OITE & ABOS Orthopedic MCQs: Ankle, Elbow & Hip

About This Board Review Set

This is Part 172 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.

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Topics Covered in Part 172

This module focuses heavily on: Ankle, Arthroplasty, Elbow, Hip.

Sample Questions from This Set

Sample Question 1: The patient has weakness with elbow flexion and has numbness down the anterior lateral aspect of the forearm....

Sample Question 2: In total hip arthroplasty, increasing the perpendicular distance from thecenterline of the femur to the center of rotation of the femoral head (femoral offset) results in...

Sample Question 3: Which of the following surgical devices employed for stabilization of the sternoclavicular joint is associated with the highest incidence of life-threatening complications?...

Sample Question 4: Figure 23 shows the radiograph of an elderly man who fell on his right arm. What is the most important determinate of a good outcome following this injury?...

Sample Question 5: Figures 42a through 42c show the clinical photographs and radiograph of a patient with diabetes mellitus who lives independently. The patient was admitted to the hospital late yesterday afternoon with clinical signs of sepsis. Parenteral an...

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Evidence consistently demonstrates that active recall through spaced MCQ practice yields substantially greater long-term retention than passive reading alone (Roediger & Karpicke, 2006). All questions in this specific module have been algorithmically verified for clinical integrity and complete explanations.

Comprehensive 100-Question Exam

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Question 1

The patient has weakness with elbow flexion and has numbness down the anterior lateral aspect of the forearm.

Explanation

DISCUSSION
The Latarjet procedure was initially described in 1959 as a modification of the Bristow procedure. It has been used as a primary procedure to address instability, but is used more commonly for patients with instability and glenoid bone loss. In 2000, Burkhart and associates reported a 67% failure rate of the Bankart procedure in patients with an inverted pear-shaped glenoid (glenoid bone loss) or an engaging Hill-Sachs lesion, with a suggestion that a bone graft procedure would be optimal in this population. Complications following the Latarjet procedure have been reported as high as 25%, with the majority attributable to nerve injury, recurrent instability, and arthritis. Many of these complications are likely secondary to surgical technique. A coracoid graft that is placed too laterally or with prominent screws will overhang the glenoid and lead to early degenerative glenohumeral arthritis. A coracoid graft placed too medially can lead to recurrent instability secondary to an ineffective subscapularis sling and bone block. A coracoid graft placed inferiorly indicates dissection close to the axillary nerve, which can place tension on the axillary nerve or cause injury from direct trauma. After harvesting the coracoid graft, the surgeon must find the musculocutaneous nerve as it enters the conjoint tendon on the medial surface about 5 cm distal to the coracoid. Excessive dissection or retraction can lead to musculocutaneous nerve palsy.

Question 2

In total hip arthroplasty, increasing the perpendicular distance from the center line of the femur to the center of rotation of the femoral head (femoral offset) results in

Explanation

The advantages to increasing femoral offset at THA are reported to
include an increased range of motion, better mechanical advantage for the abductors and decreased instability because of better soft tissue tension. According to Charnley,
increasing the femoral offset should improve the abductor lever arm which should decrease the abductor force required for walking, and therefore decrease the energy requirement for gait as well as the overall joint reactive force. The largest possible disadvantage of increasing the femoral offset is increasing the out of plane bending moment which puts stress on the prosthetic stem. Poly wear is a direct effect of surface area contact which is not changed with femoral Offset.

Question 3

Which of the following surgical devices employed for stabilization of the sternoclavicular joint is associated with the highest incidence of life-threatening complications?

Explanation

DISCUSSION: Numerous reports have documented serious complications including death from migration of intact or broken Kirschner wires or Steinmann pins into hilar structures such as the heart, pulmonary artery, and the aorta.
REFERENCES: Gilot GJ, Wirth MA, Rockwood CA: Injuries to the sternoclavicular joint, in Bucholz RW, Heckman JD, Court-Brown C (eds): Fractures in Adults. Philadelphia, PA, Lippincott, Williams and Wilkins, 2006, vol 2, pp 1373-1374.
Lyons FA, Rockwood CA Jr: Migration of pins used in operations of the shoulder. J Bone Joint Surg Am 1990;72:1262-1267.

Question 4

Figure 23 shows the radiograph of an elderly man who fell on his right arm. What is the most important determinate of a good outcome following this injury?

Explanation

DISCUSSION: Minimally displaced fractures of the proximal humerus have a good outcome if physical therapy is initiated within 2 weeks of the injury. Results are not affected by age, open reduction and internal fixation, or involvement of the greater tuberosity. Immobilization for longer than 3 weeks will often result in stiffness.
REFERENCES: Koval KJ, Gallagher MA, Marsicano JG, et al: Functional outcome after minimally displaced fractures of the proximal part of the humerus. J Bone Joint Surg Am 1997;79:203-207.
Hodgson SA, Mawson SJ, Stanley D: Rehabilitation after two-part fractures of the neck of the humerus. J Bone Joint Surg Br 2003;85:419-422.

Question 5

Figures 42a through 42c show the clinical photographs and radiograph of a patient with diabetes mellitus who lives independently. The patient was admitted to the hospital late yesterday afternoon with clinical signs of sepsis. Parenteral antibiotic therapy resolved the sepsis, and blood glucose levels are now well controlled. The patient has no palpable pulses. The ankle-brachial index is 0.70. Laboratory studies show a WBC count of 8,500/mm 3 , a serum albumin of 1.9 g/dL, and a total lymphocyte count of 1,500/mm 3 . What treatment has the best potential to optimize his survival and independence?

Explanation

DISCUSSION: The patient was admitted to the hospital with sepsis. The sepsis has resolved, leaving the patient with a negative nitrogen balance. Now that the patient is stable, metabolic support should be used to optimize his nutrition. If the serum albumin can be increased to 2.5 g/dL, he has an excellent potential to heal an amputation at the Syme ankle disarticulation level; a level that will optimize his functional independence.
REFERENCES: Pinzur MS, Stuck RR, Sage R, et al: Syme ankle disarticulation in patients with diabetes. J Bone Joint Surg Am 2003;85:1667-1672.
Pinzur MS, Smith D, Osterman H: Syme ankle disarticulation in peripheral vascular disease and diabetic foot infection: The one-stage versus two-stage procedure. Foot Ankle Int 1995;16:124-127.

Question 6

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

Explanation

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

Question 7

A 22-year-old patient underwent successful reduction of a posterolateral elbow dislocation. Management should now consist of

Explanation

DISCUSSION: The elbow usually is stable after reduction in most elbow dislocations. Ross and associates reported that supervised motion begun immediately after reduction was effective in uncomplicated dislocations. The elbow will become stiff if immobilization is applied for an extended period of time. Immediate open treatment is not indicated for a simple elbow dislocation.
REFERENCES: Ross G, McDevitt ER, Chronister R, et al: Treatment of simple elbow dislocation using an immediate motion protocol. Am J Sports Med 1999;27:308-311.
O’Driscoll SW, Jupiter JB, King GJ, et al: The unstable elbow. J Bone Joint Surg Am 2000;82:724-738.

Question 8

What are the four most common soft-tissue sarcomas to spread via the lymph node system?

Explanation

DISCUSSION: Soft-tissue sarcomas most frequently metastasize to the lung, but certain histologic types have a predilection for the lymph node system as well. Rhabdomyosarcoma, clear cell sarcoma, epithelioid sarcoma, and synovial sarcoma are four of the most common types to spread in this fashion. Careful evaluation and/or sentinel lymph node biopsy plays a role in disease staging and prognosis.
REFERENCES: Riad S, Griffin AM, Liberman B, et al: Lymph node metastasis in soft-tissue sarcoma in an extremity. Clin Orthop Relat Res 2004;426:129-134.
Blazer DG III, Sabel MS, Sondak VK: Is there a role for sentinel lymph node biopsy in the management of sarcoma? Surg Oncol 2003;12:201-206.

Question 9

A 44-year-old man was involved in a low speed rear-end motor vehicle accident 4 weeks ago. He predominantly reports pain in the back of the neck, with occasional radiation into the trapezius region bilaterally. He denies any extremity pain. The pain has not changed in intensity, but is worse with neck range of motion. Cervical spine radiographs were negative for acute osseous trauma or instability. What is the next most appropriate step in management? Review Topic

Explanation

The patient was involved in a low speed rear-end collision and sustained a whiplash-type injury, with management most often being nonsurgical. After 4 weeks of persistent pain, continued observation is not reasonable. Studies have shown that treatment including NSAIDs, activity modification and a brief duration of physical therapy allows for improved outcomes after whiplash-type injuries when compared with observation alone. An MRI scan of the cervical spine is not indicated at this time and represents an unnecessary expense. Cervical epidural and facet injections are not indicated in the treatment of patients with whiplash injuries.

Question 10

Figures 1 and 2 are the MR arthrogram images of a 16-year-old, right-hand-dominant baseball player who injured his left shoulder 4 weeks ago during a game. He now has pain, weakness, and the inability to swing a bat and can no longer do push-ups. He denies prior injury to his left shoulder. Radiographs are unremarkable. If present, what is the most likely complication after surgical treatment in this scenario?

Explanation

Posterior shoulder instability is a rare form of instability that often presents with pain rather than feelings of instability. It often occurs in young athletes during activities that put the shoulder in an “at-risk position” (flexion, adduction, internal rotation). Repetitive microtrauma can lead to posterior shoulder instability such as seen in football linemen. Swinging a bat or golf club places the lead arm in a flexed, adducted, and internally rotated position, which can lead to posterior translation of the humeral head that is forcibly reduced in follow-through, as seen in this patient. The glenohumeral joint relies on static and dynamic stabilizers. Static stabilizers help prevent instability at the end ranges of motion when the ligaments are taut. Dynamic stabilizers work to prevent subluxation at midranges of motion, at which the ligaments are lax. The rotator cuff is integral as a dynamic stabilizer of the shoulder. It works through a process called concavity compression. The four muscles of the rotator cuff compress the humeral head into the concavity of the glenoid-labrum. This prevents the humeral head from subluxing during the midranges of motion. Of the four rotator cuff muscles, the subscapularis is most important at preventing posterior subluxation. This patient has posterior instability, and various surgical techniques may be indicated depending on findings. Arthroscopic labral repair is indicated for anterior instability. Arthroscopic posterior labral repair is indicated for this patient because he has a posterior labral tear and posterior instability. If a patient has ligamentous laxity (not seen in this scenario because sulcus and Beighton sign findings would be negative), a posterior capsular shift with rotator interval closure is indicated. If a patient has excessive glenoid retroversion (not seen in this scenario with 5 degrees of retroversion), a posterior opening-wedge osteotomy is appropriate. The most common complication seen after arthroscopic posterior labral repair is stiffness, followed by recurrent instability
and degenerative joint disease.

Question 11

A 19-year-old man sustains a complete spinal cord injury at the C7 level as a result of diving into a lake. He has a blood pressure of 90/50 mm Hg, a pulse of 60/min, and respirations of 20/min. These values most likely signify

Explanation

Neurogenic shock is defined as vascular hypotension with bradycardia as a result of spinal injury. The first few minutes after spinal cord injury are associated with hypertension and tachycardia, with a subsequent drop in pressure and pulse rate.

Question 12

01 (left). What is the most appropriate next step?

Explanation

This patient has a posterior knee dislocation with an ischemic limb that does not reverse following reduction. Emergent vascular exploration and reconstruction is indicated.
Knee dislocations are associated with popliteal artery injury in 18-45% of cases and range from intimal tears to complete transection. Amputation rates of 85% have been reported if revascularization is delayed greater than 6 to 8 hours. Neurologic injury occurs in 15-40% of cases and is most common after posterolateral dislocation. The peroneal nerve is more commonly injured.
Rihn et al. reviewed the acutely dislocated knee. They recommend a vascular consult if pulses are weak, or ABI is compromised. They warn that in arterial injury, pulses, temperature and capillary refill can be normal. If the limb remains ischemic, surgical exploration and revascularization is indicated.
Medina et al. systematically reviewed neurovascular injury after knee dislocation in 862 patients. Vascular injury rate was 18%, and nerve injury rate was 25%. Repair was performed in 80% of vascular injuries, and amputation in 12%. The most vascular injury was seen in KDIIIL injuries (32%) and posterior dislocation (25%).
Figure A is an AP radiograph of a posterior knee dislocation. Figure B is a lateral showing the same injury.
Incorrect Answers:

Question 13

CLINICAL SITUATION Figures 1 through 3 are the radiographs of a 25-year-old man who is brought to the emergency department after a motorcycle collision. He is complaining of isolated knee pain. Examination reveals swelling, popliteal ecchymosis, joint line pain, and limited knee joint motion. His pulses and sensation are normal. Initial surgical management should consist of

Explanation

Discussion: Medial plateau fracture dislocations are rare. Failure to recognize this pattern can lead to poor patient outcomes secondary to poor surgical decision making. Pathognomonic findings on the anteroposterior radiograph include an intact lateral column (lateral articular surface still in continuity with tibial shaft), centrolateral articular impaction, shortening, and condylar widening. The medial femoral condyle stays with the fractured medial tibial plateau segment.
Initial management of axially unstable tibial plateau fractures with soft tissue swelling should consist of spanning external fixation and closed manipulative realignment. This allows for soft tissue recovery with the knee joint provisionally stabilized in reduced station. It also provides time for pre-operative planning, which is typically empowered via a CT scan with reconstructions. If the pattern was initially misdiagnosed as a more typically bicondylar tibial plateau fracture, the CT scan will clarify the misconception and allow for better surgical decision making.
Supine positioning is preferred for definitive fixation, but surgical approaches vary. Attempting to stabilize a medial partial articular pattern in the supine position from a lateral utility approach is fraught with difficulties. Lateral locked plating is not designed for this indication. The lateral utility approach allows for visualization of the centrolateral impaction and lateral meniscal peripheral capsular avulsion repair,
but when used alone leads to biomechanically unsound implant placement. The primary plate should be on the medial side of the tibia rather than the intact lateral column.

Question 14

In recurrent posterior shoulder instability, what is the recommended approach to the posterior capsule?

Explanation

DISCUSSION: Using an infraspinatus-splitting incision allows for excellent exposure of the posterior capsule and minimizes the risk of injury to the axillary nerve which lies inferior to the teres minor in the quadrilateral space.
REFERENCES: Dreese J, D’Alessandro D: Posterior capsulorrhaphy through infraspinatus split for posterior instability. Tech Shoulder Elbow Surg 2005;6:199-207.
Shaffer BS, Conway J, Jobe FW, et al: Infraspinatus muscle-splitting incision in posterior shoulder surgery: An anatomic and electromyographic study. Am J Sports Med 1994;22:113-120.
Fuchs B, Jost B, Gerber C: Posterior-inferior capsular shift for the treatment of recurrent voluntary posterior subluxation of the shoulder. J Bone Joint Surg Am 2000;82:16-25.

Question 15

A college basketball player is struck in the eye by a player’s hand while driving to the basket. Fluorescein evaluation reveals the injury shown in Figure 18. Management should consist of

Explanation

DISCUSSION: The athlete has a corneal abrasion. Fluorescein staining identifies the break in the epithelium when examined with ultraviolet light. Topical antibiotics are used as prophylaxis against secondary bacterial infection, and the patch, applied with the lid closed, is used for comfort and to promote epithelial healing. The accompanying symptoms, including pain, tearing, and photophobia, are usually too intense to allow a return to play. Surgery is reserved for a corneal laceration with associated loss of the anterior chamber. While a proper fundoscopic examination may be a consideration, increased intraocular pressure is not typically associated with this injury. Traumatic hemorrhage in the anterior chamber (hyphema) necessitates strict bed rest during the early phases of healing; examination will most likely reveal the red fluid level of blood settling inferiorly in the anterior chamber. It is often associated with increased intraocular pressure.
REFERENCES: Brucker AJ, Kozart DM, Nichols CW, et al: Diagnosis and management of injuries to the eye and orbit, in Torg JS (ed): Athletic Injuries to the Head, Neck, and Face. St Louis, MO, Mosby-Year Book, 1991, pp 650-670.
Zagelbaum BM: Treating corneal abrasions and lacerations. Phys Sports Med 1997;25:38-44.

Question 16

Figures 39a and 39b are the radiographs of a 45-year-old man with diabetes who fell 12 feet from a ladder and sustained an isolated closed injury to his left leg. Examination revealed that he was neurovascularly intact and compartments were soft. A damage control knee spanning external fixator was applied and after 2 weeks in the frame, his blisters have resolved and his skin now wrinkles. What is the most appropriate treatment?

Explanation

The patient has sustained a severely comminuted bicondylar fracture of the tibial plateau. The mechanism and radiographs highlight the high-energy mechanism of the injury and should warrant aggressive monitoring for compartment syndrome which is relatively common in this scenario. A staged surgical approach is warranted with application of a spanning damage control external fixator to maintain length and
alignment while the soft-tissue injury recovers and to allow for surveillance and examination of the limb. The radiographs reveal a comminuted bicondylar pattern with significant depression of the lateral articular surface and a split fracture with condylar widening. This element of the fracture will require direct elevation of the joint surface and reduction/buttress of the lateral condyle. This is best achieved with a lateral plate with subchondral rafting screws. The medial articular surface is coronally split and the posteromedial fragment is displaced. This fragment requires direct reduction and buttress via a separate posteromedial approach which is frequently performed prior to the lateral approach and fixation. A lateral buttress plate or a lateral locking plate alone does not reliably capture or adequately support the displaced posteromedial fragment. A medial and lateral plate construct is less soft-tissue friendly, particularly if inserted through a single incision. A medial plate would also fail to give direct buttress to the posteromedial fragment.

Question 17

Osteonecrosis of the humeral head is a rare complication seen after dislocation of the glenohumeral joint in skeletally immature patients. When this complication is encountered, treatment should consist of Review Topic

Explanation

This rare complication occurs after fracture-dislocation and has been seen after surgical stabilization in the adolescent. In most reported cases, prolonged observation has been shown to result in revascularization.

Question 18

The anterolateral (Watson-Jones) approach to the hip exploits the intermuscular interval between the

Explanation

DISCUSSION: The Watson-Jones approach to the hip uses the intermuscular interval between the gluteus medius and the tensor fascia lata. This is not a true internervous plane, as both muscles are supplied by the superior gluteal nerve.
REFERENCES: Hoppenfeld S, deBoer P: Surgical Exposures in Orthopaedics: The Anatomic Approach. Philadelphia, PA, JB Lippincott, 1984, pp 316-332.
Crenshaw AH (ed): Campbell’s Operative Orthopedics, ed 7. St Louis, MO, CV Mosby, 1987,

p 63.

Question 19

An otherwise healthy 33-year-old man who works in construction reports a 3-month history of knee pain. Radiographs are shown in Figures 9a and 9b. An axial T 1 -weighted MRI scan with contrast, an angiogram, and histologies are shown in Figures 9c through 9f. What is the most likely diagnosis?

Explanation

DISCUSSION: Dedifferentiated parosteal osteosarcoma designates high-grade transformation of conventional low-grade parosteal osteosarcoma. Unlike conventional parosteal osteosarcoma, where wide surgical excision alone is considered adequate treatment, patients with dedifferentiated osteosarcoma are treated with neoadjuvant chemotherapy and wide local resection. Recognition of dedifferentiated areas with angiography can localize the area that should be biopsied and thus render an accurate diagnosis. Percutaneous biopsy of hypervascular areas should prompt the administration of chemotherapy and wide local excision to optimize patient outcome.
REFERENCES: Sheth DS, Yasko AW, Raymond AK, et al: Conventional and dedifferentiated parosteal osteosarcoma: Diagnosis, treatment, and outcome. Cancer 1996;78:2136-2145.
Lewis VO, Gebhardt MC, Springfield DS: Parosteal osteosarcoma of the posterior aspect of the distal part of the femur: Oncological and functional results following a new resection technique. J Bone Joint Surg Am 2000;82:1083-1088.

Question 20

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

Explanation

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

Question 21

Figure 35 is the radiograph of a 37-year-old woman who began having right forefoot pain about 4 weeks ago after increasing her daily running mileage. She denies any specific injury. Upon examination she has tenderness over the medial forefoot with mild swelling. In addition to her activity level, what is the primary etiology of the radiograph finding?

Explanation

DISCUSSION
Stress fractures are the result of physiological bone response to increased stress. Increased stress on bone triggers an increase in remodeling, which begins with resorption of bone at the site of stress. Ongoing stress can overwhelm bone strength, resulting in a fracture. In the foot this most commonly is seen in the second metatarsal at the junction of the middle and distal thirds. Contributing factors to increased loading of the second metatarsal include hallux valgus (decreased hallux loading transfers to the second metatarsal head), hallux rigidus (offloading of the hallux attributable to pain increases second metatarsal loading), and a long second metatarsal (increased duration of contact during push-off in the stance phase).
RECOMMENDED READINGS
Shindle MK, Endo Y, Warren RF, Lane JM, Helfet DL, Schwartz EN, Ellis SJ.
Stress fractures about the tibia, foot, and ankle. J Am Acad Orthop Surg. 2012 Mar;20(3):167-

Question 22

A 22-year-old javelin thrower reports that he has had increasing discomfort in his right elbow and loss of distance from his throws for the past 3 months. Examination reveals tenderness over the medial elbow. Application of valgus torque to the elbow through a passive range of motion elicits pain from 70 degrees to 120 degrees of flexion, with no pain at the limits of extension. What structure is primarily responsible for the patient's symptoms? Review Topic

Explanation

The MCL is divided into anterior and posterior bundles; the anterior bundle is subdivided into anterior and posterior bands. Sectioning studies showed that the anterior band of the anterior bundle is the primary restraint to valgus stress at 30 degrees, 60 degrees, and 90 degrees; the posterior band of the anterior bundle is the primary restraint at 120 degrees. Medial elbow pathology in a throwing athlete can present with pain, instability, loss of velocity or control, or with ulnar nerve symptoms. Differentiating between different causes of disability can be largely accomplished through physical examination. The moving valgus stress test is performed by applying a valgus stress to a maximally flexed elbow, then passively extending the elbow. Reproduction of the patient's symptoms in the mid arc of flexion suggests MCL insufficiency. Pain at the end point of extension suggests posterior compartment symptoms, which were not present in this patient. The posterior bundle
is a secondary stabilizer at 30 degrees of flexion, and not susceptible to valgus load when the anterior bundle is intact. The annular ligament and triceps insertion are not involved with medial instability of the elbow. Olecranon osteophytes likely cause pain in terminal extension of the elbow.

Question 23

Figure below shows the radiograph obtained from a 76-year-old woman who has sharp pain in her groin, thigh, and buttocks that worsens with activity. She has been dealing with this pain for more than a year but is otherwise healthy. Recently, she has begun to notice night pain. The pain no longer responds to NSAIDs. She would like to be able to dance at her daughter's wedding in 4 months and wonders how best to proceed. What is the best next step?

Explanation

DISCUSSION:
The next best course of action is total hip arthroplasty. The patient is an otherwise healthy woman requesting pain relief and expresses a desire to be dancing in 4 months. She has had more than 6 months of symptoms that are classic hip osteoarthritis symptoms, with pain in the groin and thigh. Severe osteoarthritis is seen in the radiograph as well. NSAIDs are no longer working. Given the objective findings, the subjective reports, and the duration of symptoms, this patient merits surgery. Consideration for steroid injection is reasonable, but given her desire to be dancing in 4 months, an injection would increase her risk of infection if total hip arthroplasty were to be performed within 3 months of the
injection.

Question 24

If heel varus corrects with a Coleman block test, then the hindfoot deformity is flexible. This test proves that the varus is due to a

Explanation

DISCUSSION: The Coleman block test is used to evaluate the effect of the forefoot on the rearfoot varus. If the deformity corrects with the block, then the hindfoot deformity is flexible and the varus position is secondary to the plantar flexed first ray or valgus position of the forefoot. A rearfoot orthotic will not correct the forefoot cause of the deformity. The patient still may need a lateralizing calcaneal osteotomy to realign the hindfoot.
REFERENCES: Younger AS, Hansen ST Jr: Adult cavovarus foot. J Am Acad Orthop Surg 2005;13:302-315.
Alexander IJ, Johnson KA: Assessment and management of pes cavus in Charcot-Marie-Tooth disease. Clin Orthop Relat Res 1989;246:273-281.

Question 25

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

Explanation

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

Question 26

Which of the following structures are found in the anterior tarsal tunnel?

Explanation

DISCUSSION: The contents of the anterior tarsal tunnel are the extensor hallucis longus, tibialis anterior, extensor digitorum longus, dorsalis pedis artery, and the deep peroneal nerve. The term “anterior tarsal tunnel syndrome” is used to specifically describe the compression of the deep peroneal nerve under the inferior extensor retinaculum. With nerve compression, patients report a burning sensation across the dorsum of the foot with paresthesias in the first web space. There also may be wasting and weakness of the extensor digitorum brevis.
REFERENCES: Kuritz HM: Anterior entrapment syndromes. J Foot Surg 1976;15:143-148.
Sarrafian S: The Anatomy of the Foot and Ankle: Descriptive, Topographic, Functional, ed 2. Philadelphia, PA, JB Lippincott, 1993, pp 113-158.

Question 27

A researcher studies growth factors that have positive effects on cartilage healing. In vivo and in vitro experiments are performed with Growth Factor

Explanation

TGF-beta 1 stimulates the synthesis of extracellular matrix (ECM) and causes synovial proliferation and fibrosis.
TGF-beta is the most thoroughly investigated member of the TGF-beta superfamily. This group includes TGF-beta1, BMP-2, and BMP-7. Besides the above activities, TGF-beta1 also stimulates chondrocyte synthetic activity and decreases the catabolic activity of IL-1.
Fortier et al. reviewed the role of growth factors in cartilage repair and modification
of osteoarthritis. They found that members of the TGF-beta superfamily, FGF family, IGF1, and PDGF have all been investigated as possible treatment augments in the management of chondral injuries and early arthritis. They concluded that more research was necessary before routine application.
Illustration A shows a summary of the different growth factors and their effects on cartilage.
Incorrect Answers:

Question 28

A 42-year-old woman reports neck stiffness, upper extremity pain, clumsiness, weakness, and instability of gait. Examination reveals 4+ of 5 strength in the upper extremities and 3+ biceps, brachioradialis, and patellar reflexes with a positive Hoffman sign bilaterally. MRI and CT scans are shown in Figures 10a and 10b. Based on the history and imaging findings, what is the most likely diagnosis? Review Topic

Explanation

The sagittal T2-weighted MRI scan shows moderate-severe multilevel cervical stenosis. The cord compression is noted to be not only at the disk levels but also at the midvertebral body levels, and the posterior longitudinal ligament appears to be thickened. The CT scan confirms that the posterior longitudinal ligament is indeed thickened and ossified, compatible with a diagnosis of ossification of the posterior longitudinal ligament. This diagnosis is most common in individuals of Japanese descent and has a genetic linkage. The anterior osteophytes are smaller than those seen in diffuse idiopathic skeletal hyperostosis and are not syndesmotic. Patients with ankylosing spondylitis typically have non-marginal syndesmophytes. Patients with rheumatoid arthritis may have evidence of instability at C1-C2 on flexion-extension radiographs and subaxial subluxations.

Question 29

A 59-year-old man underwent interposition arthroplasty for osteoarthritis of the elbow 9 years ago. Over the past year the patient has had increasing pain and elbow instability. There is no clinical evidence of infection, and radiographs show no new bony process. What is the best option for this patient?

Explanation

DISCUSSION: In a series reported by Blaine and associates, 12 patients were converted from interposition to total elbow arthroplasty. This procedure was successful in 10 out of 12 patients.
REFERENCES: Blaine TA, Adams R, Morrey BF: Total elbow arthroplasty after interposition arthroplasty for elbow arthritis. J Bone Joint Surg Am 2005;87;286-292.
Cheng SL, Morrey FB: Treatment of the mobile, painful arthritic elbow by distraction interposition arthroplasty. J Bone Joint Surg Br 2000;82:233-238.

Question 30

A subtrochanteric femur fracture in which the lesser trochanter is intact is associated with what deformity?

Explanation

The most commonly seen deformity in subtrochanteric femur fractures is abduction and flexion of the proximal fragment. Subtrochanteric fractures can pose challenges in reduction because of the muscle attachments proximal and distal to the fragment. The gluteus medius and gluteus minimus attach to the greater trochanter and abduct the proximal fragment. The iliopsoas attaches to the lesser trochanter, flexing and externally rotating the proximal fragment. The short external rotators (piriformis, superior and inferior gamellus) and the obturator internus also cause external rotation of the proximal fragment.

Question 31

A 50-year-old woman who underwent a joint replacement of the hallux metatarsophalangeal joint 6 months ago now has pain and swelling about the great toe. Radiographs are shown in Figures 39a and 39b. What is the next most appropriate step in management?

Explanation

DISCUSSION: The radiographs show displacement of the prosthesis, and there has been large amounts of bone resected to insert the implant. Arthrodesis is indicated with interposition bone graft to stabilize the joint and restore length to the first ray.
REFERENCE: Myerson MS: Foot and Ankle Disorders. Philadelphia, PA, WB Saunders, 2000, pp 265-266.

Question 32

Which modality has the broadest application for reduction of postsurgical transfusion?

Explanation

DISCUSSION
TXA is easy to administer, inexpensive, and safe for virtually all patients. Multiple studies have demonstrated transfusion rates lower than 3% for total knee arthroplasty and lower than 10% for total hip arthroplasty. Regional and hypotensive anesthesia effectively reduce transfusion; however, they cannot be used in as wide a range of patients as TXA. A reduced transfusion trigger must be considered along with patient symptoms when determining the need for transfusion.

Question 33

Which of the following enzymes is used to resorb bone by mature osteoclasts?

Explanation

Osteoclasts resorb bone. Osteoclasts are derived from monocytes and macrophages that fuse to form multinucleated cells in response to receptor activator of nuclear factor kappa b (RANKL) and macrophage colony stimulating factor (MCSF). Osteoclasts attach to bone surfaces through a specific cell attachment receptor called an integrin (av¯3 or vitronectin receptor). The ruffled border refers to multiple invaginations of plasma membrane against the bone matrix surface. Lysosomes move to the ruffled border of osteoclasts and discharge lysosomal enzymes into the resorption region. These enzymes include cathepsin K, matrix metalloproteinase, and carbonic anhydrase (CA II).

Question 34

Figures 4a through 4c show the radiographs of a 43-year-old woman who sustained a twisting injury to her right ankle. She has ankle pain and tenderness medially and laterally. To help determine the optimal treatment, an external rotation stress radiograph of the ankle is obtained. This test is designed to evaluate the integrity of what structure?

Explanation

DISCUSSION: In the presence of a supination external rotation-type fracture of the distal fibula (Weber type B), stability of the ankle is best assessed by performing an external rotation stress AP view of the ankle. This test is used to assess the integrity of the deltoid ligament. The presence of a deltoid ligament rupture results in instability and generally is best managed surgically. The gravity stress test can also be used.
REFERENCES: Egol KA, Amirtharajah M, Tejwani NC, et al: Ankle stress test for predicting the need for surgical fixation of isolated fibular fractures. J Bone Joint Surg Am 2004;86:2393-2398.
McConnell T, Creevy W, Tornetta P III: Stress examination of supination external rotation-type fibular fractures. J Bone Joint Surg Am 2004;86:2171-2178.
Schock HJ, Pinzur M, Manion L, et al: The use of the gravity or manual-stress radiographs in the assessment of supination-external rotation fractures of the ankle. J Bone Joint Surg Br 2007;89:1055-1059.

Question 35

Thoracic disk herniations are most frequently found in what area of the spine?

Explanation

DISCUSSION: Although thoracic disk herniations have been reported at all levels of the thoracic spine, more than two thirds are found at T9-T12, which is the more mobile lower third of the thoracic region.
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.
Bohlman HH, Zdeblick TA: Anterior excision of herniated thoracic discs. J Bone Joint Surg Am 1988;70:70-77.

Question 36

A 75-year-old woman who fell on her right knee now reports pain and is unable to bear weight. History reveals that she underwent total knee arthroplasty on the right knee 6 years ago. Radiographs are shown in Figure 5. Management should now consist of

Explanation

DISCUSSION: The radiographs show a loose femoral component with an associated medial condyle distal femoral fracture. The treatment of choice is open reduction and internal fixation with revision of the femoral component because of the femoral component loosening.
REFERENCES: Moran MC, Brick GW, Sledge CB, et al: Supracondylar femoral fracture following total knee arthroplasty. Clin Orthop 1996;324:196-209.
McLaren AC, DuPont JA, Schroeber DC: Open reduction internal fixation of supracondylar fractures above total knee arthroplasties using the intramedullary supracondylar rod. Clin Orthop 1994;302:194-198.
Figgie MP, Goldberg VM, Figgie HE III, et al: The results of treatment of supracondylar fracture above total knee arthroplasty. J Arthroplasty 1990;5:267-276.

Question 37

Figures below show the radiographs obtained from a 79-year-old woman who has been experiencing increasing tibial pain 10 years after undergoing revision total knee arthroplasty. No evidence of infection is seen. What is the most appropriate treatment?

Explanation

DISCUSSION:
Stems are available for cemented and press-fit implantation. To be effective, press-fit stems should engage the diaphysis, as shown in Figures 3 and 4. They also assist in obtaining correct limb alignment. Short metaphyseal-engaging stems are associated with failure rates that range between 16% and 29%. Cemented stems may be shorter than press-fit stems, because they do not have to engage the diaphysis. Short, fully cemented stems offer the advantage of metaphyseal fixation. Hybrid stem fixation makes use of the metaphysis for cement fixation with metaphyseal cones or sleeves and diaphyseal-engaging press-fit stems.

Question 38

A 56-year-old mechanic has had pain in the hypothenar region of his dominant right hand for the past 6 months. He reports weakness in his grip and pain is worse with activity. Which of the following examination findings is most suggestive of a cervical etiology? Review Topic

Explanation

Hypothenar atrophy is a nonspecific sign that can be seen in ulnar neuropathy, C8 radiculopathy, or even cervical myelopathy; however, the atrophy usually is not unilateral and includes other muscle groups. The Spurling test is an excellent method of eliciting cervical radicular pain but involves hyperextension and ipsilateral rotation of the cervical spine, resulting in nerve root compression by reducing the cross-sectional area of the ipsilateral neuroforamen. Tinel’s sign at the levator scapulae, if present, is indicative of an upper cervical (C3 or C4) radiculopathy. A subluxable ulnar nerve at the cubital tunnel, while often asymptomatic, points toward cubital tunnel syndrome as an etiology for this patient’s pain. The shoulder abduction relief (SAR) sign (relief of upper extremity pain with shoulder abduction) is virtually pathognomic of cervical radiculopathy because this maneuver results in relaxation of a compressed and/or inflamed cervical nerve root. The SAR sign is the converse analog of the straight leg raising sign in the lumbar examination for lumbar radiculopathy, as it relieves tension in the nerve root, thereby relieving symptoms.

Question 39

A 65-year-old female presents with the injury seen in Figures A and B after a motor vehicle collision. She is hemodynamically unstable and undergoes emergent pelvic supra-acetabular external fixation followed by laparotomy. She is now hemodynamically stable and cleared for surgery. She has no evidence of neurologic deficit on examination. Which of the following factors is a relative contraindication to open reduction and plating of her posterior pelvic injury from an anterior approach?

Explanation

An anterior approach to the sacroiliac (SI) joint is indicated with displaced SI joint dislocations that cannot be reduced with closed or percutaneous techniques. One contraindication to anterior exposure of the SI joint is comminuted sacral fracture patterns.
Posterior pelvic ring injuries that are unable to be reduced by closed techniques may require open reduction via anterior or posterior approaches. Relative contraindications to anterior approach include comminuted sacral fractures, morbid obesity, iliac wing external fixation, and ipsilateral diverting colostomy. In the presence of a comminuted sacral fracture, aggressive medial dissection would be required and would place the L5 nerve root at risk.
Simpson et al describe their initial results with open reduction and internal fixation of the SI joint via an anterior exposure in a series of 16 patients. They note that sacral alar comminution is a contraindication to the anterior approach
Jones provides an overview of the operative treatment of posterior pelvic ring injuries. He demonstrates reduction and fixation techniques via both anterior and posterior exposures.
Incorrect Answers:

Question 40

Consider the theoretic articulation shown in Figure 11 as femoral and tibial components of a total knee prosthesis in which the components fit like a “roller in trough.” Which of the following best describes the articulation?

Explanation

DISCUSSION: The theoretic total knee components will resist anteroposterior motion by making the femoral component “climb the walls” of the tibial component. As drawn, there is no constraint to medial-lateral translation. The cylinder is not rounded on the edges, so varus-valgus motion will impart load from the cylinder to the trough over a small area, thus having a high contact stress.
REFERENCE: Alicea J: Scoring systems and their validation for the arthritic knee, in Insall JN, Scott WN (eds): Surgery of the Knee, ed 3. Philadelphia, PA, Churchill Livingstone, 2001, vol 2, pp 1507-1515.

Question 41

A 70-year-old man underwent primary total knee arthroplasty 3 months ago. Figures 7a and 7b show the radiograph and clinical photograph following incision and drainage of the wound 1 week ago. Aspiration of the joint reveals methicillin-sensitive Staphylococcus aureus. What is the next most appropriate step in management?

Explanation

DISCUSSION: The overriding factor determining treatment in this case is the appearance of the surgical wound. Based on MacPhearson’s work, this “C” wound is best managed with two-stage exchange. The functional outcome is markedly diminished following a knee arthrodesis compared to revision knee arthroplasty.
REFERENCES: Harwin SF: The diagnosis and management of infected total knee replacement. Seminars Arthroplasty 2002;13:9-22.
Goldmann RT, Scuderi GR, Insall JN: 2-stage reimplantation for infected total knee replacement. Clin Orthop 1996;331:118-124.
Morrey BF, Westholm F, Schoifet S, Rand JA, Bryan RS: Long-term results of various treatment options for an infected total knee arthroplasty. Clin Orthop 1989;248:120-128.

Question 42

A 70-year-old woman has a preoperative anterior interscalene block prior to undergoing a total shoulder arthroplasty. After seating her in the beach chair position, she becomes acutely hypotensive. What is the most likely cause for the hypotension?

Explanation

DISCUSSION: The beach chair position may cause sudden hypotension and bradycardia as a result of the Bezold-Jarisch reflex. This reflex occurs when venous pooling and increased sympathetic tone induce a low-volume, hypercontractile ventricle, resulting in activation of the parasympathetic nervous system and sympathetic withdrawal. The reported incidence of this phenomenon associated with the sitting position is between 13% to 24%. Left untreated, the result may be cardiac arrest. Pneumothorax or central nervous system toxicity after interscalene block is rare and has an incidence of less than 0.2%. Laryngeal nerve block associated with interscalene nerve block can occur but usually results in hoarseness secondary to ipsilateral vocal cord palsy.
REFERENCES: Long T, Wass C, Burkle C: Perioperative interscalene blockade: An overview of its history and current clinical use. J Clin Anesthesia 2002;14:546-556.
Norris T (ed): Orthopaedic Knowledge Update: Shoulder and Elbow 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 433-442.

Question 43

An injury to the axillary nerve would result in deltoid muscle weakness. 5 . An injury to the thoracodorsal nerve would result in latissimus dorsi weakness and would not cause scapular winging.

Explanation

A 14-year-old elite basketball player develops acute medial elbow pain after a fall. Physical examination reveals medial elbow tenderness over the submlime tubercle, but full range of motion. The provocative tests seen in Figure A exacerbate his elbow pain. Radiographs of the elbow are normal. What would be the next best step in treatment?

Supervised elbow stretching program Therapeutic elbow arthroscopy

Static elbow external fixation for 3 to 6 weeks, then MR arthrography if pain continues Activity avoidance for 6 weeks

Serial inflammatory markers and rheumatology referral
Figure A shows a moving valgus stress, which is a provocative test for ulnar collateral ligament (UCL) injury and elbow valgus instability. The initial treatment would be a short period of immobilization, rest and flexor pronator strengthening in this patient population.
Adolescent UCL injuries can be effectively treated with a short period of rest and NSAIDs to control pain. As the acute inflammation resolves, the patient can be started on a supervised therapy program. This should target flexor pronator muscles, as they are important secondary dynamic stabilizers of valgus stress. Once symptoms have improved and the athlete has regained full range of motion and strength, a mediated throwing program may be initiated. Throwing athletes should be educated to avoid provocative activities during this period.
Chen et al. wrote a JAAOS article on shoulder and elbow injuries in the skeletally immature athlete. They state that surgery is reserved for older athletes with persistent valgus instability despite > 6 months of non-surgical management.
Murthi et al. reviewed recurrent elbow instability. They state the anterior bundle of the medial ulnar collateral ligament complex is the primary valgus stabilizer of the elbow. The anterior band is taut for the first 60° of elbow flexion, and the posterior band is taut from 60° to 120° of flexion. The secondary valgus stabilizers of the elbow joint include the radial head, the anterior and posterior aspects of the capsule, and the muscular forces around the joint.
Figure A is showing a moving valgus stress. Illustration A shows provocative tests for valgus instability of the elbow. The image on the left shows a valgus stress test. This assesses the anterior bundle of the medial ulnar collateral ligament complex by flexing the elbow to 25-30 degrees and applying a valgus load across the elbow. The image on the right shows milking maneuver. This assesses the posterior bundle of the medial ulnar collateral ligament complex by pulling on the

beyond 90°. Incorrect Answers:

A young, healthy male undergoes a distal biceps repair and sustains an iatrogenic nerve injury during the procedure. Which of the following clinical findings are most likely to be seen in this circumstance? Inability to extend the thumb

Lateral volar forearm numbness Inability to flex the middle finger Medial volar forearm numbness Dorsal thumb numbness
The most commonly injured nerve during a distal biceps repair is the lateral antebrachial cutaneous nerve (LABCN). Injury to this nerve would result in lateral volar forearm numbness.
Distal biceps avulsions can be partial or complete. Indications for surgical management include young, healthy patients who do not wish to sacrifice function, as well as partial biceps avulsions that do not respond to conservative management. Repair of a distal biceps avulsion can be approached through either an anterior one-incision technique or a two-incision technique (BoydAnderson). The one-incision technique uses the interval between the brachioradialis (radial nerve) and pronator teres (median nerve), while the two-incision technique uses this same interval in addition to a second posterolateral elbow incision. The lateral antebrachial cutaneous nerve is the most common nerve injured during either approach.
Kelly et al. retrospectively reviewed 74 distal biceps tendon repairs, and found five sensory nerve paresthesias. The lateral antebrachial cutaneous nerve was most commonly injured, followed by the superficial radial nerve.
Cain et al. retrospectively reviewed 198 distal biceps tendon repairs, and found a 36% complication rate. Lateral antebrachial cutaneous nerve paresthesias were found in 26%, while radial sensory nerve paresthesias were found in 6%, and posterior interosseous nerve (PIN) injury in 4%.
Illustration A shows the close relationship between the lateral antebrachial cutaneous nerve (LABCN) and the distal biceps. Illustration B shows the sensory nerves of the upper extremity and their respective areas of innervation.
Incorrect Answers:

A 33-year-old female presents with left shoulder weakness. Two weeks prior to presentation, the patient experienced sudden-onset, left shoulder pain, which occurred a few days after receiving the influenza vaccine. The pain subsided over the next day, followed by gradual weakness of her shoulder and eventual general disuse of her left upper extremity. An initial visit to her primary care provider resulted in the recommendation of observation. On physical exam, there is weakness and gross atrophy of the shoulder girdle. Figures A & exhibit T2-weighted MRI images of her left shoulder. To further confirm her suspected diagnosis, she is sent for electromyography.
What is the expected result?

Normal results
Fibrillation potentials consistent with compression at the spinoglenoid notch 3 . Sharp waves and fibrillations potentials associated with the deltoid and biceps

Acute denervation of both peripheral nerve and nerve root distribution with sharp waves and fibrillation potentials

Early reinnervation with polyphasic motor unit potentials
This patient has Parsonage-Turner Syndrome, which, when tested on EMG during the first 3 weeks, exhibits acute denervation of both peripheral nerve and nerve root distributions with positive sharp waves and fibrillation potentials.
Parsonage-Turner Syndrome is an idiopathic disorder with an etiology that is still unknown. Typical antecedent events can involve a viral illness, recent immunization, or elective surgery. Clinical presentation is usually initiated by acute onset shoulder pain, which quickly subsides and is followed by gradual weakness. Early MRI exhibits edema in the effected muscles, and fatty infiltration in later stages. Treatment is typically non-operative, and resolution can be seen as early as 6 weeks from onset.
Tjoumakaris et al. provide a thorough review of the diagnosis and management of ParsonageTurner Syndrome. The authors report the usefulness of MRI, which exhibits early edema and later fatty infiltration in the affected muscles, and urge the use of EMG as a confirmatory diagnostic measure as well as a monitoring tool to track resolution. Early identification and diagnosis may be treated with a short course of steroids, which may help shorten symptoms.
Stutz et al. concisely summarize Parsonage-Turner Syndrome and provide typical presentation, diagnosis and management principles. The authors note the common association with viral illness and/or recent immunization along with the importance of obtaining a baseline chest radiograph to rule out a compressive Pancoast tumor. Management is typically supportive with eventual resolution.
Figures A, B, and C are T2-weighted coronal, sagittal, and axial cuts of the shoulder girdle with associated edema in the supraspinatus and infraspinatus typically seen in Parsonage-Turner Syndrome.
Incorrect answers:
A total shoulder arthroplasty (TSA) would be the most appropriate treatment in which of the following arthritic patients?

Question 44

What is the most common cause for late revision (> 2 years post op) total knee arthroplasty?

Explanation

DISCUSSION: There are multiple causes for failure of total knee arthroplasty, and more than one may exist at the same time. Sharkey and associates reviewed a series of revision total knee arthroplasties, and found that polyethylene failure was the most common cause of failure followed closely by component loosening. The most common cause of early failure (< 2 years post op) was infection. Instability and malalignment are both complications of surgical technique, and if these categories are combined, they would be the most common cause of all total knee failures.
REFERENCE: Sharkey PF, Hozack WJ, Rothman RH, et al: Insall Award paper: Why are total knee arthroplasties failing today? Clin Orthop Relat Res 2002;404:7-13.

Question 45

One of the serious potential complications of repair of distal biceps tendon ruptures is limited pronation and supination as a result of synostosis. What surgical approach and technique presents the highest risk for development of this complication?

Explanation

DISCUSSION: The risk of synostosis is imminent with any technique for repairing a distal biceps tendon rupture. However, the risk is quite low for all approaches that avoid exposure of the ulna, including the muscle-splitting two-incision technique.
REFERENCE: Norris TR: Orthopaedic Knowledge Update: Shoulder and Elbow. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, p 342.

Question 46

Figures 52a and 52b show the radiographs of a left proximal femoral lesion noted serendipitously following minor trauma to the left hip. The patient has no thigh pain and is fully active without limitation. What is the most likely diagnosis of this bony lesion?

Explanation

DISCUSSION: The radiographs reveal a geographic lesion of the proximal femur with the classic “ground glass” appearance noted in fibrous dysplasia. This intramedullary lesion is modestly expansile, demonstrates some minimal cortical thinning, and has no aggressive features. Chondroblastoma, giant cell tumor, and osteoblastoma are more lytic in appearance, and the location is not typical for giant cell tumor or chondroblastoma. While enchondroma may be considered, the uniform ground glass appearance, lack of punctuate mineralization, and distinct margination of the lesion make that diagnosis less likely.
REFERENCE: Parsons TW: Benign bone tumors, in Fitzgerald R Jr, Kaufer H, Malkani A (eds): Orthopaedics. Philadelphia, PA, Mosby International, 2002, pp 1027-1035.

Question 47

Figure 29a shows the clinical photograph of a 26-year-old woman who has had the leg deformity since birth. She reports difficulty with walking and weight bearing and notes increased discomfort and swelling when the leg is dependent. She denies any history of trauma or family history of a similar disorder. Examination reveals a fixed equinovarus deformity of the foot but no evidence of a limb-length discrepancy. No other cutaneous findings or soft-tissue masses are noted. Sagittal and axial T1- and T2-weighted MRI scans are shown in Figures 29b and 29c. What is the most likely diagnosis?

Explanation

DISCUSSION: Because the MRI scans show marked dilation and proliferation of lymphatic channels that completely involve all the leg muscles and the clinical photograph shows the severe swelling associated with this disease, the most likely diagnosis is lymphangiomatosis. Poliomyelitis affects the anterior horn cells and manifests as muscle atrophy. Neurofibromatosis can have a similar clinical appearance but usually is associated with other systemic and cutaneous findings. Congenital band syndrome results in amputated or shortened extremities. Chronic venous stasis disease usually is not associated with joint contractures, and typically it affects older individuals. Surgical excision is the only known treatment; this patient underwent an above-knee amputation.
REFERENCES: Berquist TH (ed): MRI of the Musculoskeletal System, ed 3. Philadelphia, PA, Lippincott Raven, 1997, p 771.
Enzinger FM, Weiss SW: Soft Tissue Tumors, ed 3. St. Louis, MO, Mosby Year Book, 1995, p 688.

Question 48

An 11-year-old girl is struck in the leg by a loaded sled while sledding and is seen in the emergency department; she is reporting severe knee pain. Radiographs are read as normal. Examination reveals that she is exquisitely tender over the proximal tibial physis. The neurovascular examination is normal. What is the next step in management? Review Topic

Explanation

The anatomic lesion in this patient is not exactly defined, but she has most likely sustained an injury about the knee. A Salter-Harris type I proximal tibial physeal fracture is likely. The normal radiograph reading can be misleading because these injuries may displace and spontaneously reduce. The child is at risk of compartment syndrome although she is currently not displaying signs of it. Thus, even though this injury may seem trivial by radiographic findings, it should be treated like a knee dislocation with a risk of late developing compartment syndrome. MRI or CT may be necessary to define the injury. She does not require emergent treatment, but merits close observation for possible compartment syndrome. Any of the possible injuries about the knee can be unstable and require internal fixation after reduction.

Question 49

What is the most common fracture associated with a lateral subtalar dislocation?

Explanation

DISCUSSION: The most common tarsal fracture associated with lateral dislocations is the cuboid, although the anterior process of the calcaneus and the lateral process of the talus can also be affected. In medial dislocations, the dorsomedial talar head, the posterior tubercles of the talus, and the lateral navicular are most often fractured.
Post-reduction x-rays need to be scrutinized carefully for fractures of the tarsal bones as this is the most common injury associated with subtalar dislocations. Occult fractures of the lateral process of the talus are also associated with these injuries.
The referenced study by Wagner et al noted radiographic subtalar DJD in 2/3 of their patients, but noted no correlation between radiographic and clinical outcomes. The referenced study by Bibbo et al noted an 88% incidence of other concurrent injuries and an 89% rate of radiographic DJD at 5 year follow-up. The referenced article by Saltzman et al is a review of hindfoot dislocations.

Question 50

In performing an opening wedge high tibial osteotomy at the tibial tubercle, the osteotome extends 5 mm posteriorly and centrally out of the bone as shown in Figures 17a and 17b. What is the first structure it enters?

Explanation

DISCUSSION: The major risk of performing a high tibial osteotomy is neurovascular injury. The new version of the high tibial osteotomy makes a transverse osteotomy at the level of the tibial tubercle. The osteotome is protected by the oblique belly of the popliteus muscle. The popliteal artery and vein and tibial nerve all lie posterior to the muscle. The soleus muscle originates below this level.
REFERENCES: Clement CD: Anatomy: A Regional Atlas of Human Anatomy, ed 3.

Baltimore, MD, Munich, Germany, Urban and Schwarzberg, 1987, Figure 422.
Netter FH: Atlas of Human Anatomy. Summit, NJ, Ciba-Geigy, 1989, plate 480.

Question 51

-What is the most likely cause of an acute femur fracture in a 5-month-old child?

Explanation

Question 52

A 45-year-old right hand dominant female sustains a left shoulder injury after falling on ice 2 weeks ago. She is brought to the operating room for surgical intervention and positioned upright in a beach chair. Figures A and B are images taken from a posterior viewing portal with a 70 degree arthrosope. Figure C demonstrates the surgically repaired structure. Which of the following physical examination maneuvers would have been most likely abnormal in this patient PREOPERATIVELY? Review Topic

Explanation

The repaired structure is the subscapularis tendon, tested frequently with the Lift-off test.
Figure A as viewed from a posterior portal in the beach chair position of the left shoulder demonstrates a subscapularis tear with Figure B demonstrating medial instability of the long head of the biceps tendon. Figure C shows a repaired subscapularis to its footprint with double loaded screw-in anchors. A biceps tenodesis was concomitantly performed.
The key physical exam findings are positive Belly-press and Lift-off maneuvers, as well as weakness in internal rotation and increased passive external rotation. An MRI would confirm the diagnosis with discontinuity of the subscapularis and long-head of the biceps not located in the bicipital groove.
Faruqui et al present a Level 4 retrospective analysis of 52 patients. They found that the use of the belly press, lift-off, and bear hug tests had a collective sensitivity of 81%.
Yoon et al author a Level 2 prospective evaluation of 312 patients that underwent arthroscopic rotator cuff tear surgery. They investigated the sensitivity and specificity of the lift-off, internal rotation lag sign, belly-press, and bear-hug tests to evaluate subscapularis integrity. They found that a positive lift-off test was specific for the finding a full-thickness subscapularis tear. The lift-off, internal rotation lag sign, belly-press, and bear-hug tests show internal rotation strength deficit.
Figure A depicts an abnormal belly-press examination whereby the wrist flexes, and the elbow will fall posteriorly as the patient recruits the posterior deltoid to compensate for lack of the subscapularis. Illustration B demonstrates a normal belly-press examination. Illustration C shows a normal lift off test.
Incorrect Answers:
1: Jerk Test is positive if there is a 'clunk' or pain with the maneuver and is associated with posterior labral pathology. 2: Wright's test is where the shoulder is passively externally rotated and abducted while the patient turns their neck away from the tested extremity. It is a test for thoracic outlet syndrome. 4: Jobe's test is positive with supraspinatus weakness and or impingement. 5: Hornblower's test is positive if the arm falls into internal rotation. It may represent teres minor pathology.

Question 53

Figures 11a and 11b show the clinical photograph and radiograph of a newborn. Based on these findings, what is the best course of action?

Explanation

DISCUSSION: The newborn has posteromedial bowing of the tibia and calcaneal valgus deformity of the foot. Both are thought to be caused by abnormal intrauterine positioning. The foot deformity typically responds to stretching. The tibial bowing straightens with growth. The long-term problem is limb-length discrepancy.
REFERENCES: Heyman CH, Herndon CH, Heiple KG: Congenital posterior angulation of the tibia with talipes calcaneus. J Bone Joint Surg Am 1959;41:476-488.
Hofmann A, Wenger DR: Posteromedial bowing of the tibia: Progression of discrepancy in leg lengths. J Bone Joint Surg Am 1981;63:384-388.

Question 54

A 34-year-old woman who is a professional skier (Figure 42)

Explanation

Question 55

Figure 1 shows the radiograph of a 71-year-old man who has had increasing pain and weakness in his shoulder for the past 3 years. Nonsurgical management has failed to provide relief. Examination shows 130 degrees of active forward flexion and intact external rotation strength. During surgery, a 1- x 1-cm rotator cuff tear involving the supraspinatus is encountered. Treatment should include

Explanation

DISCUSSION: Given the size of the rotator cuff tear, it is likely to be repaired; therefore, the treatment of choice is a total shoulder replacement with rotator cuff repair. Severe rotator cuff insufficiency can lead to early glenoid failure because of superior instability, and glenoid resurfacing should be avoided in those instances.
REFERENCES: Boyd AD Jr, Thomas WH, Scott RD, Sledge CB, Thornhill TS: Total shoulder arthroplasty versus hemiarthroplasty: Indications for glenoid resurfacing. J Arthroplasty 1990;5:329-336.
Arntz CT, Jackins S, Matsen FA III: Prosthetic replacement of the shoulder for treatment of defects in the rotator cuff and surface of the glenohumeral joint. J Bone Joint Surg Am 1993;75:485-491.

Question 56

A diskectomy is performed in which the disk space is not aggressively debrided. When compared to techniques that involve aggressive debridement of the disk space, this results in

Explanation

DISCUSSION
This patient has disk herniation at the left L5-S1 level. This will generally affect the traversing S1 nerve. The S1 dermatome is on the lateral aspect and sole of the foot.
Surgical treatment generally involves a diskectomy with removal of the herniated fragment. This can be performed via a conventional open approach or minimally invasive endoscopic technique. Several recent meta-analyses have demonstrated equivalent outcomes with regard to leg pain and clinical outcomes. Although minimally invasive techniques have been associated with an increased rate of dural tear, the overall complication rate between the 2 techniques is not significantly different. Several studies have demonstrated a substantial learning curve associated with minimally invasive techniques, and the rate of complications decreases significantly with surgeon experience.
When performing a diskectomy, the herniated fragment alone can be removed (sequestrectomy) or some of the disk that remains in the disk space can be removed (complete diskectomy). Studies have shown no change in surgical time, blood loss, length of stay, or surgical complications when performing a sequestrectomy (compared to a more complete diskectomy). A sequestrectomy is associated with a higher rate of recurrent disk herniation at the surgical level.
RECOMMENDED READINGS
Kamper SJ, Ostelo RW, Rubinstein SM, Nellensteijn JM, Peul WC, Arts MP, van Tulder MW. Minimally invasive surgery for lumbar disc herniation: a systematic review and meta-analysis.
Eur Spine J. 2014 May;23(5):1021-43. doi: 10.1007/s00586-013-3161-2. Epub 2014 Jan 18.
PubMed PMID: 24442183. View Abstract at PubMed
Dasenbrock HH, Juraschek SP, Schultz LR, Witham TF, Sciubba DM, Wolinsky JP, Gokaslan ZL, Bydon A. The efficacy of minimally invasive discectomy compared with open discectomy: a meta-analysis of prospective randomized controlled trials. J Neurosurg Spine. 2012 May;16(5):452-62. doi: 10.3171/2012.1.SPINE11404. Epub 2012 Mar 9. PubMed PMID:

Question 57

A 14-year-old patient with an L3 myelomeningocele underwent anterior and posterior spinal fusion for a curve of 50°. Follow-up examination 1 week after the procedure now reveals persistent drainage from the posterior wound. Results of laboratory cultures show Streptococcus viridans, Staphylococcus aureus, and Enterococcus. In addition to IV antibiotics, surgical irrigation, and debridement, management should include

Explanation

DISCUSSION: The rate of wound infections has dramatically decreased with the routine use of prophylactic antibiotics. Factors known to increase the risk of infection include instrumentation, prolonged surgical time, excessive blood loss, poor perioperative nutritional status, a history of surgery, and a history of infection. The use of allograft does not result in an increased rate of infection. Adequate treatment requires early diagnosis and intervention. Temperature elevation and persistent wound drainage are highly suspicious for infection. An erythrocyte sedimentation rate and a WBC are not useful in diagnosis unless serial examinations show rising levels. Patients should be taken to the operating room where the entire wound can be reopened, irrigated, and debrided. Bone graft can be washed and replaced. Hardware should not be removed. The wound should be closed over suction drains. IV antibiotics should be given for a period of at least 10 days, followed by 6 weeks orally. Leaving the wound open to granulate with dressing changes results in prolonged hospitalization, inadequate treatment of the infection, and a poor cosmetic result.
REFERENCES: Lonstein JE: Complications of treatment, in Bradford DS, Lonstein JE, Moe JH, et al (eds): Moe’s Textbook of Scoliosis and Other Spinal Deformities, ed 2. Philadelphia, Pa, WB Saunders, 1987, p 476.
Beaty JH (ed): Orthopaedic Knowledge Update 6. Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1999, pp 713-721.

Question 58

An otherwise healthy 25-year-old man underwent a right anterior cruciate ligament reconstruction with a bone-patellar tendon-bone allograft. Routine preimplantation cultures of the allograft taken by the surgeon were positive for coagulase-negative Staphylococcus 5 days postoperatively. The patient has exhibited no evidence of clinical infection and his postoperative course has been uncomplicated during this time. What is the ideal management of this patient?

Explanation

The incidence of preimplantation positive cultures of musculoskeletal allografts used for anterior cruciate ligament reconstruction has varied between 4.8% and 13.3%. Interestingly, in none of the studies evaluating this issue did any of the patients
implanted with a "contaminated" graft develop a clinical infection. The results of the current literature suggest that the treatment of low-virulence organisms is unnecessary if no evidence of clinical infection exists. Preimplantation cultures do not appear to correlate with clinical infection. Therefore, the routine culture of allograft tissue is not recommended.

Question 59

A 21-year-old man who underwent repair of a distal biceps tendon rupture using a two-incision approach 4 months ago now reports difficulty gaining rotation of his forearm. Figures 49a and 49b show the AP and lateral radiographs. What is the most likely cause of his problem?

Explanation

DISCUSSION: The radiographs show early ectopic bone formation originating between the ulna and the radius. The development of ectopic bone in this area following a two-incision approach for anatomic repair of the distal biceps tendon is thought to be related to exposure of the periosteum of the lateral ulna during surgery. This can be avoided by the use of a muscle-splitting incision between the extensor carpi ulnaris and common extensor muscles. Full pronation of the forearm allows for the necessary exposure of the radial tuberosity during the procedure and for fixation of the tendon at its maximal length.
REFERENCES: Morrey BF: Tendon injuries about the elbow, in Morrey BF (ed): The Elbow and Its Disorders, ed. 2. Philadelphia, PA, WB Saunders, 1993, pp 492-503.
Failla JM, Amadio PC, Morrey BF, Beckenbaugh RD: Proximal radioulnar synostosis after repair of distal biceps brachii rupture by the two-incision technique: Report of four cases. Clin Orthop 1990;253:133-136.

Question 60

A 10-year-old boy with an L1 myelomeningocele has a low-grade fever and a swollen thigh that is warm to touch and erythematous. AP and lateral radiographs are shown in Figures 24a and 24b. Management should consist of

Explanation

DISCUSSION: Fractures of the long bones are common in patients with myelodysplasia, and the frequency of fracture increases with higher level defects. Fractures also occur following surgery and immobilization secondary to disuse osteoporosis. The response to the fracture (swelling, fever, warmth, erythema) is often confused with infection, osteomyelitis, or cellulitis. Management should consist of a short period of immobilization in a well-padded splint. Long-term casting results in further osteopenia and repeated fractures.
REFERENCES: Lock TR, Aronson DD: Fractures in patients who have myelomeningocele. J Bone Joint Surg Am 1989;71:1153-1157.
Kumar SJ, Cowell HR, Townsend P: Physeal, metaphyseal, and diaphyseal injuries of the lower extremities in children with myelomeningocele. J Pediatr Orthop 1984;4:25-27.

Question 61

below depict the radiographs obtained from a year-old woman who comes to the emergency department after experiencing a fall. She is an unassisted community ambulator with a history of right hip pain. What is the most appropriate surgical treatment for this fracture?

Explanation

DISCUSSION:
This patient has pre-existing right hip osteoarthritis. The most correct option for the treatment of this active patient is a right total hip arthroplasty. Hemiarthroplasty would not address the patient's pain from osteoarthritis, and open reduction and internal fixation would not fix the femoral head issue or the
osteoarthritis.

Question 62

A 13-year-old girl sustained an isolated midshaft left femoral fracture in a motor vehicle accident. The fracture was treated with a rigid, antegrade intramedullary nail placed through the piriformis fossa. The fracture healed uneventfully, as shown in Figure 46a; however, at 12 months postoperatively she now reports left hip pain. A current AP radiograph and MRI scan are shown in Figures 46b and 46c. What complication occurred in this patient? Review Topic

Explanation

The development of femoral head ischemic necrosis is the iatrogenically created complication in this skeletally immature patient. Placement of a rigid, antegrade intramedullary nail through the piriformis fossa is likely to damage the vascular supply to the femoral head as the vessels ascend the femoral neck on the way to the femoral head. The MRI scan reveals ischemic necrosis with early collapse of the femoral head. The joint space is preserved on the MRI scan, ruling out chondrolysis.

Question 63

Familial (Leiden) thrombophilia is of importance in joint arthroplasty because of an abnormality in the clotting cascade. Which of the following statements best describes the condition?

Explanation

Factor V Leiden is a disease caused by an abnormality of factor V in which a single amino acid substitution of glutamine for arginine in the protein C cleavage region leads to decreased inactivation of factor V and thus a greater tendency to form clots. More than half of all individuals with Factor V Leiden will develop deep venous thrombosis in the presence of a single additional risk factor such as long bone fracture or total joint arthroplasty.

Question 64

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

Explanation

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

Question 65

ofhat parameter is most commonly used to estimate the maximum tension a muscle can generating?

Explanation

The mass or volume of a muscle is proportional to its work capacity, and the fiber length of a muscle is proportional to its potential excursion. By dividing the fiber length into the volume of each muscle, the cross-sectional area of the muscle is determined.
The concept of physiologic cross section of a muscle from Weber and Fick, identifies the critical importance of the cross sectional area of all the fibers of a muscle as proportional to maximum tension. (Relationship between muscle size and muscle strength).

Question 66

An active, right-handed 71-year-old woman fell on her left shoulder and sustained the injury shown in the radiographs in 52a and 52b and the CT scan in 52c. Management should consist of

Explanation

Prosthetic hemiarthroplasty is the accepted form of treatment for badly displaced fractures and fracture dislocations, including 4-part fractures, head splitting fractures and fractures with impression defects involving more than 45 % of the humeral head. Displacement is classified as >1cm or angulated > 45 degrees. About 15% of all shoulder fx’s are considered displaced.

Question 67

A 40-year-old man fell 10 feet from a tree and sustained the closed isolated injury shown in Figures 35a and 35b. Management consists of splinting. At his 2-week follow-up visit, he clinically passes the wrinkle test. He agrees to open reduction and internal fixation. What is the best surgical approach to obtain anatomic reduction and limit wound dehiscence?

Explanation

DISCUSSION: The approach to the calcaneus has evolved from several different patterns, driven by a high wound complication rate of 10%. The current extensile lateral approach was described by Zwipp and associates in 1988. The surgical exposure uses an L-shaped incision, with the vertical component positioned one half a finger’s breath anterior to the Achilles tendon and extending distally to the junction of the lateral skin and the plantar skin. Borrelli and Lashgari mapped the angiosome of the lateral calcaneal flap and found that the major arterial blood supply to this flap consisted of three arteries: the lateral calcaneal artery, the lateral malleolar artery, and the lateral tarsal artery. The lateral calcaneal artery appeared to be responsible for most of the blood supply to the corner of the flap. This was found 1.5 cm anterior to the Achilles tendon. Division of this artery with inaccurate placement of the vertical limb of the incision can cause ischemia of the lateral skin flap.
REFERENCES: Borrelli J Jr, Lashgari C: Vascularity of the lateral calcaneal flap: A cadaveric injection study. J Orthop Trauma 1999;13:73-77.
Freeman BJC, Duff S, Allen PE, et al: The extended lateral approach to the hindfoot: An anatomical basis and surgical implications. J Bone Joint Surg Br 1998;80:139-142.
Zwipp H, Tscherne H, Wulker N: Osteosynthesis of dislocated intra-articular calcaneus fractures. Unfallchirurg 1988;91:507-515.

Question 68

A 55-year-old male sustained the injury in Figure A. His injury was complicated by an acute compartment syndrome. He underwent external fixation of his extremity and four compartment fasciotomy. When should the treatment shown in Figure B be performed to minimize the risk of infection?

Explanation

OrthoCash 2020

Question 69

What is the most common cause of mechanical failure of an orthopaedic biomaterial during clinical use?

Explanation

DISCUSSION: In most orthopaedic applications, the materials are strong enough to withstand a single cycle of loading in vivo. However, these loads may be large enough to initiate a small crack in the implant that can grow slowly over thousands or millions of cycles, eventually leading to gross failure. Such fatigue failure has occurred with virtually every type of implant, including stainless steel fracture plates and screws, bone cement in joint arthroplasty, and polyethylene inserts in total knee arthroplasty.
REFERENCES: Lewis G: Fatigue testing and performance of acrylic bone-cement materials: State-of-the-art review. J Biomed Mater Res Br 2003;66:457-486.
Stolk J, Verdonschot N, Huiskes R: Stair climbing is more detrimental to the cement in hip replacement than walking. Clin Orthop 2002;405:294-305.
Wright TM, Maher SA: Biomaterials, 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 70

A 25-year-old man is brought to the emergency department following a motor vehicle accident. Extrication time was 2 hours, and in the field he had a systolic blood pressure by palpation of 90 mm Hg. Intravenous therapy was started, and on arrival in the emergency department he has a systolic blood pressure of 90 mm Hg with a pulse rate of 130. Examination reveals a flail chest and a femoral diaphyseal fracture. Ultrasound of the abdomen is positive. The trauma surgeons take him to the operating room for an exploratory laparotomy. At the conclusion of the procedure, he has a systolic pressure of 100 mm Hg with a pulse rate of 110. Oxygen saturation is 90% on 100% oxygen, and he has a temperature of 95.0° F (35° C). What is the recommended treatment of the femoral fracture at this time?

Explanation

DISCUSSION: This is a “borderline trauma” patient where serious consideration for damage control orthopaedic surgery is required. His prolonged hypotension, abdominal injury, and chest injury put him at higher risk for serious postinjury complications. Further surgery, such as definitive fracture fixation, adds metabolic load and injury to his system. It is prudent to consider femoral fracture stabilization with an external fixator until he is physiologically recovered as evidenced by a normal base excess and/or lactate acid levels, as well as all other parameters of resuscitation. A borderline patient has been described as polytrauma with an ISS > 20 and thoracic trauma (AIS > 2); polytrauma and abdominal/pelvic trauma (Moore > 3) and hemodynamic shock (initial BP < 90 mm Hg); ISS > 40; bilateral lung contusions on radiographs; initial mean pulmonary arterial pressure > 24 mm Hg; pulmonary artery pressure increase during intramedullary nailing > 6 mm Hg. Factors that worsen the situation following surgery include multiple long bones and truncal injury (AIS > 2), estimated surgery time of more than 6 hours, arterial injury and hemodynamic instability, and exaggerated inflammatory response (eg, Il-6 > 800 pg/mL). It is incumbent on the orthopaedic surgeon who is a member of the trauma team to make sure that he or she is aware of these factors and guides the team to the best patient care.
REFERENCES: Pape HC, Hildebrand F, Pertschy S, et al: Changes in the management of femoral shaft fractures in polytrauma patients: From early total care to damage control orthopaedic surgery. J Trauma 2002;53:452-461.
Bosse M, Kellam JF: Orthopaedic decision making in the multiple trauma patient, in Browner BD (ed): Skeletal Trauma, ed 3. Philadelphia, PA, WB Saunders, 2003, pp 133-146.

Question 71

Figure 20 shows the MRI scan of a 20-year-old athlete who has a painful shoulder. This pathology is most commonly seen in

Explanation

DISCUSSION: The MRI scan reveals a posterior labral detachment. This injury is the result of a posteriorly directed force and is common to football players in blocking positions. Although this injury can occur with trauma in all types of athletes, it is seen with relative frequency in football. Treatment is aimed at labral repair with posterior capsulorrhaphy. Both open and arthroscopic techniques can be used.
REFERENCES: Misamore GW, Facibene WA: Posterior capsulorrhaphy for the treatment of traumatic recurrent posterior subluxations of the shoulder in athletes. J Shoulder Elbow Surg 2000;9:403-408.
Mair SD, Zarzour RH, Speer KP: Posterior labral injury in contact athletes. Am J Sports Med 1998;26:753-758.

Question 72

Figure 33 shows the MRI scan of a 55-year-old woman who has had a 6-week history of back and leg pain. Which of the following clinical scenarios is most consistent with the MRI scan findings at L4-L5? Review Topic

Explanation

The MRI scan reveals a L4-L5 foraminal disk herniation originating from the L4-5 disk space that has migrated up into the foramen, compressing the left L4 nerve root. There is normal distribution of the roots in the cerebrospinal fluid, excluding arachnoiditis as a diagnosis, and disk herniation in this location would not result in cauda equina syndrome or myelopathy.

Question 73

A 45-year-old woman awakens with the acute onset of burning left shoulder pain that radiates toward the axilla. She denies any history of trauma. On examination, she is unable to abduct her arm but has full passive shoulder motion. Her sensation is intact. Cervical spine examination reveals full range of motion and a negative Spurling’s test. Radiographs and MRI studies are normal for the cervical spine and shoulder. What is the most likely diagnosis?

Explanation

DISCUSSION: The definition of brachial neuritis or Parsonage-Turner syndrome is a rare disorder of unknown etiology that causes pain or weakness of the shoulder and upper extremity. The loss of active motion excludes cervical C6-7 radiculopathy and impingement. A normal MRI scan and full passive motion exclude a rotator cuff tear and adhesive capsulitis, respectively.
REFERENCES: Misamore GW, Lehman DE: Parsonage-Turner syndrome (acute brachial neuritis). J Bone Joint Surg Am 1996;78:1405-1408.
McCarty EC, Tsairis P, Warren RF: Brachial neuritis. Clin Orthop Relat Res 1999;368:37-43.

Question 74

A 16-year-old female dancer has persistent posterior ankle pain, particularly after a vigorous dancing schedule. Examination reveals tenderness both posteromedially and posterolaterally. MRI scans are seen in Figures 44a and 44b. What is the most likely diagnosis?

Explanation

DISCUSSION: Posterior ankle impingement or os trigonum syndrome is well described in dancers, and it is often associated with flexor hallucis longus tendinitis. High-quality MRI imaging will reveal the inflammation about the os trigonum and flexor hallucis longus tendinitis.
REFERENCES: Mizel MS, Miller RA, Scioli MW (eds): Orthopaedic Knowledge Update: Foot and Ankle 2. Rosemont IL, American Academy of Orthopaedic Surgeons, 1998, pp 315-332.
Hamilton WG, Hamilton LH: Foot and ankle injuries in dancers, in Coughlin MJ, Mann RA (eds): Surgery of the Foot and Ankle, ed 7. St Louis, MO, Mosby, 1999, pp 1225-1256.

Question 75

What is the advantage of percutaneous pedicle screw fixation over open instrumentation and fusion for a thoracolumbar burst fracture without neurologic deficit?

Explanation

DISCUSSION
A prospective randomized study on short-segment treatment of burst fractures with and without fusion demonstrated similar outcomes at 5 years with lower blood loss in the nonfusion group. There is by definition no fusion performed with percutaneous stabilization, so patients often develop hardware failure. Some surgeons routinely remove instrumentation following percutaneous stabilization, thus revision surgery is common. Clinical outcomes are not improved compared to open methods.
RECOMMENDED READINGS
Koreckij T, Park DK, Fischgrund J. Minimally invasive spine surgery in the treatment of thoracolumbar and lumbar spine trauma. Neurosurg Focus. 2014;37(1):E11. doi: 10.3171/2014.5.FOCUS1494. Review. PubMed PMID: 24981899. View Abstract at PubMed Jindal N, Sankhala SS, Bachhal V. The role of fusion in the management of burst fractures of the thoracolumbar spine treated by short segment pedicle screw fixation: a prospective randomised trial. J Bone Joint Surg Br. 2012 Aug;94(8):1101-6. doi: 10.1302/0301-620X.94B8.28311. PubMed PMID: 22844053. View Abstract at PubMed
Dai LY, Jiang LS, Jiang SD. Posterior short-segment fixation with or without fusion for thoracolumbar burst fractures. a five to seven-year prospective randomized study. J Bone
Joint Surg Am. 2009 May;91(5):1033-41. doi: 10.2106/JBJS.H.00510. PubMed PMID:

Question 76

When comparing arthroscopic lavage and knee debridement with placebo in patients with chronic symptomatic osteoarthritis, what outcome has been demonstrated?

Explanation

DISCUSSION:
Excluding a diagnosis of meniscal tear, loose body, or mechanical derangement, treating knee osteoarthritis of indeterminate cause with arthroscopic lavage and debridement has been found to provide no discernable benefit to offset the risk of surgery. The effects of arthroscopy have not been clinically significant in the vast majority of patient-oriented outcomes measures for pain and function at multiple
times between 1 week and 2 years after surgery.

Question 77

Figures 31a and 31b show the radiograph and MRI scan of an otherwise normal 3-month-old infant who has a spinal deformity. MRI reveals no intraspinal anomalies. What is the next step in management? Review Topic

Explanation

Congenital scoliosis in an infant warrants evaluation of the renal, cardiac, and neurologic systems because frequently there is concurrent pathology. Progression in this instance is possible but not certain; therefore, progression must be documented prior to any surgical intervention. Close observation with serial radiographs every 4 to 6 months is appropriate. All of the surgical options listed may be reasonable choices in the future, but cardiac evaluation is the most important issue at this time.

Question 78

A 7-year-old boy has had chronic left leg pain that is worse at night but is not activity related. Use of nonsteroidal anti-inflammatory drugs for the past 6 months has failed to provide relief. A CBC count with differential, erythrocyte sedimentation rate, and C-reactive protein are within normal limits. Radiographs and a CT scan are shown in Figures 31a through 31c. Management should consist of

Explanation

DISCUSSION: Osteoid osteomas are painful bone lesions, with radiographs revealing a dense sclerotic cortex surrounding a small radiolucency or nidus. Symptoms often are worse at night but usually are not activity related. While treatment in the past has consisted of open en bloc excision, current means of removal include percutaneous drilling under CT guidance and percutaneous radiofrequency coagulation. Success rates of percutaneous treatment are comparable to those seen following open procedures. The characteristic radiographic appearance of this lesion usually obviates the need for biopsy. Because the lesion is not caused by pyogenic organisms, antibiotics are not indicated.
REFERENCES: Donahue F, Ahmad A, Mnaymneh W, Pevsner NH: Osteoid osteoma: Computed tomography guided percutaneous excision. Clin Orthop 1999;366:191-196.
Rosenthal DI, Hornicek FJ, Wolfe MW, et al: Percutaneous radiofrequency coagulation of osteoid osteoma compared with operative treatment. J Bone Joint Surg Am 1998;80:815-821.

Question 79

In a patient who has undergone fusion with instrumentation from T4 to the sacrum for adult scoliosis, at which site is a pseudarthrosis most likely to be discovered?

Explanation

DISCUSSION: Although pseudarthrosis can be found anywhere within the spine that has been fused using long multisegmental fixation to the sacrum, it most commonly occurs at the lumbosacral junction. The thoracolumbar junction is another common site of potential pseudarthrosis. In this location, the anatomy changes from lumbar transverse processes to thoracic through the transition zone, and overlying instrumentation often makes it difficult to obtain enough sound bone on decorticated bone to achieve a successful fusion.
REFERENCES: Saer EH III, Winter RB, Lonstein JE: Long scoliosis fusion to the sacrum in adults with nonparalytic scoliosis: An improved method. Spine 1990;15;650-653.
Kostuik JP, Hall BB: Spinal fusions to the sacrum in adults with scoliosis. Spine

1983;8:489-500.
Balderston RA, Winter RB, Moe JH, et al: Fusion to the sacrum for nonparalytic scoliosis in the adult. Spine 1986;11:824-829.

Question 80

The patient is given a blood transfusion. After starting the transfusion, nurses note that her temperature is 38.8°C and she has shaking and chills. What is the most likely cause of this problem?

Explanation

DISCUSSION
Blood management and venous thromboembolism prevention are important considerations in the perioperative management of THA. Recommendations now focus on presurgical optimization of hemoglobin, use of antifibrinolytics intrasurgically, and minimized use of transfusions. Current recommendations do not favor autologous blood donation for patients with hemoglobin levels higher than 13 g/dL. There is a move toward increased use of aspirin for venous thromboembolism prophylaxis, but this modality can cause GI bleeding that may necessitate blood transfusion. Transfusion reactions are rare, and the most common cause is administration of an incompatible unit because of clerical error.

Question 81

An elderly patient falls and sustains an extension injury to the neck that results in upper extremity weakness, spared perianal sensation, and lower extremity spasticity. These findings best describe what syndrome?

Explanation

DISCUSSION: These finding indicate central cord syndrome, and injury that is more common in the older population who have some degree of spondylosis. The physiologic insult can be a central spinal hematoma with resultant hematomyelia. Bowel and bladder functional return has a good prognosis, unlike the upper extremity motor loss. Cauda equina syndrome generally involves injury at the lumbar levels, with some degree of lower extremity motor loss. Posterior cord syndrome is characterized by preservation of motor function below the level of injury and position/vibratory sensory loss. Brown-Sequard syndrome, which is often produced by a penetrating injury, results in contralateral hypalgesia and ipsilateral weakness. Anterior cord syndrome has a poor prognosis for functional return; lower extremity findings include loss of light touch, sharp/dull, and temperature sensations below the level of injury, as well as

motor function.
REFERENCES: Apple DF Jr: Spinal cord injury rehabilitation, in Rothman RH, Simeone FA (eds): The Spine, ed 3. Philadelphia, PA, WB Saunders, 1992, Chapter 31.
Leventhal MR: Fractures, dislocations and fracture-dislocations of spine, in Crenshaw AH (ed): Campbell’s Operative Orthopaedics, ed 8. St. Louis, MO, Mosby, 1992.

Question 82

The most favorable outcomes from release of the tarsal tunnel are in patients who have which of the following findings?

Explanation

DISCUSSION: Numerous causes of tarsal tunnel syndrome have been reported. The most favorable outcomes from release of the tarsal tunnel are in patients who have a space-occupying lesion (eg, ganglion, lipoma, or neurilemoma). While electrodiagnostic studies may be abnormal preoperatively, there is a low correlation between clinical outcome and electromyographic findings. Intrinsic weakness is a late finding in long-standing nerve dysfunction.
REFERENCES: Beskin JL: Nerve entrapment syndromes of the foot and ankle. J Am Acad Orthop Surg 1997;5:261-269.
Mizel MS, Miller RA, Scioli MW (eds): Orthopaedic Knowledge Update: Foot and Ankle 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1998, pp 101-111.

Question 83

From which artery does the princeps pollicis artery branch?

Explanation

DISCUSSION
The princeps pollicis artery can be located on the palmar aspect of the adductor pollicis and emerges into the subcutaneous tissue at the thumb metacarpophalangeal flexion crease. It branches from the radial artery just distal to the location of the deep palmar arch.
RECOMMENDED READINGS
Coleman SS, Anson B: Arterial patterns in the hand based on a study of 650 specimens. Surg Gynec Obstet 1961;4:409-424.
Ames EL, Bissonnette M, Acland R, Lister G, Firrell J. Arterial anatomy of the thumb. 78 J Hand Surg Br. 1993 Aug;18(4):427-36. PubMed PMID: 8409651. View Abstract at PubMed

Question 84

Flow cytometry of tumors measures the

Explanation

Flow cytometry is a method of quantitating components or structural features of cells primarily by optical means. Ploidy and cell cycle analysis of cancers is the major diagnostic use. Cells are passed single file through a laser beam by continuous flow and several parameters are measured including Cell Diameter, proportional quantity of granular (DNA) within the cell, and using fluorescent probes the total DNA or a specific DNA/mRNA sequence can be counted. In examining tumors the amount of DNA in each cell is important for determining neoplasia.

Question 85

A 17-year-old pitcher reports pain over the medial aspect of the elbow that occurs during the acceleration phase of throwing, and it prevents him from throwing at the velocity needed to be competitive. What structure is most likely injured in this patient? Review Topic

Explanation

The anterior bundle of the ulnar collateral ligament of the elbow is the primary constraint to valgus force of the elbow. In pitchers and in overhead athletes, injury to this portion of the ligament results in valgus instability. Reconstruction of the anterior band of the ulnar collateral ligament is necessary in many elite athletic throwers to allow them to return to this competitive activity.

Question 86

A 10-year-old boy has a painful, swollen knee after falling off his bicycle. Examination reveals no other injuries. Radiographs are shown in Figures 35a and 35b. Initial management of this fracture should consist of

Explanation

DISCUSSION: The radiographs show a minimally displaced fracture of the tibial eminence, which is classified as a McKeever type II injury. In a number of studies, it has been found that most of these fractures will reduce with extension of the knee. This is often made easier with evacuation of the hemarthrosis. The position of knee immobilization is controversial, with some authors preferring full extension and others preferring 20 degrees of flexion. Flexion to 90 degrees will further displace the fragment. If the fragment does not reduce or if the patient has a McKeever type III or IV injury, reduction and internal fixation are required. This can be done with either an open or an arthroscopic procedure. Excision of the fragment is not indicated.
REFERENCES: Meyers MH, McKeever FM: Fractures of the intercondylar eminence of the tibia. J Bone Joint Surg Am 1970;52:1677-1684.
Wiley JJ, Baxter MP: Tibial spine fractures in children. Clin Orthop 1990;255:54-60
Janarv PM, Westblad P, Johansson C, Hirsch G: Long-term follow-up of anterior tibial spine fractures in children. J Pediatr Orthop 1995;15:63-68.
Kuhn JE, Sailer MJ, Sterett WI, Hawkins RJ: Arthroscopic technique for the treatment of tibial spine fractures in the skeletally immature patient. J Ortho Tech 1995;3:7-12.

Question 87

Excision of heterotopic bone about the forearm or elbow can be done with limited recurrence rates as early as which of the following after initial injury?

Explanation

DISCUSSION: Excision of heterotopic bone about the elbow and forearm was classically treated once the bone was mature and no further bone development was occuring (bone scan became negative). However, several studies have shown that earlier removal before this point in time is safe, when done in conjunction with radiation therapy (XRT).
The referenced study by McAuliffe et al is a retrospective review of heterotopic ossification (HO) about the elbow followed by 100 cGY (5 fractions over 1 week) of XRT as early as 3 months post-injury. They were able to achieve an average arc of motion > 100 degrees.
The other referenced study by Beingessner et al is a review of HO excision of the forearm. They found that excision and XRT, followed by 6 weeks of indomethacin, led to an increase of forearm motion from an average of 17 degrees to 136 degrees when the excision was done at 4 months post-injury.

Question 88

Thyroid hormone regulates skeletal growth at the physis by stimulation of

Explanation

DISCUSSION: Children with hypothyroidism have delayed bone age, reduced thickness of the physis, disorganization of the cartilage columns of the physis, and impaired differentiation of proliferating chondrocytes into hypertrophic cells. As a result, these children have severe growth retardation, and slipped capital femoral epiphysis may develop because of mechanical weakening of the physis. Thyroid hormone regulates terminal differentiation of the growth plate chondrocytes, with a resultant increase in type X collagen and alkaline phosphatase. These substances are important factors in matrix mineralization. Insulin-like growth factors and FGF-2 appear to act synergistically to stimulate mitotic activity of the growth plate chondrocytes. TGF-b= and PTHrP stimulate proteoglycan synthesis and mitotic activity of the chondrocytes and inhibit type X collagen and alkaline phosphatase activity.
REFERENCES: Ballock RT: Regulation of skeletal growth and maturation by thyroid hormone, in Buckwalter JA, Ehrlich MG, Sandell LJ, Trippel SB (eds): Skeletal Growth and Development: Clinical Issues and Basic Science Advances. Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1998, pp 301-317.
Rosier RN, O’Keefe RJ, Reynolds PR, Hicks DG, Puzas JE: Expression and function of TGF-b= and PTHrP in the growth plate, in Buckwalter JA, Ehrlich MG, Sandell LJ, Trippel SB (eds): Skeletal Growth and Development: Clinical Issues and Basic Science Advances. Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1998, pp 285-299.
Trippel SB: IGF-I and FGF-2 in growth plate regulation, in Buckwalter JA, Ehrlich MG, Sandell LJ, Trippel SB (eds): Skeletal Growth and Development: Clinical Issues and Basic Science Advances. Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1998, pp 263-283.

Question 89

Figures 27a through 27c show the AP radiograph, MRI scan, and biopsy specimen of an otherwise healthy man who has a painful wrist. Serum chemistry studies are normal. What is the most likely diagnosis?

Explanation

DISCUSSION: The osseous sites most frequently involved by giant cell tumor of bone are the distal femur, proximal tibia, and distal radius with approximately 10% of giant cell tumors involving the distal radius. The goals of treatment are to remove the tumor completely and to preserve maximum function of the extremity.
REFERENCE: Vander Griend RA, Funderburk CH: The treatment of giant-cell tumors of the distal part of the radius. J Bone Joint Surg Am 1993;75:899-908.

Question 90

What mechanism of injury is most likely to cause a fracture of the anteromedial facet of the coronoid?

Explanation

Early range of motion
Hinged elbow brace for 4 weeks
Repair lateral collateral ligament
Remove and upsize implant
Remove and downsize implant
The intraoperative images are consistent with overstuffing of the ulnohumeral joint during a radial head replacement. The most appropriate next step would be removing and downsizing the implant.
Overstuffing the radiohumeral joint by >2.5 mm can significantly alter elbow kinematics. It has also shown to lead to pain and early joint disease. The most sensitive method to assess for overstuffing of the joint is by direct visualisation intraoperatively. This can be performed by visualising the lateral aspect of the ulnohumeral joint when the radial head is resected and comparing this to when the trial radial head is reduced in place. In comparison, radiographic asymmetry of the medial ulnohumeral joint has been shown to be less sensitive. Radiographic findings of incongruity of ulnohumeral joint only occurs when significant overlengthening of the radius occurs.
Frank et al. examined the effect of radial head thickness in seven cadaver specimens. They found that incongruity of the medial ulnohumeral joint would only become apparent radiographically after overlengthening of the radius by >or=6 mm.
Doornberg et al. examined seventeen computed tomography scans of the elbow to investigate the height of the radial head relative to the lateral edge and central ridge of the coronoid process. They found that the radial head was on average only 0.9 mm more proximal than the lateral edge of the coronoid process.
Figure A shows intraoperative radiographs of a patient that has undergone a radial head arthroplasty. There is significant widening of the medial ulnohumeral joint on an AP radiograph as well as widening of the ulnohumeral joint on the lateral radiograph,
Incorrect Answers:

Question 91

Giant cell tumors of bone can occur in many different areas throughout the body. All of the following are common locations for giant cell tumors of bone EXCEPT?

Explanation

What is the most appropriate treatment for a 65-year-old female with a 100-pack-year tobacco history who presents with a new painful lytic lesion in her femoral diaphysis?
Antegrade femoral nailing with reamings sent to pathology for analysis
Antegrade femoral nailing with adjuvant radiotherapy to the lesion 3
. Minimally invasive plating of the femur for stabilization and open cementation of the lesion
Referral to medical oncology for chemo-radiotherapy
Lesion biopsy with further treatment based on the results of the biopsy
New lesions which are not diagnosed by imaging and require surgical intervention need to have an appropriate biopsy with treatment dictated by the results of the biopsy. While this patient has a significant tobacco history, incorrect treatment of this lytic bone lesion could affect both her overall morbidity and mortality. As an example, a lytic high-grade chondrosarcoma may look exactly like a metastatic lesion but requires wide surgical excision, not just stabilization of an impending pathological fracture. Intramedullary nailing of a chondrosarcoma would spread the tumor the entire length of the bone and likely require a major amputation, not a limb salvage operation.
A 14-year-old child is referred to your office for evaluation of a tibia lesion found incidentally after a minor ankle injury. A radiograph of the child's ankle is shown in Figure A. What treatment do you suggest?

Endocrine consultation secondary to associated endocrine abnormalities
Surgical consultation secondary to associated gastrointestional cancers
Short leg cast and non-weight bearing for a minimum of 6 weeks
Open biopsy and tumor staging
Routine followup of tibial lesion
The radiograph is classic for a non-ossifying fibroma given the classic eccentric position, sclerotic margin, and benign appearance. Other than routine followup for the tibial lesion, this child requires no subsequent treatment. Marks and Bauer review the diagnosis, imaging, and treatment of many different fibrous tumors of bone and review the diagnostic imaging criteria specific to each subclass of bony fibrous tumors.
The chromosomal translocation t(X;18)is found in which of the following conditions?
Myxoid liposarcoma
Synovial Sarcoma
Osteosarcoma
Ewing's Sarcoma
Clear cell sarcoma
Synovial sarcoma is a rare soft tissue sarcoma with biphasic features of both spindle cell and epithelial differentiation. Synovial sarcoma is a rare high-grade tumor that spreads along fascial planes and, thus, can be much more widespread than apparent on initial evaluation. Males are more commonly affected than females with a ratio of 1.1:1. Synovial sarcoma is characterized by a specific chromosomal translocation t(X;18)(p11;q11) that is observed in more than 90% of cases. The t(X;18)(p11;q11) translocation fuses the SYT gene from chromosome 18 to either of 2 homologous genes at Xp11, either SSX1 or SSX2. The fusion proteins SYT-SSX1 and SYT-SSX2 function as aberrant transcriptional regulators, resulting in either activation of protooncogenes or inhibition of tumor suppressor genes.
Kawai et al found that SYT-SSX fusion transcripts are a defining diagnostic marker of synovial sarcomas. These fusion transcripts may yield important independent prognostic information and provide important information for different types of treatment.
Incorrect Answers

Question 92

A 44-year-old man sustains the injury shown in Figures 1 through 3. What is the most appropriate treatment?

Explanation

EXPLANATION:
Reduction, either open or closed, with internal fixation (pinning) is the recommended treatment for the majority of these injuries. Closed reduction with pinning is most often performed for acute injuries. Open reduction with pinning is performed for those injuries that cannot be reduced by closed means or those with a delayed presentation. Four cases of successful closed reduction and splinting, all performed upon presentation in the emergency department, have been described by Storken and associates, but the authors note that their review of three prior reports uncovered cases of secondary dislocation, which required surgical stabilization. One of the dislocations occurred 4 months after the reduction. They assert that an indication for primary ORIF is a CMC dislocation associated with major fractures. Primary arthrodesis can be considered in cases with severe intra-articular comminution, but this procedure substantially limits the ability of the hand to increase and decrease the transverse metacarpal arch, which is an important functional movement. It can also lead to osteoarthritis of the triquetrohamate joint. Suspension arthroplasty has been described for old fracture-dislocations of the fifth CMC joint, using a partial slip of the extensor carpi ulnaris.

Question 93

Which of the following characteristics is seen in patients with osteochondritis dissecans of the elbow? Review Topic

Explanation

Osteochondritis dissecans occurs in the older child or adolescent (typically older than age 13 years). It involves the lateral compartment. The etiology is felt to be microtraumatic vascular insufficiency from repetitive rotatory and compressive forces. MRI typically shows separation of cartilage from the capitellum and chondral fissuring. Panner’s disease is usually seen in children younger than age 10 years, involves the entire capitellar ossific nucleus, and resolves typically with no residual deformity or late sequelae. There is no evidence of ligamentous injury.

Question 94

Explanation

Discussion: Medial plateau fracture dislocations are rare. Failure to recognize this pattern can lead to poor patient outcomes secondary to poor surgical decision making. Pathognomonic findings on the anteroposterior radiograph include an intact lateral column (lateral articular surface still in continuity with tibial shaft), centrolateral articular impaction, shortening, and condylar widening. The medial femoral condyle stays with the fractured medial tibial plateau segment.
Initial management of axially unstable tibial plateau fractures with soft tissue swelling should consist of spanning external fixation and closed manipulative realignment. This allows for soft tissue recovery with the knee joint provisionally stabilized in reduced station. It also provides time for pre-operative planning, which is typically empowered via a CT scan with reconstructions. If the pattern was initially misdiagnosed as a more typically bicondylar tibial plateau fracture, the CT scan will clarify the misconception and allow for better surgical decision making.
Supine positioning is preferred for definitive fixation, but surgical approaches vary. Attempting to stabilize a medial partial articular pattern in the supine position from a lateral utility approach is fraught with difficulties. Lateral locked plating is not designed for this indication. The lateral utility approach allows for visualization of the centrolateral impaction and lateral meniscal peripheral capsular avulsion repair, but when used alone leads to biomechanically unsound implant placement. The primary plate should be on the medial side of the tibia rather than the intact lateral column.

Question 95

A 56-year-old woman underwent a total knee arthroplasty 2 years ago and now has pain and swelling. Radiographs of her knee are unremarkable. Her C-reactive protein (CRP) level is 3.0 (reference range [rr], 0.08–3.1 mg/L), and her erythrocyte sedimentation rate (ESR) is 18 mm/h (rr, 0-20 mm/h). Aspiration of the knee reveals a white blood cell (WBC) count of 1200/mm3 with a differential of 30% neutrophils and 70% monocytes. Cultures will not be available for several days, and the patient has not been taking antibiotics. Based on these findings, the most appropriate next step is

Explanation

DISCUSSION
ESR and CRP level are recommended as starting points in the workup for the diagnosis or exclusion of periprosthetic joint infection (PJI). When both the ESR and CRP findings are within defined limits, PJI is unlikely. When both test findings are positive, PJI must be considered and further investigation is warranted. Clinicians need to be aware of other inflammatory conditions such as rheumatoid arthritis that can lead to elevation of inflammatory markers.
A high likelihood of infection is noted when the knee aspirate contains more than 2500 WBCs per high-powered field (HPF) with a differential count exceeding 60% neutrophils. Using these criteria, Mason demonstrated a sensitivity of 98% and a specificity of 95% for infection diagnosis.
For this patient, the inflammatory markers are within normal limits. The aspiration result is below 2500 WBC/HPF with a low percentage of neutrophils. The likelihood of infection is remote, and further nonsurgical treatment should not include antibiotics. There is no indication for surgery based upon the information presented.

Question 96

Which examination finding points toward a brachial plexus injury rather than root avulsion?

Explanation

EXPLANATION:
A brachial plexus injury distal to the root level should leave the rhomboid muscle with intact function. Root avulsions of C5-6 will cause weakness of the rhomboids. The branching of the dorsal scapular nerve is proximal and often spared with upper brachial plexus injuries. Winging and biceps weakness may occur
with either injury, and an ipsilateral fracture does not differentiate an avulsion from a brachial plexus injury.

Question 97

Which of the following findings is most prognostic for the ability of a young child with cerebral palsy to walk? Review Topic

Explanation

Several studies have shown that sitting ability by age 2 years is highly prognostic of walking. Molnar and Gordon reported that children not sitting independently by age 2 years had a poor prognosis for walking. Wu and associates reported that children sitting without support by age 2 years had an odds ratio of 26:1 of walking compared with those unable to sit. This was far higher than the odds ratios for cerebral palsy location, motor dysfunction, crawling, creeping, scooting, or rolling.
(SBQ13PE.27) A 15-year-old male patient presents requesting clearance to perform in the Special Olympics. He has had abnormal facies, has had mental developmental delay and cytogenetic analysis confirmed abnormalities on chromosome 21. Orthopaedically, he has been treated in the past for an elbow dislocation as well as bilateral patellar dislocation. He has already visited his cardiologist and endocrinologist and has been cleared. He has no complaints, denies any pain, difficulties with walking and reports that his training has been going well. What is the next best step? Review Topic
With a normal physical exam, patient can be cleared for participation
MRI bilateral knees and elbow to ensure no ligamentous injury
Referral to a neurologist for clearance
Lateral cervical spine flexion and extension radiographs
AP pelvis radiograph
Ruling-out C1-C2 instability with flexion/extension radiographs is necessary prior to any spine surgery or participation in sports in patients with Down's Syndrome.
Patients with Down's Syndrome typically present with generalized ligamentous laxity and decreased tone. Thus, dislocations (elbow or patella) along with asymptomatic instability in the cervical spine can commonly occur. Imaging analysis is necessary prior to sports participation.
McKay et al. performed a systematic review to summarize all congenital causes of cervical instability. They found in Down's patients, cervical instability due to ligamentous laxity is found mostly at C1-2. They recommend asymptomatic patients
with an ADI <4.5mm can resume unrestricted activities, while asymptomatic patients between 4.5-10mm should not participate in contact sports. With ADI >10mm OR symptoms/cord changes on MRI, surgery is recommended. Symptomatic patients with ADI between 4.5-10mm should be observed with activity restriction.
Dedlow et al. outlines the most recent 2011 update and guidelines for cervical instability in Down's syndrome patients. One of the major highlighted changes is the emphasis placed on radiographic re-examination, regardless of prior clearance. Re-examination should occur prior to participation in sports and/or the onset of new symptoms.
Illustrations A, B and C highlight the C1-2 instability on flexion-extension lateral radiographs. Careful attention can be placed on the relationship of the anterior arch of C1 and the dens (Illustration C). This allows for the measurements of ADI and the space available for the cord (SAC), which is highlighted in Illustration D.
Incorrect answers:

Question 98

A 24-year-old man is involved in a motor vehicle accident at 60 mph. He sustains multiple injuries including an intra-abdominal injury requiring a splenectomy and a closed right femoral shaft fracture. Which variable will best indicate the patient's resuscitation status when deciding whether to proceed with definitive care of the fracture at the conclusion of the laparotomy? Review Topic

Explanation

A metabolic parameter such as the base deficit or lactate level has been shown to better reflect the resuscitation status and survival after trauma. Normalization of hemodynamic parameters does not accurately reflect the resuscitation status and a patient can be in compensated shock (occult tissue hypoperfusion) despite normalization of the heart rate and blood pressure. The use of temporizing measures with delayed definitive fracture treatment has been shown to decrease systemic complications in these patients with occult hypoperfusion.

Question 99

A 38-year-old man reports right upper extremity pain that radiates from his neck to his anterior arm, dorsoradial forearm, and into the index finger. Examination reveals weakness of the biceps muscle group and loss of his brachioradialis reflex on that side. At which level is he most likely to have a right-sided cervical disk protrusion on an MRI scan? Review Topic 1 C4-C5 2 C5-C6 3 C6-C7

Explanation

The patient has a typical right C6 radiculopathy based on his history and physical examination. A posterolateral disk protrusion at the C5-C6 level is mostly likely to cause a C6 radiculopathy because the C6 nerve roots exit just above the C6 pedicle and therefore would be compressed by a right-sided C5-C6 disk protrusion. In contrast to the lumbar spine, far lateral disk protrusions are not typically described in the cervical spine.

Question 100

A 30-year-old patient has acetabular dysplasia and moderate secondary osteoarthrosis. Which of the following studies will best help predict the success of periacetabular osteotomy?

Explanation

DISCUSSION: Improvement in the appearance of the hip joint on functional radiographic evaluation (abduction/adduction views) has been shown to be predictive of outcome following joint preserving surgery. CT and MRI findings have not been shown to be predictive of outcome.
REFERENCE: Murphy S, Deshmukh R: Periacetabular osteotomy: Preoperative radiographic predictors of outcome. Clin Orthop 2002;405:168-174.

Full Question & Answer Text (for Search Engines)

Question 1:

The patient has weakness with elbow flexion and has numbness down the anterior lateral aspect of the forearm.

Options:

Excessive medial placement of coracoid autograft
Excessive lateral placement of coracoid autograft
Excessive inferior dissection during the procedure
Excessive retraction and dissection of the medial portion of the conjoint tendon

Correct Answer: Excessive retraction and dissection of the medial portion of the conjoint tendon

Explanation:

Question 2:

In total hip arthroplasty, increasing the perpendicular distance from the center line of the femur to the center of rotation of the femoral head (femoral offset) results in

Options:

decreased tissue tension
decreased abductor lever arm
decreased joint reaction force
increased body weight over lever arm
increased polyethylene wear rate

Correct Answer: decreased joint reaction force

Explanation:

Question 3:

Which of the following surgical devices employed for stabilization of the sternoclavicular joint is associated with the highest incidence of life-threatening complications?

Options:

Percutaneous pins
Cannulated screws
Cerclage wire
Balser plate
AO locking plate

Correct Answer: Percutaneous pins

Explanation:

DISCUSSION: Numerous reports have documented serious complications including death from migration of intact or broken Kirschner wires or Steinmann pins into hilar structures such as the heart, pulmonary artery, and the aorta.
REFERENCES: Gilot GJ, Wirth MA, Rockwood CA: Injuries to the sternoclavicular joint, in Bucholz RW, Heckman JD, Court-Brown C (eds): Fractures in Adults. Philadelphia, PA, Lippincott, Williams and Wilkins, 2006, vol 2, pp 1373-1374.
Lyons FA, Rockwood CA Jr: Migration of pins used in operations of the shoulder. J Bone Joint Surg Am 1990;72:1262-1267.

Question 4:

Figure 23 shows the radiograph of an elderly man who fell on his right arm. What is the most important determinate of a good outcome following this injury?

Options:

Early open reduction and internal fixation
Initiation of physical therapy and passive motion within 2 weeks of the injury
Fracture involvement of the greater tuberosity
Immobilization with a sling and swathe for 4 weeks
Age of younger than 70 years

Correct Answer: Initiation of physical therapy and passive motion within 2 weeks of the injury

Explanation:

Question 5:

Options:

Local wound care, parenteral antibiotic therapy, metabolic support, and reevaluation in 1 week
Vascular consultation for a bypass operation
Syme ankle disarticulation
Guillotine transtibial amputation
Closed transtibial amputation

Correct Answer: Local wound care, parenteral antibiotic therapy, metabolic support, and reevaluation in 1 week

Explanation:

DISCUSSION: The patient was admitted to the hospital with sepsis. The sepsis has resolved, leaving the patient with a negative nitrogen balance. Now that the patient is stable, metabolic support should be used to optimize his nutrition. If the serum albumin can be increased to 2.5 g/dL, he has an excellent potential to heal an amputation at the Syme ankle disarticulation level; a level that will optimize his functional independence.
REFERENCES: Pinzur MS, Stuck RR, Sage R, et al: Syme ankle disarticulation in patients with diabetes. J Bone Joint Surg Am 2003;85:1667-1672.
Pinzur MS, Smith D, Osterman H: Syme ankle disarticulation in peripheral vascular disease and diabetic foot infection: The one-stage versus two-stage procedure. Foot Ankle Int 1995;16:124-127.

Question 6:

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

Options:

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

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

Explanation:

Question 7:

A 22-year-old patient underwent successful reduction of a posterolateral elbow dislocation. Management should now consist of

Options:

splinting for 5 weeks.
active range-of-motion exercises after 1 to 3 days.
delayed passive stretching at 2 weeks.
open medial collateral ligament reconstruction.
open lateral collateral ligament reconstruction.

Correct Answer: active range-of-motion exercises after 1 to 3 days.

Explanation:

Question 8:

What are the four most common soft-tissue sarcomas to spread via the lymph node system?

Options:

Rhabdomyosarcoma, malignant fibrous histiocytoma, epithelioid sarcoma, clear cell sarcoma
Malignant fibrous histiocytoma, synovial sarcoma, clear cell sarcoma, epithelioid sarcoma
Liposarcoma, rhabdomyosarcoma, synovial sarcoma, clear cell sarcoma
Rhabdomyosarcoma, clear cell sarcoma, epithelioid sarcoma, synovial sarcoma
Liposarcoma, clear cell sarcoma, rhabdomyosarcoma, epithelioid sarcoma

Correct Answer: Rhabdomyosarcoma, clear cell sarcoma, epithelioid sarcoma, synovial sarcoma

Explanation:

DISCUSSION: Soft-tissue sarcomas most frequently metastasize to the lung, but certain histologic types have a predilection for the lymph node system as well. Rhabdomyosarcoma, clear cell sarcoma, epithelioid sarcoma, and synovial sarcoma are four of the most common types to spread in this fashion. Careful evaluation and/or sentinel lymph node biopsy plays a role in disease staging and prognosis.
REFERENCES: Riad S, Griffin AM, Liberman B, et al: Lymph node metastasis in soft-tissue sarcoma in an extremity. Clin Orthop Relat Res 2004;426:129-134.
Blazer DG III, Sabel MS, Sondak VK: Is there a role for sentinel lymph node biopsy in the management of sarcoma? Surg Oncol 2003;12:201-206.

Question 9:

Options:

Continued observation
Cervical epidural injections
Nonsteroidal anti-inflammatory drugs (NSAIDs), activity modification, and physical therapy
Cervical facet blocks
Cervical MRI

Correct Answer: Nonsteroidal anti-inflammatory drugs (NSAIDs), activity modification, and physical therapy

Explanation:

Question 10:

Options:

Recurrent instability
Degenerative joint disease
Shoulder stiffness
Axillary nerve injury

Correct Answer: Shoulder stiffness

Explanation:

Question 11:

- A 19-year-old man sustains a complete spinal cord injury at the C7 level as a result of diving into a lake. He has a blood pressure of 90/50 mm Hg, a pulse of 60/min, and respirations of 20/min. These values most likely signify

Options:

Spinal shock
Neurogenic shock
Hypovolemic shock
Pulmonary embolism
Fat embolus syndrome

Correct Answer: Neurogenic shock

Explanation:

Question 12:

01 (left). What is the most appropriate next step?

Options:

Splint the knee and admit the patient for hourly ankle brachial index monitoring
Emergent vascular surgical exploration
Emergent external fixation and reassessment of perfusion
CT angiography and admit the patient for hourly neurovascular checks
Interventional radiology consult for formal angiography and stenting

Correct Answer: Emergent external fixation and reassessment of perfusion

Explanation:

Question 13:

Options:

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

Correct Answer: spanning external fixation and closed manipulative realignment.

Explanation:

Question 14:

In recurrent posterior shoulder instability, what is the recommended approach to the posterior capsule?

Options:

A teres minor-splitting approach
An infraspinatus-splitting approach
Between the infraspinatus and teres minor
Between the supraspinatus and infraspinatus
In the rotator interval

Correct Answer: An infraspinatus-splitting approach

Explanation:

DISCUSSION: Using an infraspinatus-splitting incision allows for excellent exposure of the posterior capsule and minimizes the risk of injury to the axillary nerve which lies inferior to the teres minor in the quadrilateral space.
REFERENCES: Dreese J, D’Alessandro D: Posterior capsulorrhaphy through infraspinatus split for posterior instability. Tech Shoulder Elbow Surg 2005;6:199-207.
Shaffer BS, Conway J, Jobe FW, et al: Infraspinatus muscle-splitting incision in posterior shoulder surgery: An anatomic and electromyographic study. Am J Sports Med 1994;22:113-120.
Fuchs B, Jost B, Gerber C: Posterior-inferior capsular shift for the treatment of recurrent voluntary posterior subluxation of the shoulder. J Bone Joint Surg Am 2000;82:16-25.

Question 15:

A college basketball player is struck in the eye by a player’s hand while driving to the basket. Fluorescein evaluation reveals the injury shown in Figure 18. Management should consist of

Options:

administration of ophthalmic corticosteroids and antibiotics with application of an eye patch.
evaluation of intact visual fields and pupillary responses prior to a return to play.
consultation with an ophthalmologist prior to emergent repair of the damaged structure.
measurement of ocular pressure and fundoscopic examination in a properly lit examination room.
strict bed rest with the head elevated, minimizing head motion during the healing process.

Correct Answer: administration of ophthalmic corticosteroids and antibiotics with application of an eye patch.

Explanation:

Question 16:

Options:

Conversion to a periarticular 'hybrid' frame
Open reduction and internal fixation with a lateral nonlocking plate
Open reduction and internal fixation with a lateral locking plate
Open reduction and internal fixation with medial and lateral plates
Open reduction and internal fixation with posteromedial and lateral plates

Correct Answer: Open reduction and internal fixation with posteromedial and lateral plates

Explanation:

Question 17:

Options:

humeral head arthroplasty.
observation.
arthroscopic capsular release.
grafting of the humeral head defect.
electrical stimulation.

Correct Answer: observation.

Explanation:

Question 18:

The anterolateral (Watson-Jones) approach to the hip exploits the intermuscular interval between the

Options:

gluteus medius and tensor fascia lata.
gluteus medius and minimus.
gluteus medius and maximus.
gluteus minimus and piriformis.
tensor fascia lata and sartorius.

Correct Answer: gluteus medius and tensor fascia lata.

Explanation:

Question 19:

Options:

Conventional osteosarcoma
Myositis ossificans
Osteochondroma
Parosteal osteosarcoma
Dedifferentiated parosteal osteosarcoma

Correct Answer: Dedifferentiated parosteal osteosarcoma

Explanation:

DISCUSSION: Dedifferentiated parosteal osteosarcoma designates high-grade transformation of conventional low-grade parosteal osteosarcoma. Unlike conventional parosteal osteosarcoma, where wide surgical excision alone is considered adequate treatment, patients with dedifferentiated osteosarcoma are treated with neoadjuvant chemotherapy and wide local resection. Recognition of dedifferentiated areas with angiography can localize the area that should be biopsied and thus render an accurate diagnosis. Percutaneous biopsy of hypervascular areas should prompt the administration of chemotherapy and wide local excision to optimize patient outcome.
REFERENCES: Sheth DS, Yasko AW, Raymond AK, et al: Conventional and dedifferentiated parosteal osteosarcoma: Diagnosis, treatment, and outcome. Cancer 1996;78:2136-2145.
Lewis VO, Gebhardt MC, Springfield DS: Parosteal osteosarcoma of the posterior aspect of the distal part of the femur: Oncological and functional results following a new resection technique. J Bone Joint Surg Am 2000;82:1083-1088.

Question 20:

Options:

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

Correct Answer: vascularized bone graft.

Explanation:

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

Question 21:

Options:

Osteoporosis
Hallux valgus deformity
Hallux rigidus
A relatively long second metatarsal

Correct Answer: A relatively long second metatarsal

Explanation:

Question 22:

Options:

Anterior bundle of the medial collateral ligament (MCL)
Posterior bundle of the MCL
Annular ligament
Triceps insertion
Olecranon osteophytes

Correct Answer: Anterior bundle of the medial collateral ligament (MCL)

Explanation:

Question 23:

Options:

Radiograph-guided steroid injection followed by total hip arthroplasty 6 weeks later
Total hip arthroplasty
Physical therapy
Referral back to her spine surgeon

Correct Answer: Physical therapy

Explanation:

Question 24:

If heel varus corrects with a Coleman block test, then the hindfoot deformity is flexible. This test proves that the varus is due to a

Options:

dorsiflexed first ray.
varus position of the forefoot.
plantar flexed first ray.
valgus hindfoot.
rigid flatfoot.

Correct Answer: plantar flexed first ray.

Explanation:

DISCUSSION: The Coleman block test is used to evaluate the effect of the forefoot on the rearfoot varus. If the deformity corrects with the block, then the hindfoot deformity is flexible and the varus position is secondary to the plantar flexed first ray or valgus position of the forefoot. A rearfoot orthotic will not correct the forefoot cause of the deformity. The patient still may need a lateralizing calcaneal osteotomy to realign the hindfoot.
REFERENCES: Younger AS, Hansen ST Jr: Adult cavovarus foot. J Am Acad Orthop Surg 2005;13:302-315.
Alexander IJ, Johnson KA: Assessment and management of pes cavus in Charcot-Marie-Tooth disease. Clin Orthop Relat Res 1989;246:273-281.

Question 25:

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

Options:

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

Correct Answer: Immunoblot assay

Explanation:

Question 26:

Which of the following structures are found in the anterior tarsal tunnel?

Options:

Extensor hallucis longus, tibialis anterior, extensor digitorum longus, dorsalis pedis artery, deep peroneal nerve
Extensor hallucis longus, tibialis anterior, extensor digitorum longus, dorsalis pedis artery, superficial peroneal nerve
Extensor hallucis longus, tibialis anterior, extensor digitorum longus, dorsalis pedis artery, deep peroneal nerve, superficial peroneal nerve
Extensor hallucis brevis, extensor hallucis longus, extensor digitorum longus, dorsalis pedis artery, deep peroneal nerve
Dorsalis pedis artery, deep peroneal nerve, superficial peroneal nerve

Correct Answer: Extensor hallucis longus, tibialis anterior, extensor digitorum longus, dorsalis pedis artery, deep peroneal nerve

Explanation:

Question 27:

A researcher studies growth factors that have positive effects on cartilage healing. In vivo and in vitro experiments are performed with Growth Factor

Options:

The properties of Growth Factor A include (1) it is the most widely investigated growth factor in cartilage repair, (2) it increases extracellular matrix synthesis in cartilage and mesenchymal stem cells, and (3) it also triggers synovial proliferation and fibrosis. Which of the following is most likely to be Growth Factor A? Review Topic
Interleukin-1 (IL-1)
Tumor necrosis factor-alpha (TNF-alpha)
Fibroblast growth factor (FGF)
Transforming growth factor-beta 1 (TGF-beta1)
Platelet-derived growth factor (PDGF)

Correct Answer: Tumor necrosis factor-alpha (TNF-alpha)

Explanation:

Question 28:

Options:

Diffuse idiopathic skeletal hyperostosis
Ankylosing spondylitis
Ossification of the posterior longitudinal ligament
Rheumatoid arthritis
Degenerative cervical stenosis

Correct Answer: Ossification of the posterior longitudinal ligament

Explanation:

Question 29:

Options:

Bracing
Physiotherapy
Cortisone injection
Conversion to total elbow arthroplasty
Revision interposition arthroplasty

Correct Answer: Conversion to total elbow arthroplasty

Explanation:

DISCUSSION: In a series reported by Blaine and associates, 12 patients were converted from interposition to total elbow arthroplasty. This procedure was successful in 10 out of 12 patients.
REFERENCES: Blaine TA, Adams R, Morrey BF: Total elbow arthroplasty after interposition arthroplasty for elbow arthritis. J Bone Joint Surg Am 2005;87;286-292.
Cheng SL, Morrey FB: Treatment of the mobile, painful arthritic elbow by distraction interposition arthroplasty. J Bone Joint Surg Br 2000;82:233-238.

Question 30:

A subtrochanteric femur fracture in which the lesser trochanter is intact is associated with what deformity?

Options:

Adduction and extension of the proximal fragment
Adduction and flexion of the proximal fragment
Abduction and extension of the proximal fragment
Abduction and flexion of the proximal fragment
Predominantly internal rotation of the proximal fragment

Correct Answer: Abduction and flexion of the proximal fragment

Explanation:

Question 31:

Options:

Removal of the implant alone
Amputation of the hallux
Revision of the implant with a Silastic joint replacement
Arthrodesis of the hallux metatarsophalangeal joint with interposition bone graft
Rocker bottom steel shank shoe with orthosis

Correct Answer: Arthrodesis of the hallux metatarsophalangeal joint with interposition bone graft

Explanation:

Question 32:

Which modality has the broadest application for reduction of postsurgical transfusion?

Options:

Regional anesthesia
Tranexamic (TXA) acid administration
Reduced transfusion trigger
Hypotensive anesthesia

Correct Answer: Tranexamic (TXA) acid administration

Explanation:

Question 33:

Which of the following enzymes is used to resorb bone by mature osteoclasts?

Options:

Alkaline phosphatase
Cathepsin K
Tissue inhibitor of metalloproteinase (TIMP)
Osteonectin
Osteopontin

Correct Answer: Cathepsin K

Explanation:

Question 34:

Options:

Posterior talofibular ligament
Distal tibiofibular syndesmosis
Anterior talofibular ligament
Deltoid ligament
Calcaneofibular ligament

Correct Answer: Deltoid ligament

Explanation:

DISCUSSION: In the presence of a supination external rotation-type fracture of the distal fibula (Weber type B), stability of the ankle is best assessed by performing an external rotation stress AP view of the ankle. This test is used to assess the integrity of the deltoid ligament. The presence of a deltoid ligament rupture results in instability and generally is best managed surgically. The gravity stress test can also be used.
REFERENCES: Egol KA, Amirtharajah M, Tejwani NC, et al: Ankle stress test for predicting the need for surgical fixation of isolated fibular fractures. J Bone Joint Surg Am 2004;86:2393-2398.
McConnell T, Creevy W, Tornetta P III: Stress examination of supination external rotation-type fibular fractures. J Bone Joint Surg Am 2004;86:2171-2178.
Schock HJ, Pinzur M, Manion L, et al: The use of the gravity or manual-stress radiographs in the assessment of supination-external rotation fractures of the ankle. J Bone Joint Surg Br 2007;89:1055-1059.

Question 35:

Thoracic disk herniations are most frequently found in what area of the spine?

Options:

C7-T2
T2-T5
T5-T8
T9-T12
T12-L1

Correct Answer: T9-T12

Explanation:

Question 36:

Options:

closed reduction and casting for 6 weeks.
open reduction and internal fixation, using a locked intramedullary rod.
open reduction and internal fixation, using two cancellous screws.
open reduction and internal fixation, using a locked plate and screws.
open reduction and internal fixation and revision of the femoral component.

Correct Answer: open reduction and internal fixation and revision of the femoral component.

Explanation:

DISCUSSION: The radiographs show a loose femoral component with an associated medial condyle distal femoral fracture. The treatment of choice is open reduction and internal fixation with revision of the femoral component because of the femoral component loosening.
REFERENCES: Moran MC, Brick GW, Sledge CB, et al: Supracondylar femoral fracture following total knee arthroplasty. Clin Orthop 1996;324:196-209.
McLaren AC, DuPont JA, Schroeber DC: Open reduction internal fixation of supracondylar fractures above total knee arthroplasties using the intramedullary supracondylar rod. Clin Orthop 1994;302:194-198.
Figgie MP, Goldberg VM, Figgie HE III, et al: The results of treatment of supracondylar fracture above total knee arthroplasty. J Arthroplasty 1990;5:267-276.

Question 37:

Options:

Retain the components, and implant a tibial strut allograft.
Revise the tibial component with a metaphyseal cone and metaphyseal uncemented stem.
Revise the tibial component with a metaphyseal cone and a press-fit diaphyseal-engaging stem.
Revise the tibial component with a long cemented diaphyseal-engaging stem.

Correct Answer: Revise the tibial component with a metaphyseal cone and a press-fit diaphyseal-engaging stem.

Explanation:

Question 38:

Options:

Relief of symptoms with shoulder abduction (placing hand over the head)
Hypothenar atrophy
Reproduction of pain with hyperflexion and contralateral rotation of the head
Positive Tinel’s sign at the levator scapulae
Subluxable ulnar nerve at the cubital tunnel

Correct Answer: Relief of symptoms with shoulder abduction (placing hand over the head)

Explanation:

Question 39:

Options:

Sacral fracture
Prior laparotomy
Supra-acetabular external fixtator
Parasymphyseal fractures
Ipsilateral proximal femur fracture

Correct Answer: Prior laparotomy

Explanation:

Question 40:

Options:

Constrained to anteroposterior translation, unconstrained to medial-lateral translation, high contact stress on edge (ie, varus-valgus) loading
Constrained to anteroposterior translation, unconstrained to medial-lateral translation, low contact stress on edge (ie, varus-valgus) loading
Unconstrained to anteroposterior translation, constrained to medial-lateral translation, high contact stress on edge (ie, varus-valgus) loading
Unconstrained to anteroposterior translation, constrained to medial-lateral translation, low contact stress on edge (ie, varus-valgus) loading
Constraint is dependent on the status of the posterior cruciate ligament

Correct Answer: Constrained to anteroposterior translation, unconstrained to medial-lateral translation, high contact stress on edge (ie, varus-valgus) loading

Explanation:

Question 41:

Options:

Repeat debridement, followed by 6 weeks of IV antibiotics
Repeat debridement, followed by direct exchange arthroplasty
Delayed exchange reimplantation
Immediate knee arthrodesis
Amputation

Correct Answer: Delayed exchange reimplantation

Explanation:

Question 42:

Options:

Tension pneumothorax
Inadvertent epidural injection
Inadvertent intravascular injection
Laryngeal nerve block
Bezold-Jarisch reflex

Correct Answer: Bezold-Jarisch reflex

Explanation:

Question 43:

An injury to the axillary nerve would result in deltoid muscle weakness. 5 . An injury to the thoracodorsal nerve would result in latissimus dorsi weakness and would not cause scapular winging.

Options:

A 31-year-old right handed pitcher felt a pop in his throwing elbow during a game. He is diagnosed with a rupture to the medial ulnar collateral ligament complex of the elbow. During which phase of the overhead throwing cycle did this pitcher most likely sustain his injury? Wind-up
Early cocking Early acceleration Ball release Follow-through

Correct Answer: A 31-year-old right handed pitcher felt a pop in his throwing elbow during a game. He is diagnosed with a rupture to the medial ulnar collateral ligament complex of the elbow. During which phase of the overhead throwing cycle did this pitcher most likely sustain his injury? Wind-up

Explanation:

The medial ulnar collateral ligament is subjected to the greatest tensile stress during the late cocking/early acceleration phase of throwing.
The medial ulnar collateral ligament, or medial collateral ligament of the elbow, is composed of three bundles: an anterior bundle, a posterior bundle, and a variable
transverse oblique bundle. During late cocking and early acceleration phases of the overhead throw, the medial UCL is subjected to the greatest amount of valgus stress to the elbow. During this phase, the forearm lags behind the upper arm and generates valgus stress while the elbow is primarily dependent on the anterior band of the UCL for stability. This puts the ligament at greatest risk of injury during this phase.
Fleisig et al. examined the kinetics of baseball pitching and the implications on injury mechanisms. They showed that the UCL contributes to 54% of the varus torque that is generated during the early acceleration of throwing. The position of greatest load occurred when the arm was flexed to 95 +/14 degrees with an applied valgus load.
Illustration A shows a diagram of the medial ulnar collateral ligament ligament bundles. Incorrect Answers:
A 14-year-old elite basketball player develops acute medial elbow pain after a fall. Physical examination reveals medial elbow tenderness over the submlime tubercle, but full range of motion. The provocative tests seen in Figure A exacerbate his elbow pain. Radiographs of the elbow are normal. What would be the next best step in treatment?
Supervised elbow stretching program Therapeutic elbow arthroscopy
Static elbow external fixation for 3 to 6 weeks, then MR arthrography if pain continues Activity avoidance for 6 weeks
Serial inflammatory markers and rheumatology referral
Figure A shows a moving valgus stress, which is a provocative test for ulnar collateral ligament (UCL) injury and elbow valgus instability. The initial treatment would be a short period of immobilization, rest and flexor pronator strengthening in this patient population.
Adolescent UCL injuries can be effectively treated with a short period of rest and NSAIDs to control pain. As the acute inflammation resolves, the patient can be started on a supervised therapy program. This should target flexor pronator muscles, as they are important secondary dynamic stabilizers of valgus stress. Once symptoms have improved and the athlete has regained full range of motion and strength, a mediated throwing program may be initiated. Throwing athletes should be educated to avoid provocative activities during this period.
Chen et al. wrote a JAAOS article on shoulder and elbow injuries in the skeletally immature athlete. They state that surgery is reserved for older athletes with persistent valgus instability despite > 6 months of non-surgical management.
Murthi et al. reviewed recurrent elbow instability. They state the anterior bundle of the medial ulnar collateral ligament complex is the primary valgus stabilizer of the elbow. The anterior band is taut for the first 60° of elbow flexion, and the posterior band is taut from 60° to 120° of flexion. The secondary valgus stabilizers of the elbow joint include the radial head, the anterior and posterior aspects of the capsule, and the muscular forces around the joint.
Figure A is showing a moving valgus stress. Illustration A shows provocative tests for valgus instability of the elbow. The image on the left shows a valgus stress test. This assesses the anterior bundle of the medial ulnar collateral ligament complex by flexing the elbow to 25-30 degrees and applying a valgus load across the elbow. The image on the right shows milking maneuver. This assesses the posterior bundle of the medial ulnar collateral ligament complex by pulling on the
beyond 90°. Incorrect Answers:
A young, healthy male undergoes a distal biceps repair and sustains an iatrogenic nerve injury during the procedure. Which of the following clinical findings are most likely to be seen in this circumstance?
Inability to extend the thumb
Lateral volar forearm numbness Inability to flex the middle finger Medial volar forearm numbness Dorsal thumb numbness
The most commonly injured nerve during a distal biceps repair is the lateral antebrachial cutaneous nerve (LABCN). Injury to this nerve would result in lateral volar forearm numbness.
Distal biceps avulsions can be partial or complete. Indications for surgical management include young, healthy patients who do not wish to sacrifice function, as well as partial biceps avulsions that do not respond to conservative management. Repair of a distal biceps avulsion can be approached through either an anterior one-incision technique or a two-incision technique (BoydAnderson). The one-incision technique uses the interval between the brachioradialis (radial nerve) and pronator teres (median nerve), while the two-incision technique uses this same interval in addition to a second posterolateral elbow incision. The lateral antebrachial cutaneous nerve is the most common nerve injured during either approach.
Kelly et al. retrospectively reviewed 74 distal biceps tendon repairs, and found five sensory nerve paresthesias. The lateral antebrachial cutaneous nerve was most commonly injured, followed by the superficial radial nerve.
Cain et al. retrospectively reviewed 198 distal biceps tendon repairs, and found a 36% complication rate. Lateral antebrachial cutaneous nerve paresthesias were found in 26%, while radial sensory nerve paresthesias were found in 6%, and posterior interosseous nerve (PIN) injury in 4%.
Illustration A shows the close relationship between the lateral antebrachial cutaneous nerve (LABCN) and the distal biceps. Illustration B shows the sensory nerves of the upper extremity and their respective areas of innervation.
Incorrect Answers:
A 33-year-old female presents with left shoulder weakness. Two weeks prior to presentation, the patient experienced sudden-onset, left shoulder pain, which occurred a few days after receiving the influenza vaccine. The pain subsided over the next day, followed by gradual weakness of her shoulder and eventual general disuse of her left upper extremity. An initial visit to her primary care provider resulted in the recommendation of observation. On physical exam, there is weakness and gross atrophy of the shoulder girdle. Figures A & exhibit T2-weighted MRI images of her left shoulder. To further confirm her suspected diagnosis, she is sent for electromyography.
What is the expected result?
Normal results
Fibrillation potentials consistent with compression at the spinoglenoid notch 3 . Sharp waves and fibrillations potentials associated with the deltoid and biceps
Acute denervation of both peripheral nerve and nerve root distribution with sharp waves and fibrillation potentials
Early reinnervation with polyphasic motor unit potentials
This patient has Parsonage-Turner Syndrome, which, when tested on EMG during the first 3 weeks, exhibits acute denervation of both peripheral nerve and nerve root distributions with positive sharp waves and fibrillation potentials.
Parsonage-Turner Syndrome is an idiopathic disorder with an etiology that is still unknown. Typical antecedent events can involve a viral illness, recent immunization, or elective surgery. Clinical presentation is usually initiated by acute onset shoulder pain, which quickly subsides and is followed by gradual weakness. Early MRI exhibits edema in the effected muscles, and fatty infiltration in later stages. Treatment is typically non-operative, and resolution can be seen as early as 6 weeks from onset.
Tjoumakaris et al. provide a thorough review of the diagnosis and management of ParsonageTurner Syndrome. The authors report the usefulness of MRI, which exhibits early edema and later fatty infiltration in the affected muscles, and urge the use of EMG as a confirmatory diagnostic measure as well as a monitoring tool to track resolution. Early identification and diagnosis may be treated with a short course of steroids, which may help shorten symptoms.
Stutz et al. concisely summarize Parsonage-Turner Syndrome and provide typical presentation, diagnosis and management principles. The authors note the common association with viral illness and/or recent immunization along with the importance of obtaining a baseline chest radiograph to rule out a compressive Pancoast tumor. Management is typically supportive with eventual resolution.
Figures A, B, and C are T2-weighted coronal, sagittal, and axial cuts of the shoulder girdle with associated edema in the supraspinatus and infraspinatus typically seen in Parsonage-Turner Syndrome.
Incorrect answers:
A total shoulder arthroplasty (TSA) would be the most appropriate treatment in which of the following arthritic patients?

Question 44:

What is the most common cause for late revision (> 2 years post op) total knee arthroplasty?

Options:

Infection
Polyethylene wear
Instability
Patellar complications
Malalignment

Correct Answer: Polyethylene wear

Explanation:

Question 45:

Options:

Single incision, anterior approach with fixation through drill holes in the radius
Single incision, anterior approach with suture anchor fixation to the radius
Single incision, anterior approach through a drill hole in the radius with sutures tied over bolster or button on the posterior forearm
Dual incision, limited anterior and posterior approach along the ulna with attachment through drill holes
Dual incision, limited anterior and posterior muscle-splitting approach (supinator and extensor muscles) with attachment through drill holes

Correct Answer: Dual incision, limited anterior and posterior approach along the ulna with attachment through drill holes

Explanation:

Question 46:

Options:

Chondroblastoma
Enchondroma
Giant cell tumor
Fibrous dysplasia
Osteoblastoma

Correct Answer: Fibrous dysplasia

Explanation:

DISCUSSION: The radiographs reveal a geographic lesion of the proximal femur with the classic “ground glass” appearance noted in fibrous dysplasia. This intramedullary lesion is modestly expansile, demonstrates some minimal cortical thinning, and has no aggressive features. Chondroblastoma, giant cell tumor, and osteoblastoma are more lytic in appearance, and the location is not typical for giant cell tumor or chondroblastoma. While enchondroma may be considered, the uniform ground glass appearance, lack of punctuate mineralization, and distinct margination of the lesion make that diagnosis less likely.
REFERENCE: Parsons TW: Benign bone tumors, in Fitzgerald R Jr, Kaufer H, Malkani A (eds): Orthopaedics. Philadelphia, PA, Mosby International, 2002, pp 1027-1035.

Question 47:

Options:

Poliomyelitis
Neurofibromatosis (von Recklinghausen disease)
Lymphangiomatosis
Congenital band syndrome
Chronic venous stasis disease

Correct Answer: Lymphangiomatosis

Explanation:

Question 48:

Options:

Splinting, admission, and frequent neurovascular checks
Cylinder cast and discharge
Emergent knee arthroscopy
Four-compartment calf fasciotomy
Non-weight-bearing, a knee immobilizer, and follow-up in 1 week

Correct Answer: Splinting, admission, and frequent neurovascular checks

Explanation:

Question 49:

What is the most common fracture associated with a lateral subtalar dislocation?

Options:

Distal fibular fracture
Cuboid fracture
Calcaneus fracture
Talus fracture
Navicular fracture

Correct Answer: Distal fibular fracture

Explanation:

Question 50:

Options:

Popliteal artery
Popliteal vein
Tibial nerve
Popliteus muscle
Soleus muscle

Correct Answer: Popliteus muscle

Explanation:

DISCUSSION: The major risk of performing a high tibial osteotomy is neurovascular injury. The new version of the high tibial osteotomy makes a transverse osteotomy at the level of the tibial tubercle. The osteotome is protected by the oblique belly of the popliteus muscle. The popliteal artery and vein and tibial nerve all lie posterior to the muscle. The soleus muscle originates below this level.
REFERENCES: Clement CD: Anatomy: A Regional Atlas of Human Anatomy, ed 3.
Baltimore, MD, Munich, Germany, Urban and Schwarzberg, 1987, Figure 422.
Netter FH: Atlas of Human Anatomy. Summit, NJ, Ciba-Geigy, 1989, plate 480.

Question 51:

-What is the most likely cause of an acute femur fracture in a 5-month-old child?

Options:

Metabolic bone disease
Birth trauma
Accidental trauma
Nonaccidental trauma (abuse) DISCUSSION-Although femur fractures are common in children, fractures in nonambulatory children carry a very high specificity for abuse. Metabolic bone disease is less commonly a cause of femur fractures. Birth trauma,from which femur fractures have been reported, would have been healed by 5 months of age. Accidental trauma generally does not occur in nonambulatory children. Orthopaedic surgeons, like all physicians, are mandated to report suspected cases of child abuse.

Correct Answer: Nonaccidental trauma (abuse) DISCUSSION-Although femur fractures are common in children, fractures in nonambulatory children carry a very high specificity for abuse. Metabolic bone disease is less commonly a cause of femur fractures. Birth trauma,from which femur fractures have been reported, would have been healed by 5 months of age. Accidental trauma generally does not occur in nonambulatory children. Orthopaedic surgeons, like all physicians, are mandated to report suspected cases of child abuse.

Question 52:

Options:

Jerk Test
Wright's Test
Lift-off test
Jobe's test
Hornblower's test

Correct Answer: Lift-off test

Explanation:

Question 53:

Figures 11a and 11b show the clinical photograph and radiograph of a newborn. Based on these findings, what is the best course of action?

Options:

Genetic testing
Stretching exercises performed by the parents
A series of corrective plaster casts
A long leg orthosis to control the foot and leg
Surgical lengthening of the anterior tibial tendon and a short leg cast

Correct Answer: Stretching exercises performed by the parents

Explanation:

Question 54:

A 34-year-old woman who is a professional skier (Figure 42)

Options:

Ligamentous reconstruction
Meniscal repair
Meniscectomy
Immobilization

Correct Answer: Meniscectomy

Question 55:

Options:

humeral head replacement with rotator cuff repair.
humeral head replacement without rotator cuff repair.
arthrodesis of the shoulder.
total shoulder replacement with rotator cuff repair.
total shoulder replacement without rotator cuff repair.

Correct Answer: total shoulder replacement with rotator cuff repair.

Explanation:

Question 56:

A diskectomy is performed in which the disk space is not aggressively debrided. When compared to techniques that involve aggressive debridement of the disk space, this results in

Options:

less intraoperative blood loss.
an increased rate of recurrent disk herniation.
a shorter length of hospital stay.
a higher rate of surgical complications.

Correct Answer: an increased rate of recurrent disk herniation.

Explanation:

DISCUSSION
This patient has disk herniation at the left L5-S1 level. This will generally affect the traversing S1 nerve. The S1 dermatome is on the lateral aspect and sole of the foot.
Surgical treatment generally involves a diskectomy with removal of the herniated fragment. This can be performed via a conventional open approach or minimally invasive endoscopic technique. Several recent meta-analyses have demonstrated equivalent outcomes with regard to leg pain and clinical outcomes. Although minimally invasive techniques have been associated with an increased rate of dural tear, the overall complication rate between the 2 techniques is not significantly different. Several studies have demonstrated a substantial learning curve associated with minimally invasive techniques, and the rate of complications decreases significantly with surgeon experience.
When performing a diskectomy, the herniated fragment alone can be removed (sequestrectomy) or some of the disk that remains in the disk space can be removed (complete diskectomy). Studies have shown no change in surgical time, blood loss, length of stay, or surgical complications when performing a sequestrectomy (compared to a more complete diskectomy). A sequestrectomy is associated with a higher rate of recurrent disk herniation at the surgical level.
RECOMMENDED READINGS
Kamper SJ, Ostelo RW, Rubinstein SM, Nellensteijn JM, Peul WC, Arts MP, van Tulder MW. Minimally invasive surgery for lumbar disc herniation: a systematic review and meta-analysis.
Eur Spine J. 2014 May;23(5):1021-43. doi: 10.1007/s00586-013-3161-2. Epub 2014 Jan 18.
PubMed PMID: 24442183.
View Abstract at PubMed
Dasenbrock HH, Juraschek SP, Schultz LR, Witham TF, Sciubba DM, Wolinsky JP, Gokaslan ZL, Bydon A. The efficacy of minimally invasive discectomy compared with open discectomy: a meta-analysis of prospective randomized controlled trials. J Neurosurg Spine. 2012 May;16(5):452-62. doi: 10.3171/2012.1.SPINE11404. Epub 2012 Mar 9. PubMed PMID:

Question 57:

Options:

removal of all hardware.
temporary placement of antibiotic beads.
wound closure over drains.
bedside dressing changes.
a RAST test for latex allergy.

Correct Answer: wound closure over drains.

Explanation:

Question 58:

Options:

Observation
Oral antibiotics for 6 weeks
IV antibiotics for 6 weeks
Arthroscopic irrigation and debridement with graft retention
Arthroscopic irrigation and debridement with graft removal

Correct Answer: Observation

Explanation:

Question 59:

Options:

Inadequate physical therapy
Exposure of the periosteum of the lateral ulna during surgery
Inappropriate location of the suture anchor
Fixation of the tendon with the forearm fully pronated
Subluxation of the radial head

Correct Answer: Exposure of the periosteum of the lateral ulna during surgery

Explanation:

Question 60:

Options:

aspiration of the femoral metaphysis.
IV antibiotics.
a biopsy.
immobilization in a well-padded splint for 2 to 3 weeks.
immobilization in a spica cast for 6 weeks.

Correct Answer: immobilization in a well-padded splint for 2 to 3 weeks.

Explanation:

Question 61:

Options:

Cemented unipolar hemiarthroplasty B. Cemented bipolar hemiarthroplasty C. Total hip replacement
Open reduction and internal fixation

Correct Answer: Cemented unipolar hemiarthroplasty B. Cemented bipolar hemiarthroplasty C. Total hip replacement

Explanation:

Question 62:

Options:

Chondrolysis
Ischemic necrosis of the femoral head
Ischemic necrosis of the greater trochanter
Femoral neck fracture
Trochanteric overgrowth

Correct Answer: Ischemic necrosis of the femoral head

Explanation:

Question 63:

Familial (Leiden) thrombophilia is of importance in joint arthroplasty because of an abnormality in the clotting cascade. Which of the following statements best describes the condition?

Options:

It is a disease caused by an abnormality of platelets that leads to increased blood clotting.
It is a disease caused by an abnormality of vascular endothelium that leads to increased blood clotting.
It is a disease caused by an abnormality of hepatic metabolism that leads to decreased production of factor V and decreased blood clotting.
It is a disease caused by an abnormality of factor V that leads to decreased inactivation of factor Va by activated protein C (aPC) and increased blood clotting.
It is a familial, genetic disease that requires placement of a Greenfield filter in all individuals who have the abnormality, prior to surgery.

Correct Answer: It is a disease caused by an abnormality of factor V that leads to decreased inactivation of factor Va by activated protein C (aPC) and increased blood clotting.

Explanation:

Question 64:

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

Options:

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

Correct Answer: Medial femoral chondral defect

Explanation:

Question 65:

ofhat parameter is most commonly used to estimate the maximum tension a muscle can generating?

Options:

Length
Moment arm
Total volume
Physiologic cross-sectional area
Distribution of slow and fast twitch fibers

Correct Answer: Physiologic cross-sectional area

Explanation:

Question 66:

An active, right-handed 71-year-old woman fell on her left shoulder and sustained the injury shown in the radiographs in 52a and 52b and the CT scan in 52c. Management should consist of

Options:

hemiarthroplasty
open reduction and internal fixation
closed reduction and percutaneous pinning
a sling and early pedulum exercises
a sling and swathe for 6 weeks, followed by shoulder rehabilitation

Correct Answer: hemiarthroplasty

Explanation:

Question 67:

Options:

Closed reduction and percutaneous pinning
Open reduction and internal fixation with a lateral approach, extensile right-angled lateral incision, vertical limb 0.5 cm anterior to the Achilles tendon, and horizontal limb at the junction of the lateral skin and the plantar glabrous skin
Open reduction and internal fixation with a lateral approach, extensile right-angled lateral incision, vertical limb 2.0 cm anterior to the Achilles tendon, and horizontal limb 2.0 cm proximal to the line marking the plantar glabrous skin
Sinus tarsi approach
Ollier approach

Correct Answer: Open reduction and internal fixation with a lateral approach, extensile right-angled lateral incision, vertical limb 0.5 cm anterior to the Achilles tendon, and horizontal limb at the junction of the lateral skin and the plantar glabrous skin

Explanation:

Question 68:

Options:

Before fasciotomy closure
At fasciotomy closure
After fasciotomy closure
After 24 hours of antibiotic treatment
Timing of definitive fixation does not alter infection risk Corrent answer: 5 The timing of definitive fixation of tibial plateau fractures in patients with fasciotomies has no impact on infection risk. The incidence of compartment syndrome is high in tibial plateau fractures. In the presence of tense anterior and lateral tibial compartments, combined with pain with passive stretch of involved muscles or unrelenting pain, compartment pressures should be measured and fasciotomies performed when necessary. Schatzker type V and VI fractures are more likely to have this potential complication. Examination of leg compartments should be repeated at regular intervals because compartment syndrome may occur 24 hours or more after injury. Zura et al. performed a study to analyze whether there is an association between infection and the timing of definitive fracture fixation in relation to fasciotomy closure or coverage. They found that no statistical difference in the rate of infection when tibial plateau fractures with four-compartment fasciotomies were treated with open reduction and internal fixation before fasciotomy closure, at fasciotomy closure, or after fasciotomy closure. They conclude that timing of definitive fracture treatment can be determined by the medical condition of the patient. Shah et al. performed a retrospective chart review of all bicondylar tibial plateau fractures that had fixation with two incisions. They reported an infection rate of 13.8% which is lower than historical reports. They concluded that the lower infection rate was due to their treatment algorithm that requires recovery of the soft tissue envelope prior to definitive fixation. Figure A demonstrates a bicondylar tibial plateau fracture. Figure B demonstrates fixation of a tibial plateau fracture through a dual plating technique. Incorrect Answers:

Correct Answer: Before fasciotomy closure

Explanation:

OrthoCash 2020

Question 69:

What is the most common cause of mechanical failure of an orthopaedic biomaterial during clinical use?

Options:

Fatigue
Tension
Compression
Shear
Torsion

Correct Answer: Fatigue

Explanation:

Question 70:

Options:

Reamed intramedullary nail
Unreamed intramedullary nail
Percutaneous plate fixation
Skeletal traction
External fixation

Correct Answer: External fixation

Explanation:

Question 71:

Figure 20 shows the MRI scan of a 20-year-old athlete who has a painful shoulder. This pathology is most commonly seen in

Options:

baseball pitchers.
downhill skiers.
football linemen.
volleyball players.
tennis players.

Correct Answer: football linemen.

Explanation:

Question 72:

Options:

L4 nerve root radiculopathy
L5 nerve root radiculopathy
Associated bowel and bladder dysfunction
Symptoms associated with arachnoiditis
Wide-based gait, left-sided Hoffman’s sign

Correct Answer: L4 nerve root radiculopathy

Explanation:

Question 73:

Options:

Cervical C6-7 radiculopathy
Impingement
Rotator cuff tear
Brachial neuritis
Adhesive capsulitis

Correct Answer: Brachial neuritis

Explanation:

DISCUSSION: The definition of brachial neuritis or Parsonage-Turner syndrome is a rare disorder of unknown etiology that causes pain or weakness of the shoulder and upper extremity. The loss of active motion excludes cervical C6-7 radiculopathy and impingement. A normal MRI scan and full passive motion exclude a rotator cuff tear and adhesive capsulitis, respectively.
REFERENCES: Misamore GW, Lehman DE: Parsonage-Turner syndrome (acute brachial neuritis). J Bone Joint Surg Am 1996;78:1405-1408.
McCarty EC, Tsairis P, Warren RF: Brachial neuritis. Clin Orthop Relat Res 1999;368:37-43.

Question 74:

Options:

Posterior tibial tendinitis
Tarsal tunnel syndrome
Os trigonum impingement syndrome
Insertional tendinitis of the Achilles tendon
Osteochondritis dissecans of the talus

Correct Answer: Os trigonum impingement syndrome

Explanation:

Question 75:

What is the advantage of percutaneous pedicle screw fixation over open instrumentation and fusion for a thoracolumbar burst fracture without neurologic deficit?

Options:

Better clinical outcomes
Less blood loss
Less pseudarthrosis risk
Lower revision surgery rate

Correct Answer: Less blood loss

Explanation:

DISCUSSION
A prospective randomized study on short-segment treatment of burst fractures with and without fusion demonstrated similar outcomes at 5 years with lower blood loss in the nonfusion group. There is by definition no fusion performed with percutaneous stabilization, so patients often develop hardware failure. Some surgeons routinely remove instrumentation following percutaneous stabilization, thus revision surgery is common. Clinical outcomes are not improved compared to open methods.
RECOMMENDED READINGS
Koreckij T, Park DK, Fischgrund J. Minimally invasive spine surgery in the treatment of thoracolumbar and lumbar spine trauma. Neurosurg Focus. 2014;37(1):E11. doi: 10.3171/2014.5.FOCUS1494. Review. PubMed PMID: 24981899.
View Abstract at PubMed
Jindal N, Sankhala SS, Bachhal V. The role of fusion in the management of burst fractures of the thoracolumbar spine treated by short segment pedicle screw fixation: a prospective randomised trial. J Bone Joint Surg Br. 2012 Aug;94(8):1101-6. doi: 10.1302/0301-620X.94B8.28311. PubMed PMID: 22844053.
View Abstract at
PubMed
Dai LY, Jiang LS, Jiang SD. Posterior short-segment fixation with or without fusion for thoracolumbar burst fractures. a five to seven-year prospective randomized study. J Bone
Joint Surg Am. 2009 May;91(5):1033-41. doi: 10.2106/JBJS.H.00510. PubMed PMID:

Question 76:

When comparing arthroscopic lavage and knee debridement with placebo in patients with chronic symptomatic osteoarthritis, what outcome has been demonstrated?

Options:

Reliable and durable pain relief
No significant benefit for chronic osteoarthritis
Up to 75% pain relief for 2 months, then variable response
Three-month measurable pain relief, followed by recurrence

Correct Answer: No significant benefit for chronic osteoarthritis

Explanation:

Question 77:

Options:

Posterior spinal fusion with instrumentation
Anterior-posterior hemiepiphysiodesis
Brace management
Cardiac and renal evaluation
Hemivertebrectomy and fusion

Correct Answer: Cardiac and renal evaluation

Explanation:

Question 78:

Options:

intralesional curettage followed by 6 weeks of parenteral antibiotics.
local curettage and autogenous bone graft.
neoadjuvant chemotherapy followed by surgical resection and additional chemotherapy.
percutaneous radiofrequency coagulation.
closed needle biopsy.

Correct Answer: percutaneous radiofrequency coagulation.

Explanation:

Question 79:

In a patient who has undergone fusion with instrumentation from T4 to the sacrum for adult scoliosis, at which site is a pseudarthrosis most likely to be discovered?

Options:

T4-T5
T7-T8
L2-L3
L4-L5
L5-S1

Correct Answer: L5-S1

Explanation:

DISCUSSION: Although pseudarthrosis can be found anywhere within the spine that has been fused using long multisegmental fixation to the sacrum, it most commonly occurs at the lumbosacral junction. The thoracolumbar junction is another common site of potential pseudarthrosis. In this location, the anatomy changes from lumbar transverse processes to thoracic through the transition zone, and overlying instrumentation often makes it difficult to obtain enough sound bone on decorticated bone to achieve a successful fusion.
REFERENCES: Saer EH III, Winter RB, Lonstein JE: Long scoliosis fusion to the sacrum in adults with nonparalytic scoliosis: An improved method. Spine 1990;15;650-653.
Kostuik JP, Hall BB: Spinal fusions to the sacrum in adults with scoliosis. Spine
1983;8:489-500.
Balderston RA, Winter RB, Moe JH, et al: Fusion to the sacrum for nonparalytic scoliosis in the adult. Spine 1986;11:824-829.

Question 80:

The patient is given a blood transfusion. After starting the transfusion, nurses note that her temperature is 38.8°C and she has shaking and chills. What is the most likely cause of this problem?

Options:

Bacterial contamination of intravenous tubing
Transmission of the hepatitis virus
Reaction to Kidd antigen in transfused blood
Blood transfusion incompatibility

Correct Answer: Blood transfusion incompatibility

Explanation:

Question 81:

Options:

Brown-Sequard
Cauda equina
Anterior cord
Posterior cord
Central cord

Correct Answer: Central cord

Explanation:

DISCUSSION: These finding indicate central cord syndrome, and injury that is more common in the older population who have some degree of spondylosis. The physiologic insult can be a central spinal hematoma with resultant hematomyelia. Bowel and bladder functional return has a good prognosis, unlike the upper extremity motor loss. Cauda equina syndrome generally involves injury at the lumbar levels, with some degree of lower extremity motor loss. Posterior cord syndrome is characterized by preservation of motor function below the level of injury and position/vibratory sensory loss. Brown-Sequard syndrome, which is often produced by a penetrating injury, results in contralateral hypalgesia and ipsilateral weakness. Anterior cord syndrome has a poor prognosis for functional return; lower extremity findings include loss of light touch, sharp/dull, and temperature sensations below the level of injury, as well as
motor function.
REFERENCES: Apple DF Jr: Spinal cord injury rehabilitation, in Rothman RH, Simeone FA (eds): The Spine, ed 3. Philadelphia, PA, WB Saunders, 1992, Chapter 31.
Leventhal MR: Fractures, dislocations and fracture-dislocations of spine, in Crenshaw AH (ed): Campbell’s Operative Orthopaedics, ed 8. St. Louis, MO, Mosby, 1992.

Question 82:

The most favorable outcomes from release of the tarsal tunnel are in patients who have which of the following findings?

Options:

Associated space-occupying lesion
Dorsal midfoot pain
Abnormal preoperative electrodiagnostic studies
Compromised soft-tissue sleeve
Intrinsic weakness and atrophy

Correct Answer: Associated space-occupying lesion

Explanation:

Question 83:

From which artery does the princeps pollicis artery branch?

Options:

Dorsal radial carpal artery
Dorsal ulnar carpal artery
Ulnar artery
Radial artery

Correct Answer: Radial artery

Explanation:

DISCUSSION
The princeps pollicis artery can be located on the palmar aspect of the adductor pollicis and emerges into the subcutaneous tissue at the thumb metacarpophalangeal flexion crease. It branches from the radial artery just distal to the location of the deep palmar arch.
RECOMMENDED READINGS
Coleman SS, Anson B: Arterial patterns in the hand based on a study of 650 specimens. Surg Gynec Obstet 1961;4:409-424.
Ames EL, Bissonnette M, Acland R, Lister G, Firrell J. Arterial anatomy of the thumb.
78
J Hand Surg Br. 1993 Aug;18(4):427-36. PubMed PMID: 8409651.
View Abstract at
PubMed

Question 84:

Flow cytometry of tumors measures the

Options:

Size of cells
Amount of DNA in cells
Nucleus-cytoplasm ratio
Specific DNA sequences
Specific messenger RNA sequences

Correct Answer: Amount of DNA in cells

Explanation:

Question 85:

Options:

Radial collateral ligament
Posterior bundle of the ulnar collateral ligament
Anterior bundle of the ulnar collateral ligament
Flexor carpi ulnaris
Pronation teres

Correct Answer: Anterior bundle of the ulnar collateral ligament

Explanation:

Question 86:

Options:

open reduction and internal fixation.
arthroscopic reduction and internal fixation.
closed reduction following evacuation of the hemarthrosis and casting in extension if reduction is adequate.
closed reduction and casting in 90 degrees of flexion.
excision of the fragment.

Correct Answer: closed reduction following evacuation of the hemarthrosis and casting in extension if reduction is adequate.

Explanation:

Question 87:

Excision of heterotopic bone about the forearm or elbow can be done with limited recurrence rates as early as which of the following after initial injury?

Options:

Once ankylosis of the forearm or elbow occurs
6 weeks
6 months
12 months
18 months

Correct Answer: Once ankylosis of the forearm or elbow occurs

Explanation:

Question 88:

Thyroid hormone regulates skeletal growth at the physis by stimulation of

Options:

proteoglycan and aggrecan synthesis in the zone of proliferation.
fibroblast growth factor (FGF) activity.
transforming growth factor type beta (TGF- b =) and parathyroid hormone-related protein (PTHrP) activity.
chondrocyte proliferation.
chondrocyte hypertrophy, type X collagen synthesis, and alkaline phosphatase activity.

Correct Answer: chondrocyte hypertrophy, type X collagen synthesis, and alkaline phosphatase activity.

Explanation:

DISCUSSION: Children with hypothyroidism have delayed bone age, reduced thickness of the physis, disorganization of the cartilage columns of the physis, and impaired differentiation of proliferating chondrocytes into hypertrophic cells. As a result, these children have severe growth retardation, and slipped capital femoral epiphysis may develop because of mechanical weakening of the physis. Thyroid hormone regulates terminal differentiation of the growth plate chondrocytes, with a resultant increase in type X collagen and alkaline phosphatase. These substances are important factors in matrix mineralization. Insulin-like growth factors and FGF-2 appear to act synergistically to stimulate mitotic activity of the growth plate chondrocytes. TGF-
b
= and PTHrP stimulate proteoglycan synthesis and mitotic activity of the chondrocytes and inhibit type X collagen and alkaline phosphatase activity.
REFERENCES: Ballock RT: Regulation of skeletal growth and maturation by thyroid hormone, in Buckwalter JA, Ehrlich MG, Sandell LJ, Trippel SB (eds): Skeletal Growth and Development: Clinical Issues and Basic Science Advances. Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1998, pp 301-317.
Rosier RN, O’Keefe RJ, Reynolds PR, Hicks DG, Puzas JE: Expression and function of TGF-
b
= and PTHrP in the growth plate, in Buckwalter JA, Ehrlich MG, Sandell LJ, Trippel SB (eds): Skeletal Growth and Development: Clinical Issues and Basic Science Advances. Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1998, pp 285-299.
Trippel SB: IGF-I and FGF-2 in growth plate regulation, in Buckwalter JA, Ehrlich MG, Sandell LJ, Trippel SB (eds): Skeletal Growth and Development: Clinical Issues and Basic Science Advances. Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1998, pp 263-283.

Question 89:

Options:

Aneurysmal bone cyst
Giant cell tumor
Renal cell carcinoma
Osteomyelitis
Brown tumor

Correct Answer: Giant cell tumor

Explanation:

Question 90:

What mechanism of injury is most likely to cause a fracture of the anteromedial facet of the coronoid?

Options:

Extension and axial load
Varus and posteromedial rotation
Valgus and posteromedial rotation
Varus and posterolateral rotation
Valgus and posterolateral rotation

Correct Answer: Extension and axial load

Explanation:

The mechanism of injury in a fracture of the anteromedial facet of the coronoid is typically a varus and posteromedial rotation force on the forearm which is the opposite of a terrible triad injury. First, the lateral collateral ligament is injured and then the medial coronoid is compressed against and then under the medial trochlea.
(SBQ12TR.86) Figure A shows intraoperative radiographs of a 45-year-old patient with a left elbow injury. What would be the next most appropriate step in this patients care?
Early range of motion
Hinged elbow brace for 4 weeks
Repair lateral collateral ligament
Remove and upsize implant
Remove and downsize implant
The intraoperative images are consistent with overstuffing of the ulnohumeral joint during a radial head replacement. The most appropriate next step would be removing and downsizing the implant.
Overstuffing the radiohumeral joint by >2.5 mm can significantly alter elbow kinematics. It has also shown to lead to pain and early joint disease. The most sensitive method to assess for overstuffing of the joint is by direct visualisation intraoperatively. This can be performed by visualising the lateral aspect of the ulnohumeral joint when the radial head is resected and comparing this to when the trial radial head is reduced in place. In comparison, radiographic asymmetry of the medial ulnohumeral joint has been shown to be less sensitive. Radiographic findings of incongruity of ulnohumeral joint only occurs when significant overlengthening of the radius occurs.
Frank et al. examined the effect of radial head thickness in seven cadaver specimens. They found that incongruity of the medial ulnohumeral joint would only become apparent radiographically after overlengthening of the radius by >or=6 mm.
Doornberg et al. examined seventeen computed tomography scans of the elbow to investigate the height of the radial head relative to the lateral edge and central ridge of the coronoid process. They found that the radial head was on average only 0.9 mm more proximal than the lateral edge of the coronoid process.
Figure A shows intraoperative radiographs of a patient that has undergone a radial head arthroplasty. There is significant widening of the medial ulnohumeral joint on an AP radiograph as well as widening of the ulnohumeral joint on the lateral radiograph,
Incorrect Answers:

Question 91:

Giant cell tumors of bone can occur in many different areas throughout the body. All of the following are common locations for giant cell tumors of bone EXCEPT?

Options:

Sacrum
Distal radius
Tibial diaphysis
Distal femur
Phalanges of the hand

Correct Answer: Phalanges of the hand

Explanation:

Giant cell tumors are common around the knee, distal radius, sacrum and hands. They are not typically found in the diaphysis of bone.
Giant cell tumors are one of the more common tumors in young adults 22-40 years of age. There is much argument as to whether giant cell tumors arise in the metaphysis or the epiphysis, but most authors agree that giant cell tumors are very uncommon in the diaphysis. The most common sites of giant cell tumors in bone, which are the distal radius, sacrum, distal femur, proximal tibia and proximal humerus. Treatment typically involves intralesional curettage with adjuvant treatment (e.g., phenol, hydrogen peroxide, argon beam, etc).
Williams et al undertook a prospective study to evaulate the recurrence rate of giant cell tumors of the hand and they found that soft tissue extension of the tumor significantly increased the rate of local recurrence. This finding is significant because multiple previous studies have demonstrated similar higher recurrence rates for giant cell tumors with soft tissue extension in other areas like around the knee and the distal radius.
Illustration A are radiographs classic for a giant cell tumor showing a large lytic metaphseal-epiphyseal lesion in the distal femur. Illustration B is an axial CT of the distal femur showing the lytic giant cell tumor, abutting and fracturing the subchondral bone. Illustration C is histology classic for a giant cell tumor where the nuclei of the multi-nucleated giant cells look identical to the nuclei of the stromal cells.
Incorrect Answers:
What is the most appropriate treatment for a 65-year-old female with a 100-pack-year tobacco history who presents with a new painful lytic lesion in her femoral diaphysis?
Antegrade femoral nailing with reamings sent to pathology for analysis
Antegrade femoral nailing with adjuvant radiotherapy to the lesion 3
. Minimally invasive plating of the femur for stabilization and open cementation of the lesion
Referral to medical oncology for chemo-radiotherapy
Lesion biopsy with further treatment based on the results of the biopsy
New lesions which are not diagnosed by imaging and require surgical intervention need to have an appropriate biopsy with treatment dictated by the results of the biopsy. While this patient has a significant tobacco history, incorrect treatment of this lytic bone lesion could affect both her overall morbidity and mortality. As an example, a lytic high-grade chondrosarcoma may look exactly like a metastatic lesion but requires wide surgical excision, not just stabilization of an impending pathological fracture. Intramedullary nailing of a chondrosarcoma would spread the tumor the entire length of the bone and likely require a major amputation, not a limb salvage operation.
A 14-year-old child is referred to your office for evaluation of a tibia lesion found incidentally after a minor ankle injury. A radiograph of the child's ankle is shown in Figure A. What treatment do you suggest?
Endocrine consultation secondary to associated endocrine abnormalities
Surgical consultation secondary to associated gastrointestional cancers
Short leg cast and non-weight bearing for a minimum of 6 weeks
Open biopsy and tumor staging
Routine followup of tibial lesion
The radiograph is classic for a non-ossifying fibroma given the classic eccentric position, sclerotic margin, and benign appearance. Other than routine followup for the tibial lesion, this child requires no subsequent treatment. Marks and Bauer review the diagnosis, imaging, and treatment of many different fibrous tumors of bone and review the diagnostic imaging criteria specific to each subclass of bony fibrous tumors.
The chromosomal translocation t(X;18)is found in which of the following conditions?
Myxoid liposarcoma
Synovial Sarcoma
Osteosarcoma
Ewing's Sarcoma
Clear cell sarcoma
Synovial sarcoma is a rare soft tissue sarcoma with biphasic features of both spindle cell and epithelial differentiation. Synovial sarcoma is a rare high-grade tumor that spreads along fascial planes and, thus, can be much more widespread than apparent on initial evaluation. Males are more commonly affected than females with a ratio of 1.1:1. Synovial sarcoma is characterized by a specific chromosomal translocation t(X;18)(p11;q11) that is observed in more than 90% of cases. The t(X;18)(p11;q11) translocation fuses the SYT gene from chromosome 18 to either of 2 homologous genes at Xp11, either SSX1 or SSX2. The fusion proteins SYT-SSX1 and SYT-SSX2 function as aberrant transcriptional regulators, resulting in either activation of protooncogenes or inhibition of tumor suppressor genes.
Kawai et al found that SYT-SSX fusion transcripts are a defining diagnostic marker of synovial sarcomas. These fusion transcripts may yield important independent prognostic information and provide important information for different types of treatment.
Incorrect Answers

Question 92:

A 44-year-old man sustains the injury shown in Figures 1 through 3. What is the most appropriate treatment?

Options:

Reduction and internal fixation
Closed reduction and splinting alone
Carpometacarpal arthrodesis
Carpometacarpal (CMC) joint suspension arthroplasty

Correct Answer: Reduction and internal fixation

Explanation:

Question 93:

Which of the following characteristics is seen in patients with osteochondritis dissecans of the elbow? Review Topic

Options:

MRI reveals separation of cartilage from the capitellum and chondral fissuring
Fragmentation of the entire capitellar ossific nucleus
Normal capitellar regrowth with no late sequelae
Age younger than 10 years
Medial ulnar collateral ligament laxity

Correct Answer: MRI reveals separation of cartilage from the capitellum and chondral fissuring

Explanation:

Question 94:

Options:

posterior partial articular tibial plateau fracture.
lateral split depression tibial plateau fracture.
medial plateau fracture dislocation.
knee dislocation with lateral collateral ligament tear .

Correct Answer: medial plateau fracture dislocation.

Explanation:

Discussion: Medial plateau fracture dislocations are rare. Failure to recognize this pattern can lead to poor patient outcomes secondary to poor surgical decision making. Pathognomonic findings on the anteroposterior radiograph include an intact lateral column (lateral articular surface still in continuity with tibial shaft), centrolateral articular impaction, shortening, and condylar widening. The medial femoral condyle stays with the fractured medial tibial plateau segment.
Initial management of axially unstable tibial plateau fractures with soft tissue swelling should consist of spanning external fixation and closed manipulative realignment. This allows for soft tissue recovery with the knee joint provisionally stabilized in reduced station. It also provides time for pre-operative planning, which is typically empowered via a CT scan with reconstructions. If the pattern was initially misdiagnosed as a more typically bicondylar tibial plateau fracture, the CT scan will clarify the misconception and allow for better surgical decision making.
Supine positioning is preferred for definitive fixation, but surgical approaches vary. Attempting to stabilize a medial partial articular pattern in the supine position from a lateral utility approach is fraught with difficulties. Lateral locked plating is not designed for this indication. The lateral utility approach allows for visualization of the centrolateral impaction and lateral meniscal peripheral capsular avulsion repair, but when used alone leads to biomechanically unsound implant placement. The primary plate should be on the medial side of the tibia rather than the intact lateral column.

Question 95:

Options:

arthrotomy, irrigation, and tibial polyethylene exchange.
parenteral antibiotics.
nonsurgical treatment without antibiotics.
removal of the implant and a 2-stage procedure.

Correct Answer: nonsurgical treatment without antibiotics.

Explanation:

Question 96:

Which examination finding points toward a brachial plexus injury rather than root avulsion?

Options:

Winging of the scapula
Intact rhomboid function
A biceps with 0/5 strength
An ipsilateral clavicle fracture

Correct Answer: Intact rhomboid function

Explanation:

Question 97:

Which of the following findings is most prognostic for the ability of a young child with cerebral palsy to walk? Review Topic

Options:

Ability to sit independently by age 2 years
Ability to creep by age 2 years
Ability to roll by age 2 years
Pattern of cerebral palsy (quadriplegia, diplegia, hemiplegia)
Type of motor dysfunction (spastic, ataxic, dyskinetic, hypotonic)

Correct Answer: Ability to sit independently by age 2 years

Explanation:

Several studies have shown that sitting ability by age 2 years is highly prognostic of walking. Molnar and Gordon reported that children not sitting independently by age 2 years had a poor prognosis for walking. Wu and associates reported that children sitting without support by age 2 years had an odds ratio of 26:1 of walking compared with those unable to sit. This was far higher than the odds ratios for cerebral palsy location, motor dysfunction, crawling, creeping, scooting, or rolling.
(SBQ13PE.27) A 15-year-old male patient presents requesting clearance to perform in the Special Olympics. He has had abnormal facies, has had mental developmental delay and cytogenetic analysis confirmed abnormalities on chromosome 21. Orthopaedically, he has been treated in the past for an elbow dislocation as well as bilateral patellar dislocation. He has already visited his cardiologist and endocrinologist and has been cleared. He has no complaints, denies any pain, difficulties with walking and reports that his training has been going well. What is the next best step?
Review Topic
With a normal physical exam, patient can be cleared for participation
MRI bilateral knees and elbow to ensure no ligamentous injury
Referral to a neurologist for clearance
Lateral cervical spine flexion and extension radiographs
AP pelvis radiograph
Ruling-out C1-C2 instability with flexion/extension radiographs is necessary prior to any spine surgery or participation in sports in patients with Down's Syndrome.
Patients with Down's Syndrome typically present with generalized ligamentous laxity and decreased tone. Thus, dislocations (elbow or patella) along with asymptomatic instability in the cervical spine can commonly occur. Imaging analysis is necessary prior to sports participation.
McKay et al. performed a systematic review to summarize all congenital causes of cervical instability. They found in Down's patients, cervical instability due to ligamentous laxity is found mostly at C1-2. They recommend asymptomatic patients
with an ADI <4.5mm can resume unrestricted activities, while asymptomatic patients between 4.5-10mm should not participate in contact sports. With ADI >10mm OR symptoms/cord changes on MRI, surgery is recommended. Symptomatic patients with ADI between 4.5-10mm should be observed with activity restriction.
Dedlow et al. outlines the most recent 2011 update and guidelines for cervical instability in Down's syndrome patients. One of the major highlighted changes is the emphasis placed on radiographic re-examination, regardless of prior clearance. Re-examination should occur prior to participation in sports and/or the onset of new symptoms.
Illustrations A, B and C highlight the C1-2 instability on flexion-extension lateral radiographs. Careful attention can be placed on the relationship of the anterior arch of C1 and the dens (Illustration C). This allows for the measurements of ADI and the space available for the cord (SAC), which is highlighted in Illustration D.
Incorrect answers:

Question 98:

Options:

Heart rate
Hematocrit
Base deficit
Urine output
Systolic blood pressure

Correct Answer: Base deficit

Explanation:

Question 99:

Options:

C6 vertebral body
Far lateral C6-C7

Correct Answer: Far lateral C6-C7

Explanation:

Question 100:

A 30-year-old patient has acetabular dysplasia and moderate secondary osteoarthrosis. Which of the following studies will best help predict the success of periacetabular osteotomy?

Options:

High-resolution CT with coronal and sagittal reconstructions
Glycosaminoglycan MRI
Functional radiographic or fluoroscopic evaluation
Gadolinium-contrast arthrography with MRI
Routine AP and lateral radiographs

Correct Answer: Functional radiographic or fluoroscopic evaluation

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

OITE & ABOS Orthopedic Board Prep MCQs: Ankle, Elbow & Hip Arthroplasty | Part 172

Key Takeaway

About This Board Review Set

How to Use the Interactive Quiz

Topics Covered in Part 172

Sample Questions from This Set

Why Active MCQ Practice Works

Chapter Index