges can occur with ALS, especially fibrillation potentials and fasciculation potentials. In ALS, the motor nerve conduction study will be abnormal, but a co-existing normal sensory study is definitive for this disease.
REFERENCES: de Carvalho M, Johnsen B, Fuglsang-Frederiksen A: Medical technology assessment: Electrodiagnosis in motor neuron diseases and amyotrophic lateral sclerosis. Neurophysiol Clin 2001;31:341-348.
Daube JR: Electrodiagnostic studies in amyotrophic lateral sclerosis and other motor neuron disorders. Muscle Nerve 2000;23:1488-1502.
Troger M, Dengler R: The role of electromyography (EMG) in the diagnosis of ALS. Amyotroph Lateral Scler Other Motor Neuron Disord 2000;1:S33-S40.

Question 46

Increased hip intracapusular pressures can lead to diminished femoral head perfusion. What leg position has been shown to create the lowest intracapsular hip pressures after femoral neck fracture?

Explanation

DISCUSSION: In the referenced study by Bonnaire et al, extension and internal rotation had the highest intercapsular pressure. They found that the greatest decrease in pressure was found with flexion, abduction and external rotation. This is a possible etiology to the common position in which these patients will present to the emergency room. Traction was shown to increase pressure in the joint capsule.

Question 47

A 21-year-old man has had posterior neck discomfort for the past 6 months. Radiographs, an MRI scan, and a photomicrograph of the biopsy specimen are shown in Figures 17a through 17d. What is the most likely diagnosis?

Explanation

DISCUSSION: Forty percent of osteoblastomas occur in the spine, and they can become large and locally aggressive lesions. They generally occur in the posterior elements but can occur in the ribs and transverse processes. Microscopic analysis of the lesion will reveal hyperchromatic osteoblasts separated by incompletely mineralized bars of bone. Recommended treatment is en bloc excision. Fibrous dysplasia, giant cell tumor, and hemangioma can have similar radiographic appearances; therefore, biopsy may be required to differentiate them from more aggressive lesions. Osteochondromas are characterized by an osteocartilaginous growth arising from the cortex.
REFERENCES: Bridwell KH, Ogilvie JW: Primary tumors of the spine, in Bridwell KH, DeWald RL (eds): The Textbook of Spinal Surgery. Philadelphia, PA, JB Lippincott, 1991,

vol 2, pp 1143-1174.

Enneking WF: Musculoskeletal Tumor Surgery. New York, NY, Churchill Livingstone, 1983, pp 1043-1053.

Question 48

A 30-year-old man landed on his shoulder in a fall off his mountain bike. An AP radiograph and CT scan are shown in Figures 34a and 34b. Management should consist of

Explanation

DISCUSSION: The radiograph shows a valgus impacted four-part fracture. The humeral head is deeply depressed into the metaphysis but is still articulating with the glenoid as seen on the CT scan. Unlike a “classic” four-part fracture in which the head is dislocated out of the glenoid and devoid of any soft-tissue attachments (high risk of osteonecrosis), this valgus impacted head will have a medial soft-tissue hinge with a lower risk of osteonecrosis. It is most amenable to open reduction and internal fixation with minimal soft-tissue stripping techniques. Bone grafting may be necessary on occasion. Nonsurgical management for displaced proximal humeral fractures generally results in a poor outcome. This patient does not have a humeral head defect. A hemiarthroplasty is not indicated.
REFERENCES: Jakob RP, Miniaci A, Anson PS, et al: Four-part valgus impacted fractures of the proximal humerus. J Bone Joint Surg Br 1991;73:295-298.
Resch H, Povacz P, Frohlich R, et al: Percutaneous fixation of three- and four-part fractures of the proximal humerus. J Bone Joint Surg Br 1997;79:295-300.

Question 49

Nutritional rickets is associated with which of the following changes in chemical blood level?

Explanation

DISCUSSION: Nutritional rickets is associated with decreased dietary intake of Vitamin D, resulting in low levels of Vitamin D that result in decreased intestinal absorption of calcium

and low to normal serologic levels of calcium. To boost serum calcium levels, there is a compensatory increase in PTH and bone resorption, leading to increased alkaline

phosphatase levels.
REFERENCES: Brinker MR: Cellular and molecular biology, immunology, and genetics in orthopaedics, in Miller MD (ed): Review of Orthopaedics, ed 3. Philadelphia, PA, WB Saunders, 2001, pp 81-94.
Pettifor J: Nutritional and drug-induced rickets and osteomalacia, in Farrus MJ (ed): Primer on the Metabolic Bone Diseases and Disorders of Mineral Metabolism, ed 5. Philadelphia, PA, Lippincott Williams and Wilkins, 2003, pp 399-466.
Einhorn TA: Metabolic bone disease, in Einhorn TA, O’Keefe RJ, Buckwalter JA (eds): Orthopaedic Basic Science: Foundations of Clinical Practice, ed 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, in press.

Question 50

Which of the following pelvic injury types has the highest reported mortality rate?

Explanation

mechanism injuries all have lower mortality rates than APC injuries.

OrthoCash 2020

Question 51

After performing a total hip arthroplasty through a posterolateral approach, an orthopaedic surgeon is unable to adequately externally rotate the leg and subsequently exposes the anterior capsule. When releasing the inferior aspect of the anterior capsule, pulsatile bleeding is encountered. A branch of which artery is most likely lacerated?

Explanation

DISCUSSION
Branches of the lateral femoral circumflex artery arise from the inferior aspect of the anterior hip capsule. They can be injured when removing the anterior capsule from any approach. The inferior gluteal artery supplies the gluteus maximus. The medial femoral circumflex artery enters the hip joint along the path of the obturator externus tendon. The femoral artery crosses the anterior hip joint in the superior-to-inferior direction and is located just medial to the hip joint.

Question 52

When treating thoracic disk herniations, which of the following surgical approaches has the highest reported rate of neurologic complications?

Explanation

DISCUSSION: Numerous surgical approaches have been used for thoracic diskectomy, including the most recent VATS. One of the first approaches described, posterior laminectomy, involves manipulation of the spinal cord, which the other approaches avoid. The posterior approach had dismal results, including further neurologic deterioration and even paralysis.
REFERENCES: Belanger TA, Emery SE: Thoracic disc disease and myelopathy, in Frymoyer JW, Wiesel SW (eds): The Adult and Pediatric Spine. Philadelphia, PA, Lippincott Williams and Wilkins, 2004, pp 855-864.
Benjamin V: Diagnosis and management of thoracic disc disease. Clin Neurosurg

1983;30:577-605.
Russell T: Thoracic intervertebral disc protrusion: Experience of 67 cases and review of the literature. Br J Neurosurg 1989;3:153-160.
Fessler RG, Sturgill M: Review: Complications of surgery for thoracic disc disease. Surg Neurol 1998;49:609-618.

Question 53

Serum phosphate levels are high. Tumoral calcinosis is a heritable condition that is characterized by periarticular metastatic calcification. Most patients are black, and the inheritance is usually autosomal recessive. Metastatic calcifications occur around joints and in the skin, marrow, teeth, and blood vessels. The periarticular masses may grow quite large and are attached to the fascia, but they are extra-articular. The masses may occur at the shoulder, hip, and elbow. Radiographically: The masses are composed of heavy, amorphous calcification in nodules. Laboratory:

Explanation

Which of the following describes the histopathology of tumoral calcinosis:

Question 54

Which of the following rehabilitation methods should be used for the first 24 hours following a blunt injury to the quadriceps musculature to avoid short-term stiffness?

Explanation

A West Point study utilizing a three-phase protocol after quads contusion was cited. Phase I was to limit hemorrhage. Rest, ice, compression and elevation were used for 24 to 48 hours depending on the severity of the contusion. Rest involved ace wrap to entire leg and hip and knee flexed to tolerance. When the patient was pain free at rest and thigh girth had stabilized Phase II had begun. The purpose of this phase was to restore ROM. Ice and cool whirlpool were continued, gravity assisted motion and active flexion and extension exercises are started. Weightbearing to tolerance in continued and crutches are discontinued when 90 degrees of motion, no limp and good quad control is attained. Phase III starts when there is 120 degrees of pain free active motion and participation in noncontact sports is allowed, when full strength, motion and endurance is achieved contact sports can be resumed. A thigh pad is worn for 3-6 months.
In the past immobilization in full extension was recommended, but it was noticed that the lack of flexion prolonged disability. Flexion of the knee during the first 24 hours also aids in limiting the extent of intramuscular hematoma.
Myositis ossificans is higher in any patient presenting after a quad contusion and has active knee ROM of less than 120 degrees and delay in treatment greater than 3 days.

Question 55

A 45-year-old construction worker sees a surgeon 23 days after sustaining an eccentric injury to his dominant right elbow. An MRI demonstrates a distal biceps tendon rupture with 5 cm of proximal retraction. In the operating room, the surgeon encounters good tissue quality but finds that primary repair can only be performed with the elbow hyperflexed to 70°. What is the best next step?

Explanation

Distal biceps ruptures, although relatively less common in comparison with other upper extremity tendon injuries, still garner considerable attention in the orthopaedic literature. The mechanism of injury typically results from an eccentric extension load to a flexed elbow. A biceps-deficient arm can result in up to 40% loss of supination strength and up to 80% loss of supination endurance. A delay in diagnosis can compromise the ability to reduce the tendon back to its anatomic insertion without having to hyperflex the elbow. Current literature confirms the ability to safely proceed with primary repair even with the elbow flexed up to 100° without fear of developing a flexion contracture. With time, patients can anticipate restoration of full elbow extension. An interposition graft should be used for a poor residual tendon quality stump <4 cm in length and in cases of delay to surgery of >6 weeks. Biceps to brachialis tendon transfer does not restore supination
strength. Isolated debridement of the distal tendon would not be an appropriate treatment.

Question 56

What condition favors pollicization in hypoplasia of the thumb?

Explanation

DISCUSSION
The decision to ablate and pollicize vs preserve and reconstruct is based on the stability of the carpometacarpal joint. A stable thumb is more easily used in prehension activities of grasping and pinching. All other responses are associated with surgical options for reconstruction of the thumb. The carpometacarpal joint is the “keystone” for thumb-to-hand attachment. Without a stable carpometacarpal joint, pollicization may be required. No other response necessitates pollicization.
RECOMMENDED READINGS
McCarroll HR. Congenital anomalies: a 25-year overview. J Hand Surg Am. 2000 Nov;25(6):1007-37. Review. PubMed PMID: 11119659. View Abstract at PubMed
Manske PR, Goldfarb CA. Congenital failure of formation of the upper limb. Hand Clin. 2009 May;25(2):157-70. doi: 10.1016/j.hcl.2008.10.005. Review. PubMed PMID: 19380058.View Abstract at PubMed

Question 57

A 73-year-old man is scheduled to have mature heterotopic bone resected from around his left total hip arthroplasty. The optimal management for prophylaxis against the return of heterotopic bone postoperatively is radiation therapy that consists of

Explanation

DISCUSSION: Patients require prophylaxis for heterotopic bone after resection to prevent recurrence. The optimal management has been found to be a dose of 700 cGy in one dose delivered either pre- or postoperatively. A dose of 2,000 to 3,000 cGy is considered excessive. Radiation therapy consisting of 1,000 cGy in five doses is an acceptable prophylaxis; however, it will require an extended hospital stay of 3 to 4 days and is more problematic for the patient who must be transported for radiation therapy for 5 days. A dose of 400 cGy is not as effective in prophylaxis for heterotopic bone formation.
REFERENCES: Healy WL, Lo TC, DeSimone AA, Rask B, Pfeifer BA: Single-dose irradiation for the prevention of heterotopic ossification after total hip arthroplasty: A comparison of doses of five hundred and fifty and seven hundred centigray. J Bone Joint Surg Am 1995;77:590-595.
Pelligrini VD Jr, Gregoritch SJ: Preoperative irradiation for the prevention of heterotopic ossification following total hip arthroplasty. J Bone Joint Surg Am 1996;78:870-881.
Pelligrini VD Jr, Konski AA, Gastel JA, Rubin P, Evarts CM: Prevention of heterotopic ossification with irradiation after total hip arthroplasty: Radiation therapy with a single dose of eight hundred centigray administered to a limited field. J Bone Joint Surg Am 1992;74:186-200.

Question 58

An 18-year-old man was in a motor vehicle accident and sustained a closed head injury, right displaced scapular body and glenoid fractures, a right proximal humeral fracture, fractures of ribs one through three, facial fractures, and bilateral pubic rami fractures with minimal displacement. He has a systolic blood pressure of 80/40 mm Hg despite fluid resuscitation. A radiograph is shown in Figure 17. Spiral CT does not identify any thoracic or abdominal injuries. What is the next most appropriate step in management?

Explanation

DISCUSSION: The patient has sustained high-energy upper extremity and chest injuries. He continues to remain hemodynamically unstable with no obvious thoracic or abdominal injury responsible for bleeding. The pelvic fracture is unlikely to be causing significant bleeding. A scapulothoracic dissociation and possible disruption of one of the great vessels of the upper extremity should be considered. Evaluation of peripheral pulses or blood pressure indices bilaterally in the upper extremities is a simple way to evaluate the need for further work-up. If there is any discrepancy or further concern, angiography of the involved extremity is necessary.
REFERENCES: Althausen PL, Lee MA, Finkemeier CG: Scapulothoracic dissociation: Diagnosis and treatment. Clin Orthop 2003;416:237-244.
Witz M, Korzets Z, Lehmann J: Traumatic scapulothoracic dissociation. J Cardiovasc Surg 2000;41:927-929.

Question 59

The majority of severe cervical spine injuries occurring in contact sports evolve during axial loading and flexion of the cervical spine. At what minimum degree of flexion does axial loading place the cervical spine at risk during contact sports?

Explanation

DISCUSSION: The paravertebral musculature, the intervertebral disks, and the normal lordotic curvature of the cervical spine can absorb much of the imparted energy of collision. However, when the neck is flexed approximately 30 degrees, the normal lordotic curvature is flattened and the forces applied to the vertex of the head are directed at a straight segmented column. In this situation, the cervical spine is less able to absorb the applied force. With mounting axial load, compressive deformation occurs within the intervertebral disks, causing angular deformation and buckling. The spine will fail in flexion, with resultant fracture, subluxation, or dislocation. A rotatory component added to axial compression can cause concomitant extension, rotation, and shear injury patterns. The National Football Head and Neck Injury Registry has made two recommendations to the NCAA Football Rules Committee to minimize the risk of such injuries: (1) No player should intentionally strike an opponent with the crown or top of the helmet; and (2) No player should deliberately use his helmet to butt or ram an opponent.
REFERENCES: Thomas BE, McCullen GM, Yuan HA: Cervical spine injuries in football players. J Am Acad Orthop Surg 1999;7:338-347.
Torg JS, Truex R Jr, Quedenfeld TC, Burstein A, Spealman A, Nichols C III: The National Football Head and Neck Injury Registry: Report and conclusions 1978. JAMA 1979;241:1477-1479.

Question 60

What is the most common bacteria cultured from dog and cat bites to the upper extremity?

Explanation

DISCUSSION: To define bacteria responsible for dog and cat bite infections, a prospective study yielded a median of five bacterial isolates per culture. Pasteurella is most common from both dog bites (50%) and cat bites (75%). Pasteurella canis was the most frequent pathogen of dog bites, and Pasteurella multocida was the most common isolate of cat bites. Other common aerobes included streptococci, staphylococci, moraxella, and neisseria.
REFERENCE: Talan DA, Citron DM, Abrahamian FM, et al: Bacteriologic analysis of infected dog and cat bites. Emergency Medicine Animal Bite Infection Study Group. N Engl J Med 1999;340:85-92.

Question 61

A 51-year-old woman has had progressively increasing right knee pain for the past 6 months. She has a history of metastatic renal cell carcinoma to the lung and the skeletal system. Radiographs are seen in Figures 18a and 18b. The next step in management of the right distal femur lesion should consist of

Explanation

DISCUSSION: In a patient with known metastatic disease, the surgeon must rule out additional lesions throughout the femur prior to surgical management. Lesions located in the diaphysis or in the peritrochanteric region may influence the surgical procedure.
REFERENCES: Frassica FJ, Gitelis S, Sim FH: Metastatic bone disease: General principles, pathophysiology, evaluation, and biopsy. Instr Course Lect 1992;41:293-300.
Sim FH: Metastatic bone disease of the pelvis and femur. Instr Course Lect 1992;41:317-327.

Question 62

Compact bone, titanium, stainless steel, cobalt-chrome

Explanation

(1001) Q1-1308:
In a patient with a previous compression hip screw in place at the time of total hip arthroplasty, what precautionary measures should be undertaken after hardware removal to prevent a periprosthetic fracture:

Question 63

A 4-year-old boy sustained a nondisplaced, but complete, fracture of the left proximal tibial metaphysis 1 year ago. The fracture healed uneventfully in an anatomic position. Examination of the injured extremity now reveals 18° of valgus compared with 3° of valgus on the opposite side. Management should now include

Explanation

DISCUSSION: The development of a valgus deformity after this type of fracture is a well-known occurrence, and the patient’s parents should be informed about this risk. In a patient who is age 4 years, the natural history is one of gradual correction by the development of a physiologic varus deformity at the distal tibial physis; therefore, no active intervention is needed at this time. Bracing has no effect on the deformity, and the child is too young for any procedure on the growth plate. Proximal tibial osteotomy is reserved until the patient nears skeletal maturity because of the risk of recurrence of the deformity. Lateral stapling can be done near skeletal maturity if the deformity persists, but this is unlikely to be necessary.
REFERENCES: Zionts LE, MacEwen GD: Spontaneous improvement of posttraumatic tibia valga. J Bone Joint Surg Am 1986;68:680-687.
Beaty JH, Kumar A: Fractures about the knee in children. J Bone Joint Surg Am 1994;76:1870-1880.

Question 64

Which of the following statements is true regarding the superomedial fragment of an intra-articular calcaneus fracture?

Explanation

DISCUSSION: The superomedial fragment of a intra-articular calcaneus fracture is also referred to as the sustentacular fragment or “constant fragment” (Illustrations A, B). In their CT analysis of acute calcaneal fractures, Gilmer et al describe that the superomedial piece typically does not move in these fractures due to its strong ligamentous attachments to the talus. For this reason, it is commonly referred to as the "constant fragment." The superiomedial fragment is important during ORIF of calcaneal fractures, because fixation from the lateral side is typically based off this "constant" fragment as a guide to provide anatomic fixation. Additionally, the flexor hallucis longus (FHL) tendon wraps inferiorly around this piece within an osseus groove (illustration C). Illustration D shows the classification and position of these fractures.

Question 65

An open biopsy specimen of a radiodense distal clavicle lesion in a 12-year-old girl shows chronic polyclonal inflammatory cells without granuloma formation. Laboratory studies show that bacterial, fungal, and acid-fast bacillus cultures are negative. Subsequently, a similar lesion is noted in the fibula. The next most appropriate step in management should consist of

Explanation

DISCUSSION: The most likely diagnosis is chronic multifocal osteomyelitis. This is a culture-negative polyostotic disease that is most commonly found in young people. The treatment of choice is anti-inflammatory drugs. The pathology does not suggest eosinophilic granuloma. Antiviral therapy, broad-spectrum antibiotics, and surgical resection are not indicated for this disease.
REFERENCE: Carr AJ, Cole WG, Roberton DM, Chow CW: Chronic multifocal osteomyelitis. J Bone Joint Surg Br 1993;75:582-591.

Question 66

Figure 49 shows an acute axial MRI scan of a right knee. What is the most likely diagnosis? Review Topic

Explanation

The MRI scan shows bone bruises in the medial aspect of the patella and the lateral aspect of the lateral femoral condyle. Both of these signs are typical for a lateral dislocation of the patella with spontaneous reduction. In addition, there may be associated tearing of the medial retinaculum or distal aspect of the vastus medialis.

Question 67

A 55-year-old patient with rheumatoid arthritis reports increasing elbow pain and swelling for the past 2 months. She underwent a cemented, semiconstrained elbow arthroplasty 8 years ago. Laboratory studies show a normal peripheral white blood cell count; however, the erythrocyte sedimentation rate and C-reactive protein level are elevated. Radiographs are shown in Figures 48a and 48b. Which of the following organisms is most difficult to eradicate? Review Topic

Explanation

The patient's history and radiographs are suspicious for a relatively aggressive infection. Staphylococcus epidermidis is difficult to eradicate because of its encapsulation. The lytic area surrounding both the ulnar and humeral components suggests that the prosthesis is also loose. This revision will require component removal, antibiotic spacer placement, and parenteral antibiotics.

Question 68

A 25-year-old patient undergoes the procedure seen in Figure A. Which of the following statements best describes the incorporation of the graft and biopsy results of the graft at one year? Review Topic

Explanation

The patient underwent an osteochondral autograft transfer (OAT) with multiple plugs (also known as mosaicplasty) for a full-thickness chondral defect of the medial femoral condyle. The chondrocytes in the graft remain viable, the transferred cartilage heals, and biopsy reveals articular cartilage composed primarily of type II collagen.
Articular cartilage defects can be treated by a variety of methods including debridement, fixation of unstable osteochondral fragments, marrow stimulation techniques (microfracture, abrasion chondroplasty), cartilage replacement techniques (osteochondral autograft and allograft) and cellular techniques (autologous chondrocyte implantation). Osteochondral autograft transfer is performed by harvesting normal articular cartilage with underlying bone from lesser weightbearing areas (e.g. intercondylar notch) and transferring the graft to a recipient socket at the site of the chondral defect. Graft incorporation occurs by integration of the bony graft into the subchondral bone and healing of the overlying cartilage layer.
Hangody et al. reviewed the outcomes of autologous osteochondral mosaicplasty in professional athletes. They found successful outcomes similar to that of less athletic patients, despite a higher rate of preoperative osteoarthritic changes in the athletic population. The authors noted that histological evaluation revealed good graft incorporation in all 11 cases.
Alford et al. authored a two part Current Concepts article on cartilage restoration. They constructed an algorithm (Illustration A) highlighting many factors that impact treatment choice, including patient activity level and defect characteristics such as location and size. This algorithm also illustrates comorbidities (malalignment, ligament insufficiency) that warrant correction prior to addressing the chondral defect.
Figure A shows a full-thickness chondral defect (left) and subsequent osteochondral autograft transfer (right). Illustration A is a treatment algorithm for the management of chondral defects, as discussed above. Illustration B shows a microfracture procedure, a marrow stimulation technique resulting in fibrocartilage filling of the chondral defect. Illustration C shows an osteochondral allograft transplant, a cartilage replacement technique useful for large defects in which donor graft is obtained from a cadaver hemicondyle and transferred to a recipient socket at the site of the chondral defect. Illustration D shows the autologous chondrocyte implantation technique, a two-stage procedure consisting of 1. Cartilage biopsy for growth of autologous
chondrocytes, and 2. Subsequent injection of autologous chondrocytes beneath a periosteal patch.
Incorrect

Question 69

A 23-year-old man who was the restrained driver in a car involved in a high-speed motor vehicle accident sustained the closed injury shown in Figures 32a through 32c. Which of the following factors has the greatest impact on the risk of osteonecrosis?

Explanation

DISCUSSION: The incidence of osteonecrosis following displaced talar neck fractures is most related to the extent of initial fracture displacement. With increasing fracture displacement, the tenuous vascular supply to the talar body is more at risk for damage, thereby increasing the risk of osteonecrosis. Although displaced talar neck fractures have historically been considered a surgical emergency, recent studies have shown that the timing of surgical intervention bears no impact on the development of osteonecrosis. While nicotine use has an influence on fracture healing, it has never been shown to be a factor in osteonecrosis, nor has posterior-to-anterior screw fixation or the quality of fracture reduction.
REFERENCES: Lindvall E, Haidukewych G, Dipasquale T, et al: Open reduction and stable fixation of isolated, displaced talar neck and body fractures. J Bone Joint Surg Am 2004;86:2229-2234.
Vallier HA, Nork SE, Barei DP, et al: Talar neck fractures: Results and outcomes. J Bone Joint Surg Am 2004;86:1616-1624.

Question 70

With the arm abducted 90 degrees and fully externally rotated, which of the following glenohumeral ligaments resists anterior translation of the humerus?

Explanation

DISCUSSION: With the arm in the abducted, externally rotated position, the anterior band of the inferior glenohumeral ligament complex moves anteriorly, preventing anterior humeral head translation. Both the coracohumeral ligament and the superior glenohumeral ligament restrain the humeral head to inferior translation of the adducted arm, and to external rotation in the adducted position. The middle glenohumeral ligament is a primary stabilizer to anterior translation with the arm abducted to 45 degrees. The posterior band of the inferior glenohumeral ligament complex resists posterior translation of the humeral head when the arm is internally rotated.
REFERENCES: Harryman DT II, Sidles JA, Harris SL, et al: The role of the rotator interval capsule in passive motion and stability of the shoulder. J Bone Joint Surg Am 1992;74:53-66.
Wang VM, Flatow EL: Pathomechanics of acquired shoulder instability: A basic science perspective. J Shoulder Elbow Surg 2005;14:2S-11S.

Question 71

Which of the following is considered a contraindication to cement injection techniques, such as kyphoplasty or vertebroplasty, in the treatment of osteoporotic compression fractures?

Explanation

DISCUSSION: When retropulsion of the posterior vertebral wall is present, nothing prohibits the cement from following the path of least resistance into the canal or from pushing a bone fragment further into the canal; most clinicians consider it a contraindication to these techniques. Patient age itself is not a contraindication as long as there are no medical contraindications to surgery. An acute fracture in a patient who remains immobile and hospitalized because of pain may be a good indication for such a technique. Prior compression fracture and older compression fractures are not contraindications, but pain relief may be less predictable.
REFERENCES: Phillips FM, Pfeifer BA, Leiberman IH, et al: Minimally invasive treatment of osteoporotic vertebral compression fractures: Vertebroplasty and kyphoplasty. Instr Course Lect 2003;52:559-567.
Truumees E, Hilibrand A, Vaccaro AR: Percutaneous vertebral augmentation. Spine J 2004;4:218-229.
Rao RD, Singrakhia MD: Painful osteoporotic vertebral fracture: Pathogenesis, evaluation, and roles of vertebroplasty and kyphoplasty in its management. J Bone Joint Surg Am 2003;85:2010-2022.

Question 72

A 72-year-old woman is scheduled to undergo right total hip arthroplasty. Her preoperative radiograph is shown in Figure below. To avoid increasing this patient’s combined offset while maintaining her leg length, what is the most appropriate surgical plan?

Explanation

DISCUSSION:
The management of patients with proximal femoral deformity can be difficult. Appropriate implant selection and preoperative templating are critical. In this patient, it would be difficult to avoid increasing the combined offset by too much, which could contribute to the overtensioning of the soft tissues and trochanteric pain. By medializing the acetabular component (decreasing the combined offset), using a low offset femoral component or a cemented component placed more valgus (decreasing the combined offset), and making a longer neck cut (to avoid shortening of the lower extremity), restoration of the patient’s native offset and leg length can be achieved.

Question 73

An 18-year-old collegiate football player injures his right shoulder during a tackle. He reports pain and numbness in the shoulder and numbness radiating to his fingers. His symptoms improve within 15 minutes and he has no residual symptoms. This condition is best known as

Explanation

DISCUSSION: The condition described in this case is known as a stinger or burner. It is caused by stretching the upper trunk of the brachial plexus in the C5 and C6 nerve roots. The symptoms are temporary and last 15 to 20 minutes. There are no residual deficits, unless the patient has had multiple repetitive injuries. Once motor and sensory examination findings and reflexes have normalized, the athlete can return to play. Acute spinal cord injury may cause temporary complete paralysis in the upper and lower extremities with resolution of symptoms within 24 hours. Central cord syndrome affects the upper more than lower extermities and affects mostly elderly patients. Nerve root avulsions lead to permanent deficits and have a poor prognosis for return of function. Guillain-BarDe syndrome is an autoimmune disease that presents as an ascending paralysis with weakness in the legs that spreads to the upper limbs and the face along with complete loss of deep tendon reflexes.
REFERENCES: Safran MR: Nerve injury about the shoulder in athletes. Part 2: Long thoracic nerve, spinal accessory nerve, burners/stingers, thoracic outlet syndrome. Am J Sports Med 2004;32:1063-1076. Aval SM, Durand P Jr, Shankwiler JA: Neurovascular injuries to the athlete’s shoulder: Part I. J Am Acad Orthop Surg 2007;15:249-256.

Question 74

Which of the following treatments for osteoporosis is a direct inhibitor of RANK ligand (RANK-L)?

Explanation

Prolia, or denosumab, is a newly approved drug used to treat osteoporosis and has a mechanism of action similar to osteoprotegerin (inhibits binding of RANKL to RANK).
RANKL (Receptor activator of nuclear factor kappa-B ligand) is a key molecule for osteoclast differentiation and activation. Inhibition of RANKL activity with anti-RANKL antibody reduces osteoclastogenesis, resulting in inhibition of bone resorption.
Capozzi et al. author a review article on denosumab. They state the medication confers improved bone mineral density and prevents new fragility fractures similar to alendronate. However, denosumab presents less risk of atypical femoral fractures and
osteonecrosis of the jaw.
Yasuda et al. present a review that details the creation of three elegant animal models to mimic metabolic bone disease and how the animal models can create a template to help cure human metabolic bone disease. These enable modeling of osteoporosis, hypercalcemia, and osteopetrosis by treating normal mice with soluble RANKL (sRANKL), adenovirus expressing sRANKL, and anti-mouse RANKL neutralizing antibody, respectively. They report that these animal models can be established in about 14 days using normal mice.
Illustration A demonstrates the mechanism of action of bisphosphonates and denosumab.
Incorrect Answers:
1: Romosozumab is the first humanized anti-sclerostin monoclonal antibody that has been demonstrated to increase bone formation. 2: Zoledronic acid (Reclast) is a nitrogen containing bisphosphonates that inhibits osteoclast resorption by inhibiting the enzyme farnesyl diphosphate synthase. 4: Teriparatide (Forteo) comprises the first 34 amino acids of the 84 amino acid parathyroid hormone (PTH) and can reproduce the primary effects of PTH by activating adenyl cyclase. 5: Blosozumab is an investigational monoclonal anti-sclerostin antibody showing osteoanabolic properties with the potential to improve clinical outcomes in patients with osteoporosis.

Question 75

A 62-year-old active man returns for routine follow-up 16 years after hip replacement. He has no hip pain. Radiographs reveal a well-circumscribed osteolytic lesion around a single acetabular screw. All hip components are perfectly positioned. Comparison radiographs obtained 6 months later show an increase in the size of the osteolytic lesion. CT depicts a well-described lesion that is 3 cm at its largest diameter and is localized around one screw hole with an eccentric femoral head. What treatment is appropriate, assuming that well-fixed cementless total hip components are in place?

Explanation

DISCUSSION:
Given a well-fixed acetabular metal shell and a localized osteolytic lesion, good outcomes can be expected from liner revision in this clinical scenario with retention of the metal socket, assuming no damage to the components or other unexpected findings arise during revision surgery. Here, complete cup revision is not warranted, considering the appropriate implant position. Beaulé and associates reviewed 83 consecutive patients (90 hips) in whom a well-fixed acetabular component was retained in a clinical scenario such as the one described. No hip showed recurrence or expansion of periacetabular osteolytic lesions. If the metal cup is unstable, acetabular component revision may be indicated.

Question 76

A 26-year-old weightlifter has increasing pain in his left shoulder for 4 months. Nonsurgical treatment consisting of anti-inflammatory medication, corticosteroid injections, and rest fails to alleviate his symptoms. He undergoes an arthroscopic distal clavicle resection with excision of the distal 8 mm of clavicle (Mumford procedure). Three months after surgery, he reports mild pain and popping by his clavicle. His clavicle demonstrates mild posterior instability on examination without any obvious deformity on his radiographs. What structures were compromised during his excision?

Explanation

The posterior and superior acromioclavicular ligaments provide the most restraint to posterior translation of the acromioclavicular joint and must be preserved during a Mumford procedure. Anterior and superior acromioclavicular joint ligaments are the opposite of the preferred response and prevent anterior translation of the clavicle. Injuries to the conoid and trapezoid ligaments are more pronounced with grade III or higher acromioclavicular separations, with superior migration of the clavicle relative to the acromion.

Question 77

A 22-year-old man reports that he initially dislocated his shoulder while playing basketball 2 years ago and was subsequently treated with an arthroscopic Bankart repair. Despite appropriate rehabilitation, the patient continues to report recurrent instability. An axillary view radiograph and CT scan are shown in Figures 57a and 57b. What is the most appropriate management at this time? Review Topic

Explanation

Although the changes are subtle on the radiograph, an anterior inferior glenoid bone defect is clearly evident on the CT scan. With loss of greater than 20% to 25% of the glenoid width, patients may experience persistent instability despite appropriate labral repair and capsulorrhaphy. Therefore, nonsurgical management with supervised therapy or surgical treatments that do not address the bony defect, such as arthroscopic or open labral repair and capsulorrhaphy, are not likely to stabilize the joint. An open shoulder stabilization procedure with a bone block should address the defect and stabilize the joint. Shoulder arthrodesis is not warranted in this patient at this time because the shoulder is likely salvageable.

Question 78

Figures 91a through 91c are the radiographs of a 10-year-old boy who has a 6-month history of progressive heel pain. The patient is a year-round soccer player and now experiences pain with most every step. What is the most appropriate management?

Explanation

The patient has calcaneal apophysitis, an overuse syndrome common in children ages 9 to 12 years. Symptoms are usually the result of excess tension and a tight heel cord. Management includes activity modification, as well as heel cord stretching, nonsteroidal anti-inflammatory drugs, icing, and other modalities. Radiographs are typically negative; MRI is unnecessary. Custom orthotics are not indicated. The condition is self-limiting, in that the symptoms fully resolve once the apophyses fuses, such that surgery is rarely indicated.

Question 79

A 28-year-old male sustains a fall on icy ground and fractures his ankle. An intraoperative fluoroscopy image is shown in Figure A. This fixation suggests that the mechanism of injury was one of

Explanation

Moore I
Moore II
Schatzker III
Schatzker V
OTA type 41B3
Figure A shows a Moore Type II fracture. Moore type II fractures consist of fractures involving the entire tibial condyle, where the fracture line begins in the opposite compartment and extends across the tibial eminence.
A number of classification systems are used to describe tibial plateau fractures. The main classification systems that are widely used include Schatzker, AO/OTA, Hohl and Moore. The Moore classification describes high energy fracture-subluxation injuries of the knee. This is thought to have clinical implications as the type of fracture pattern can indicate an associated soft-tissue injury.
Moore retrospectively reviewed over a 1000 proximal tibia fractures to devise a classification systems based on the characteristic of five types of tibia plateau fracture patterns. He believed this system helped to better understand knee instability and concomitant soft-tissue injury. For example, Moore Type III fractures (rim avulsion) are associated with a high rate of neurovascular injury.
Figure A shows a fracture involving the entire tibial condyle. Illustration A shows a schematic diagram of the Moore classification (I - V). Illustration B shows a table that
describes the Moore classification (I - V).
Incorrect Answers:

Question 80

A 32-year-old male sustains a posterior wall acetabulum fracture as the result of a high-speed motor vehicle collision. Improved patient-reported outcomes after surgical treatment are associated with which of the following variables?

Explanation

DISCUSSION: Patient functional outcomes after acetabular fractures have been shown to be related to postoperative hip strength, regardless of surgical approach.
The reference by Borrelli et al evaluated muscle strength and outcomes after acetabular surgery via an anterior approach. They report that hip extension strength was affected least(6%), whereas abduction, adduction, and flexion strength was affected to a greater degree. They note that hip muscle strength after operative treatment of a displaced acetabular fracture directly influences patient outcome.
The reference by Engsberg et al is a review of patients that underwent ORIF of acetabular fractures through anterior or posterior approaches. They report that maximizing hip muscle strength may improve gait, and improvement in hip muscle strength and gait is likely to improve functional outcome. Worsening functional outcomes were correlated with decreased gait kinematics and stride length.

Question 81

Which structure is the primary stabilizer of the lesser metatarsophalangeal (MTP) joint?

Explanation

DISCUSSION
Synovitis of the second MTP occurs in association with instability of the joint. This can be idiopathic or secondary to an external deforming force (such as a hallux valgus or shoe wear causing a claw toe). The primary stabilizer of the MTP joint for translation in the vertical plane is the plantar plate. The flexor digitorum brevis flexes the MTP joint, and the flexor digitorum longus flexes
all joints of the toe. The collateral ligaments are primary stabilizers in the transverse plane and secondary stabilizers in the sagittal plane.
RECOMMENDED READINGS
Deland JT, Sung IH. The medial crosssover toe: a cadaveric dissection. Foot Ankle Int. 2000 May;21(5):375-8. PubMed PMID: 10830654.View Abstract at PubMed
Suero EM, Meyers KN, Bohne WH. Stability of the metatarsophalangeal joint of the lesser toes: a cadaveric study. J Orthop Res. 2012 Dec;30(12):1995-8. doi: 10.1002/jor.22173. Epub 2012 Jun 13. PubMed PMID: 22696467. View Abstract at PubMed
CLINICAL SITUATION FOR QUESTIONS 91 THROUGH 95
Figure 91a is the sagittal plane ultrasound of the second web space of a 48-year-old woman who has noted burning pain in the ball of her right foot for 2 years. The pain intermittently radiates into her second and the third toes. Figure 91b shows the surgical procedure and Figure 91c is the pathologic specimen.
A

Question 82

Figure 28 shows the postoperative radiograph of a 36-year-old patient. The cerclage cable was placed for a minimal medial calcar fracture seen during femoral preparation. In the immediate postoperative period, what is the highest level of activity that would be safely permitted?

Explanation

DISCUSSION: The incidence of femoral fracture in primary cementless total hip arthroplasty ranges from 1.5% to 27.8%. It is imperative that the implant and fracture are stable both intraoperatively and postoperatively. Cerclage wiring or cerclage cabling is the current recommended treatment for nondisplaced calcar fractures and minimally displaced proximal fractures. Berend and associates reviewed the results of 58 total hips in 55 patients with intraoperative calcar fracture managed with single or multiple cerclage wires or cables and immediate full weight bearing. Follow-up averaged 7.5 years, and there were no revisions of the femoral component. No patients had severe thigh pain.
REFERENCES: Berend KR, Lombardi AV Jr, Mallory TH, et al: Cerclage wires or cables for the management of intraoperative fracture associated with a cementless, tapered femoral prosthesis: Results at 2 to 16 years. J Arthroplasty 2004;19:17-21.
Schmidt AH, Kyle RF: Periprosthetic fractures of the femur. Orthop Clin North Am 2002;33:143-152.
Greidanus NV, Mitchell PA, Masri BA, et al: Principles of management and results of treating the fractured femur during and after total hip arthroplasty. Instr Course Lect 2003;52:309-322.

Question 83

In total knee arthroplasty, in vitro testing has shown that cross-linking can diminish the rate of polyethylene wear by 30% to 80%. What other change in material properties is possible when polyethylene is highly cross-linked?

Explanation

DISCUSSION:
The most important concern regarding highly cross-linked polyethylene relates to decreased mechanical properties. Cross-linking results in reduced ductility, tensile strength, and fatigue crack propagation resistance. These problems have not been shown to cause implant failure in the most recent clinical trials, but they remain the most important mechanical issues associated with current material processing methods.

Question 84

Figures 35a and 35b show the radiographs of a 7-year-old patient who has progressive deformity of the right thigh accompanied by a dull persistent pain radiating to the knee. Examination reveals an obvious bulge in the right thigh, with flexion of the hip beyond 50° only if the hip is allowed to externally rotate. Management should consist of

Explanation

DISCUSSION: The patient has radiographic signs of osteogenesis imperfecta, including osteopenia, mild acetabular protrusio, cortical thinning, and bowing associated with anterior stress fracturing. The treatment of choice is correction of the bow with osteotomies, followed by intramedullary fixation to prevent further deformity. Biphosphonates, such as pamidronate, may be useful in increasing bone density and preventing fractures. Large multicenter studies on biphosphonate efficacy are currently in progress.
REFERENCES: Zionts LE, Ebramzadeh E, Stott NS: Complications in the use of the Bailey-Dubow extensible nail. Clin Orthop 1998;348:186-195.
Luhmann SJ, Sheridan JJ, Capelli AM, Schoenecker PL: Management of lower-extremity deformities in osteogenesis imperfecta with extensible intramedullary rod technique: A 20-year experience. J Pediatr Orthop 1998;18:88-94.
Glorieux FH, Bishop NJ, Plotkin H, Chabot G, Lanoue G, Travers R: Cyclic administration of pamidronate in children with severe osteogenesis imperfecta. N Engl J Med 1988;339:947-952.

Question 85

A 22-year-old college baseball pitcher reports the recent onset of anterior and posterosuperior shoulder pain in his throwing shoulder. Examination shows a 15-degree loss of internal rotation, tenderness over the coracoid, and a positive relocation test. Radiographs are normal, and an MRI scan without contrast shows no definitive lesions. A rehabilitation program is prescribed. Which of the following regimens should be initially employed? Review Topic

Explanation

Throwing athletes, particularly pitchers, have a high incidence of shoulder pain. Recent evidence suggests that posteroinferior capsular tightness and scapular dyskinesis may play a substantial role in the pathologic cascade, culminating in the development of articular surface rotator cuff tears and tearing of the posterosuperior labrum. These patients have posterosuperior shoulder pain primarily. Furthermore, these athletes are susceptible to a muscular fatigue syndrome, the SICK (Scapular malposition, Inferior medial border prominence, Coracoid pain and malposition, and dysKinesis of scapular movement) scapula syndrome. This patient has an internal rotation deficit and tenderness over the coracoid. The internal rotation deficit is addressed by stretching the posterior capsule. The tenderness over the coracoid has been attributed to a contracture of the pectoralis minor tendon secondary to scapular malposition. The initial phase of the rehabilitation regimen is directed at stretching the posterior capsule and pectoralis minor tendon.

Question 86

A 15-year-old boy reports feeling a pop and notes sudden giving way of the left knee while playing basketball. He has immediate pain and swelling in the knee. An AP radiograph is shown in Figure 32. A small avulsion fragment from the lateral tibial margin is the only finding. What is the most likely diagnosis?

Explanation

DISCUSSION: An avulsion fracture from the lateral tibial margin carries the eponym Segond fracture and is pathognomonic for an anterior cruciate ligament (ACL) tear. The fragment is located posterior to Gerdy’s tubercle and is superior and anterior to the fibular head. It represents an avulsion of the lateral capsular ligament of the knee and is caused by the same mechanism that causes the ACL tear. The pes anserinus is the insertion point of the medial hamstrings and would not be affected in a lateral avulsion injury. The posterior cruciate ligament may be seen on a lateral view if associated with an avulsion fragment, but a tear of the PCL generally cannot be diagnosed on an AP view. The insertion of the iliotibial band is broad and is unlikely to produce an avulsion injury such as that seen in the radiograph. This view is not consistent with the appearance of a lateral collateral ligament injury.
REFERENCES: Beaty JH (ed): Orthopaedic Knowledge Update 6. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 533-557.
Larson RL, Tailon M: Anterior cruciate ligament insufficiency: Principles of treatment. J Am Acad Orthop Surg 1994;2:26-35.

Question 87

below show the radiograph and the MRI scan obtained from a year-old woman with a month history of left hip pain. Which presurgical factor is most commonly associated with a poor outcome after a hip joint salvage procedure?

Explanation

DISCUSSION:
MRI reveals an anterior labral tear, and the radiograph shows minimal arthritis with possible dysplasia. The most common location of pain in patients with a labral tear is the groin, and the most common physical finding is a positive impingement test result. Pain during sitting, clicking, and buttock pain are frequently described by patients with a labral tear, but these symptoms are less common than groin pain. A positive posterior impingement test finding is more common in patients with a posterior labral tear. Although age over 40 years and a body mass index higher than 30 can adversely affect clinical outcomes after joint preservation procedures such as PAO, hip arthroscopy, and femoral acetabular impingement surgery, the presence of hip arthritis on presurgical radiographs is the most commonly mentioned cause of failed hip joint preservation surgery. Tönnis grade is a radiographic measure of hip arthritis. A higher Outerbridge score is associated with more frequent poor outcomes after hip arthroscopy; however, the
Outerbridge cartilage score is determined by direct visualization at the time of surgery. The Outerbridge
score cannot be determined presurgically.

Question 88

below shows the radiograph obtained from a year-old woman who returns status post total hip arthroplasty 14 years earlier. She denies pain and has no discomfort on examination. She then undergoes revision total hip arthroplasty with head and liner exchange and bone grafting. After a physical therapy session two days after surgical intervention, she develops inability to dorsiflex the foot while she is sitting in a chair. The initial treatment should consist of

Explanation

DISCUSSION:
Gamma irradiation produces free radicals. Although these free radicals can form cross-links with other polyethylene chains, the free radicals can also form a bond with oxygen, resulting in early oxidation. Gamma irradiation in air produces the highest risk for oxidized polyethylene, resulting in the highest risk for wear, delamination, and subsequent osteolysis. This patient demonstrates severe periarticular osteolysis. When she is asymptomatic, this suggests the acetabular and femoral components remain well fixed to the bone. Consequently, she can be treated by removing the wear generator (polyethylene exchange), along with bone grafting of the osteolytic defect. Considering the extensive amount of osteolysis indefinite observation would not be appropriate. A foot drop develops 2 days after surgery. As a result, it can be assumed that the nerve was not injured directly during the surgical procedure. Although MRI or CT may be indicated to identify an evolving hematoma, the immediate concern is to minimize pressure on the sciatic nerve. Tension on the nerve can be reduced by flexing the surgical knee and positioning the bed flat.

Question 89

What do the T2-weighted, fat-saturated MRI scans shown in Figures 1 through 4 reveal?

Explanation

The MRI scans show that edema is noted on the femoral insertion of the ACL consistent with a high-grade or complete ACL tear. The ACL is not visualized on the sagittal view, although the torn meniscus can be seen in the notch. On the coronal image, there is an empty lateral wall sign indicating proximal
disruption of the ACL. The medial meniscus images show a disruption of normal meniscus morphology consistent with a bucket handle medial meniscus tear. Note the appearance on the sagittal MRI scan of what appears to be a second soft-tissue density in line with the PCL. This "double PCL" sign is highly indicative of a displaced medial meniscus tear rather than a displaced lateral meniscus tear.

Question 90

A 14-year-old boy with a history of cerebral palsy has a clawed hallux, cavus foot deformity, and associated pain. Examination reveals pain under the first metatarsal head and a rigid first tarsometatarsal joint. Treatment should consist of

Explanation

DISCUSSION: In a retrospective study for clawing of the hallux with associated cavus foot deformities, the modified Robert Jones tendon transfer was shown to be effective in relieving symptoms related to clawing of the hallux in 90% of patients but was not reliable in relieving pain under the first metatarsal head, with success in only 43% of patients. In three patients, pain under the metatarsal head was relieved initially but recurred by 18 months. The return of symptoms in these cases is the result of stretching of the muscle and tendon of the extensor hallucis longus by the more powerful peroneus longus. Basal dorsal wedge osteotomy at the time of the modified Robert Jones procedure is recommended.
REFERENCES: Mizel MS, Miller RA, Scioli MW (eds): Orthopaedic Knowledge Update: Foot and Ankle 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1998, pp 79-100.
Tynan MC, Klenerman L: The modified Robert Jones tendon transfer in cases of pes cavus and clawed hallux. Foot Ankle Int 1994;15:68-71.

Question 91

Which of the following hip fracture patterns is at increased risk of proximal fragment flexion malreduction with dynamic hip screw fixation?

Explanation

DISCUSSION: Left-sided unstable intertrochanteric hip fractures are at increased risk of malreduction compared to unstable right-sided fractures fixed with dynamic hip screws. In left-sided fractures the rotational torque imparted to the proximal head and neck fragment can cause loss of reduction leading to potential failures of fixation. With these left sided injuries, the rotational torque can cause an anterior spike, whereas with right-sided injuries the rotational torque causes compression and reduction of the fracture. In addition, if a nail is used for these injuries and the proximal fracture fragment is not being held by the nail itself, this phenomenon can be seen as well.
Mohan et al conducted a study to assess the effect of clockwise rotational torque onto the fracture configuration in unstable and stable intertrochanteric fractures fixed with a dynamic hip screw construct. They found that 11 out of 30 unstable fractures showed an anterior spike (flexion malreduction) in left-sided fixations due to clockwise torque. This malreduction was not present in right-sided or stable fractures.

Question 92

A characteristic genetic translocation has been noted in which of the following tumors?

Explanation

DISCUSSION: There have been no characteristic gene translocations or rearrangements noted in osteosarcoma, chondrosarcoma, neurofibrosarcoma, or epithelioid sarcoma. In contrast, Ewing’s sarcoma has been noted to have a consistent genetic translocation t(11:22).
REFERENCES: Brockstein BE, Peabody TD, Simon MA: Soft tissue sarcomas, in Vokes EE Golomb HM (eds): Oncologic Therapies. New York, NY, Springer-Verlag, 1999, pp 925-952.
Simon MA, Springfield DS, et al: Management of Surgical Specimens: Surgery for Bone and Soft Tissue Tumors. Philadelphia, PA, Lippincott Raven, 1998, pp 67-75.

Question 93

A baseball player has had diffuse scapular soreness for the past 8 weeks. He reports that it began insidiously over several days and gradually has become worse. He denies any history of trauma. Examination reveals drooping of the shoulder, with lateral winging of the scapula at rest. He is otherwise neurologically intact. What is the best course of action?

Explanation

DISCUSSION: Lateral scapular winging is characteristic of trapezius palsy, whereas medial scapular winging is characteristic of long thoracic nerve palsy. During sports activity, injury to the spinal accessory nerve is rare but may occur with blunt or stretching trauma. Patients often report an asymmetric neckline, drooping shoulder, winging of the scapula, and weakness of forward elevation. Evaluation should include a complete electrodiagnostic examination.
REFERENCES: Wiater JM, Bigliani LU: Spinal accessory nerve injury. Clin Orthop 1999;368:5-16.
Wiater JM, Flatow EL: Long thoracic nerve injury. Clin Orthop 1999;368:17-27.
Mariani PP, Santoriello P, Maresca G: Spontaneous accessory nerve palsy. J Shoulder Elbow Surg 1998;7:545-546.
Porter P, Fernandez GN: Stretch-induced spinal accessory nerve palsy: A case report. J Shoulder Elbow Surg 2001;10:92-94.
Cohn BT, Brahms MA, Cohn M: Injury to the eleventh cranial nerve in a high school wrestler. Orthop Rev 1986;15:59-64.

Question 94

Figure 56 is the radiograph of a 62-year-old noninsulin-dependent woman with diabetes who twisted her ankle while walking and felt a pop. At the emergency department she describes heel pain. What is the best course of action?

Explanation

DISCUSSION
The radiograph reveals a displaced calcaneal tuberosity fracture. Displacement of a large tuberosity fragment necessitates urgent fracture reduction and stabilization. Delayed reduction results in compromise of the skin and soft tissues at the posterior heel. This injury occurs frequently in patients with diabetes. Protected weight-bearing activity does not address the displaced fragment or the threatened skin. Closed reduction, if possible, will not maintain the tuberosity fragment in a reduced position and will likely result in redisplacement. The fragment is large enough that it may be fixed and not excised. The Achilles tendon inserts on the displaced tuberosity fragment, so tuberosity reduction and fixation is necessary to achieve proper Achilles function.
RECOMMENDED READINGS
Beavis RC, Rourke K, Court-Brown C. Avulsion fracture of the calcaneal tuberosity: a case report and literature review. Foot Ankle Int. 2008 Aug;29(8):863-6. Review. PubMed PMID: 18752789.View Abstract at PubMed
Gardner MJ, Nork SE, Barei DP, Kramer PA, Sangeorzan BJ, Benirschke SK. Secondary soft tissue compromise in tongue-type calcaneus fractures. J Orthop Trauma. 2008 Aug;22(7):439-45. PubMed PMID: 18670282. View Abstract at PubMed
RESPONSES FOR QUESTIONS 57 THROUGH 59
- High strain
- Low strain
For each fracture detailed, select the appropriate description.
A simple fracture pattern that is anatomically reduced and compressed and treated with an 8-hole conventional plate with 4 bicortical conventional screws placed on each side of the fracture
- High strain
- Low strain

Question 95

An active 66-year-old man who underwent total shoulder arthroplasty 3 years ago now reports pain. Laboratory studies reveal an elevated erythrocyte sedimentation rate and C-reactive protein. Intraoperative frozen section reveals greater than 10 white blood cells per high power field on two slides and the Gram stain reveals gram-positive cocci in clusters. What is the most appropriate surgical treatment to eradicate the infection and maintain function? Review Topic

Explanation

The prosthesis is grossly infected. Removal of the components and placement of an antibiotic spacer is necessary to eradicate the infection and allow for a second stage reimplantation. Resection arthroplasty is an option to treat the infection but the functional outcome would be limited. Bone grafting with concurrent infection is not likely to heal and should be delayed until the second stage. Humeral head exchange and debridement or arthroscopic debridement alone is unlikely to eradicate the infection.

Question 96

All of the following techniques can help to prevent valgus angulation during intramedullary nailing of proximal one-third tibia fractures EXCEPT:

Explanation

DISCUSSION: Proximal tibial shaft fractures treated with intramedullary nails are most commonly malreduced with apex anterior and valgus deformities. Several techniques are available to overcome this malalignment: proximal and lateral nail starting point, usage of a femoral distractor or temporary plating, suprapatellar nailing, and lateral parapatellar approaches. Suprapatellar nailing portals do not affect coronal angulation - they only affect the apex anterior deformity.
A final technical trick is the usage of blocking (Poller) screws - the referenced article by Ricci et al had 100% correction and maintenance of reduction with usage of blocking screws without other adjunct techniques. These should be placed in the lateral aspect of the proximal and distal fragments when needed.
The referenced study by Krettek et al is a biomechanical evaluation of blocking screws in a tibial model that showed significantly increased strength when they were utilized.

Question 97

An 8-year-old boy sustains nondisplaced midshaft fractures of the tibia and fibula after being struck by a car while he was riding his bicycle. No other injuries are noted, but the patient reports pain with passive motion of his toes. His neurovascular examination is otherwise normal. What is the best course of action?

Explanation

DISCUSSION: Pain with passive motion of the toes is a recognized early sign of increased compartment pressures. At a minimum, a baseline evaluation of the leg compartment pressures should be obtained. While it is normal for the patient to have pain related to the associated muscle contusions, any significant concerns should be addressed immediately in light of the severe consequences likely when a compartment syndrome occurs.
REFERENCES: Mubarak SJ, Owen CA, Hargens AR, et al: Acute compartment syndromes: Diagnosis and treatment with the aid of the wick catheter. J Bone Joint Surg Am

1978;60:1091-1095.

Matsen FA III, Veith RG: Compartmental syndromes in children. J Pediatr Orthop

1981;1:33-41.

Question 98

A 12-year-old girl who plays softball has chronic lateral hindfoot aching pain that is aggravated by weight-bearing activity. She reports that the pain has recurred after initial improvement with cast immobilization, and it continues to limit her overall level of activity. Radiographs are seen in Figures 40a through 40c. What is the most appropriate surgical treatment?

Explanation

DISCUSSION: The patient has a calcaneonavicular tarsal coalition. Symptoms of calcaneonavicular coalitions typically are seen between the ages of 10 and 14 years. The cause of pain has not been clearly established. It has been postulated that the coalition stiffens with maturity and microfractures can result, producing pain. Resection of a calcaneonavicular coalition generally has been associated with a satisfactory result. Soft-tissue interposition, most commonly using the extensor digitorum brevis muscle, appears to be helpful. A hindfoot arthrodesis (usually triple) would be reserved if coalition resection proves to be unsuccessful. Achilles tendon lengthening and orthotic support, as well as debridement of the sinus tarsi, are not expected to result in a satisfactory outcome. The patient does not have a flatfoot deformity.
REFERENCES: Vaccaro AR (ed): Orthopaedic Knowledge Update 8. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2005, pp 757-765.
Lemley F, Berlet G, Hill K, et al: Current concepts review: Tarsal coalition. Foot Ankle Int 2006;27:1163-1169.

Question 99

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 100

A patient who underwent total knee arthroplasty 6 years ago now reports knee pain for the past 3 days following dental surgery. Cultures of the aspirate are positive for Staphylococcus epidermidis. Management should consist of

Explanation

DISCUSSION: The patient has an early prosthesis infection as a result of hematogenous seeding from dental surgery. Irrigation and debridement with polyethylene exchange and IV antibiotics have been successful in early postoperative infections; it is less likely to be effective for a late hematogenous infection. Immediate total component exchange also may be effective, but it should be reserved for failure of irrigation and debridement.
REFERENCES: 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 323-337.
Goldman RT, Scuderi GR, Insall JN: 2-stage reimplantation for infected total knee replacement. Clin Orthop 1996;331:118-124.

Full Question & Answer Text (for Search Engines)

Question 1:

Options:

Painful os trigonum
Posterior ankle soft-tissue impingement
Stricture in the knot of Henry
Flexor digitorum longus tendinitis
Flexor hallucis longus tendinitis

Correct Answer: Flexor hallucis longus tendinitis

Explanation:

Question 2:

Options:

Bed rest for 6 weeks, followed by mobilization in a thoracolumbosacral orthosis until the fracture has healed
Anterior corpectomy with strut grafting and placement of an anterior plate spanning L1 to L3
Anterior corpectomy with strut grafting, followed by posterior spinal fusion and instrumentation
Posterior spinal fusion and instrumentation from T11 to L4
L2 laminectomy and posterior spinal fusion and instrumentation from T11 to L4

Correct Answer: L2 laminectomy and posterior spinal fusion and instrumentation from T11 to L4

Explanation:

DISCUSSION: The patient has a burst fracture with probable unilateral entrapment of the cauda equina within the elements of the fractured lamina. A dural tear is likely in this scenario as well. It is recommended that this type of burst fracture be treated surgically with laminectomy, freeing of the entrapped nerve roots, and dural repair followed by stabilization of the fracture by either a posterior or combined approach. The degree of kyphosis and the extent of anterior canal compromise does not warrant corpectomy in this patient. Therefore, after completing the laminectomy and dural repair, posterior fusion and instrumentation should be sufficient to stabilize the fracture.
REFERENCES: Cammisa FP Jr, Eismont FJ, Green BA: Dural laceration occurring with burst fractures and associated laminar fractures. J Bone Joint Surg Am 1989;71:1044-1052.
Spivak JM, Connolly PJ (eds): Orthopaedic Knowledge Update: Spine 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, pp 201-216.

Question 3:

- What is the most common nerve injury following a Monteggia fracture-dislocation of the forearm in adults?

Options:

Posterior interosseous
Anterior interosseous
Radial
Median
Ulnar

Correct Answer: Posterior interosseous

Explanation:

According to Rockwood and Green the most commonly injured nerve associated with a Monteggia fracture is the posterior interosseous nerve, a branch of the radial nerve.

Question 4:

Options:

Lateral
Posterior
Posterolateral
Anterior
Anteromedial

Correct Answer: Lateral

Explanation:

Question 5:

What radiographic view will best reveal degeneration of the pisotriquetral joint in a patient who is being evaluated for pisotriquetral arthrosis?

Options:

True lateral
Lateral in 30 degrees of pronation
Lateral in 30 degrees of supination
Posteroanterior in 30 degrees of pronation
Carpal tunnel

Correct Answer: Lateral in 30 degrees of supination

Explanation:

Question 6:

Figure 17 shows the AP radiograph of a 75-year-old man with right hip pain. The femoral component is loose. The mechanism of loosening is most likely secondary to

Options:

osteolysis.
fatigue failure of the implant.
failure of bone ingrowth.
wear debris from cerclage wire.
trochanteric impingement.

Correct Answer: failure of bone ingrowth.

Explanation:

DISCUSSION: The femoral construct shown in the radiograph has failed to produce ingrowth of the stem. The stem has subsided and rotated. Impingement of the trochanter did not occur until after the stem subsided. There is no evidence of osteolysis or third-body wear debris from the cerclage wire. A larger femoral stem needs to be implanted to achieve rigid fixation.
REFERENCES: Pelicci PM, Tria AJ Jr, Garvin KL (eds): Orthopaedic Knowledge Update:
Hip and Knee Reconstruction 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000, pp 217-238.
Peter CL, Rivero DP, Kull LR, et al: Revision total hip arthroplasty without cement: Subsidence of proximally porous-coated femoral components. J Bone Joint Surg Am 1995;77:1217-1226.

Question 7:

Options:

Silicone replacement arthroplasty through a volar approach
Surface replacement arthroplasty through a volar approach
Silicone replacement arthroplasty through a dorsal approach
Surface replacement arthroplasty through a dorsal approach

Correct Answer: Silicone replacement arthroplasty through a volar approach

Explanation:

EXPLANATION:
A recent systematic review compared silicone replacement, pyrocarbon replacement, and surface replacement arthroplasty for PIP arthritis. Silicone arthroplasty through a volar approach showed the greatest gains in arc of motion and had the lowest rate of revision surgeries. The rates of revision surgeries from low to high for each type of arthroplasty were 6% for silicone volar, 10% for silicone lateral, 11%
Surface replacement arthroplasty through a volar
for silicone dorsal, 18% for surface replacement dorsal, and 37% for surface replacement volar. Revision surgeries include implant replacement (to silicone or maintaining the surface replacement), arthrodesis, explantation, amputation, and other procedures.
approach showed the highest revision rate
,
the worst gain in arc of motion
, and
the greatest extension lag.
However, substantial pain relief and higher satisfaction still were reported after surface replacement
arthroplasty, regardless of the complications.

Question 8:

Clinical evidence suggests that grafts for replacing a torn anterior cruciate ligament often stretch after surgery. What is the most probable mechanism for this behavior?

Options:

Gross failure at the attachment sites
Fatigue failure of the ligament tissue
Creep of the graft material
Water absorption by the graft material
Elastic stretch of collagen fibers

Correct Answer: Creep of the graft material

Explanation:

DISCUSSION: The stretching of the graft occurs over time as the graft is loaded. Time-dependent deformation under load is called creep and is common in viscoelastic materials such as ligament tissue. Creep can occur under both static and cyclic load conditions; time-dependent deformation will occur as long as load is applied to the tissue. Similarly, when a graft is initially tensioned to a given deformation at surgery, the load generated in the graft will decrease over time; this behavior is called stress relaxation and also is indicative of a viscoelastic material. Water content may affect the viscoelastic properties by changing the friction between collagen fibers, but studies have shown little difference in water content between grafts and normal ligaments. Fatigue failures may manifest themselves through damage to the ligament tissue, but this would require higher loads than are routinely experienced by grafts. Elastic stretch is recoverable and, therefore, does not contribute to a permanent stretch. Similarly, gross failure at the attachment would not cause a stretch, but rather a catastrophic instantaneous instability.
REFERENCES: Boorman RS, Thornton GM, Shrive NG, et al: Ligament grafts become more susceptible to creep within days after surgery. Acta Orthop Scand 2002;73:568-574.
Buckwalter JA, Einhorn TA, Simon SR (eds): Orthopaedic Basic Science: Biology and Biomechanics of the Musculoskeletal System, ed 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000, pp 596-609.
Lu L, Kaufman KR, Yaszemski MJ: Biomechanics, in Einhorn TA, O’Keefe RJ,
Buckwalter JA (eds): Orthopaedic Basic Science: Foundations of Clinical Practice, ed 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, in press.

Question 9:

Options:

Oral cephalosporin
IV cephalexin and dressing changes
Betadine dressing and a short leg cast
Debridement of the wound and removal of the hardware
Debridement of the wound and maintenance of the hardware

Correct Answer: Debridement of the wound and maintenance of the hardware

Explanation:

Question 10:

- Figure 67 shows the AP radiograph of both knees of a 26-year-old woman. A review of the patient’s medical record will most likely reveal a history of

Options:

Trauma
Hemophilia
Reiter’s syndrome
Rheumatoid arthritis
Systemic lupus erythematosus

Correct Answer: Systemic lupus erythematosus

Explanation:

Question 11:

Injury to the popliteal artery during total knee arthroplasty (TKA) is most likely to occur when placing a sharp retractor

Options:

directly posterior to the posterior cruciate ligament (PCL).
posteromedial to the PCL.
posterolateral to the PCL.
in the posteromedial corner of the knee.

Correct Answer: posterolateral to the PCL.

Explanation:

Question 12:

On MRI, a nonsanguinous effusion has what appearance?

Options:

White (high-signal intensity) on T1- and T2-weighted images
White on T1-weighted images and black (low-signal intensity) on T2-weighted images
Black on T1- and T2-weighted images
Black on T1-weighted images and white on T2-weighted images
Gray (intermediate-signal intensity) on T1-weighted images and white on T2-weighted images

Correct Answer: Black on T1-weighted images and white on T2-weighted images

Explanation:

Question 13:

Which of the following changes in the parameters of the gait cycle occurs in the transition from normal walking to running?

Options:

Increased time in stance and swing phase
Addition of a double leg float phase
Decreased vertical ground reaction forces
Decreased arc of motion in the hip, knee, and ankle
Decreased joint reaction forces in the hip, knee, and ankle

Correct Answer: Addition of a double leg float phase

Explanation:

The same basic mechanisms that have been described for the biomechanics of the foot and ankle are not significantly altered during running. The major differences observed during running are that the gait cycle is altered considerably; the amount of force generated, as measured by force plated data, is markedly increased; the range of motion of the joints of the lower extremities is increased; and the phasic activity of the muscles of the lower extremities is altered. During walking one foot is always in contact with the ground; as the speed of gait increases a float phase incorporated into the gait cycle, during which time both feet are off the ground. There also is no longer a period of double limb support. As the speed of gait continues to increase, the time the foot spends on the ground, both in real time and in percentage of cycle, decreases considerably.
Question 71 -
Examination of a 5-year-old child who has fibular hemimelia reveals the foot has two rays and is stiff in equinus and valgus. The level of the foot is just proximal to the midshaft of the contralateral tibia, and the knee has full active flexion and extension, but slight valgus. Treatment should include
Amputation through the midshaft of the tibia
Correction of the foot deformity and lengthening with a ring fixator
Knee disarticulation
Ankle disarticulation
Ankle disarticulation and contralateral epiphyseodesis of the proximal tibia Answer: 4
Congenital absence of the fibula, also called fibula hemimelia, has several manifestations. These range from complete absence of the fibula with missing lateral rays of the foot (i.e. terminal longitudinal deficiency) to absence of only a portion of the fibula without foot involvement (i.e. intercalary longitudinal; deficiency). Congenital fibular deficiency usually occurs sporadically without a known cause. The child with complete absence of the fibula presents clinically with an anterolateral bow of the tibia, an equinovalgus deformity of the foot, and a tarsal coalition. The talotibial joint is usually malformed, with the fused talocalcaneus having a flat upper surface that articulates with the tibia in a valgus and equinus position. The foot may be missing one or two lateral rays. There is always significant shortening of the epsilateral femur. Treatment: There is a reasonable consensus that complete fibular hemimelia is best treated by performing an ankle disarticulation in early childhood and fitting a Syme-type prosthesis. Children with lesser (<5cm) at birth may be a candidate for lengthening procedures, but the exact indications and results of these procedures have not been well defined. Children with large discrepancies (>5cm) at birth and those with major foot deformities are better managed with amputation.

Question 14:

Options:

Incomplete C5 spinal cord injury
Complete C5 spinal cord injury
Complete C6 spinal cord injury
Central spinal cord injury
Brown-STquard syndrome

Correct Answer: Complete C5 spinal cord injury

Explanation:

Question 15:

Options:

Intraarticular penetration of the screw
Position of the screw cephalad to the sciatic notch
Screw starting point at the anterior inferior iliac spine
Screw starting point at the gluteal pillar
Screw position between the inner and outer tables of the ilium

Correct Answer: Intraarticular penetration of the screw

Explanation:

Question 16:

Options:

Release of the coracoacromial ligament
Use of an arthroscopic rather than open technique
Overresection of the distal clavicle
Treatment with corticosteroid injections before surgery

Correct Answer: Overresection of the distal clavicle

Explanation:

Question 17:

Options:

Compartment syndrome
Loss of elbow motion
Avascular necrosis (AVN) of the radial head
Nonunion of the fracture site

Correct Answer: Loss of elbow motion

Explanation:

DISCUSSION
This girl sustained a fracture dislocation of the elbow with a severely displaced and rotated radial neck fracture. Required treatment was open reduction and internal fixation (ORIF). Less severely displaced radial neck fractures can be treated with closed reduction, percutaneous pinning, or flexible nail manipulation. In this scenario, interposed capsular tissue and rotation of the radial head were indications for ORIF. ORIF is associated with a higher risk for poor
outcomes. Complications following ORIF of radial neck fractures in children include posterior interosseous neuropraxia, valgus angulation, premature closure of the radial head physis, AVN of the radial head, nonunion, and elbow stiffness. Stiffness is most common. Compartment syndrome, infection, and anterior interosseous nerve palsy are less common complications.
CLINICAL SITUATION FOR QUESTIONS 47 THROUGH 50
A 6-year-old boy arrives at the emergency department with forearm pain. Today he was picking up his backpack when he felt a pop in his forearm that resulted in the current injury. His history is significant for 6 other fractures treated nonsurgically. His mother states that she had 15 fractures during childhood but is healthy now. Both the boy and his mother have blue sclera. Figures 47a and 47b are the radiographs of his injured forearm.

Question 18:

Options:

Provocative lumbar diskography
Laboratory studies, including a complete blood cell (CBC) count, erythrocyte sedimentation rate (ESR), and urinalysis
Cognitive intervention, exercise, and smoking cessation
Bilateral lower extremity electromyography and nerve conduction velocity studies
Lumbar myelogram with a postmyelography CT scan of the lumbar spine

Correct Answer: Cognitive intervention, exercise, and smoking cessation

Explanation:

DISCUSSION: The MRI scan reveals a rudimentary disk at the L5-S1 level, suggesting transitional anatomy. There is a posterior disk bulge at L3-4. At L4-5, there is disk desiccation and loss of disk height, with a posterior disk bulge and a high intensity zone in the posterior annulus, suggesting an annular tear. While these and similar radiographic findings have been associated with the severity of a patient’s pain, they are also commonly found in cross-sectional studies of asymptomatic subjects. Carragee and associates found 59% of symptomatic patients undergoing diskography have high intensity zones as compared to 25% of asymptomatic subjects of a similar patient profile. Diskographic injections provoked pain in disks with high intensity zones approximately 70% of the time whether the individual was previously symptomatic or not. This patient’s non-specific pain pattern does not require further work-up as she is not a surgical candidate.
REFERENCES: Carragee EJ, Paragioudakis SJ, Khurana S: 2000 Volvo Award winner in clinical studies: Lumbar high-intensity zone and discography in subjects without low back problems. Spine 2000;25:2987-2992.
Pneumaticos SG, Reitman CA, Lindsey RW: Diskography in the evaluation of low back pain.
J Am Acad Orthop Surg 2006;14:46-55.
Brox JI, Sorensen R, Friis A, et al: Randomized clinical trial of lumbar instrumented fusion and cognitive intervention and exercises in patients with chronic low back pain and disc degeneration. Spine 2003;28:1913-1921.
Carragee EJ: Clinical practice: Persistent low back pain. N Engl J Med 2005;352:1891-1898.

Question 19:

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 20:

Which complication is most common after syndesmotic fixation?

Options:

Synostosis of the distal tibiofibular joint
Failure of fixation with subsequent loss of reduction
Malreduction of the distal tibiofibular joint
Posttraumatic ankle arthrosis

Correct Answer: Malreduction of the distal tibiofibular joint

Explanation:

DISCUSSION
The injury radiographs reveal a supination external rotation IV ankle fracture with evidence of medial clear space widening exceeding 4 mm and an increase relative to the superior tibiotalar clear space. This indicates injury to the deltoid ligament and necessitates surgical reduction and fixation to restore and maintain ankle stability. Following stabilization of the fibula, an intraoperative stress examination of the syndesmosis such as an external rotation stress test under fluoroscopy or lateral pull on the fibula (the Cotton test) should be performed to determine the integrity of the syndesmosis. Radiographic evidence of tibiofibular clear space widening, medial clear space widening with external rotation, and lateral displacement of the distal fibula when pulled is consistent with syndesmotic injury. In contrast to the presurgical stress test, once the fibula has been reduced and stabilized lateral talar translation can occur only if the syndesmosis is injured in addition to the deltoid ligament. Failure of the syndesmotic screw without evidence of malalignment of the mortise and a pain-free ankle are not indications for further surgery because these patients have satisfactory outcomes when compared to those who have intact or removed screws. Hardware removal following fibula ORIF is indicated when patients have pain directly related to hardware prominence. Resolution of joint pain or stiffness is not a reliable outcome following hardware removal. Although fibular fracture can occur, this is a rare complication. Malreduction of the syndesmosis is the most common complication following ORIF of the syndesmosis and is improved with direct visualization; however, malreduction still may occur with direct visualization.
RECOMMENDED READINGS
Manjoo A, Sanders DW, Tieszer C, MacLeod MD. Functional and radiographic results of patients with syndesmotic screw fixation: implications for screw removal. J Orthop Trauma. 2010 Jan;24(1):2-6. doi: 10.1097/BOT.0b013e3181a9f7a5. PubMed PMID: 20035170.
View
Abstract at PubMed
Jenkinson RJ, Sanders DW, Macleod MD, Domonkos A, Lydestadt J. Intraoperative diagnosis of syndesmosis injuries in external rotation ankle fractures. J Orthop Trauma. 2005 Oct;19(9):604-9. PubMed PMID: 16247304.
View Abstract at PubMed
Stark E, Tornetta P 3rd, Creevy WR. Syndesmotic instability in Weber B ankle fractures: a clinical evaluation. J Orthop Trauma. 2007 Oct;21(9):643-6. PubMed PMID: 17921840.
View
Abstract at PubMed
Brown OL, Dirschl DR, Obremskey WT. Incidence of hardware-related pain and its effect on functional outcomes after open reduction and internal fixation of ankle fractures. J Orthop Trauma. 2001 May;15(4):271-4. PubMed PMID: 11371792.
View Abstract at PubMed

Question 21:

A 9-year-old child sustained a fracture-dislocation of C-5 and C-6 with a complete spinal cord injury. What is the likelihood that scoliosis will develop during the remaining years of his growth?

Options:

10%
20%
50%
70%
100%

Correct Answer: 100%

Explanation:

DISCUSSION: The incidence of late spinal deformity after complete spinal cord injury in children depends on the level of the spinal cord injury and the age of the patient at the time of injury. If a cervical level injury occurs before age 10 years, paralytic scoliosis will develop in virtually 100% of patients.
REFERENCES: Brown JC, Swank SM, Matta J, et al: Late spinal deformity in quadriplegic children and adolescents. J Pediatr Orthop 1984;4:456-461.
Lancourt JE, Dickson JH, Carter RE: Paralytic spinal deformity following traumatic spinal-cord injury in children and adolescents. J Bone Joint Surg Am 1981;63:47-53.
Dearolf WW III, Betz RR, Vogel LC, et al: Scoliosis in pediatric spinal cord-injured patients.
J Pediatr Orthop 1990;10:214-218.

Question 22:

Options:

Hematoma
Lipoma
Soft-tissue sarcoma
Pyomyositis
Hemangioma

Correct Answer: Soft-tissue sarcoma

Explanation:

Question 23:

Options:

Hyperextension casting of the thoracolumbar spine for 6 weeks
In situ posterior fusion with instrumentation
Posterior fusion with instrumentation, with sagittal plane correction
Posterior decompression, followed by posterior fusion with instrumentation, with sagittal plane correction
Anterior decompression and partial corpectomy, with anterior instrumentation

Correct Answer: Posterior fusion with instrumentation, with sagittal plane correction

Explanation:

DISCUSSION: The patient has a displaced burst fracture. Fusion with instrumentation has shown better results than casting alone. Posterior fusion with instrumentation, with sagittal plane correction, yields the best results. Decompression occurs indirectly with correction of the kyphosis. Anterior decompression is unnecessary.
REFERENCES: Lalonde F, Letts M, Yang JP, et al: An analysis of burst fractures of the spine in adolescents. Am J Orthop 2001;30:115-120.
Clark P, Letts M: Trauma to the thoracic and lumbar spine in the adolescent. Can J Surg 2001;44:337-345.
Been HD, Bouma GJ: Comparison of two types of surgery for thoraco-lumbar burst fractures: Combined anterior and posterior stabilization vs posterior instrumentation only. Acta Neurochir (Wien) 1999;141:349-357.

Question 24:

Which of the following findings is considered a contraindication for posterior decompression (with or without fusion) for myelopathy?

Options:

Subluxation of more than 3.5 mm at one or more motion segments
Dynamic angulation of more than 11° at one or more motion segments
Subaxial cervical lordosis of more than 25° (as measured from C2 to C7)
Fixed kyphosis of more than 10°
Anteroposterior spinal canal diameter of less than 8 mm

Correct Answer: Fixed kyphosis of more than 10°

Explanation:

Question 25:

Options:

a brief (2 to 3 days) period of bed rest and nonsteroidal anti-inflammatory drugs.
bed rest for 2 weeks and nonsteroidal anti-inflamatory drugs, followed by physical therapy.
epidural steroid injections.
lumbar radiographs and MRI of the lumbar spine.
electromyography.

Correct Answer: a brief (2 to 3 days) period of bed rest and nonsteroidal anti-inflammatory drugs.

Explanation:

Question 26:

Which of the following factors has been shown to increase mortality in poly-trauma patients with severe head injuries?

Options:

Delayed fixation of fractures
Decreased intracranial pressure
Intra-abdominal injury
Intra-operative hypotension
Decreased platelet count

Correct Answer: Delayed fixation of fractures

Explanation:

Question 27:

Options:

posterior; flexor carpi radialis
posterior; flexor carpi ulnaris
posterior; flexor digitorum superficialis to the long finger
mobile wad; flexor carpi radialis
mobile wad; flexor carpi ulnaris

Correct Answer: mobile wad; flexor carpi ulnaris

Explanation:

Question 28:

Joint contact pressure in normal or artificial joints can best be minimized by what mechanism?

Options:

Increasing joint force and contact area
Increasing joint force and decreasing contact area
Decreasing joint force and contact area
Decreasing joint force and increasing contact area
Decreasing joint force only

Correct Answer: Decreasing joint force and increasing contact area

Explanation:

DISCUSSION: Joint contact pressure is a stress and as such is defined as the load transferred across the joint divided by the contact area between the joint surfaces (the area over which the joint load is distributed). Therefore, any mechanism that decreases the load across the joint
(eg, a walking aid) will decrease the stress. Similarly, any mechanism that increases the area over which the load is distributed (eg, using a more conforming set of articular surfaces in a knee joint arthroplasty) will also decrease the stress. Other mechanisms that influence joint contact pressure include the elastic modulus of the materials (cartilage in the case of natural joints and polyethylene in joint arthroplasty) and the thickness of the structures through which the joint loads pass.
REFERENCES: Bartel DL, Bicknell VL, Wright TM: The effect of conformity, thickness, and material on stresses in UHMWPE components for total joint replacement. J Bone Joint Surg Am 1986;68:1041-1051.
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 29:

Options:

glenohumeral arthrodesis.
total shoulder arthroplasty.
humeral arthroplasty.
open synovectomy and rotator cuff repair.
anterior acromioplasty and rotator cuff repair.

Correct Answer: humeral arthroplasty.

Explanation:

Question 30:

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 31:

Options:

skeletal traction and reduction, followed by a halo jacket and nonsurgical stabilization.
skeletal traction, closed reduction, and posterior fixation/fusion.
skeletal traction, anterior decompression and fusion, followed by posterior stabilization and fusion.
skeletal traction and surgical posterior fusion, followed by anterior decompression and fusion.
general anesthesia, closed reduction, and a halo jacket for 3 to 4 months until stable.

Correct Answer: skeletal traction, closed reduction, and posterior fixation/fusion.

Explanation:

DISCUSSION: This is a classic bilateral facet dislocation. When there is no evidence of a disk herniation, treatment should include careful skeletal traction, closed reduction, and posterior fusion. There is no role for anterior procedures. These fractures are unstable and require surgical intervention.
REFERENCES: Herkowitz HN, Garfin SR, Eismont FJ: Rothman-Simone The Spine, ed 5. Philadelphia, PA, Saunders Elsevier, 2006, pp 1120-1128.
Coe JD, Warden KE, Sutterlin CE, et al: Biomechanical evaluation of cervical spinal stabilization methods in a human cadaveric model. Spine 1989;14:1122-1131.

Question 32:

Options:

Closed reduction and long arm cast immobilization
Closed reduction and short arm cast immobilization
Closed reduction and percutaneous pinning
Open reduction and internal fixation with Kirschner wires
Open reduction and internal fixation with a headless, cannulated compression screw

Correct Answer: Open reduction and internal fixation with a headless, cannulated compression screw

Explanation:

DISCUSSION: The patient has a scaphoid fracture involving the proximal pole. Surgical treatment is recommended for such fractures because of the prolonged period of cast immobilization necessary and the increased risk of delayed union, nonunion, and/or osteonecrosis with nonsurgical management. A cannulated compression screw, inserted in the central scaphoid via a dorsal approach, is biomechanically advantageous and provides greater stability for fracture healing than Kirschner wires. Recently, good outcomes have been reported with arthroscopic-assisted percutaneous fixation of nondisplaced or minimally displaced scaphoid fractures.
REFERENCES: Rettig ME, Raskin KB: Retrograde compression screw fixation of acute proximal pole scaphoid fractures. J Hand Surg Am 1999;24:1206-1210.
Chan KW, McAdams TR: Central screw placement in percutaneous screw scaphoid fixation: A cadaveric comparison of proximal and distal techniques. J Hand Surg Am 2004;29:74-79.
Bedi A, Jebson PJ, Hayden RJ, et al: Internal fixation of acute non-displaced scaphoid waist fractures via a limited dorsal approach: An assessment or radiographic and functional outcomes. J Hand Surg Am 2007;32:326-333.
McCallister WV, Knight J, Kaliappan R, et al: Central placement of the screw in simulated fractures of the scaphoid waist: A biomechanical study. J Bone Joint Surg Am 2003;85:72-77.

Question 33:

Options:

indirect fracture reduction via traction and early mobilization.
volar plate arthroplasty.
open reduction and internal fixation.
closed reduction and percutaneous pin fixation.
cast immobilization.

Correct Answer: indirect fracture reduction via traction and early mobilization.

Explanation:

Question 34:

Options:

Physiotherapy
Long-arm cast
Cannulated screw fixation
Plate fixation of the ulna
Hinged-elbow bracing

Correct Answer: Cannulated screw fixation

Explanation:

Question 35:

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

Options:

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

Correct Answer: Tenodesis or tenotomy

Explanation:

Question 36:

Options:

Increased rate of union
Decreased rate of infection
Shorter operative time
Lower rates of hip pain
Lower rates of knee pain

Correct Answer: Increased rate of union

Explanation:

Question 37:

Options:

Bulky gauze dressings with no compression of the traumatized tissues and early non-weight-bearing ambulation
Bulky gauze dressings with snug compression of the residual limb and early non-weight-bearing ambulation
Immediate intraoperative prosthetic fitting with a vacuum-formed prosthetic limb, followed by immediate weight bearing
Rigid plaster dressing, a cast change at 5 to 7 days, and partial weight bearing with an attached pylon when the wound shows signs of healing without infection
Compression dressing and delayed application of a weight-bearing pylon until the sutures are removed and the wound is well healed

Correct Answer: Rigid plaster dressing, a cast change at 5 to 7 days, and partial weight bearing with an attached pylon when the wound shows signs of healing without infection

Explanation:

Question 38:

-An otherwise healthy 15-year-old wrestler has a 6-cm cutaneous lesion on the posterior aspect of his right elbow that he reports as a spider bite. What is the most likely diagnosis?

Options:

Psoriasis
Tinea corporis
Herpes simplex virus
Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) DISCUSSION-Patients who have skin and soft-tissue infections caused by CA-MRSA often describe the lesion as a spider bite. The cytotoxin Panton-Valentine leukocidin that is produced by many strains of CA-MRSA causes tissue necrosis, resulting in rapid development of an abscess and the appearance of a spider bite.Patients with psoriasis have thick, red skin with flaky, silver-white patches. Tinea corporis is a general term for a cutaneous fungal infection. The lesion appears as a well-demarcated erythematous plaque with a raised border and central hypopigmentation, giving it a ring-like appearance. Primary infection with herpes simplex virus can produce constitutional symptoms with burning, tingling, or stinging at the site. Grouped vesicles with clear fluid 1 to 2 mm in size form on an erythematous base and then rupture,leaving moist ulcers or crusted plaques.

Correct Answer: Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) DISCUSSION-Patients who have skin and soft-tissue infections caused by CA-MRSA often describe the lesion as a spider bite. The cytotoxin Panton-Valentine leukocidin that is produced by many strains of CA-MRSA causes tissue necrosis, resulting in rapid development of an abscess and the appearance of a spider bite.Patients with psoriasis have thick, red skin with flaky, silver-white patches. Tinea corporis is a general term for a cutaneous fungal infection. The lesion appears as a well-demarcated erythematous plaque with a raised border and central hypopigmentation, giving it a ring-like appearance. Primary infection with herpes simplex virus can produce constitutional symptoms with burning, tingling, or stinging at the site. Grouped vesicles with clear fluid 1 to 2 mm in size form on an erythematous base and then rupture,leaving moist ulcers or crusted plaques.

Explanation:

CLINICAL SITUATION FOR QUESTIONS 44 AND 45
Figure 44 is the MRI scan of a 14-year-old soccer player who injured his right knee during a game.He describes feeling a “pop” and he needed help walking off the field. His knee is visibly swollen. A Lachman test demonstrates asymmetry with no endpoint.

Question 39:

Options:

axillary nerve.
musculocutaneous nerve.
median nerve.
radial nerve.

Correct Answer: musculocutaneous nerve.

Explanation:

Question 40:

Options:

Distal femoral osteotomy
Proximal tibial osteotomy
Lateral unicompartmental knee arthroplasty
Total knee arthroplasty (TKA)

Correct Answer: Distal femoral osteotomy

Explanation:

Question 41:

The carpal tunnel canal is narrowest (smallest cross-sectional area) at what level?

Options:

Proximal to the carpal bones
At the level of the lunate
At the hook of the hamate
At the base of the metacarpals
Does not change from proximal to distal

Correct Answer: At the hook of the hamate

Explanation:

Question 42:

below show the clinical photograph and radiograph obtained from a year-old man who has deformity and pain 1 year after primary total hip arthroplasty. What is the reason for the observed deformity?

Options:

A Vancouver type B1 fracture
Residual leg-length discrepancy
Loosening and subsidence of the femoral stem into anteversion
Loosening and subsidence of the femoral stem into retroversion

Correct Answer: Loosening and subsidence of the femoral stem into retroversion

Explanation:

Question 43:

Which of the following prognostic indicators is associated with the least favorable outcome for patients newly diagnosed with osteosarcoma?

Options:

High histologic grade
Tumor size greater than 8 cm
Extracompartmental growth
Solitary pulmonary metastasis
Solitary bone metastasis

Correct Answer: Solitary bone metastasis

Explanation:

DISCUSSION: Distant bone metastasis is associated with an extremely poor prognosis for patients with osteosarcoma (5-year survival rate of less than 10%). Most osteosarcomas are high grade and extracompartmental, and approximately half are greater than 8 cm at presentation. The 5-year survival rate for these patients is approximately 70%. Patients with a solitary pulmonary metastasis have a prognosis worse than patients without detectable metastases but not as bad as those with bone metastases.
REFERENCES: Bielack SS, Kempf-Bielack B, Delling G, et al: Prognostic factors in high-grade osteosarcoma of the extremities or trunk: An analysis of 1,702 patients treated on neoadjuvant cooperative osteosarcoma study group protocols. J Clin Oncol 2002;20:776-790.
Heck RK, Stacy GS, Flaherty MJ, et al: A comparison study of staging systems for bone sarcomas. Clin Orthop Relat Res 2003;415:64-71.
Kager L, Zoubeck A, Potschger U, et al: Primary metastatic osteosarcoma: Presentation and outcome of patients treated on neoadjuvant Cooperative Osteosarcoma Study Group protocols.
J Clin Oncol 2003;21:2011-2018.

Question 44:

Options:

The anteromedial (AM) bundle limits translation and the posterolateral (PL) bundle controls rotation.
The PL bundle limits translation and the AM bundle controls rotation.
The anterolateral (AL) bundle limits translation and the posteromedial (PM) bundle controls rotation.
Both the AL and the PM control rotation equally.
The AL bundle controls rotation and the PM bundle limits translation.

Correct Answer: The anteromedial (AM) bundle limits translation and the posterolateral (PL) bundle controls rotation.

Explanation:

Question 45:

Options:

Syrinx of the cervical spine
Intracranial mass
Myasthenia gravis
Amyotrophic lateral sclerosis (ALS)
Fascioscapulohumeral dystrophy

Correct Answer: Amyotrophic lateral sclerosis (ALS)

Explanation:

Question 46:

Increased hip intracapusular pressures can lead to diminished femoral head perfusion. What leg position has been shown to create the lowest intracapsular hip pressures after femoral neck fracture?

Options:

flexion and internal rotation
extension and external rotation
flexion, abduction, and external rotation
extension, adduction, and internal rotation
there are no differences in hip pressures with any position

Correct Answer: flexion and internal rotation

Explanation:

Question 47:

Options:

Fibrous dysplasia
Osteochondroma
Osteoblastoma
Giant cell tumor
Hemangioma

Correct Answer: Osteoblastoma

Explanation:

DISCUSSION: Forty percent of osteoblastomas occur in the spine, and they can become large and locally aggressive lesions. They generally occur in the posterior elements but can occur in the ribs and transverse processes. Microscopic analysis of the lesion will reveal hyperchromatic osteoblasts separated by incompletely mineralized bars of bone. Recommended treatment is en bloc excision. Fibrous dysplasia, giant cell tumor, and hemangioma can have similar radiographic appearances; therefore, biopsy may be required to differentiate them from more aggressive lesions. Osteochondromas are characterized by an osteocartilaginous growth arising from the cortex.
REFERENCES: Bridwell KH, Ogilvie JW: Primary tumors of the spine, in Bridwell KH, DeWald RL (eds): The Textbook of Spinal Surgery. Philadelphia, PA, JB Lippincott, 1991,
vol 2, pp 1143-1174.
Enneking WF: Musculoskeletal Tumor Surgery. New York, NY, Churchill Livingstone, 1983, pp 1043-1053.

Question 48:

A 30-year-old man landed on his shoulder in a fall off his mountain bike. An AP radiograph and CT scan are shown in Figures 34a and 34b. Management should consist of

Options:

immobilization in a sling and swathe.
open reduction and internal fixation.
humeral arthroplasty.
subscapularis transfer into the humeral head articular defect.
a hanging cast.

Correct Answer: open reduction and internal fixation.

Explanation:

Question 49:

Nutritional rickets is associated with which of the following changes in chemical blood level?

Options:

Low Vitamin D levels
High to normal calcium levels
High phosphate levels
Decreased PTH
Decreased alkaline phosphatase levels

Correct Answer: Low Vitamin D levels

Explanation:

DISCUSSION: Nutritional rickets is associated with decreased dietary intake of Vitamin D, resulting in low levels of Vitamin D that result in decreased intestinal absorption of calcium
and low to normal serologic levels of calcium. To boost serum calcium levels, there is a compensatory increase in PTH and bone resorption, leading to increased alkaline
phosphatase levels.
REFERENCES: Brinker MR: Cellular and molecular biology, immunology, and genetics in orthopaedics, in Miller MD (ed): Review of Orthopaedics, ed 3. Philadelphia, PA, WB Saunders, 2001, pp 81-94.
Pettifor J: Nutritional and drug-induced rickets and osteomalacia, in Farrus MJ (ed): Primer on the Metabolic Bone Diseases and Disorders of Mineral Metabolism, ed 5. Philadelphia, PA, Lippincott Williams and Wilkins, 2003, pp 399-466.
Einhorn TA: Metabolic bone disease, in Einhorn TA, O’Keefe RJ, Buckwalter JA (eds): Orthopaedic Basic Science: Foundations of Clinical Practice, ed 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, in press.

Question 50:

Which of the following pelvic injury types has the highest reported mortality rate?

Options:

Anterior posterior compression (APC) III injury
Lateral compression (LC) III injury
Transverse-posterior wall acetabular fracture
Vertical Shear
Combined mechanical injury (CMI) Corrent answer: 1 Anterior posterior compression (APC) injuries have the highest mortality rates of the fracture patterns listed. APC injuries have high rates of concomitant thoracic and abdominal visceral injuries leading to the highest rates of mortality among pelvic fractures. Lateral compression (LC) fractures have particularly high incidences of associated brain and head injury with lower mortality than APC injuries. Overall, as the grade of pelvic ring injury increases the rates of associated injuries increases, regardless of exact mechanism of injury. The overall mortality rate for any pelvic trauma is roughly 15%, with APC III mortality around 37%, and overall APC mortality rates around 26%. LC of any grade has an estimated mortality around 13%. Vertical shear and CMI have estimated mortality of 25% and 17.1%, respectively. The lowest mortality rates are following acetabular fractures with estimates around 1.5%. Dalal et al retrospectively reviewed 340 trauma patients with pelvic injuries to analyze organ injury, resuscitative requirements, and outcomes. They found the highest mortality rates were in APC III and that more severe APC injuries had greater organ damage and mortality. They conclude that the mechanical force type and classification of injury are predictors of organ injury pattern, resuscitation needs, and mortality. Eastridge et al reviewed 1,014 injured pedestrians for pelvic injuries, associated injuries, and relationship of treatments to outcomes. They found the highest mortality rates were associated with APC III and LC III injuries patterns at 50%. They conclude that pelvic fractures are a sign of significant energy imparted on the body and severity of associated injuries lead to the high rates of morbidity and mortality. Illustration A and B show an APC III and LC III injury, respectively. Incorrect Answers:

Correct Answer: Lateral compression (LC) III injury

Explanation:

mechanism injuries all have lower mortality rates than APC injuries.
OrthoCash 2020

Question 51:

Options:

Inferior gluteal
Medial femoral circumflex
Lateral femoral circumflex
Femoral

Correct Answer: Lateral femoral circumflex

Explanation:

Question 52:

When treating thoracic disk herniations, which of the following surgical approaches has the highest reported rate of neurologic complications?

Options:

Video-assisted thoracoscopic approach (VATS)
Posterior
Posterior-lateral
Transthoracic
Transpedicular

Correct Answer: Posterior

Explanation:

DISCUSSION: Numerous surgical approaches have been used for thoracic diskectomy, including the most recent VATS. One of the first approaches described, posterior laminectomy, involves manipulation of the spinal cord, which the other approaches avoid. The posterior approach had dismal results, including further neurologic deterioration and even paralysis.
REFERENCES: Belanger TA, Emery SE: Thoracic disc disease and myelopathy, in Frymoyer JW, Wiesel SW (eds): The Adult and Pediatric Spine. Philadelphia, PA, Lippincott Williams and Wilkins, 2004, pp 855-864.
Benjamin V: Diagnosis and management of thoracic disc disease. Clin Neurosurg
1983;30:577-605.
Russell T: Thoracic intervertebral disc protrusion: Experience of 67 cases and review of the literature. Br J Neurosurg 1989;3:153-160.
Fessler RG, Sturgill M: Review: Complications of surgery for thoracic disc disease. Surg Neurol 1998;49:609-618.

Question 53:

Options:

Serum calcium normal
Serum alkaline phosphatase normal
Urine calcium is low
Serum phosphate is often high When symptomatic, the masses are excised.

Correct Answer: Serum calcium normal

Explanation:

Which of the following describes the histopathology of tumoral calcinosis:

Question 54:

- Which of the following rehabilitation methods should be used for the first 24 hours following a blunt injury to the quadriceps musculature to avoid short-term stiffness?

Options:

Heat
Gentle active flexion-extension exercises
Isokinetic strengthening
Electrical muscle stimulation
Immobilization of the limb with the knee in full flexion

Correct Answer: Immobilization of the limb with the knee in full flexion

Explanation:

Question 55:

Options:

Proceed with primary repair with the elbow hyperflexed
Use interposition allograft to reconstruct with elbow in extension
Tenodese distal biceps tendon to underlying brachialis muscle
Forego primary repair, but perform stump debridement

Correct Answer: Proceed with primary repair with the elbow hyperflexed

Explanation:

Question 56:

What condition favors pollicization in hypoplasia of the thumb?

Options:

Extrinsic tendon abnormalities involving the flexor and extensor
Narrowing of the first web space
Insufficiency of the ulnar collateral ligament of the metaphalangeal joint
Unstable carpometacarpal joint

Correct Answer: Unstable carpometacarpal joint

Explanation:

DISCUSSION
The decision to ablate and pollicize vs preserve and reconstruct is based on the stability of the carpometacarpal joint. A stable thumb is more easily used in prehension activities of grasping and pinching. All other responses are associated with surgical options for reconstruction of the thumb. The carpometacarpal joint is the “keystone” for thumb-to-hand attachment. Without a stable carpometacarpal joint, pollicization may be required. No other response necessitates pollicization.
RECOMMENDED READINGS
McCarroll HR. Congenital anomalies: a 25-year overview. J Hand Surg Am. 2000 Nov;25(6):1007-37. Review. PubMed PMID: 11119659.
View Abstract at PubMed
Manske PR, Goldfarb CA. Congenital failure of formation of the upper limb. Hand Clin. 2009 May;25(2):157-70. doi: 10.1016/j.hcl.2008.10.005. Review. PubMed PMID: 19380058.
View Abstract at PubMed

Question 57:

Options:

400 cGy in one dose.
700 cGy in one dose.
1,000 cGy in five doses.
2,000 cGy in 10 doses.
3,000 cGy in 10 doses.

Correct Answer: 700 cGy in one dose.

Explanation:

Question 58:

Options:

Pelvic angiography
Intracranial pressure monitoring
Pelvic external fixation
Evaluation of peripheral pulses
Urgent open stabilization of the clavicular and humeral fractures

Correct Answer: Evaluation of peripheral pulses

Explanation:

Question 59:

Options:

15 degrees
30 degrees
45 degrees
60 degrees
75 degrees

Correct Answer: 30 degrees

Explanation:

Question 60:

What is the most common bacteria cultured from dog and cat bites to the upper extremity?

Options:

Pasteurella
Streptococcus
Staphylococcus
Bacteroides
Moraxella

Correct Answer: Pasteurella

Explanation:

DISCUSSION: To define bacteria responsible for dog and cat bite infections, a prospective study yielded a median of five bacterial isolates per culture. Pasteurella is most common from both dog bites (50%) and cat bites (75%). Pasteurella canis was the most frequent pathogen of dog bites, and Pasteurella multocida was the most common isolate of cat bites. Other common aerobes included streptococci, staphylococci, moraxella, and neisseria.
REFERENCE: Talan DA, Citron DM, Abrahamian FM, et al: Bacteriologic analysis of infected dog and cat bites. Emergency Medicine Animal Bite Infection Study Group. N Engl J Med 1999;340:85-92.

Question 61:

Options:

angiography.
curettage and cementation.
resection and modular distal femoral knee replacement.
radiation therapy.
a technetium Tc 99m bone scan and AP and lateral radiographs of the entire right femur.

Correct Answer: a technetium Tc 99m bone scan and AP and lateral radiographs of the entire right femur.

Explanation:

Question 62:

Compact bone, titanium, stainless steel, cobalt-chrome

Options:

The correct order of modulus of elasticity is as follows in Gpa (psi x 10 6 ):
Compact bone: 21 (3)
Titanium: 96 (14)
Stainless Steel: 193 (28)
Cobalt-Chrome: 235 (34)

Correct Answer: The correct order of modulus of elasticity is as follows in Gpa (psi x 10 6 ):

Explanation:

Question 63:

Options:

observation.
a knee-ankle-foot orthosis.
a medial proximal tibial epiphyseodesis.
a proximal tibial osteotomy.
lateral proximal tibial stapling.

Correct Answer: observation.

Explanation:

Question 64:

Which of the following statements is true regarding the superomedial fragment of an intra-articular calcaneus fracture?

Options:

Tibialis posterior tendon runs within its groove
Fragment typically does not move due to its attachment to the talus
Fragment typically does not move due to its attachment to the navicular
Fragment typically displaces superior and laterally
Fragment typically displaces superior and medially

Correct Answer: Tibialis posterior tendon runs within its groove

Explanation:

Question 65:

Options:

antiviral therapy.
IV broad-spectrum antibiotics.
partial claviculectomy and fibulectomy.
symptomatic relief with anti-inflammatory drugs.
bone marrow aspiration and biopsy.

Correct Answer: symptomatic relief with anti-inflammatory drugs.

Explanation:

Question 66:

Figure 49 shows an acute axial MRI scan of a right knee. What is the most likely diagnosis? Review Topic

Options:

Patellar tendon rupture
Lateral dislocation of the patella
Quadriceps tendon rupture
Anterior cruciate ligament rupture
Posterior cruciate ligament rupture

Correct Answer: Lateral dislocation of the patella

Explanation:

Question 67:

Options:

Streptococcus viridans
Staphylococcus epidermidis
Escherichia coli
Vibrio parahaemolyticus
Clostridium difficile

Correct Answer: Staphylococcus epidermidis

Explanation:

Question 68:

Options:

The transplanted chondrocytes are viable and articular cartilage heals. Biopsy shows type I collagen.
The transplanted chondrocytes are viable and articular cartilage heals. Biopsy shows type II collagen.
The transplanted chondrocytes are nonviable and cartilage is used as a scaffold for growth of new articular cartilage. Biopsy shows type II collagen.
The transplanted chondrocytes are nonviable and articular cartilage is gradually replaced by fibrocartilage. Biopsy shows type I collagen.
The transplanted chondrocytes are nonviable and articular cartilage is gradually replaced by fibrocartilage. Biopsy shows mixture of type I and II collagen.

Correct Answer: The transplanted chondrocytes are viable and articular cartilage heals. Biopsy shows type I collagen.

Explanation:

Question 69:

Options:

Surgical stabilization within 6 to 8 hours of injury
Extent of initial fracture displacement
Nicotine use
Posterior-to-anterior screw fixation
Anatomic fracture reduction

Correct Answer: Extent of initial fracture displacement

Explanation:

DISCUSSION: The incidence of osteonecrosis following displaced talar neck fractures is most related to the extent of initial fracture displacement. With increasing fracture displacement, the tenuous vascular supply to the talar body is more at risk for damage, thereby increasing the risk of osteonecrosis. Although displaced talar neck fractures have historically been considered a surgical emergency, recent studies have shown that the timing of surgical intervention bears no impact on the development of osteonecrosis. While nicotine use has an influence on fracture healing, it has never been shown to be a factor in osteonecrosis, nor has posterior-to-anterior screw fixation or the quality of fracture reduction.
REFERENCES: Lindvall E, Haidukewych G, Dipasquale T, et al: Open reduction and stable fixation of isolated, displaced talar neck and body fractures. J Bone Joint Surg Am 2004;86:2229-2234.
Vallier HA, Nork SE, Barei DP, et al: Talar neck fractures: Results and outcomes. J Bone Joint Surg Am 2004;86:1616-1624.

Question 70:

With the arm abducted 90 degrees and fully externally rotated, which of the following glenohumeral ligaments resists anterior translation of the humerus?

Options:

Coracohumeral
Superior glenohumeral
Middle glenohumeral
Anterior band of the inferior glenohumeral ligament complex
Posterior band of the inferior glenohumeral ligament complex

Correct Answer: Anterior band of the inferior glenohumeral ligament complex

Explanation:

DISCUSSION: With the arm in the abducted, externally rotated position, the anterior band of the inferior glenohumeral ligament complex moves anteriorly, preventing anterior humeral head translation. Both the coracohumeral ligament and the superior glenohumeral ligament restrain the humeral head to inferior translation of the adducted arm, and to external rotation in the adducted position. The middle glenohumeral ligament is a primary stabilizer to anterior translation with the arm abducted to 45 degrees. The posterior band of the inferior glenohumeral ligament complex resists posterior translation of the humeral head when the arm is internally rotated.
REFERENCES: Harryman DT II, Sidles JA, Harris SL, et al: The role of the rotator interval capsule in passive motion and stability of the shoulder. J Bone Joint Surg Am 1992;74:53-66.
Wang VM, Flatow EL: Pathomechanics of acquired shoulder instability: A basic science perspective. J Shoulder Elbow Surg 2005;14:2S-11S.

Question 71:

Which of the following is considered a contraindication to cement injection techniques, such as kyphoplasty or vertebroplasty, in the treatment of osteoporotic compression fractures?

Options:

Patient age of more than 85 years
Retropulsion of the posterior vertebral wall
Acute fracture in a hospitalized patient
Prior compression fracture
Fracture age of 4 months

Correct Answer: Retropulsion of the posterior vertebral wall

Explanation:

DISCUSSION: When retropulsion of the posterior vertebral wall is present, nothing prohibits the cement from following the path of least resistance into the canal or from pushing a bone fragment further into the canal; most clinicians consider it a contraindication to these techniques. Patient age itself is not a contraindication as long as there are no medical contraindications to surgery. An acute fracture in a patient who remains immobile and hospitalized because of pain may be a good indication for such a technique. Prior compression fracture and older compression fractures are not contraindications, but pain relief may be less predictable.
REFERENCES: Phillips FM, Pfeifer BA, Leiberman IH, et al: Minimally invasive treatment of osteoporotic vertebral compression fractures: Vertebroplasty and kyphoplasty. Instr Course Lect 2003;52:559-567.
Truumees E, Hilibrand A, Vaccaro AR: Percutaneous vertebral augmentation. Spine J 2004;4:218-229.
Rao RD
, Singrakhia MD: Painful osteoporotic vertebral fracture: Pathogenesis, evaluation, and roles of vertebroplasty and kyphoplasty in its management. J Bone Joint Surg Am 2003;85:2010-2022.

Question 72:

Options:

Lateralize the acetabular component, use a low offset femoral component, and make a shorter neck cut
Medialize the acetabular component, use a low offset femoral component, and make a longer neck cut
Lateralize the acetabular component, use a high offset femoral component, and make a shorter neck cut
Medialize the acetabular component, use a high offset femoral component, and make a longer neck cut

Correct Answer: Medialize the acetabular component, use a low offset femoral component, and make a longer neck cut

Explanation:

Question 73:

Options:

acute and transient spinal cord injury.
central cord syndrome.
nerve root avulsion.
Guillain-Barre syndrome.
stinger/burner.

Correct Answer: stinger/burner.

Explanation:

Question 74:

Which of the following treatments for osteoporosis is a direct inhibitor of RANK ligand (RANK-L)?

Options:

Romosozumab
Zoledronic acid
Denosumab
Teriparatide
Blosozumab

Correct Answer: Denosumab

Explanation:

Question 75:

Options:

Revision of the polyethylene liner, removal of the screw, and debridement of the osteolytic lesion with or without bone grafting
Revision of the acetabular component to a newer design without screws
Removal of the screw, revision of the polyethylene liner, and stem cell injection into the lytic lesion
Removal of the offending screw from the metal socket and placement of a new polyethylene liner in the existing socket

Correct Answer: Revision of the polyethylene liner, removal of the screw, and debridement of the osteolytic lesion with or without bone grafting

Explanation:

Question 76:

Options:

Anterior and superior acromioclavicular joint ligaments
Posterior and superior acromioclavicular joint ligaments
Conoid ligament
Trapezoid ligament

Correct Answer: Posterior and superior acromioclavicular joint ligaments

Explanation:

Question 77:

Options:

Supervised physical therapy
Arthroscopic capsulorrhaphy and labral repair
Open shoulder capsulorrhaphy and labral repair
Open shoulder capsulorrhaphy and bone block
Shoulder arthrodesis

Correct Answer: Open shoulder capsulorrhaphy and bone block

Explanation:

Question 78:

Options:

MRI
Custom orthotics
Activity modification
Calcaneal epiphysiodesis
Percutaneous Achilles tendon lengthening

Correct Answer: Activity modification

Explanation:

Question 79:

A 28-year-old male sustains a fall on icy ground and fractures his ankle. An intraoperative fluoroscopy image is shown in Figure A. This fixation suggests that the mechanism of injury was one of

Options:

Pronation-abduction
Supination-adduction
Pronation-external rotation
Supination-external rotation
Dorsiflexion-axial loading

Correct Answer: Pronation-abduction

Explanation:

The fixation of the medial malleolus in the figure consists of a contoured reconstruction plate placed in buttress (antiglide) mode with screws running parallel to the joint surface and perpendicular to the fracture line. This fixation is indicated for vertical fractures of the medial malleolus from a supination-adduction (SA) shearing force.
A vertical fracture of the medial malleolus is characteristic of a Lauge-Hansen SA fracture. Bimalleolar SA fractures will also demonstrate a distal fibular avulsion. Another characteristic is impaction of anteromedial distal tibia by the talar dome. An anteromedial surgical approach allows visualization of this region, elevation of impaction, and bone grafting of the defect if necessary.
Dumigan et al. analyzed 4 different methods of treating vertical shear fractures with polyurethane models. They found that fixation with a 4 hole 1/3 tubular plate with 2 screws in the distal fragment was stiffer than fixation with the same plate with 1 screw in the distal fragment (3 in the proximal), fixation with two 3.5mm cortical screws with washers, and fixation with two 4mm cortical screws with washers. They recommend plating over screw-alone constructs.
McConnell et al. reported 8 cases of anteromedial marginal impaction in SA fractures. They note that 44 fractures were SA type. Following reduction and fixation, all 8 patients had excellent outcome and no arthritis. They recommend an anteromedial approach to the medial malleolus for visualization.
Figure A is a lateral radiograph showing fixation of both malleoli with reconstruction plates. Illustration A is an postoperative AP fluoroscopy image. Illustration B is an injury film demonstrating the same SA ankle fracture. Illustration C shows articular impaction at the medial shoulder of the ankle joint typical of SA injuries. Illustration D shows marginal impaction in SA fractures.
Incorrect Answers
(SBQ12TR.76) A 24-year-old male sustains the fracture dislocation shown in Figure
A. How is this fracture pattern best classified?
Moore I
Moore II
Schatzker III
Schatzker V
OTA type 41B3
Figure A shows a Moore Type II fracture. Moore type II fractures consist of fractures involving the entire tibial condyle, where the fracture line begins in the opposite compartment and extends across the tibial eminence.
A number of classification systems are used to describe tibial plateau fractures. The main classification systems that are widely used include Schatzker, AO/OTA, Hohl and Moore. The Moore classification describes high energy fracture-subluxation injuries of the knee. This is thought to have clinical implications as the type of fracture pattern can indicate an associated soft-tissue injury.
Moore retrospectively reviewed over a 1000 proximal tibia fractures to devise a classification systems based on the characteristic of five types of tibia plateau fracture patterns. He believed this system helped to better understand knee instability and concomitant soft-tissue injury. For example, Moore Type III fractures (rim avulsion) are associated with a high rate of neurovascular injury.
Figure A shows a fracture involving the entire tibial condyle. Illustration A shows a schematic diagram of the Moore classification (I - V). Illustration B shows a table that
describes the Moore classification (I - V).
Incorrect Answers:

Question 80:

Options:

Increased age
Increased hip flexion-extension arc
Immediate weight-bearing
Increased hip strength
Decreased stride length

Correct Answer: Increased age

Explanation:

Question 81:

Which structure is the primary stabilizer of the lesser metatarsophalangeal (MTP) joint?

Options:

Flexor digitorum brevis
Flexor digitorum longus
Plantar plate
Collateral ligament

Correct Answer: Plantar plate

Explanation:

DISCUSSION
Synovitis of the second MTP occurs in association with instability of the joint. This can be idiopathic or secondary to an external deforming force (such as a hallux valgus or shoe wear causing a claw toe). The primary stabilizer of the MTP joint for translation in the vertical plane is the plantar plate. The flexor digitorum brevis flexes the MTP joint, and the flexor digitorum longus flexes
all joints of the toe. The collateral ligaments are primary stabilizers in the transverse plane and secondary stabilizers in the sagittal plane.
RECOMMENDED READINGS
Deland JT, Sung IH. The medial crosssover toe: a cadaveric dissection. Foot Ankle Int. 2000 May;21(5):375-8. PubMed PMID: 10830654.
View Abstract at PubMed
Suero EM, Meyers KN, Bohne WH. Stability of the metatarsophalangeal joint of the lesser toes: a cadaveric study. J Orthop Res. 2012 Dec;30(12):1995-8. doi: 10.1002/jor.22173. Epub 2012 Jun 13. PubMed PMID: 22696467.
View Abstract at PubMed
CLINICAL SITUATION FOR QUESTIONS 91 THROUGH 95
Figure 91a is the sagittal plane ultrasound of the second web space of a 48-year-old woman who has noted burning pain in the ball of her right foot for 2 years. The pain intermittently radiates into her second and the third toes. Figure 91b shows the surgical procedure and Figure 91c is the pathologic specimen.
A
B
C

Question 82:

Options:

Immediate full weight bearing
Protected weight bearing
Toe touch weight bearing
Non-weight-bearing
50% weight bearing

Correct Answer: Immediate full weight bearing

Explanation:

DISCUSSION: The incidence of femoral fracture in primary cementless total hip arthroplasty ranges from 1.5% to 27.8%. It is imperative that the implant and fracture are stable both intraoperatively and postoperatively. Cerclage wiring or cerclage cabling is the current recommended treatment for nondisplaced calcar fractures and minimally displaced proximal fractures. Berend and associates reviewed the results of 58 total hips in 55 patients with intraoperative calcar fracture managed with single or multiple cerclage wires or cables and immediate full weight bearing. Follow-up averaged 7.5 years, and there were no revisions of the femoral component. No patients had severe thigh pain.
REFERENCES: Berend KR, Lombardi AV Jr, Mallory TH, et al: Cerclage wires or cables for the management of intraoperative fracture associated with a cementless, tapered femoral prosthesis: Results at 2 to 16 years. J Arthroplasty 2004;19:17-21.
Schmidt AH, Kyle RF: Periprosthetic fractures of the femur. Orthop Clin North Am 2002;33:143-152.
Greidanus NV, Mitchell PA, Masri BA, et al: Principles of management and results of treating the fractured femur during and after total hip arthroplasty. Instr Course Lect 2003;52:309-322.

Question 83:

Options:

Increased ductility
Increased wettability
Diminished fatigue strength
Decreased resistance to abrasive wear

Correct Answer: Diminished fatigue strength

Explanation:

Question 84:

Options:

multiple osteotomies and femoral rodding.
pharmocologic doses of vitamin D and phosphate.
biopsy, followed by appropriate chemotherapy.
pamidronate therapy.
radiation therapy and a bone marrow transplant.

Correct Answer: multiple osteotomies and femoral rodding.

Explanation:

Question 85:

Options:

Stretching the posterior capsule and pectoralis minor tendon
Stretching the posterior capsule and strengthening the subscapularis
Stretching the posterior capsule and using shoulder plyometrics
Stretching the anterior capsule and strengthening all components of the rotator cuff
Stretching the anterior capsule and improving pitching mechanics

Correct Answer: Stretching the posterior capsule and pectoralis minor tendon

Explanation:

Question 86:

Options:

Avulsion of the lateral collateral ligament
Avulsion of the pes anserinus
Avulsion of the iliotibial band
Tear of the anterior cruciate ligament
Tear of the posterior cruciate ligament

Correct Answer: Tear of the anterior cruciate ligament

Explanation:

Question 87:

Options:

Age older than 40 years
Body mass index higher than 30
Tönnis grade of 2 or higher
Outer bridge grade of III or IV

Correct Answer: Tönnis grade of 2 or higher

Explanation:

Question 88:

Options:

lying completely supine in bed.
remaining seated and placing the postsurgical leg on a stool.
transferring to bed with the head of the bed no lower than 60°.
transferring back to bed with the head of the bed level and the surgical knee flexed.

Correct Answer: transferring back to bed with the head of the bed level and the surgical knee flexed.

Explanation:

Question 89:

What do the T2-weighted, fat-saturated MRI scans shown in Figures 1 through 4 reveal?

Options:

Posterior cruciate ligament (PCL) tear, isolated
PCL tear and medial meniscus tear
Anterior cruciate ligament (ACL) tear, isolated
ACL tear and medial meniscus tear

Correct Answer: ACL tear and medial meniscus tear

Explanation:

The MRI scans show that edema is noted on the femoral insertion of the ACL consistent with a high-grade or complete ACL tear. The ACL is not visualized on the sagittal view, although the torn meniscus can be seen in the notch. On the coronal image, there is an empty lateral wall sign indicating proximal
disruption of the ACL. The medial meniscus images show a disruption of normal meniscus morphology consistent with a bucket handle medial meniscus tear. Note the appearance on the sagittal MRI scan of what appears to be a second soft-tissue density in line with the PCL. This "double PCL" sign is highly
indicative of a displaced medial meniscus tear rather than a displaced lateral meniscus tear.

Question 90:

Options:

extensor hallus longus lengthening.
midfoot osteotomy.
first metatarsal osteotomy.
transfer of the extensor hallucis longus to the neck of the first metatarsal.
transfer of the extensor hallucis longus to the neck of the first metatarsal with first metatarsal osteotomy.

Correct Answer: transfer of the extensor hallucis longus to the neck of the first metatarsal with first metatarsal osteotomy.

Explanation:

Question 91:

Which of the following hip fracture patterns is at increased risk of proximal fragment flexion malreduction with dynamic hip screw fixation?

Options:

Right-sided unstable intertrochanteric fracture
Left-sided unstable intertrochanteric fracture
Left-sided stable intertrochanteric fracture
Right-sided stable intertrochanteric fracture
All unstable intertrochanteric fractures

Correct Answer: Right-sided unstable intertrochanteric fracture

Explanation:

Question 92:

A characteristic genetic translocation has been noted in which of the following tumors?

Options:

Ewing’s sarcoma
Chondrosarcoma
Neurofibrosarcoma
Osteosarcoma
Epithelioid sarcoma

Correct Answer: Ewing’s sarcoma

Explanation:

Question 93:

Options:

Immediate MRI of the brain
Electromyography and nerve conduction velocity studies
Physical therapy and observation
Lyme titer
Psychiatric consultation

Correct Answer: Electromyography and nerve conduction velocity studies

Explanation:

Question 94:

Options:

- Protected weight-bearing activity for 6 weeks
- Closed reduction and cast application
- Urgent open reduction and internal fixation
- Excision of the calcaneal tuberosity

Correct Answer: - Closed reduction and cast application

Explanation:

DISCUSSION
The radiograph reveals a displaced calcaneal tuberosity fracture. Displacement of a large tuberosity fragment necessitates urgent fracture reduction and stabilization. Delayed reduction results in compromise of the skin and soft tissues at the posterior heel. This injury occurs frequently in patients with diabetes. Protected weight-bearing activity does not address the displaced fragment or the threatened skin. Closed reduction, if possible, will not maintain the tuberosity fragment in a reduced position and will likely result in redisplacement. The fragment is large enough that it may be fixed and not excised. The Achilles tendon inserts on the displaced tuberosity fragment, so tuberosity reduction and fixation is necessary to achieve proper Achilles function.
RECOMMENDED READINGS
Beavis RC, Rourke K, Court-Brown C. Avulsion fracture of the calcaneal tuberosity: a case report and literature review. Foot Ankle Int. 2008 Aug;29(8):863-6. Review. PubMed PMID: 18752789.
View Abstract at PubMed
Gardner MJ, Nork SE, Barei DP, Kramer PA, Sangeorzan BJ, Benirschke SK. Secondary soft tissue compromise in tongue-type calcaneus fractures. J Orthop Trauma. 2008 Aug;22(7):439-45. PubMed PMID: 18670282.
View Abstract at PubMed
RESPONSES FOR QUESTIONS 57 THROUGH 59
- High strain
- Low strain
For each fracture detailed, select the appropriate description.
A simple fracture pattern that is anatomically reduced and compressed and treated with an 8-hole conventional plate with 4 bicortical conventional screws placed on each side of the fracture
- High strain
- Low strain

Question 95:

Options:

Removal of the components and placement of an antibiotic spacer
Removal of the components, placement of an antibiotic spacer, and bone grafting of the glenoid defect
Resection arthroplasty
Exchange of the humeral head and debridement
Arthroscopic debridement

Correct Answer: Removal of the components and placement of an antibiotic spacer

Explanation:

Question 96:

All of the following techniques can help to prevent valgus angulation during intramedullary nailing of proximal one-third tibia fractures EXCEPT:

Options:

Use of a blocking screw lateral to midline in the proximal segment
Use of a blocking screw lateral to midline in the distal segment
Use of a lateral tibial nail starting point
Use of supplementary plate and screw fixation
Suprapatellar nailing portal

Correct Answer: Use of a blocking screw lateral to midline in the proximal segment

Explanation:

Question 97:

Options:

Hospital admission with a referral to social services for evaluation for child neglect
Long leg casting and reevaluation in 24 hours
Short leg casting and reevaluation in 24 hours
Electrical studies of nerve function in 3 to 6 weeks if there is no improvement
Compartment pressure measurements and inpatient treatment as indicated

Correct Answer: Compartment pressure measurements and inpatient treatment as indicated

Explanation:

DISCUSSION: Pain with passive motion of the toes is a recognized early sign of increased compartment pressures. At a minimum, a baseline evaluation of the leg compartment pressures should be obtained. While it is normal for the patient to have pain related to the associated muscle contusions, any significant concerns should be addressed immediately in light of the severe consequences likely when a compartment syndrome occurs.
REFERENCES: Mubarak SJ, Owen CA, Hargens AR, et al: Acute compartment syndromes: Diagnosis and treatment with the aid of the wick catheter. J Bone Joint Surg Am
1978;60:1091-1095.
Matsen FA III, Veith RG: Compartmental syndromes in children. J Pediatr Orthop
1981;1:33-41.

Question 98:

Options:

Correction of the flatfoot deformity
Achilles tendon lengthening followed by orthotic support
Excision of the tarsal coalition
Sinus tarsi debridement
Triple arthrodesis

Correct Answer: Excision of the tarsal coalition

Explanation:

DISCUSSION: The patient has a calcaneonavicular tarsal coalition. Symptoms of calcaneonavicular coalitions typically are seen between the ages of 10 and 14 years. The cause of pain has not been clearly established. It has been postulated that the coalition stiffens with maturity and microfractures can result, producing pain. Resection of a calcaneonavicular coalition generally has been associated with a satisfactory result. Soft-tissue interposition, most commonly using the extensor digitorum brevis muscle, appears to be helpful. A hindfoot arthrodesis (usually triple) would be reserved if coalition resection proves to be unsuccessful. Achilles tendon lengthening and orthotic support, as well as debridement of the sinus tarsi, are not expected to result in a satisfactory outcome. The patient does not have a flatfoot deformity.
REFERENCES: Vaccaro AR (ed): Orthopaedic Knowledge Update 8. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2005, pp 757-765.
Lemley F, Berlet G, Hill K, et al: Current concepts review: Tarsal coalition. Foot Ankle Int 2006;27:1163-1169.

Question 99:

Options:

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

Correct Answer: periprosthetic fracture.

Explanation:

Question 100:

Options:

IV antibiotics.
arthroscopic irrigation and debridement, following by IV antibiotics.
irrigation and debridement, polyethylene exchange, and IV antibiotics.
one-stage component removal and reimplantation, followed by IV antibiotics.
two-stage component removal and reimplantation, with IV antibiotics in the interim period.

Correct Answer: irrigation and debridement, polyethylene exchange, and IV antibiotics.

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

Orthopedic Surgery Board Review MCQs: Trauma, Spine & Upper Extremity | Part 235

Key Takeaway

About This Board Review Set

How to Use the Interactive Quiz

Topics Covered in Part 235

Sample Questions from This Set

Why Active MCQ Practice Works

Chapter Index