OITE & ABOS Orthopedic Board Review MCQs | Part 20

About This Board Review Set

This is Part 20 of the comprehensive OITE and AAOS Orthopedic Surgery Board Review series authored by Dr. Mohammed Hutaif, Consultant Orthopedic & Spine Surgeon.

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

How to Use the Interactive Quiz

Two distinct learning modes are available:

Study Mode — After selecting an answer, you immediately see whether you are correct or incorrect, together with a full clinical explanation and literature references.
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Pro Tip: Use keyboard shortcuts A–E to select options, F to flag a question for review, and Enter to jump to the next unanswered question.

Topics Covered in Part 20

This module focuses heavily on: Arthroplasty, Hip, Nerve, Shoulder, Spine, Wrist.

Sample Questions from This Set

Sample Question 1: 03 The sagittal oblique MRI scan shown in Figure 70 reveals a lesion in the shoulder that typically affects what neurologic structure?...

Sample Question 2: A 52-year-old man with a BMI of 40 and primary osteoarthritis undergoes total hip arthroplasty through a posterolateral approach. To retract the femur anteriorly when exposing the acetabulum, the surgeon places a sharp curved retractor over...

Sample Question 3: A 10-year-old girl was thrown over the handlebars of her bicycle and landed directly on her left shoulder. She was treated with a figure-of-8 strap and analgesics. Follow-up examination 2 weeks later reveals that the lateral end of the clav...

Sample Question 4: A 21-year-old man sustains multiple gunshot wounds to his right upper extremity. He can not extend his digits or his thumb but can extend and radially deviate his wrist. An injury to the radial nerve or one of its branches has most likely o...

Sample Question 5: Figure below shows the radiograph obtained from a 68-year-old man who fell 3 weeks after undergoing a successful left primary total hip arthroplasty. He is experiencing a substantial increase in pain and an inability to bear weight. What is...

Why Active MCQ Practice Works

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

Comprehensive 100-Question Exam

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Question 1

03 The sagittal oblique MRI scan shown in Figure 70 reveals a lesion in the shoulder that typically affects what neurologic structure?

Explanation

Ganglion cysts in the shoulder has been reported in the literature and when they occur in the shoulder typically compress the suprascapular nerve at the spinoglenoid notch primarily affecting the infraspinatus muscle, but depending on their size may also affect the supraspinatus motor brances.
The cysts form either because of a lesion of the capsulolabral complex at the superior/posterosuperior glenoid in the shoulder or because of myxoid degeneration of the capsule.
back to this question next question

Question 2

A 52-year-old man with a BMI of 40 and primary osteoarthritis undergoes total hip arthroplasty through a posterolateral approach. To retract the femur anteriorly when exposing the acetabulum, the surgeon places a sharp curved retractor over (anterior to) the anterior inferior iliac spine. Pulsatile bleeding is encountered. A branch of which artery has been injured?

Explanation

DISCUSSION

Video 182 for reference
The femoral artery crosses the hip joint anterior to the anterior hip capsule. The medial femoral circumflex artery enters the joint along the route of the obturator externus. The obturator artery enters the hip joint beneath the transverse acetabular ligament. The iliac circumflex vessel arises superior to the hip joint.

RESPONSES FOR QUESTIONS 183 THROUGH 188
For each clinical scenario described below, identify the corresponding anteroposterior pelvic radiographic image shown above.

Question 3

A 10-year-old girl was thrown over the handlebars of her bicycle and landed directly on her left shoulder. She was treated with a figure-of-8 strap and analgesics. Follow-up examination 2 weeks later reveals that the lateral end of the clavicle is superiorly dislocated relative to the acromion. A radiograph of the shoulder shows calcification lateral to the coracoid process at the level of the acromion, and the clavicle is superiorly displaced. Management should consist of

Explanation

DISCUSSION: In adults, a direct blow on the acromion usually results in an acromioclavicular dislocation. In children, however, the usual injury from this mechanism is a physeal fracture of the lateral clavicle. The clavicular shaft fragment, analogous to the metaphyseal portion of a physeal fracture, herniates through the periosteum, leaving the distal periosteal sleeve in contact with the lateral (distal) physeal fragment. The treatment of choice is immobilization until the patient is pain-free.
REFERENCES: Falstie-Jensen S, Mikkelsen P: Pseudodislocation of the acromioclavicular joint. J Bone Joint Surg Br 1982;64:368-369.
Havranek P: Injuries of the distal clavicular physis in children. J Pediatr Orthop 1989;9:213-215.

Question 4

A 21-year-old man sustains multiple gunshot wounds to his right upper extremity. He can not extend his digits or his thumb but can extend and radially deviate his wrist. An injury to the radial nerve or one of its branches has most likely occurred at which of the following locations?

Explanation

DISCUSSION: In this patient, the radial nerve is most likely injured at the level of the radial neck. The radial nerve emerges from the posterior cord of the brachial plexus and travels along the spiral groove of the humerus. At the level of the lateral humeral condyle, the radial nerve branches into the posterior interosseous nerve after giving off two cutaneous branches, the superficial radial and the posterior cutaneous. The posterior interosseous nerve travels through the supinator muscle and winds around the radial neck. At this level, the posterior interosseous nerve is vulnerable to injury, particularly following fracture or penetrating trauma.
REFERENCES: Netter F: The Ciba Collection of Medical Illustrations: The Musculoskeletal System, Part 1: Anatomy, Physiology and Metabolic Disorders. West Caldwell, NJ, Ciba-Geigy Corporation, 1987, vol 8, p 53.
Hollinshead W: Anatomy for Surgeons: The Back and Limbs, ed 3. Philadelphia, PA, Harper and Row, 1982, vol 3, pp 428-429.

Question 5

Figure below shows the radiograph obtained from a 68-year-old man who fell 3 weeks after undergoing a successful left primary total hip arthroplasty. He is experiencing a substantial increase in pain and an inability to bear weight. What is an appropriate treatment plan?

Explanation

DISCUSSION:
The fracture has occurred around the stem, representing a Vancouver type B fracture, and the stem is clearly loose, making it a type B2 fracture. The appropriate treatment is removal of the loose in situ stem; ORIF of the femur using cerclage wires, cables, or a plate; and insertion of a longer revision stem such as a tapered fluted modular titanium or fully porous coated cylindrical stem to bypass the fracture. All of the other options are incorrect, because they represent inappropriate treatment options for a Vancouver type B2 fracture.

Question 6

A study is designed that examines fractures in children with osteogenesis imperfecta after being treated with bisphosphonates compared with a placebo. A difference is found for which the P value is greater than what is considered to be statistically significant. What is the next appropriate statistical analysis?

Explanation

DISCUSSION: When a study yields a negative result between treatment groups, the next step is to perform a power analysis. The power, by definition, is the probability of rejecting the null hypothesis: in this example the null hypothesis would be that children treated with bisphosphonates would have fewer fractures than the untreated control population. The power analysis helps answer the question as to whether the null hypothesis should be rejected and the finding is real, or whether the sample size was too small or the effect of treatment too subtle to demonstrate a difference between the treatment and control groups.
REFERENCES: Buckwalter JA, Einhorn TA, Simon SR (eds): Orthopaedic Basic Science: Biology and Biomechanics of the Musculoskeletal System, ed 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000, p 7.
Kocher MS, Zurakowski D: Clinical epidemiology and biostatistics: A primer for orthopaedic surgeons. J Bone Joint Surg Am 2004;86:607-620.

Question 7

Figures 1 and 2 are the CT and MRI scans of a patient with shoulder instability. Contrasting these two imaging techniques for decision making in shoulder instability would suggest

Explanation

A 43-year-old woman is involved in a motor vehicle collision. She sustains the isolated injury shown in the radiograph in Figure 1. Her neurovascular examination is compromised. What is the most likely deficit?

A. Inability to flex the distal interphalangeal joint of the index finger

B. Positive Froment’s sign

C. Weakness with wrist extension

D. Decreased capillary refill

Question 8

A 44-year-old man reports persistent left leg pain following a L5-S1 hemilaminotomy and partial diskectomy. Examination shows a grade 4 weakness of the left extensor hallucis longus and a positive left straight leg raise. A radiograph is shown in Figure 1a, and sagittal and axial MRI scans are shown in Figures 1b and 1c. Nonsurgical management consisting of medication, physical therapy, and injections has failed to provide relief. Surgical management should consist of

Explanation

DISCUSSION: The patient has a grade I isthmic spondylolisthesis at L5-S1. He has an L5 radiculopathy with foraminal stenosis. Any further treatment needs to include an arthrodesis and foraminal decompression. Isolated interbody fusion is contraindicated in patients with spondylolisthesis, as is total disk arthroplasty. Therefore, the best procedure is a posterior fusion with instrumentation and bone graft along with a foraminal decompression.
REFERENCES: Spivak JM, Connolly PJ (eds): Orthopaedic Knowledge Update: Spine 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, pp 311-317.
Moller H, Hedlund R: Instrumented and noninstrumented posterolateral fusion in adult spondylolisthesis: A prospective randomized study: Part 2. Spine 2000;25:1716-1721.

Question 9

A 16-year-old high school football player has diffuse pain with attempted digital flexion after injuring the ring finger of the dominant hand 1 week ago. Examination reveals that he is unable to flex the distal interphalangeal joint. Management should consist of

Explanation

DISCUSSION: The patient has an avulsion of the flexor digitorum profundus. Treatment should include surgical exploration and tendon reinsertion. This is not an avulsion of the flexor digitorum superficialis because the patient’s deficiency is the inability to flex the distal interphalangeal joint, not the proximal interphalangeal joint. Surgical release of the anterior interosseous nerve is not indicated because the flexor digitorum profundus of the ring finger is innervated by the ulnar nerve. A median nerve contusion causes wrist pain and/or numbness and tingling in the median nerve distribution.
REFERENCES: Strickland JW: Flexor tendons: Acute injuries, in Green DP, Hotchkiss RN, Pederson WC (eds): Green’s Operative Hand Surgery, ed 4. Philadelphia, PA, 1999,

pp 1851-1897.
Leddy JP: Avulsions of the flexor digitorum profundus. Hand Clin 1985;1:77-83.

Question 10

The direct anterior (Smith-Peterson) approach to hip arthroplasty is most commonly associated with injury to what nerve?

Explanation

DISCUSSION:
Some authors have reported the incidence of lateral femoral cutaneous nerve neuropraxia following hip arthroplasty with the direct anterior approach to be near 80%, but resolution of the sensory deficits has been observed in most patients over time. Femoral nerve palsy has been reported to occur in .64% to 2.3% direct lateral (Hardinge) and anterolateral (Watson-Jones) approaches, and the superior gluteal nerve may be injured with proximal extension of the abductor muscular dissection. The posterior approach has been reported to be associated with sciatic nerve injury, especially in cases of dysplasia. Pudendal nerve injury has not been reported with the anterior, anterolateral, direct lateral, or posterior approaches to hip
arthroplasty. It has been reported following hip arthroscopy and the use of a traction table, however.

Question 11

Performing reconstruction of the anterior cruciate ligament by drilling the femoral tunnel via an anteromedial portal, in contrast to transtibial drilling, affords what theoretical benefit? Review Topic

Explanation

Recent trends in anterior cruciate ligament reconstruction include an emphasis on anatomic rather than isometric reconstruction of the ligament. According to some studies, this more effectively restores knee kinematics and with this, rotatory stability. Transtibial drilling affords limited access to the lateral intercondylar wall and has been associated with vertical graft orientation. The anteromedial portal, in contrast, allows independent femoral tunnel drilling and more anatomic positioning of the graft. A more anatomically positioned tunnel established via an anteromedial portal may afford increased tunnel and graft obliquity. This has been suggested to resolve rotatory instability. Knee flexion angle during the course of reaming has been studied to assess favorable and negative tunnel characteristics and hazards to regional anatomic structures. When compared with transtibial drilling, the anteromedial portal is associated with shorter femoral tunnels, posterior tunnel wall integrity compromise, and increased risk to lateral femoral articular cartilage and subchondral bone posteriorly.

Question 12

Decreased risk of shoulder and elbow injury in a throwing athlete has been demonstrated with which of the following? Review Topic

Explanation

Posterior capsular contracture has been demonstrated to significantly impair the ability of the humeral head to translate anterior and inferiorly during the late cocking and early acceleration phases of the throwing motion. This results in an obligatory posterosuperior translation of the humeral head that may contribute to posterior superior glenohumeral internal impingement with posterosuperior labral and articular-sided rotator cuff pathology. Posterior capsular stretching in throwing athletes has been demonstrated to decrease the likelihood of clinically significant shoulder or elbow injury. Periscapular muscle and rotator cuff strengthening are important for optimal scapulothoracic rhythm, stable scapular position for throwing, and rotator cuff function but less directly established to result in a decreased risk of shoulder and elbow injury than posterior capsular stretching. Partial-thickness rotator cuff repair and superior labral repair may be necessary for treatment of symptomatic lesions unresponsive to nonsurgical management, but these do not necessarily correlate with decreased shoulder and elbow injury risk.

Question 13

A high school athlete reports the sudden onset of low back pain while performing a dead lift. Examination reveals lumbar paraspinal spasm and a positive straight leg raising test. Deep tendon reflexes, motor strength, and sensation in the lower extremities are normal. Radiographic findings are normal. If symptoms persist for longer than a few weeks, what is the best course of action?

Explanation

DISCUSSION: In the adolescent population, a lumbar herniated disk is characterized by a paucity of clinical findings, with a positive straight leg raising test the only consistently positive finding. This may result in a prolonged period of nonsurgical management that fails to provide relief. Activities that place a significant shear load on the lumbar spine, such as the dead lift, are associated with an increased risk of central disk herniation. An adolescent who lifts weights and has a history of back pain that fails to respond to a short period of active rest should undergo MRI evaluation for the diagnosis of a lumber herniated disk.
REFERENCES: Epstein JA, Epstein NE, Marc J, et al: Lumbar intervertebral disk herniation in teenage children: Recognition and management of associated anomalies. Spine 1984;9:427-432.
Hashimoto K, Fujita K, et al: Lumbar disc herniation in children. J Pediatr Orthop

1990;10:394-396.

Question 14

A 20-year-old minor league baseball pitcher is diagnosed with a symptomatic torn ulnar collateral ligament (UCL) in his pitching elbow. Nonsurgical management consisting of rest and physical therapy aimed at elbow strengthening has failed to provide relief. He has concomitant cubital tunnel symptoms that worsen while throwing. What is his best surgical option?

Explanation

DISCUSSION: High-level pitchers with symptomatic UCL tears require reconstruction, with autograft being the best studied graft selection. With concomitant ulnar nerve symptoms, a simultaneous ulnar nerve transposition provides good results. Ligament “repairs” and allograft reconstructions have not shown good long-term results.
REFERENCES: Azar FM, Andrews JR, Wilk KE, et al: Operative treatment of ulnar collateral ligament injuries of the elbow in athletes. Am J Sports Med 2000;28:16-23.
Ciccotti MG, Jobe FW: Medial collateral ligament instability and ulnar neuritis in the athlete’s elbow. Instr Course Lect 1999;48:383-391.

Question 15

The newborn foot deformity seen in Figures 64a and 64b should initially treated with

Explanation

DISCUSSION: Mild to moderate metatarsus adductus is best treated with observation and possible passive stretching exercises because most of these feet will self correct. Numerous types of shoes, braces, and splints have been devised but the efficacy of these have not been determined. Serial casting is reserved for severe metatarsus adductus in the infant, although a medial surgical release may be indicated if the deformity is symptomatic and persists beyond age 4 years.
REFERENCES: Abel MF (ed): Orthopaedic Knowledge Update: Pediatrics 3. Rosemont, IL, American AcademAyL-oMfadOenrathCooppayedic Surgeons, 2006, pp 240-241.
Farsetti P, Weinstein SL, Ponseti IV: The Long-term functional and radiographic outcomes of untreated
and non-operatively treated metatarsus adductus. J Bone Joint Surg Am 1994;76:257-265. Question 65
A 4-year-old girl has been limping for the past 2 months. There is no history of trauma, previous injury, fever, or other systemic complaints. Examination reveals a moderate right knee effusio n with a 10-degree knee flexion contracture. What is the next most appropriate step in evaluation?
Arthroscopy
Antinuclear antibody
MRI
Bone scan
HLA-B27
DISCUSSION: The patient presents with juvenile idiopathic arthritis manifestations. The American College of Rheumatology defines this as one or more joints involved with swelling of 6 weeks or longer. A positive antinuclear antibody test would be diagnostic. Consideration should be made to have the patient see an ophthalmologist for evaluation of possible uveitis. Although the patient could have Lyme disease, that choice is not an option. The presence of an elevated antinuclear antibody by itself should not necessarily be used for diagnosing arthritis; however, the test does have clinical utility as a screening test. The frequency of a positive antinuclear antibody test is greatest in younger girls with oligoarticular disease and carries an increased risk for anterior uveitis. Arthroscopy might be indicated if this patient was presenting with a discoid meniscus, but there is no history of clicking, which is often one of the classic signs of discoid meniscus. MRI would not be used to diagnose juvenile idiopathic arthritis, but
MRI would be useful to help diagnose discoid meniscus. A bone scan would show increased uptake in the patient’s knee but again, this would not help diagnose her condition. HLA-B27 has no role in diagnosing juvenile idiopathic arthritis, especially in females.
REFERENCES: Iesaka K, Kubiak EN, Bong LR, et al: Orthopaedic surgical management of hip and knee involvement in patients with juvenile rheumatoid arthritis. Am J Orthop 2006;35:67-73.
Wright DA: Juvenile idiopathic arthritis, in Morrissey RT, Weinstein SL (eds): Love l and Winter’s Pediatric Orthopaedics, ed 6. Philadelphia PA, Lippincott Williams and Wilkins, 2006, pp 405-438. Question 66
An 18-month-old girl is brought in by her parents because of concerns about intoeing, bowlegs, and tripping and fa ling. Prenatal and birth history are otherwise unremarkable. The child’s growth and
development appear to be normal and she has a normal neurologic exam, a straight spine with no defects, and the hips are stable. Examination reveals hip internal rotation of 40 degrees and hip external rotation of 60 degrees. The thigh-foot angle is internal 30 degrees. Feet are straight and supple. Gait is characterized by intoeing with occasional tripping and falling. Based on these findings, what is the most appropriate action?
No treatment because internal tibial torsion slowly resolves on its own
Immediate treatment with a Denis-Browne bar
Distal tibial osteotomies
Proximal femoral derotational osteotomies
Treatment with twister cables PREFERRED RESPONSE: 1
DISCUSSION: The child has classic internal tibial torsion that is very commonly seen in younger children who are just beginning to walk. The normal outcome is for slow resolution of this problem and it seldom requires any treatment. Treatment with a Denis-Browne bar or with twister cables has not been proven to be effective. Surgical treatment at this point is premature and clearly not indicated.
REFERENCES: Lincoln TL, Suen PW: Common rotational variations in children. J Am Acad Orthop Surg 2003;11:312-320.
Staheli LT, Corbett M, Wyss C, et al: Lower-extremity rotational problems in children: Normal values to guide management. J Bone Joint Surg Am 1985;67:39-47.

Question 16

A 28-year-old construction worker sustains the closed injury shown in Figures A and B after a fall from a height. He is taken to the operating room. What is the next best step?

Explanation

This patient has an extraarticular distal tibia fracture and distal fibula fracture. Reamed intramedullary nailing and fibular plating is indicated in this case.
In the distal tibial metaphysis, there is no snug endosteal fit for an IM nail. Center-center nail placement in both proximal and distal fragments is necessary to maintain alignment. There is also increased stress on distal locking bolts to maintain fracture alignment. Assuming static medial-lateral distal locking screws, accurate coronal plane and rotational alignment is achieved by fibular plating as a first step. This also
prevents late loss of alignment because of distal locking screw toggle. Reamed nailing allows a stiffer, larger nail to be placed, and allows redistribution of endosteal osteogenic material to the fracture site. Although there is endosteal vascular compromise, this does not affect fracture healing because of intact periosteal supply.
Bhandari et al. conducted a prospective, randomized, blinded comparison of 622 patients who had reamed nailing, and 604 who had unreamed nailing. For closed fractures, a significantly greater number in the unreamed group required bone grafting, implant exchange and dynamization. There was no difference in groups for open fracture nailing.
Egol et al. retrospectively reviewed distal metaphyseal tibia-fibula fractures treated with IM nailing with (25 cases) and without (47 cases) adjunctive plating. They found that plating was associated with maintenance of reduction (significant) as was the use of 2 medial-lateral distal locking bolts (not significant). They recommend fibular plating when IM nailing for distal tibia fractures.
Figures A and B show an extraarticular distal tibia fracture with distal fibula fracture. Incorrect Answers

Question 17

The Magnetic resonance imaging signal characteristics of a high-grade soft-tissue sarcoma are best described as

Explanation

After plain radiographs of the affected area have been obtained, magnetic resonance imaging modality is the best imaging modality for detecting and characterizing the lesion, regarding definition of normal muscle, fascial boundaries, and the tumor mass. Although MR imaging is not specific in determining whether lesions are benign or malignant, it can be useful in evaluation
other characteristics, such as size, pattern of growth, integrity of natural boundaries, and homogeneity.
Intravenous contrast agents are not necessary to evaluate neurovascular structures. Both the T1 & T2 weighted images are essential to detect and characterize soft tissue lesions.
Most Tumors have long T1 and T2 relaxation times, therefore, in most instances signal intensity alone is of limited benefit. Exceptions are lipoma, hematoma, intra-lesional hemorrhage.
Hemorrhage may occur in some soft tissue lesions, especially sarcomas, leading to the low T1 and high T2 intensity sound on MR. Miller, indicates that Water, CSF, acute hemorrhage and soft tissue tumors appear dark on T1 and light on T2.

Question 18

What spinal nerves in the cauda equina are primarily responsible for innervation of the bladder?

Explanation

DISCUSSION: The spinal nerves primarily responsible for bladder function are the S2, S3, and S4 nerve roots. With significant compression of the cauda equina by either disk herniation, tumor, or degenerative stenosis, bladder dysfunction may result.
REFERENCES: Hoppenfeld S: Physical Examination of the Spine and Extremities. Norwalk, CT, Appleton-Century-Crofts, 1976, p 254.
Pick TP, Howden R (edS): Gray’s Anatomy. New York, NY, Bounty Books, 1977, p 1004.

Question 19

When performing a saline load test to evaluate for a traumatic arthrotomy of the knee, a mininum of how much saline should be utilized?

Explanation

DISCUSSION: A saline load test is commonly utilized to evaluate for intraarticular penetration of superficial lacerations (traumatic arthrotomies). In this technique, a large gauge needle is used (18 ga) and saline is injected into the knee with passive ROM provided. Saline egress from the soft tissue injury is a positive test (traumatic arthrotomy present).
The study by Nord et al found that the volumes of saline that were needed in order to effectively diagnose 75%, 90%, 95%, and 99% of the knee arthrotomies were 110, 145, 155, and 175 mL, respectively.
The other referenced study by Keese et al found that 50 mL of saline successfully identified only 46% of known knee arthrotomies and that 194 mL was needed to reach a 95% identification rate.

Question 20

The scoring system for impending pathologic fractures devised by Mirels involves assessment of which of the following factors?

Explanation

DISCUSSION: The scoring system published by Mirels in 1989 is based on the following characteristics: the location of the lesion, the amount of pain the patient is experiencing, the type of lesion (either lucent, mixed, or blastic), and the lesion size. The tumor is scored from 1 to 3 in each category and a total score is obtained that correlates to fracture risk. Prophylactic fixation is advised for lesions with scores of higher than 8, and consideration for stabilization should be strongly considered for scores of 8. The Mirels scoring system can be useful as an adjunct to clinical decision making.
REFERENCES: Mirels H: Metastatic disease in long bones: A proposed scoring system for diagnosing impending pathologic fractures. 1989. Clin Orthop Relat Res 2003;415:S4-S13.
Damron TA, Morgan H, Prakash D, et al: Critical evaluation of Mirels’ rating system for impending pathologic fractures. Clin Orthop Relat Res 2003;415:S201-S207.

Question 21

A 30-year-old woman has pain in her right hand. The radiograph, CT scan, and biopsy specimen are seen in Figures 38a through 38c. What is the most likely diagnosis?

Explanation

DISCUSSION: An enchondroma is the most common primary tumor of the long bones of the hand. The lesion is usually asymptomatic and often is detected when there is a pathologic fracture.
REFERENCES: Shimizu K, Kotoura Y, Nishijima N, Nakamura T: Enchondroma of the distal phalanx of the hand. J Bone Joint Surg Am 1997;79:898-900.
Takigawa K: Chondroma of the bones of the hand: A review of 110 cases. J Bone Joint Surg Am 1971;53:1591-1600.

Question 22

Figure 53a shows the AP radiograph of a 70-year-old patient who is scheduled to undergo unicompartmental knee arthroplasty. Figure 53b shows the immediate postoperative radiograph, and the radiograph shown in Figure 53c, obtained 6 months after surgery, shows a medial tibial plateau fracture. The etiology of the fracture is best related to

Explanation

DISCUSSION: While all of the above may contribute to the etiology of a tibial plateau fracture following unicompartmental knee arthroplasty, the recent literature has clearly noted that pin placement for fixation of tibial resection guides is the most critical factor associated with a tibial plateau fracture following unicompartmental knee arthroplasty. Vince and Cyran suggest that fractures associated with unicompartmental knee arthroplasty might be avoidable by limiting the number and paying attention to the location of the pin holes that are created to secure the tibial resection guides. Brumby and associates suggest avoiding multiple guide pin holes in the proximal tibia for unicompartmental knee arthroplasty. They currently recommend the use of one centrally placed pin and an ankle clamp to stabilize the resection guide. Yang and associates note that a medial tibial plateau fracture in association with minimally invasive unicompartmental knee arthroplasty can be eliminated by avoiding fixation pins close to the medial tibial cortex.
REFERENCES: Brumby SA, Carrington R, Zayontz S, et al: Tibial plateau stress fracture: A complication of unicompartmental knee arthroplasty using 4 guide pinholes. J Arthroplasty 2003;18:809-812.
Yang KY, Yeo SJ, Lo NN: Stress fracture of the medial tibial plateau after minimally invasive unicompartmental knee arthroplasty: A report of 2 cases. J Arthroplasty 2003;18:801-803.
Vince KG, Cyran LT: Unicompartmental knee arthroplasty: New indications, more complications? J Arthroplasty 2004;19:9-16.

Question 23

A 10-year-old boy has 2 months of right knee pain that started at summer camp. The patient denies constitutional symptoms. There is no lymphadenopathy present. CT of the chest shows no signs of metastatic disease. Imaging studies and biopsy results are shown in Figures A-E. What is the most likely diagnosis?

Explanation

The age, imaging and histology are consistent with an osteosarcoma. The radiograph shows an aggressive (lytic, mottled, sclerotic) appearing lesion around the distal femur metadiaphyseal region. The T2 weighted MRI image shows a significant soft tissue mass which appears to arise from the distal femur with destruction of the adjacent cortex. The biopsy shows an infiltrative pattern with elements of osteoid and bone.
Treatment for osteosarcoma includes neoadjuvant chemotherapy, wide resection, and adjuvant chemotherapy.

Question 24

A 45-year-old woman has had radiating pain in the medial ankle for the past 3 months. Examination reveals a small mass in the retromedial ankle region and a positive Tinel’s sign. An intraoperative photograph and a hematoxylin/eosin biopsy specimen are shown in Figures 24a and 24b. Treatment should consist of

Explanation

DISCUSSION: Neurilemoma is a benign tumor of nerve sheath origin, and peak incidence is in the third through sixth decades. The tumor is well encapsulated on the surface of a peripheral nerve. MRI findings may be significant for a “string sign.” A positive Tinel’s sign in the distribution of the nerve affected may be present. Grossly, the lesion is well encapsulated in a nerve sheath. Microscopically, there are structures referred to as Antoni A (a pattern of spindle cells arranged in intersecting bundles) and Antoni B (areas with less cellularity with loosely arranged cells). These lesions are benign, and treatment should consist of marginal excision. Nerve function may be preserved by careful dissection, excising the lesion parallel to the nerve fascicles so the lesion may be extruded. Recurrence is rare.
REFERENCES: Walling AK: Soft tissue and bone tumors, in Coughlin MJ, Mann RA (eds): Surgery of the Foot and Ankle, ed 7. St Louis, MO, Mosby, 1999, pp 1007-1032.
Simon M, Springfield D: Surgery for the Bone and Soft-Tissue Tumors. Philadelphia, PA, Lippincott Williams & Wilkins, 1998, pp 530-531.

Question 25

.What is the most appropriate treatment if instability is present at the time of evaluation?

Explanation

Question 26

-Figures a and b are the posteroanterior and lateral radiographs of a 13-year-old girl with a progressive curve despite bracing with a thoracolumbosacral orthosis. Examination reveals no pain or neurologic findings. The lumbar curve measures 59 degrees and the thoracic curve measures 52 degrees.The most appropriate treatment is

Explanation

Question 27

An 11-year-old boy sustained an injury to his arm in gym class. He denies prior pain in the arm. Radiographs are shown in Figures 48a and 48b. What is the next most appropriate step in the management of this lesion?

Explanation

DISCUSSION: This radiolucent lesion with a “fallen leaf sign” is typical for a unicameral bone cyst(UBC). The most appropriate treatment is to allow the fracture to heal with clinical and radiographic observation. Curettage and bone grafting is not the best initial management for UBC. Wide resection is not indicated for UBC. The proximal humerus is the most common site for UBC. While staging studies consisting of MRI, bone scan, and CT of the chest are appropriate for lesions suspected of being malignant, the classical appearance of this UBC is such that this work-up is not necessary initially. Following fracture healing, aspiration and injection of the cyst may be indicated.
REFERENCES: Dormans JP, Pill SG: Fractures through bone cysts: Unicameral bone cysts, aneurysmal bone cysts, fibrous cortical defects, and nonossifying fibromas. Instr Course Lect 2002;51:457-467.
Deyoe L, Woodbury DF: Unicameral bone cyst with fracture. Orthopedics 1985;8:529-531.

Question 28

1 and 2 show the radiograph and CT obtained from a year-old woman who underwent right total hip replacement in She initially did well with no pain. She was last seen 7 years ago and was having mild hip pain at that time. She was found to have a supra-acetabular cyst on radiographs. She has had severe right hip pain for the past 9 months while using a walker for ambulation. The initial blood work reveals an estimated erythrocyte sedimentation rate of 32 mm/hr, a C-reactive protein level of 5 mg/L, a serum cobalt level of 4 µg/L, and a serum chromium level of 6 µg/L. Right hip aspiration is performed, revealing a white blood cell count of 139, 52% neutrophils, and a negative leukocyte esterase test. What is the best next step?

Explanation

DISCUSSION:
The hip replacement was performed in 1995, during the period when the previous generation of polyethylene was utilized. This polyethylene was subjected to irradiation in air, with subsequent oxidation and consequent osteolysis after implantation. The mechanism of osteolysis begins with the uptake of polyethylene particles by macrophages, which then initiate an inflammatory cascade and the release of osteolytic factors. This cycle continues, with eventual implant loosening and failure. The imaging shows significant osteolysis and raises concern for pelvic discontinuity and acetabular implant failure. The surgical treatment consists of acetabular reconstruction. In this patient, concern exists for discontinuity based on the substantial amount of bone loss and nonsupportive anterior and posterior columns. This scenario requires complex acetabular revision using a custom triflange device, distraction with a jumbo acetabular component, or placement of a porous metal cup/cage construct with augmentation. The laboratory values are not consistent with infection or failure due to metal debris.

Question 29

Which of the following parameters is considered most important when assessing an acetabular fracture for surgical indications?

Explanation

DISCUSSION: The most important aspect in the decision for surgery in an acetabular fracture is the ability of the femoral head to remain concentrically reduced under the dome in AP and Judet oblique views of the pelvis. If this parameter is present, then the need for surgery is determined by other aspects such as fragmentation, age, incongruity, and displacement. If the head remains stable under the dome without traction, there is sufficient acetabular dome to provide stability, and nonsurgical treatment may be appropriate.
REFERENCES: Tile M: Assessment and management of acetabular fractures, in Tile M (ed): Pelvic and Acetabular Fractures, ed 2. Baltimore, MD, Williams and Wilkins, 1995, pp 305-354.
Letournel E: Acetabular fractures: Classification and management. Clin Orthop 1980;151:81-106.
Letournel E, Judet R: Fractures of the Acetabular, ed 2. Berlin, Springer-Verlag, 1993, pp 29-49.

Question 30

A 42-year-old woman who has had an 18-month history of severe low back pain is referred to your office for surgical evaluation. She reports that the pain initially began with right lower extremity pain and management consisted of oral analgesics, nonsteroidal anti-inflammatory drugs, and muscle relaxants. She has seen a chiropractor as well as a pain management specialist and she is status-post epidural steroid injections. She has also completed exhaustive physical therapy, as she is a certified athletic trainer and runs a health fitness program at a community hospital. Currently, she denies lower extremity pain and her pain is isolated to her low back and is subjectively graded as 8/10, with 10 being the worst pain she has ever experienced. The pain is interfering with her activities of daily living and she is seeking definitive treatment. Figures 32a through 32c show current MRI scans. Based on the current available medical literature, what is the most appropriate treatment?

Explanation

DISCUSSION: The MRI scans reveal advanced degenerative disk disease at L5-S1. Nonsurgical management has failed to provide relief and the patient is quite debilitated as a result of her back pain. Fritzell and associates demonstrated that in a well-informed and selected group of patients with severe low back pain, lumbar fusion can diminish pain and decrease disability more efficiently than commonly used nonsurgical treatments. In a recent updated Cochrane Review of surgery for degenerative lumbar spondylosis, it was noted that while Fritzell and associates appeared to provide strong evidence in favor of fusion, a more recent trial by Brox and associates demonstrated no difference between those patients undergoing lumbar fusion compared to those receiving cognitive intervention and exercise. The Cochrane Review suggests that this may reflect a difference between the control groups. Fritzell and associates compared lumbar fusion to standard 1990s “usual care,” whereas Brox and associates compared lumbar fusion to a “modern rehabilitation program.” Bear in mind that this patient is a certified athletic trainer and runs a hospital health fitness department; therefore, at least for purposes of this question, it can be assumed that she has participated in a “modern rehabilitation program.” The Cochrane Review goes on to state that preliminary results of three small trials of intradiskal electrotherapy suggest that it is ineffective and that preliminary data from three trials of disk arthroplasty do not permit firm conclusions.
REFERENCES: Gibson JN, Waddell G: Surgery for degenerative lumbar spondylosis: Updated Cochrane Review. Spine 2005;30:2312-2320.
Fritzell P, Hagg O, Wessberg P, et al: 2001 Volvo Award Winner in Clinical Studies: Lumbar fusion versus nonsurgical treatment for chronic low back pain: A multicenter randomized controlled trial from the Swedish Lumbar Spine Study Group. Spine 2001;26:2521-2532.
Brox JI, Sorensen R, Friis A, et al: Randomized clinical trial of lumbar instrumented fusion and cognitive intervention and exercises in patients with chronic low back pain and disc degeneration. Spine 2003;28:1913-1921.

Question 31

What is the most common complication following distal biceps tendon repair?

Explanation

DISCUSSION
The distal biceps tendon is commonly torn with an eccentric contraction of the biceps when the elbow is taken into extension. Patients treated nonsurgically will note loss of at least 50% supination strength and may develop discomfort with resistive activities. The video shows the squeeze test to evaluate the integrity of the biceps tendon. The test is similar to the Thompson test in the evaluation of an Achilles tendon rupture. The distal arm is squeezed with the elbow flexed 60 to 80 degrees and the forearm pronated. By shortening the musculotendinous unit, the intact biceps tendon will lead to forearm supination. If the biceps is torn, the forearm will not supinate as shown in the video. The maneuver is performed with the elbow in flexion to minimize tension on the brachialis muscle and isolate the biceps. Ruland and associates evaluated 25 patients with suspected distal biceps ruptures and correctly diagnosed all but 1 false-positive result that involved a partial tear. The lacertus fibrosus is not evaluated with this maneuver.
When considering a repair, a 1- or 2-incision technique may be performed. Chavan and associates performed a systematic review comparing the 2 techniques and reported similar complication rates. The 2-incision technique was associated with more instances of significant loss of forearm rotation and more unsatisfactory clinical results. The 1-incision technique is associated with a higher incidence of lateral antebrachial cutaneous neuropathy likely attributable to retraction. The biceps insertion is a thin semilunar area on the posterior/ulnar aspect of the radial tuberosity centered at approximately 30 degrees anterior to the lateral/coronal plane with the arm fully supinated. Forthman and associates used CT scan to asses 30 cadaveric specimens and noted that the biceps tuberosity orientation would prohibit an anatomic repair in 35% of arms for which the 1-incision technique was used.
Mazzocca and associates reported the highest load to failure of the Endobutton (440 newton (N)) compared to fixation with suture anchor (381 N), Wartenberg syndrome (310 N), and an interference screw (232 N). Greenberg and associates noted greater load to failure for the Endobutton (584 N) compared to suture anchor (254 N) and transosseous tunnel (178 N) constructs. Spang and associates reported comparable strength of the Endobutton repair when compared to suture anchors. Fifty N of force is required to hold the elbow flexed at 90 degrees against gravity, which is well below the strength of the repairs studied.
Neuropraxia of the lateral antebrachial cutaneous nerve branch is the most common complication associated with distal biceps repair, with a reported incidence as high as 40%. The nerve branch lies between the biceps and brachialis as it crosses the surgical field in the antecubital fossa. The neuropathy may be related to aggressive retraction, particularly when using the 1-incision technique, and often resolves with time. Cain and associates reported minor complications were common (but major complications uncommon) following distal biceps repair. Reported complications are lateral antebrachial cutaneous paresthesia (26%), radial sensory nerve paresthesia (6%), posterior interosseous nerve injury (4%), and rerupture (2%).
RECOMMENDED READINGS
Ruland RT, Dunbar RP, Bowen JD. The biceps squeeze test for diagnosis of distal biceps tendon ruptures. Clin Orthop Relat Res. 2005 Aug;(437):128-31. PubMed PMID: 16056039.
Forthman CL, Zimmerman RM, Sullivan MJ, Gabel GT. Cross-sectional anatomy of the bicipital tuberosity and biceps brachii tendon insertion: relevance to anatomic tendon repair. J Shoulder Elbow Surg. 2008 May-Jun;17(3):522-6. doi: 10.1016/j.jse.2007.11.002. Epub 2008 Mar 6. PubMed PMID: 18325797.
Chavan PR, Duquin TR, Bisson LJ. Repair of the ruptured distal biceps tendon: a systematic review. Am J Sports Med. 2008 Aug;36(8):1618-24. doi: 10.1177/0363546508321482. Review. PubMed PMID: 18658024.
Mazzocca AD, Burton KJ, Romeo AA, Santangelo S, Adams DA, Arciero RA. Biomechanical evaluation of 4 techniques of distal biceps brachii tendon repair. Am J Sports Med. 2007 Feb;35(2):252-

Question 32

Iliosacral screws placed for stabilization of posterior pelvic ring injuries (eg, sacroiliac dislocation) that exit the sacrum anteriorly are most likely to injure which of the following structures?

Explanation

DISCUSSION: Iliosacral screws have gained popularity for posterior stabilization of pelvic ring disruptions, but complications attributed to incorrect placement are a clinical problem. The L5 nerve root is at greatest risk and is in closest proximity to a malpositioned screw (exiting the sacrum). The L4 root is more anterior at this level. The S1 root is still intraosseous at this level and is at risk but not from the screw exiting anteriorly at this level. The arteries are at risk but are more anterior and are at less risk than the L5 nerve root.
REFERENCE: Ebraheim NA, Haman SP, Xu R, Stanescu S, Yeasting RA: The lumbosacral nerves in relation to dorsal SI screw placement and their locations on plain radiographs. Orthopedics 2000;23:245-247.

Question 33

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

Explanation

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

Question 34

Figures 30a and 30b are the radiographs of a 61-year-old man with diabetes who fell from a ladder and sustained an isolated closed fracture. After realignment and splint application, what is the most appropriate next step in management?

Explanation

The patient has sustained a high-energy severely comminuted AO/OTA C2 fracture of the distal tibia. This injury is notably fraught with soft-tissue complications that can lead to disastrous clinical results. In general, a staged protocol is now preferred in an effort to avoid these complications and has shown substantial decreases in infection rates and wound healing problems. A CT scan is certainly appropriate for preoperative planning but should be obtained after frame application because the indirect reduction that is achieved improves one's ability to understand the fracture characteristics and morphology. Hybrid external fixation has fallen out of favor because of its limited biomechanic rigidity and clinical results. Open reduction and
internal fixation in the acute phase (6 to 8 hours) or sub-acute phase (2 to 3 days) is difficult.

Question 35

Figures 1 and 2 demonstrate the radiographs obtained from a 35-year-old woman with end-stage debilitating osteoarthritis of the right hip. She is contemplating total hip arthroplasty (THA). She has a history of right hip dysplasia and underwent hip osteotomy as an adolescent. Over the years, nonsurgical treatment, including weight loss, activity modifications, and intra-articular injections, has failed. Her infection work-up reveals laboratory findings within defined limits. Which bearing surface is contraindicated for this patient?

Explanation

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

Question 36

Figure 20 shows the plain radiograph of a 70-year-old woman who has shoulder pain and is unable to reach above chest level as a result of a fall 3 months ago. An MRI scan of the shoulder shows a large rotator cuff tear. Examination reveals atrophy of the infraspinatus muscle, active forward elevation of 40 degrees, active external rotation of 30 degrees, passive forward elevation of 150 degrees, and passive external rotation of 60 degrees. The patient has no external rotation strength against resistance. Treatment should include

Explanation

This defines a 70y/o lady who 3 months ago sustained a large, to massive rotator cuff tear, not only by MRI, but by physical exam as well. In any age group or duration from injury, massive rotator cuff tears do poorly with surgical intervention. Now add in 3months duration and 70 yr age and boy doesn't rehabilitation sound good.

Question 37

A 29-year-old man who lifts weights states that he injured his left shoulder while performing a bench press 2 days ago. The following morning he noted ecchymosis and swelling in the left chest wall. Examination reveals ecchymosis and tenderness and deformity in the left anterior chest wall and axillary fold that is accentuated with resisted adduction of the arm. Passive range of motion beyond 90 degrees of forward flexion and 45 degrees of external rotation is extremely painful. Glenohumeral stability is difficult to assess because of severe guarding. Figure 29 shows an MRI scan. Management should consist of

Explanation

DISCUSSION: Rupture of the pectoralis major tendon most commonly occurs during bench pressing. Wolfe and associates have shown that the most inferiorly located fibers of the sternal head lengthen disproportionately during the final 30 degrees of humeral extension during the bench press. This creates a mechanical disadvantage in the final portion of the eccentric phase of the lift; with forceful flexion of the shoulder these maximally stretched fibers may rupture. In most patients, particularly in young athletes, the treatment of choice is anatomic repair of the ruptured tendon to its insertion in the proximal humerus either with suture anchors or transosseous sutures. Following surgery, most patients experience a near normal return of strength and significant improvement in the cosmetic appearance of the deformity. While more technically challenging, repair of chronic rupture is possible and is indicated in some patients.
REFERENCES: Wolfe SW, Wickiewicz TL, Cavanaugh JT: Ruptures of the pectoralis major muscle: An anatomic and clinical analysis. Am J Sports Med 1992;20:587-593.
Schepsis AA, Grafe MW, Jones HP, Lemos MJ: Rupture of the pectoralis major muscle: Outcome after repair of acute and chronic injuries. Am J Sports Med 2000;28:9-15.

Question 38

A 54-year-old woman undergoes an interposition arthroplasty that fails and requires conversion to a total elbow arthroplasty. She has progressive elbow pain and radiographic loosening. Erythrocyte sedimentation rate and C-reactive protein are normal. Joint aspiration is positive for Staphylococcus epidermidis. What surgical treatment would best optimize function and decrease risk of recurrence?

Explanation

The most reliable surgical option in this case for eradicating a deep infection following a total elbow arthroplasty is a two-stage revision. One study, however, reported that staged reimplantation of an infected total elbow replacement could be successful in the setting of organisms other than S epidermidis. Arthroscopic debridement is not a viable option with poorly fixed or loose components. A single-stage revision, while considered an option in hip and knee arthroplasty, has not been definitively proven to be an option for revision total elbow arthroplasty. Single-stage revision has shown moderate success in the setting of Staphylococcus aureus infections, although with only short-term follow-up. A resection arthroplasty would likely be successful in managing the deep infection but would not optimize the functional result. Resection arthroplasty
is best reserved for low-demand or infirm patients.

Question 39

A 21-year-old football player had severe pain and immediate swelling in the left anteromedial chest wall while bench pressing near maximal weights several days ago. Examination at the time of injury revealed a mass on the anteromedial chest wall. Follow-up examination now reveals decreased swelling, and axillary webbing is observed. The patient has weakness to adduction and forward flexion. The injured muscle originates from the

Explanation

DISCUSSION: The patient has a pectoralis major rupture, an injury that occurs most commonly during weight lifting. Grade III injuries represent complete tears of either the musculotendinous junction or an avulsion of the tendon from the humerus, the most common injury site. Examination will most likely reveal ecchymoses and swelling in the proximal arm and axilla, and strength testing will show weakness with internal rotation and in adduction and forward flexion. Axillary webbing, caused by a more defined inferior margin of the anterior deltoid as the result of rupture of the pectoralis, can be seen as the swelling diminishes. Surgical repair is the treatment of choice for complete ruptures. Nonsurgical treatment is associated with significant losses in adduction, flexion, internal rotation, strength, and peak torque. The pectoralis major originates from the proximal clavicle and the border of the sternum, including ribs two through six. The pectoralis major inserts (rather than originates) on the humerus. The coracoid process is the insertion site for the pectoralis minor, as well as the origin for the conjoined tendon. The pectoralis major has no attachment or origin from the scapula. The anterior deltoid originates from the lateral one third of the clavicle and the anterior acromion.
REFERENCES: Miller MD, Johnson DL, Fu FH, Thaete FL, Blanc RO: Rupture of the pectoralis major muscle in a collegiate football player: Use of magnetic resonance imaging in early diagnosis. Am J Sports Med 1993;21:475-477.
Wolfe SW, Wickiewicz TL, Cavanaugh JT: Ruptures of the pectoralis major muscle: An anatomic and clinical analysis. Am J Sports Med 1992;20:587-593.

Question 40

A patient has a C6 spinal cord injury. Following stabilization of the spine, the patient should be advised that their expected maximum level of function

Explanation

A patient with an injury at the level of: C4 injury needs puffer control; C5 can use hand controls; C6 can use a manual wheelchair and sliding board transfers; C7 allows independent transfers; and no cervical injury routinely allows ambulation with crutches and leg braces.

Question 41

The major benefit of irrigation with a castile soap solution over irrigation with bacitracin solution for the treatment of the open fracture shown in Figure 42 can be seen in which of the following outcomes?

Explanation

DISCUSSION: The mainstay of early treatment of open fractures includes irrigation and debridement. Prior to the development of antibiotics, this was traditionally accomplished with some form of detergent irrigation. Antibiotic irrigation has been in favor more recently but has mixed scientific results related to its use. Results of at least one major study show the use of a nonsterile liquid soap additive (castile soap) is at least as effective as the use of bacitracin with regards to the rate of postoperative infection and fracture healing, and shows a significant decrease in problems with soft-tissue healing.
REFERENCE: Anglen JO: Comparison of soap and antibiotic solutions for irrigation of lower-limb open fracture wounds: A prospective, randomized study. J Bone Joint Surg Am 2005;87:1415-1422.

Question 42

Following total knee arthroplasty, a patient is noted to have asymmetrical absent pulses and poor capillary refill. What is the next most appropriate step in management?

Explanation

is still under
perform an
DISCUSSION: An assessment of the location of the vascular compromise is necessary prior to surgical exploration. Vascular repair will most likely require a separate surgical exposure. Vascular reperfusion may be accomplished at the time of an arteriogram with the use of a stent in certain situations. Return to the operating room with vascular surgical consultation and intraoperative arteriogram is appropriate.
An immediate postoperative compartment syndrome is unlikely. Magnetic resonance angiogram is not appropriate because of the potential for a delay in diagnosis.
REFERENCE: Smith DE, McGraw RW, Taylor DC, et al: Arterial complications and total knee arthroplasty. J Am Acad Orthop Surg 2001 ;9;253-257.

Question 43

The use of nonsteroidal anti-inflammatory drugs following femoral nailing has been associated with which of the following?

Explanation

DISCUSSION: The risk of femoral nonunion after intramedullary nailing is significantly increased when NSAIDs are administered post-operatively.
Giannoudis et al assessed factors which could affect union in 32 patients with nonunion of a fracture of the diaphysis of the femur and 67 matched patients whose fracture had united. They found that there was no relationship between the rate of union and the type of implant, mode of locking, reaming, distraction or smoking. They also concluded that there was a marked association between nonunion and the use of NSAIDs after injury and delayed healing was noted in patients who took NSAIDs and whose fractures had united.
Burd et al performed a study to determine if patients with an acetabular fracture, who received indomethacin for prophylaxis against HO, were at risk of delayed healing or nonunion of any associated fractures of long bones. The study group consisted of 112 patients who had sustained at least one concomitant fracture of a long bone; of which 36 needed no prophylaxis, 38 received focal radiation and 38 received indomethacin. When comparing patients who received indomethacin with those who did not, a significant difference was noted in the rate of long bone nonunion (26% vs 7%).

Question 44

Figure 17 shows the clinical photograph of a 45-year-old female tennis player who has right arm pain and weakness with elevation after undergoing a cervical biopsy several months ago. The cause of her shoulder weakness is damage to the

Explanation

DISCUSSION: The patient has primary scapulotrapezius winging caused by surgical damage to the spinal accessory nerve during a lymph node biopsy. Other causes include blunt trauma, traction, and penetrating injuries. With spinal accessory palsy, the shoulder appears depressed and laterally translated because of unopposed serratus anterior muscle function. With primary serratus anterior winging that is the result of long thoracic nerve palsy, the scapula assumes a position of elevation and medial translation with the inferior angle rotated medially. The thoracodorsal nerve innervates the latissimus dorsi and is not associated with scapular winging.
REFERENCES: Kuhn JE, Plancher KD, Hawkins RJ: Scapular winging. J Am Acad Orthop Surg 1995;3:319-325.
Wright TA: Accessory spinal nerve injury. Clin Orthop 1975;109:15-18.

Question 45

A tendon repair is thought to be weakest during which phase of tendon healing?

Explanation

Healing after a tendon repair or rupture has the following stages: inflammatory, cellular proliferation, and remodeling. During the inflammatory phase, neutrophils and macrophages migrate into the injury site and release chemotactic factors that recruit fibroblasts. A tendon is thought to be weakest 5 to 21 days after repair, which coincides with the inflammatory phase. During the proliferative phase, inflammatory cells secrete cytokines and growth factors (platelet-derived growth factor, insulin-like growth factor, bone morphogenetic protein (BMP)-12 and BMP 13, and transforming growth factor-beta) that promote differentiation of fibroblasts. Fibrosis and decreased cellularity are the hallmarks of the remodeling stage.

Question 46

What is the primary indication for performing a total wrist arthroplasty in a patient with painful rheumatoid arthritis?

Explanation

The most conservative indications for a total wrist arthroplasty are to spare motion on one side and to improve activities of daily living. Component loosening, dislocation, and wound problems are frequent. Suitable patients can be of various ages, wrist motion, and radiographic stages of arthritis. Ipsilateral total elbow arthroplasty, type III degenerative changes of the wrist, age older than 55, and limited range of motion are neither primary indications nor contraindications to a total wrist arthroplasty.

Question 47

A 13-year-old boy has knee pain after sustaining a mild twisting injury while playing basketball 4 weeks ago. Radiographs and MRI scans are shown in Figures 24a through 24d, and biopsy specimens are shown in Figures 24e and 24f. Treatment should consist of

Explanation

DISCUSSION: The imaging studies and histology are consistent with high-grade osteosarcoma. The standard treatment for osteosarcoma is neoadjuvant chemotherapy combined with wide surgical resection that can be performed with amputation or limb salvage depending on characteristics unique to each tumor and each patient. In most patients, limb salvage surgery can be performed with reconstruction using allografts and/or megaprostheses. Osteosarcoma is poorly responsive to radiation therapy. Chemotherapy alone, in the absence of appropriate surgery, has not proven effective.
REFERENCES: Simon MA, Springfield DS: Surgery for Bone and Soft-Tissue Tumors. Philadelphia, PA, Lippincott-Raven, 1998, pp 265-274.
Gibbs CP, Weber K, Scarborough MT: Malignant bone tumors. Instr Course Lect 2002;51:413-428.

Question 48

A baseball pitcher has intractable posterior and superior shoulder pain. The arthroscopic view seen in Figure 25 shows no Bankart or Hill-Sachs lesion and a negative drive-through sign. There are no signs of ligamentous laxity, but active compression and anterior slide tests are positive. Treatment should consist of

Explanation

DISCUSSION: According to Morgan and associates, a type II SLAP lesion can create or is associated with a superior instability pattern. They suggest that this can exist without a co-existing anteroinferior instability pattern. They reported that repair of the SLAP lesion alone resulted in satisfactory outcomes in 90% of patients and a return to throwing in more than 90% of pitchers. The arthroscopic findings in this patient do not support a diagnosis of anteroinferior laxity or instability; therefore, thermal capsular shift or capsular placation is not necessary.
REFERENCES: Morgan CD, Burkhart SS, Palmeri M, et al: Type II SLAP lesions: Three subtypes and their relationships to superior instability and rotator cuff tears. Arthroscopy 1998;14:553-565.
Mileski RA, Snyder RJ: Superior labral lesions in the shoulder: Pathoanatomy and surgical management. J Am Acad Orthop Surg 1998;6:121-131.
Levitz CL, Dugas J, Andrews JR: The use of arthroscopic thermal capsulorrhaphy to treat internal impingement in baseball players. Arthroscopy 2001;17:573-577.

Question 49

A 51-year-old woman with no preoperative neurologic deficit is undergoing elective anterior cervical diskectomy and fusion (ACDF) with plating and fusion for a C5-6 disk herniation with right-sided neck pain. Thirty minutes into the surgery the neurophysiologic monitoring shows a rapid drop and then loss of amplitude in the right cortical somatosensory-evoked potential waveform. All other waveforms remained normal and unchanged, including right-sided cervical (subcortical) and peripheral (Erb’s point), and those from the left-sided upper extremity and both lower extremities. What is the most likely cause of the change? Review Topic

Explanation

The change noted is focal and confined to the cortex, sparing the opposite side, both lower extremities, and the subcortical waveforms, making all the choices unlikely with the exception of carotid compression with focal cortical ischemia. This may be associated with poor collateral flow from the opposite hemisphere due to an incomplete circle of Willis.

Question 50

A 52-year-old man has had right shoulder pain in the deltoid region that increases at night for the past 2 months. He denies any history of trauma. Examination reveals mild tenderness over the greater tuberosity, and the Neer and Hawkins impingement signs are positive. AP and outlet lateral radiographs are shown in Figures 24a and 24b. Initial management should consist of

Explanation

DISCUSSION: The patient has the findings of classic subacromial impingement. Initial management should consist of stretching exercises directed at the posterior capsule and a program of rotator cuff and deltoid strengthening exercises performed below the horizontal in a “safe” plane. The judicious use of subacromial cortisone injections (one or two) may be helpful. Anterior acromioplasty is reserved for patients who have failed to respond to nonsurgical management.
REFERENCES: Morrison DS, Frogameni AD, Woodworth P: Non-operative treatment of subacromial impingement syndrome. J Bone Joint Surg Am 1997;79:732-737.
Neer CS: Impingement lesions. Clin Orthop 1983;173:70-77.
Blair B, Rokito AS, Cuomo F, et al: Efficacy of injections of corticosteroids for subacromial impingement syndrome. J Bone Joint Surg Am 1996;78:1685-1689.

Question 51

A 65-year-old man undergoes total shoulder arthroplasty. Examination in the recovery room reveals the absence of voluntary deltoid and biceps contraction, weakness of wrist extension, and absence of sensation over the lateral arm and radial forearm. Management should now consist of

Explanation

One and two are incorrect because they would show artifact, which would interfere with evaluation of a brachial plexus lesion unless a hematoma is suspected. Number 3 is incorrect as timing of the EMG is important because electrophysiologic signs of denervation do not become apparent for more than two weeks after the injury and therefore should be performed four to six weeks after surgery if no clinical recovery is occurring. However, an electromyogram obtained early in the course of a neurologic injury may demonstrate a preexisting degenerative lesion. Answer number five is incorrect because in the literature it has been suggested that injuries to the brachial plexus showing no spontaneous improvement within three months should undergo surgical exploration. The answer number four is correct because after the neurological deficit is identified, efforts should be directed at maintaining passive motion of affected joint through the recovery phase. Temporary static splinting can be beneficial as well.

Question 52

It is important to avoid which of the following exercises in the immediate postoperative period after humeral head replacement for an acute four-part fracture?

Explanation

DISCUSSION: It is critical to withhold active range of motion of the shoulder within the first 6 weeks after arthroplasty for acute fracture to prevent tuberosity avulsion. When radiographic and clinical findings show that the tuberosities are healed, active motion may be instituted, usually at 6 to 8 weeks. Immediate passive range-of-motion exercises, including external rotation with a stick, pendulum, and passive elevation, should begin within the limits of the repair on the day of surgery to prevent stiffness.
REFERENCES: Hartstock LA, Estes WJ, Murray CA, et al: Shoulder hemiarthroplasty for proximal humerus fractures. Orthop Clin North Am 1998;29:467-475.
Hughes M, Neer CS: Glenohumeral joint replacment and postoperative rehabilitation. Phys Ther 1975;55:850-858.

Question 53

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 54

The anterior portal of a hip arthroscopy places what structure at greatest risk for injury?

Explanation

DISCUSSION: The average location of the anterior portal is 6.3 cm distal to the anterior superior iliac spine. The lateral femoral cutaneous nerve typically has divided into three or more branches at the level of the anterior portal. The portal usually passes within several millimeters of the most medial branch. Injury to the nerve can lead to meralgia paresthetica. The femoral nerve lies an average minimum distance of 3.2 cm from the anterior portal. The ascending branch of the lateral circumflex artery lies approximately 3.7 cm inferior to the anterior portal. Neither the ascending branch of the medial circumflex artery nor the superior gluteal nerve are

at risk.
REFERENCES: Byrd JWT: Operative Hip Arthroscopy. New York, NY, Thieme Medical Publishers, 1998, pp 83-91.
Arendt EA (ed): Orthopaedic Knowledge Update: Sports Medicine 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 281-289.

Question 55

A 37-year-old man with a history of congenital flatfoot reports worsening pain on the medial aspect of his ankle for the past year. The pain is worse with weight bearing and is better with rest and the use of an ankle brace. What findings are shown on the MRI scans shown in Figures 18a through 18c?

Explanation

DISCUSSION: The MRI scans reveal an enlarged posterior tibial tendon, with degenerative signal within the tendon and an excessive amount of fluid in its sheath. This is a type II tear, as noted by Conti and associates, which is the most commonly seen tear.
REFERENCES: Slovenkai MP: Clinical and radiographic evaluation (Adult flatfoot: Posterior tibial tendon dysfunction). Foot Ankle Clin 1997;2:241-260.
Conti S, Michelson J, Jahss M: Clinical significance of magnetic resonance imaging in preoperative planning for reconstruction of posterior tibial tendon ruptures. Foot Ankle 1992;13:208-214.

Question 56

A 22-year-old man sustained a stable pelvic fracture, bilateral femur fractures, and a left closed humeral shaft fracture in a motor vehicle accident. Examination 24 hours after injury reveals that the patient is confused and has shortness of breath. A clinical photograph of his conjunctiva is shown in Figure 44. He has a temperature of 101 degrees F (38.3 degrees C) and a pulse rate of 120/min. Laboratory studies show a hemoglobin level of 8 g/dL, a platelet count of 50,000/mm3, and a PaO2 of 57 mm Hg on 2L of oxygen. What is the most likely diagnosis?

Explanation

DISCUSSION: The major criteria for the diagnosis of fat embolism syndrome include hypoxemia (PaO2 of less than 60 mm Hg), central nervous system depression, and a petechial rash that is most often located in the axillae, conjunctivae, and palate. The rash is often transient. Tachycardia, pyrexia, anemia, thrombocytopenia, and the presence of fat in the urine are all considered minor criteria. To establish the diagnosis of fat embolism syndrome, one major and four minor signs should be present. Pulmonary embolism, which is the major differential diagnosis, usually is not associated with conjunctival petechia or thrombocytopenia.
REFERENCE: Buckwalter JA, Einhorn TA, Simon SR (eds): Orthopaedic Basic Science: Biology and Biomechanics of the Musculoskeletal System, ed 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000, pp 308-316.

Question 57

What significant structure is most at risk during a posterior approach of the Achilles tendon near its musculotendinous junction?

Explanation

DISCUSSION: The sural nerve crosses near the midline at the level of the musculotendinous junction before descending to its more lateral location distally. The saphenous nerve and vein are further medial and at less risk. The posterior tibial nerve is at risk only during deep dissection, such as harvesting flexor hallucis longus tendon graft. The plantaris muscle lies in this area but is of little clinical significance.
REFERENCES: Webb J, Moorjani N, Radford M: Anatomy of the sural nerve and its relation to the Achilles tendon. Foot Ankle Int 2000;21:475-477.
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 58

A 78-year-old man with ankylosing spondylitis sustains a minor fall. Shortly afterward he experiences sudden worsening of his chronic back pain and is brought to the emergency department by his caregiver. Radiographs and a CT scan of the spine do not show a clear fracture. What is the most appropriate next step?

Explanation

DISCUSSION
Patients with ankylosing spondylitis are at high risk for occult fractures after low-energy injuries. Although radiographs and a CT scan do not demonstrate a spinal fracture in this patient, high risk for an unstable occult fracture necessitates further imaging with MRI to ensure that no fractures are missed. Although a CT scan is typically the primary imaging modality for workup of spine injuries in similar patients, CT and MRI complement each other and each detects fractures that are missed using the other modality. A CT myelogram might detect cord or root compression but would not aid in the diagnosis of an occult fracture. Nonsteroidal anti-inflammatory drugs are first-line treatment for idiopathic low-back pain. In a patient with ankylosing spondylitis at high risk for fracture, further workup is needed to rule out an occult fracture. Flexion and extension radiographs of the spine are inferior to MRI for evaluating occult fractures and ligamentous injuries. The primary concern for this patient remains an unstable spinal fracture, which necessitates an MRI of the spine before initiating a workup for other possible causes of his back pain.
RECOMMENDED READINGS
Duane TM, Cross J, Scarcella N, Wolfe LG, Mayglothling J, Aboutanos MB, Whelan JF, Malhotra AK, Ivatury RR. Flexion-extension cervical spine plain films compared with MRI in the diagnosis of ligamentous injury. Am Surg. 2010 Jun;76(6):595-8. PubMed PMID: 20583514. View Abstract at PubMed
Hitchon PW, From AM, Brenton MD, Glaser JA, Torner JC. Fractures of the thoracolumbar spine complicating ankylosing spondylitis. J Neurosurg. 2002 Sep;97(2 Suppl):218-22. PubMed PMID: 12296682. View Abstract at PubMed
Koivikko MP, Koskinen SK. MRI of cervical spine injuries complicating ankylosing spondylitis. Skeletal Radiol. 2008 Sep;37(9):813-9. doi: 10.1007/s00256-008-0484-x. Epub 2008 Apr

Question 59

Figure 12 shows the radiograph of a patient who has anterior knee pain. History reveals a femoral fracture at age 5 years. What is the most likely cause of the deformity?

Explanation

DISCUSSION: The radiograph shows a recurvatum deformity of the proximal tibia with growth arrest of the tibial tubercle apophysis. This deformity has been described in association with femoral shaft fractures in children and has been attributed to a clinically silent, concommitant injury to the proximal tibial physes and also to iatrogenic injury associated with a proximal tibial traction pin. Overlengthened hamstrings and rupture of the posterior cruciate ligament may lead to knee hyperextension; however, these problems should not cause bone deformity. Osgood-Schlatter disease occurs when growth is nearly complete and usually leads to prominence of the tibial tubercle. Patellar tendon rupture is rare in children and would not cause this deformity unless the repair was performed with screws across the apophysis.
REFERENCES: Hresko MT, Kasser JR: Physeal arrest about the knee associated with non-physeal injuries of the lower extremity. J Bone Joint Surg Am 1989;71:698-703.
Bowler JR, Mubarak SJ, Wenger DR: Tibial physeal closure and genu recurvatum after femoral fracture: Occurrence without a tibial traction pin. J Pediatric Orthop 1990;10:653-657.

Question 60

Acetabular reconstruction followed by external beam irradiation The plain radiographs show a purely lytic destructive lesion that is poorly marginated. The technetium bone scan does not show any major uptake. The computerized tomography scan shows purely lytic bone destruction with breakthrough of the cortical bone. Complete destruction of the cortical bone is suggestive of a malignancy. The magnetic resonance image shows a lesion that is homogenously low on T1-weighted images and high on T2-weighted images. Surgeons cannot make a definitive diagnosis based upon the radiographic features. The most common malignancies in this age group are:

Explanation

Slide 1 Slide 2 Slide 3 Slide 4
A 50-year-old woman has had severe hip pain for 4 months. Her plain radiographs (Slide 1), technetium bone scan (Slide 2), computerized tomography scan (Slide 3), and coronal T1- and T2-weighted magnetic resonance images (Slide 4) are presented. The most likely diagnosis based upon the radiographs would be:

Question 61

Where does the median nerve pass in the proximal forearm?

Explanation

DISCUSSION: The median nerve passes through the pronator teres and deep to the flexor digitorum superficialis. The ulnar artery passes deep to both.
REFERENCES: Anderson JE (ed): Grant’s Atlas of Anatomy, ed 7. Baltimore, MD, Williams and Wilkins, 1978, pp 6-55.
Hoppenfeld S, deBoer P: Surgical Exposures in Orthopaedics: The Anatomic Approach. Philadelphia, PA, JB Lippincott, 1984, p 120.

Question 62

Figures 70a and 70b show the sagittal MRI scan and axial CT of a patient who has decreased range of motion in the cervical spine. In which of the following directions would the cervical motion be most significantly limited?

Explanation

MRI and CT demonstrate an abnormality in the alantoaxial region (C1-C2). See chart in reference. “C1-C2 -Flexion/Extension 30 degrees - Sidebending 10 degrees - Rotation – 70 degrees”

Question 63

A further workup reveals elevations in serum cobalt and chromium levels and fluid collections surrounding the hip on MARS MR imaging. Revision THA is recommended. The most common complication following revision of a failed metal-on-metal hip arthroplasty is

Explanation

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

Question 64

Figure 39 shows the AP radiograph of a 62-year-old man with degenerative osteoarthritis secondary to trauma. History reveals that he underwent total elbow arthroplasty 3 years ago. He continues to report instability and constant pain. A complete work-up, including aspiration and cultures, is negative. Treatment should consist of removal of the components and

Explanation

DISCUSSION: An unconstrained prosthesis dislocation is a disconcerting problem that is not easily resolved; however, revision to a semiconstrained prosthesis would best achieve both pain relief and stability. Removal of the components and distraction arthroplasty or conversion to a resection arthroplasty are options, but the results would be unpredictable with regards to pain relief, postoperative motion, or elbow stability. Arthrodesis is poorly tolerated. With revision to another unconstrained prosthesis, there is the risk of continued redislocation because of chronic ligamentous insufficiency.
REFERENCES: Linscheid RL: Resurfacing elbow replacement arthroplasty: Rationale, technique and results, in Morrey BF (ed): The Elbow and Its Disorders, ed 3. Philadelphia, PA, WB Saunders, 2000, pp 602-610.
Morrey BF, King GJ: Revision of failed total elbow arthroplasty, in Morrey BF (ed): The Elbow and Its Disorders, ed 3. Philadelphia, PA, WB Saunders, 2000, pp 685-700.

Question 65

-Which type of cells has been implicated in the process shown inFigure?

Explanation

Question 66

Exostoses in which of the following anatomic locations is the most likely to undergo malignant transformation in a patient with multiple hereditary exostosis (MHE)?

Explanation

DISCUSSION: Although osteochondromas can occur in almost every bone in patients with MHE, proximally located lesions are more likely to undergo malignant transformation. Annual radiographs of the shoulder girdles and pelvis are indicated in patients with MHE. Any enlarging osteochondromas are a concern as possible malignancies.
REFERENCES: Peterson HA: Multiple hereditary osteochondromata. Clin Orthop 1989;239:222.
McCornack EB: The surgical management of hereditary multiple exostosis. Orthop Rev 1981;10:57.

Question 67

Refers to the effectiveness of various antibiotics against a particular microorganism.

Explanation

DISCUSSION
Knowledge of the basic nomenclature of antibiotic use is important to effectively treat patients and communicate with colleagues. The effectiveness of an antimicrobial against an infecting organism is measured by the MIC, which refers to the concentration needed to prevent growth of a microorganism on culture medium, and MBC, which is the smallest concentration of the antibiotic necessary to kill the microorganism in culture. Typically, an antibiotic is considered bactericidal if the MBC is no more than 4 times the MIC. The spectrum of antimicrobial coverage refers to an agent’s effectiveness against a range of bacteria. An antibiogram refers to the tabulation of prevalence of different bacteria in a specific setting or specific patient population. Antibiotic susceptibility and resistance refers to the bacteria’s ability to be affected or unaffected by a given antibiotic.

Question 68

A 45-year-old woman has severe anterior knee pain. Her radiographs indicate end-stage patellofemoral compartment osteoarthritis. The tibiofemoral compartments are preserved. Extensive nonsurgical treatment has failed to provide relief, and she is offered patellofemoral arthroplasty (PFA). What is the most common long-term mode of failure for PFA using an implant with an onlay prosthesis design?

Explanation

DISCUSSION:
Contemporary onlay-design trochlear prostheses in PFA replace the entire anterior trochlear surface. Previous inlay designs were inset within the native trochlea and carried a higher risk of catching and patellar instability, particularly in patients with trochlear dysplasia; they also generally have higher failure rates. The current most common mode of failure is progression of arthritis throughout the knee, in some series as high as 25% at 15 years. Aseptic loosening, particularly of cemented implants, is less common. Infection is an uncommon long-term complication. Patients considering PFA should be advised of the risk of arthritis progression. Many authors routinely obtain a preoperative MRI to assess the status of the tibiofemoral compartments.

Question 69

An MRI scan of the brain of a patient with spastic diplegia will most likely show

Explanation

Microcephaly literally means small brain. This is used to identify certain primary developmental anomolies as well as secondary changes seen in neonatal hypoxia and encephalomalacia. These individuals demonstrate long survival, but with moderate mental retardation and variable spastic weakness. Though they can show the physical characteristics of the question above, it is not a diagnostic feature in spastic diplegics. Unless, of course, their spastic diplegia is specifically related to developmental anoxic event (cerebral palsy) causing a compromise in total mass brain tissues.
Agnesis of the corpus callosum is a rare anomaly that is asymptomatic neurologically unless tests designed specifically to test the transfer of information from one cerebral hemisphere to another is employed. Additionally, the corpus callosum is intimately related to the development of the limbic system which governs major CNS roles as behavior, memory, and emotions. Therefore, this would not involve the neurologically challenged spastic diplegic individuals.

Question 70

Figure 99 shows a dorsal approach for a midfoot arthrodesis following a Lisfranc injury in a 43-year-old woman. The base of the second metatarsal is labeled with the letter B. The interval used to create this exposure is

Explanation

DISCUSSION
The interval shown is between the extensor hallucis longus (left) and the extensor hallucis brevis (right), which is not an internervous plane because both are innervated by the deep peroneal nerve. The neurovascular bundle is under the extensor hallucis brevis muscle. Both
muscles are innervated by branches of the deep peroneal nerve. The superficial peroneal

Question 71

The subcutaneous nerve most at risk for transection during an anterior surgical exposure of the ankle is the

Explanation

DISCUSSION
The dorsal medial cutaneous nerve arising from the superficial peroneal nerve crosses the inferior extent of a routine extensile surgical exposure to the ankle joint. The extensile anterior incision develops the interval between the tibialis anterior and extensor hallucis tendons, and, although the deep peroneal nerve is lateral and posterior to the extensor hallucis longus, the nerve most at risk during this exposure is the cutaneous branch supplying the dorsal medial foot to the great toe. Ankle replacement surgery is becoming more common; consequently, surgeons must be familiar with this anatomic landmark and risks related to its transection during surgery.
The medial plantar nerve is at risk when medial hindfoot incisions are made through the
abductor hallucis muscle during tarsal tunnel release and harvest of the flexor hallucis tendon for transfer. The dorsal cutaneous branch of the sural nerve supplies the lateral dorsal

Question 72

A 16-year-old boy has had left knee pain and swelling after sustaining a minor twisting injury while playing basketball 2 weeks ago. Figures 5a through 5e show the radiograph, MRI scans, and biopsy specimens. What is the most likely diagnosis?

Explanation

DISCUSSION: The imaging studies and histology are most consistent with Ewing’s sarcoma. Tuberculosis can show small round blue cells on histology (lymphocytes associated with chronic infection) but would more typically involve the knee joint and periarticular bone. Osteosarcoma and MFH do not have small round blue cells histologically.
REFERENCES: Sissons HA, Murray RO, Kemp HBS: Orthopaedic Diagnosis. Berlin, Springer-Verlag, 1984, pp 254-256.
Wafa H, Grimer RJ: Surgical options and outcomes in bone sarcoma. Expert Rev Anticancer Ther 2006;6:239-248.

Question 73

A 45-year-old man underwent a fingertip amputation through the distal phalanx after his ring finger was caught in a garage door. He was treated in the emergency department with a revision amputation by advancement of the flexor digitorum profundus (FDP) tendon to the extensor mechanism. Three months following the injury, he is able to fully flex his injured ring finger to touch his palm, but he reports that it is difficult for him to make a tight fist due to decreased flexion of his other fingers. What is this complication called?

Explanation

EXPLANATION:
The quadrigia effect can occur due to over-advancement of the FDP tendon during repair (usually greater than 1 cm), development of FDP tendon adhesions, and (as in this case) "over the top" repair of the FDP tendon to the extensor tendon after amputation at the distal phalanx level. All of these conditions result in a functionally shortened FDP tendon of the injured digit. Because the FDP tendons of the long, ring, and small digits share a common muscle belly, excursion of the combined tendons is equal to the shortest tendon. Therefore, the uninjured digits will not have full excursion of their respective FDP tendons and will not be able to close into a full fisting position. Treatment of this condition is most commonly release
of the injured FDP tendon. A lumbrical plus deformity can occur in amputations distal to the flexor digitorum superficialis insertion through the middle phalanx. The FDP tendon retracts and increases tension on the lumbrical muscle, which leads to paradoxical interphalangeal (IP) joint extension with attempted flexion. Intrinsic tightness and interphalangeal joint contractures can be caused by hand trauma but would not lead to the clinical condition this patient has.

Question 74

Which of the following is a long-term complication of ankle arthrodesis for posttraumatic arthritis?

Explanation

DISCUSSION: Ankle arthrodesis for posttraumatic ankle arthrosis provides reliable pain relief. However, the long-term sequela of joint arthrodesis is the development of arthrosis in the surrounding joints. Over time, following ankle arthrodesis, the ipsilateral hindfoot and midfoot joints show signs of joint space wear, and this may be symptomatic. With a stable ankle arthrodesis, progressive limb-length discrepancy or talar osteonecrosis is not expected. Ankle arthrodesis has not been definitively linked to ipsilateral knee arthritis or contralateral ankle arthritis.
REFERENCES: Coester LM, Saltzman CL, Leupold J, Pontarelli W: Long-term results following ankle arthrodesis for post-traumatic arthritis. J Bone Joint Surg Am 2001;83:219-228.
Mazur JM, Schwartz E, Simon SR: Ankle arthrodesis: Long-term follow-up with gait analysis. J Bone Joint Surg Am 1979;61:964-975.

Question 75

A 13-year-old gymnast presents with ongoing knee pain for the past few months. She tried conservative measures including kinesiotaping, physical therapy and rest. On physical exam, she has normal valgus alignment, negative patellar tilt and discomfort with resisted open chain knee extension. A representative radiographs are shown in Figure A-C. What is the most likely clinical diagnosis? Review Topic

Explanation

Based on history, physical examination and radiographic findings this patient has patellofemoral syndrome
Evaluation of a patient with patellofemoral pain requires a physical examination and plain radiographs. Appropriate examination of all structures around the knee is critical to rule out other diagnoses. An MRI is useful for evaluating intra-articular or intra-osseous lesions, if clinical suspicion is suggestive of this. Treatment is predominantly conservative, with focus on low impact exercises that maximize aerobic conditioning.
Earl et al. review the epidemiology, etiology and management of patellofemoral syndrome. They note that there is no clear cause of this issue, although issues related to the quadriceps and dynamic malalignment may be contributory.
Outerbridge et al. describe overuse injuries in the young athletic patient. They provide an overview of diagnosis and management specific to this patient population.
Figures A, B and C show AP, lateral and merchant radiographs of a normal knee in a skeletally immature individual. No osseous abnormalities are identified.
Incorrect

Question 76

An 18-year-old lacrosse player sustained a hamstring pull during a game. Examination the next day reveals ecchymosis through the posterior thigh and a palpable defect in the hamstring musculature in the middle third of the thigh. What is the most likely site of anatomic injury?

Explanation

DISCUSSION: Hamstring strains are common in athletes. Basic science research and clinical data indicate that the majority of these injuries occur at the myotendinous junction, not within the muscle belly. Avulsion of hamstring origin from the ischial tuberosity does occur but is less common. Complete tearing of all hamstring muscles is unlikely to occur.
REFERENCES: Griffin LY (ed): Orthopaedic Knowledge Update: Sports Medicine. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1994, pp 17-33.
Clanton TO, Coupe KJ: Hamstring strains in athletes: Diagnosis and treatment. J Am Acad Orthop Surg 1998;6:237-248.

Question 77

A 52-year-old woman underwent open reduction and internal fixation for radial and ulnar shaft fractures 2 months ago. In a second fall she refractured her forearm and required revision surgery with bone grafting. One month after the second operation she notes erythema, swelling, and drainage from the volar radial incision. In addition to antibiotic treatment, management should consist of

Explanation

DISCUSSION: Deep infections after plating of closed fractures of the forearm are unusual. However, the risk increases with repeat surgeries. Debridement of all infected, nonviable tissue is the initial step in management. The fixation may be retained if it is stable, but if the plate and screws are loose, they should be removed and revision performed after removal of nonviable bone. Either external fixation or repeat plating may be performed. Late infections after fracture union may be treated with plate and screw removal, debridement, and IV antibiotics.
REFERENCES: Kellam JF, Fischer TJ, Tornetta P III, Bosse MJ, Harris MB (eds): Orthopaedic Knowledge Update: Trauma 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000, pp 53-63.
Moed BR, Kellam JF, Foster RJ, Tile M, Hansen ST Jr: Immediate internal fixation of open fractures of the diaphysis of the forearm. J Bone Joint Surg Am 1986;68:1008-1017.
Chapman MW, Gordon JE, Zissimos AG: Compression-plate fixation of acute fractures of the diaphysis of the radius and ulna. J Bone Joint Surg Am 1989;71:159-169.

Question 78

A patient sustained the injuries shown in the radiographs and clinical photograph seen in Figures 10a through 10c. The neurovascular examination is normal. The first step in emergent management of the extremity injuries should consist of

Explanation

DISCUSSION: The figures show an open tibial fracture, a femoral shaft fracture, and femoral head dislocation. The most urgent treatment is reduction of the femoral head, as timing to reduction has been correlated with preventing osteonecrosis. After reduction of the femoral head, the next priority is wound management, followed by stabilization of the femoral and tibial fractures with either splinting, traction, or external fixation.
REFERENCES: Sahin V, Karakas ES, Aksu S, et al: Traumatic dislocation and fracture-dislocation of the hip: A long-term follow-up study. J Trauma 2003;54:520-529.
Moed BR, WillsonCarr SE, Watson JT: Results of operative treatment of fractures of the posterior wall of the acetabulum. J Bone Joint Surg Am 2002;84:752-758.

Question 79

A 14-year-old boy reports a 4-month history of increasing backache with difficulty walking long distances. His parents state that he walks with his knees slightly flexed and is unable to bend forward and get his hands to his knees. He denies numbness, tingling, and weakness in his legs and denies loss of bladder and bowel control. A lateral radiograph of the lumbosacral spine is shown in Figure 18. What is the best surgical management for this condition?

Explanation

DISCUSSION: The patient has a grade 4 spondylolisthesis. Optimal surgical management is posterior spinal fusion from L4 to the sacrum. The use of instrumentation is controversial. Vertebrectomy is typically reserved for spondylo-optosis (grade 5) cases. Spinal fusion from

L5 to S1 usually is not successful for a slip that is greater than 50%. Isolated anterior spinal fusion has not been successful, and direct repair of the pars defect is only useful for spondylolysis without spondylolisthesis.
REFERENCES: Lenke LG, Bridwell KH: Evaluation and surgical treatment of high-grade isthmic dysplastic spondylolisthesis. Instr Course Lect 2003;52:525-532.
Ginsburg GM, Bassett GS: Back pain in children and adolescents: Evaluation and differential diagnosis. J Am Acad Orthop Surg 1997:5:67-78.

Question 80

What is the most common cause for poor outcomes in patients who undergo total shoulder arthroplasty?

Explanation

DISCUSSION: In an article in the Journal of Shoulder and Elbow, 431 total shoulder arthroplasties were performed with a cemented all-polyethylene glenoid component between 1990 and 2000. Follow-up averaged 4.2 years. In total, 53 surgical complications occurred in 53 patients (12%). Of these, 32 were major complications (7.4%), with 17 of these requiring reoperation. Index complications in order of frequency included rotator cuff tearing, postoperative glenohumeral instability, and periprosthetic humeral fracture. Notably, glenoid and humeral component loosening requiring reoperation occurred in only one shoulder. Data from the contemporary patient group suggest that there are fewer complications of shoulder arthroplasty and less need for reoperation. Especially striking is the near absence of component revision because of loosening or other mechanical factors. Complications involving the brachial plexus have been reported following total shoulder arthroplasty but are not as common of a cause for failure.
REFERENCES: Chin PY, Sperling JW, Cofield RH, et al: Complications of total shoulder arthroplasty: Are they fewer or different? J Shoulder Elbow Surg 2006;15:19-22.
Hasan SS, Leith JM, Campbell B, et al: Characteristics of unsatisfactory shoulder arthroplasties. J Shoulder Elbow Surg 2002;11:431-441.

Question 81

-What gene is implicated in spinal muscular atrophy?

Explanation

Question 82

The swelling pressure in cartilage is predominantly due to the association of exchangeable water with which of the following substances? Review Topic

Explanation

Biglycan and versican are two of the small proteoglycans in cartilage. Biglycan plays a role in molecular association between cartilage and other molecules. Versican is more associated with the cell surface and plays multiple roles. Aggrecan has a longer core protein with multiple keratin sulfate and chondroitin sulfate chains. The molecular weight is around 1,000,000. Aggrecan aggregates on hyaluronic acid with link proteins. Aggrecan can associate with 50 times its weight in water. The resulting swelling pressure is retained by 20% by type II collagen. This results in the physiologic properties of articular cartilage. Type IX collage plays a role in matrix molecule association with type II collagen.

Question 83

A 30-year-old man underwent an open Bankart repair with capsulorrhaphy for recurrent anterior instability 6 months ago. In a recent fall, he described a hyperabduction and external rotation mechanism of injury. He denies dislocating his shoulder. He now has anterior shoulder pain, weakness, and the sensation of instability. Examination reveals tenderness just lateral to the coracoid and bicipital groove. An MRI scan is shown in Figure 31. Management should now consist of

Explanation

DISCUSSION: Subscapularis tendon tears are being recognized with increasing frequency, and the mechanism of injury involves hyperabduction and external rotation. The patient will have anterior shoulder pain and may report a sensation of instability. Examination will reveal anterior shoulder tenderness over the lesser tuberosity and bicipital groove, and the Gerber lift-off test usually is positive. The MRI scan shown here reveals an intact anterior labrum. The subscapularis tendon is avulsed and retracted, with no evidence of the biceps tendon within the groove; this implies dislocation of the biceps, a common accompanying feature of a subscapularis tear. This injury is also recognized as a complication after open anterior shoulder stabilizations where the subscapularis has been incised as part of the approach. Therefore, the appropriate management involves repair of the subscapularis. The injury does not represent a recurrence so immobilization or revision stabilization, which may be reasonable treatment for recurrent instability, is not indicated. The findings are not consistent with a superior labral tear.
REFERENCES: Deutsch A, Altchek DW, Veltri DM, et al: Traumatic tears of the subscapularis tendon: Clinical diagnosis, magnetic resonance imaging findings, and operative treatment. Am J Sports Med 1997;25:13-22.
Gerber C, et al: Isolated rupture of the subscapularis tendon. J Bone Joint Surg Am 1996;78:1015-1023.

Question 84

Vertebral fractures are common in the thoracolumbar spine. What is the most important factor that determines the strength of the cancellous bone in the vertebral body?

Explanation

DISCUSSION: Cancellous bone strength and stiffness are determined primarily by the apparent density (the amount of bone per unit volume). Strength varies approximately as the square of the density, and stiffness as the cube of the density; therefore, these are very strong relationships. Cancellous bone strength also depends on the mineral content, the rate of loading (it is viscoelastic), the anatomic level, and the trabecular number (an histomorphometry term), but all to a markedly lesser extent than density.
REFERENCES: Carter DR, Hayes WC: The compressive behavior of bone as a two-phase porous structure. J Bone Joint Surg Am 1977;59:954-962.
Keaveny TM: Strength of trabecular bone, in Cowin SC (ed): Bone Mechanics Handbook. Boca Raton, FL, CRC Press, 2001, pp 16-1-16-8.

Question 85

A full-term newborn has webbing at the knees, rigid clubfeet, a Buddha-like posture of the lower extremities, and no voluntary or involuntary muscle action at and below the knees. Radiographs of the spine and pelvis reveal an absence of the lumbar spine and sacrum. What maternal condition is associated with this diagnosis?

Explanation

DISCUSSION: The history, physical examination, and radiographic findings are consistent with type IV sacral agenesis or caudal regression syndrome. These children are born with no lumbar spine or sacrum. The T12 vertebra is often prominent posteriorly. Popliteal webbing and knee flexion contractures are common with this diagnosis. There is a higher incidence of this diagnosis when the mother has diabetes mellitus. Maternal drug abuse and alcoholism can produce phenotypically unique children but without the findings described here. Maternal idiopathic scoliosis is not associated with caudal regression syndrome.
REFERENCES: Chan BW, Chan KS, Koide T, et al: Maternal diabetes increases the risk of caudal regression caused by retinoic acid. Diabetes 2002;51:2811-2816.
Zaw W, Stone DG: Caudal regression syndrome in twin pregnancy with type II diabetes.

J Perinatol 2002;22:171-174.

Question 86

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

Explanation

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

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

Question 87

During an open reduction internal fixation of a humerus fracture using the posterior approach, a surgeon can identify the posterior antebrachial cutaneous nerve and trace it proximally to which of the following nerves?

Explanation

DISCUSSION: The posterior antebrachial cutaneous nerve branches from the radial nerve in the axilla. It extends distally to innervate the skin on the back of the arm. Gerwin et al recommended identifying the nerve first when approaching the humerus from the posterior shaft. It can be traced proximally to safely identify the radial nerve before any proximal exposure of the shaft is done. Gerwin et al in their review also found that the radial nerve crossed the posterior aspect of the humerus an average of 20.7 +/- 1.2 centimeters proximal to the medial epicondyle to 14.2 +/-

Question 88

Figure 42 shows the sagittal T2-weighted MRI scan of a patient’s right knee. These findings are most commonly seen with a complete tear of the

Explanation

DISCUSSION: The MRI scan reveals disruption of the lateral capsule and ligaments with

fluid in the soft tissues laterally. Additionally, there is a large bone bruise on the medial

femoral condyle. This combination indicates injury to the posterolateral complex. These injuries often have coexisting anterior and/or posterior cruciate ligament injuries. Failure to recognize the posterolateral corner injury can lead to failure of anterior or posterior cruciate ligament reconstructions.
REFERENCES: LaPrade RF, Gilbert TJ, Bollom TS, et al: The magnetic resonance imaging appearance of individual structures of the posterolateral knee: A prospective study of normal knees and knees with surgically verified grade III injuries. Am J Sports Med 2000;28:191-199.
Ross G, Chapman AW, Newberg AR, et al: Magnetic resonance imaging for the evaluation of acute posterolateral complex injuries of the knee. Am J Sports Med 1997;25:444-448.

Question 89

A 24-year-old man has bilateral hip pain. An examination and imaging studies (plain radiographs and MR imaging) confirm evidence of femoroacetabular impingement (FAI) with a CAM deformity in both hips. The patient mentions that he has a 19-year-old brother who has occasional hip pain. With respect to his brother’s pain, how should you counsel the patient?

Explanation

CLINICAL SITUATION FOR QUESTIONS 145 THROUGH 147
Figures 145a and 145b are the radiographs of a 56-year-old man who has had persistent pain in his right groin since undergoing primary total hip surgery 11 months ago. His erythrocyte sedimentation rate (ESR) is 38 mm/h (reference range [rr], 0-20 mm/h) and C-reactive protein (CRP) level is 28 mg/L (rr, 0.08-3.1 mg/L). A hip aspiration performed while the patient was taking antibiotics demonstrated 3200 white blood cells/µL with no growth. Treatment should consist of

Question 90

The nerve to the abductor digiti quinti, implicated in some patients who have chronic heel pain, is most commonly a branch of what larger nerve?

Explanation

DISCUSSION: The nerve to the abductor digiti quinti is the first branch of the lateral plantar nerve. It branches off while the nerve is still on the medial side of the foot and also innervates a portion of the plantar fascia. It can become entrapped beneath the deep fascia of the abductor hallucis muscle and has been associated with some forms of chronic heel pain.
REFERENCES: Baxter DE, Pfeffer GB: Treatment of chronic heel pain by surgical release of the first branch of the lateral plantar nerve. Clin Orthop 1992;279:229-236.
Schon LC, Glennon TP, Baxter DE: Heel pain syndrome: Electrodiagnostic support for nerve entrapment. Foot Ankle 1993;14:129-135.

Question 91

A 30-year-old man underwent replantation of his dominant thumb at the metacarpophalangeal joint level 2 days ago. Since replantation, the temperature of the thumb has been between 87.8 F (31 C) and 93.2 F (34 C). The temperature is now 82.4 F (28 C), and there is brisk capillary refill and venous engorgement. Management at this time should include

Explanation

Discussion: The patient is experiencing impending failure of the replanted thumb. In a study by Moneim and Chacon, they found that vascular thrombosis in the postoperative period is the major factor in failure after replantation. When it occurs, it has to be aggressively dealt with by surgical exploration and revision of the vascular repair. The best results are obtained within 11 hours of the repair and nonsurgical management uniformly led to failure.

Question 92

Reconstruction of the injured structure is performed. After surgery, the patient initially notes limitation in motion, and later develops recurrent instability of the knee. Which factor most likely contributed to the development of instability?

Explanation

DISCUSSION
The anteromedial bundle originates on the anterior and proximal aspect of the lateral femoral condyle and inserts on the anteromedial aspect of the anterior cruciate ligament (ACL) footprint on the proximal tibia. The posterolateral bundle originates posterior and distal to 63 the anteromedial bundle and inserts on the posterolateral aspect of the tibial footprint. The fibers are parallel when the knee is in an extended position. As the knee moves into flexion,
the fibers of the anteromedial bundle rotate externally with respect to the posterolateral bundle. The anteromedial bundle is tensioned in both flexion and extension. The posteromedial bundle is tensioned in extension, but relaxes as the knee moves into flexion.
The lateral meniscus is more commonly injured with an acute injury to the ACL. The medial meniscus is injured more commonly when the ACL is chronically unstable.
The ACL is an intra-articular and intrasynovial structure. It is innervated by posterior articular branches from the tibial nerve. Innervation of the ACL involves several types of mechanoreceptors (Ruffini, Pacini, Golgi tendon, and free-nerve endings) that may contribute to proprioceptive function of the knee and modulation of quadriceps function.
Injury to the ACL is predominantly associated with instability to anterior translation of the tibia in extension. The ACL plays a secondary role to limit internal rotation of the tibia, and a loss of ACL stability is confirmed by the reduction of the tibia from a position of anterior translation and internal rotation (pivot shift). The radiographs demonstrate anterior placement of the femoral tunnel. The convex shape of the lateral femoral condyle can make it more difficult to visualize the anatomic femoral origin of the ACL. Failure to identify the
anatomic footprint can result in anterior placement of the femoral tunnel. Anterior ACL graft placement can result in its impingement against the posterior cruciate ligament and early limitation of knee flexion. Over time, impingement on the graft may result in stretching of the graft and recurrent knee instability symptoms.
RECOMMENDED READINGS
Duthon VB, Barea C, Abrassart S, Fasel JH, Fritschy D, Ménétrey J. Anatomy of the anterior cruciate ligament. Knee Surg Sports Traumatol Arthrosc. 2006 Mar;14(3):204-13. Epub 2005 Oct 19. Review. PubMed PMID: 16235056. View Abstract at PubMed
Zantop T, Petersen W, Sekiya JK, Musahl V, Fu FH. Anterior cruciate ligament anatomy and function relating to anatomical reconstruction. Knee Surg Sports Traumatol Arthrosc. 2006 Oct;14(10):982-92. Epub 2006 Aug 5. Review. PubMed PMID: 16897068. View Abstract at PubMed

Question 93

When treating a stable 2-part intertrochanteric hip fracture with a sliding hip screw construct, what is the minimum amount of screw holes that are needed in the side plate for successful fixation?

Explanation

DISCUSSION: A two part stable intertrochanteric femur fracture can be treated with a sliding hip screw, with good biomechanical and clinical results.
The referenced article by Bolhofner et al reviews a series of 69 patients with a sliding hip screw and two hole side plate and notes that they did not have any failure of the side plate construct.
The referenced article by McLoughlin et al is a biomechanical evaluation of 2 versus 4 hole plates and found that peak load in the failure test was not found to be statistically different between the two-hole and four-hole designs. In cyclic testing, the two-hole configuration exhibited statistically smaller fragment migration in both shear and distraction than the four-hole design.

Question 94

Figures 1 through 3 are the weight-bearing radiograph and MRI scans of a 27-year-old man who twisted his knee coming down awkwardly from a lay-up during a basketball game. He felt a sharp stabbing pain in the posterior aspect of his knee at the time of the injury. Physical examination reveals a trace effusion, full range of motion but pain with hyperflexion >90° degrees and tenderness over the affected joint line. What is the most appropriate treatment at this time?

Explanation

The MRI scan shows a posterior horn medial meniscus root avulsion with bony edema at the tibial root insertion. The radiograph shows no significant degenerative changes. If left untreated, posterior meniscal
root tears lead to progressive degenerative changes as a result of the altered tibiofemoral contact pressures and areas. Nonsurgical treatment including injections, physical therapy, and unloader braces are more appropriate in the older patient with pre-existing advanced degenerative changes.

Question 95

A 37-year-old electrician is diagnosed with a frozen shoulder after sustaining an electrical injury at work 2 weeks ago. Examination reveals that he cannot actively or passively externally rotate or abduct the arm. The glenohumeral joint and scapula move in a 1:1 ratio. Radiographs are shown in Figures 15a and 15b. The best course of action should be

Explanation

DISCUSSION: The patient’s history, examination, and radiographs are classic for locked posterior dislocation of the glenohumeral joint. Posterior dislocation of the shoulder remains the most commonly missed dislocation of a major joint. Up to 80% are missed on initial presentation. The primary cause for failure to accurately diagnose this injury is inadequate radiographic evaluation. The typical presentation is a shoulder locked in internal rotation with loss of abduction. An axillary view not only will make the definitive diagnosis but will help assess the size of the articular surface defect and help plan treatment. This view can be done expediently as part of every trauma series. The AP view is suspicious for a posteriorly dislocated humerus with loss of the humeral neck profile, a vacant glenoid sign, and an anterior humeral head compression fracture (reverse Hill-Sachs lesion).
REFERENCES: Hawkins RJ, Neer CS II, Pianta RM, Mendoza FX: Locked posterior dislocation of the shoulder. J Bone Joint Surg Am 1987;69:9-18.
Norris TR (ed): Orthopaedic Knowledge Update: Shoulder and Elbow. Rosement, IL, American Academy of Orthopaedic Surgeons, 1997, pp 181-189.
Rockwood CA Jr, Thomas SC, Matsen FA III: Subluxations and dislocations about the glenohumeral joint, in Rockwood CA Jr, Green DP, Bucholz RW (eds): Fractures in Adults, ed 3. Philadelphia, PA, JB Lippincott, 1991, vol 1, pp 1058-1065.

Question 96

Which repair technique for an osteochondral lesion of the medial talus shoulder produces hyaline cartilage that is similar to native cartilage and will not degrade over time?

Explanation

DISCUSSION
Autologous osteochondral transplantation (typically involving tubular grafts harvested from the knee) has been shown to replace a talar defect with viable hyaline cartilage. The results over the medium term show good clinical outcomes, and MRI studies reveal cartilage repair similar to native cartilage. Chondroplasty and arthroscopic bone-marrow stimulation are both associated with good clinical results for smaller lesions, but these techniques develop fibrocartilaginous repair tissue composed of type I collagen instead of hyaline cartilage. Osteochondral transplantation of fresh allografts performed less than 14 days after harvest contains high chondrocyte viability. Few clinical studies report long-term results, but radiographic studies demonstrate high rates of collapse and resorption. Joint space narrowing has been noted in 60% of ankles treated with bulk grafts after an average of 44 months. Autologous chondrocyte implantation (both periosteum-covered and matrix-associated techniques) has been shown to create hyaline cartilage in some studies, but fibrocartilage creation has been reported in others.
RECOMMENDED READINGS
Schachter AK, Chen AL, Reddy PD, Tejwani NC. Osteochondral lesions of the talus. J Am Acad Orthop Surg. 2005 May-Jun;13(3):152-8. Review. PubMed PMID: 15938604. View Abstract at PubMed
Mitchell ME, Giza E, Sullivan MR. Cartilage transplantation techniques for talar cartilage lesions. J Am Acad Orthop Surg. 2009 Jul;17(7):407-14. Review. PubMed PMID: 19571296. View Abstract at PubMed
Murawski CD, Kennedy JG. Operative treatment of osteochondral lesions of the talus. J Bone Joint Surg Am. 2013 Jun 5;95(11):1045-54. doi: 10.2106/JBJS.L.00773. Review. PubMed PMID: 23780543. View Abstract at PubMed

Question 97

A 45-year-old woman with stage II posterior tibial tendinitis has failed to respond to nonsurgical management. Recommended treatment now includes posterior tibial tendon debridement and medial calcaneal displacement osteotomy along with transfer of what tendon?

Explanation

DISCUSSION: The flexor digitorium longus is the commonly accepted tendon transfer for posterior tibial tendon insufficiency. The flexor hallucis longus has to be carefully rerouted to avoid crossing the neurovascular bundle and has not been shown clinically to provide superior results to flexor digitorum longus transfer. Use of the peroneus longus results in loss of plantar flexion strength of the first metatarsal, contributing to the flatfoot deformity. The anterior tibial tendon is in the anterior compartment and fires out of phase with the posterior tibial tendon.
REFERENCES: Sitler DF, Bell SJ: Soft tissue procedures. Foot Ankle Clin 2003;8:503-520.
Guyton GP, Jeng C, Krieger LE, et al: Flexor digitorum longus transfer and medial displacement calcaneal osteotomy for posterior tibial tendon dysfunction: A middle-term clinical follow-up. Foot Ankle Int 2001;22:627-632.

Question 98

The histology of the lesion is shown in Figure 101d. What is the most likely complication after treatment of this lesion?

Explanation

DISCUSSION FOR QUESTIONS 101 THROUGH 103:
The MRI scans show a well-circumscribed inhomogenous mass at the anterior ankle joint consistent with a diagnosis of pigmented villonodular synovitis (PVNS), not an anatomic variant. An inflammatory mass,such as the pannus of rheumatoid arthritis, would reveal moderate signal intensity with relatively uniform signal throughout. The mass is well encapsulated, respecting tissue boundaries and not showing invasive characteristics as malignancies would. The arthroscopic image is also consistent with the reddish-brown frond-like tissue of PVNS. PVNS of the ankle can be treated arthroscopically. If this mode of treatment is chosen, a tissue sample should be sent to pathology for microscopic analysis; débridement should be performed on the remaining tissue. Removal of the instrumentation without débridement will not provide treatment and will result in disease progression. Tourniquet placement does not provide therapeutic benefit.
Brachytherapy has not been described for the treatment of PVNS of the ankle. The histologic image shows multiple multinucleated giant cells, hemosiderin, and very few mitotic figures – consistent with a diagnosis of PVNS. A common complication of PVNS treatment is local recurrence. Arthrofibrosis and chondrolysis are not seen with proper surgical care of these patients. Because this is not an infectious lesion, disseminated infection after treatment is highly unlikely. PVNS rarely metastasizes.
RESPONSES FOR QUESTIONS 104 THROUGH 106
Toe is fused too straight (plantar flexed)
Toe is fused in too much valgus
Toe is fused in too much dorsiflexion
There is a nonunion of the fusion
Excessive shortening of the first metatarsal during preparation for fusion What is the most likely diagnosis for each patient?

Question 99

A 20-year-old football player sustains a dorsiflexion external rotation injury to his right ankle. During sideline evaluation, which of the following findings best indicates a syndesmosis ankle sprain without diastasis?

Explanation

DISCUSSION: The inability to single leg hop is considered the best indicator of a syndesmosis ankle sprain without diastasis. Tenderness along the syndesmosis, the deltoid, or over the anterior talofibular ligament or anterior distal tibia/fibula may present later, following the initial injury. The squeeze test and tenderness with dorsiflexion and external rotation may be positive but often are not present initially. The best determinant for prediction of return to play is the amount of tenderness along the syndesmosis, measured from the distal fibula up the syndesmosis.
REFERENCES: Nussbaum ED, Hosea TM, et al: Prospective evaluation of syndesmosis ankle sprains without diastasis. Am J Sports Med 2001;29:31-35.
Miller CD, Shelton WR, Barrett GR, et al: Deltoid and syndesmosis ligament injury of the ankle without fracture. Am J Sports Med 1985;23:746-750.
Amendola A: Controversies in diagnosis and management of syndesmosis injuries of the ankle. Foot Ankle 1992;13:44-50.

Question 100

A 61-year-old man reports right shoulder pain and loss of external rotation since having a seizure 5 months ago. MRI scans are shown in Figures 82a and 82b. What is the most appropriate treatment? Review Topic

Explanation

The patient has a chronic posterior shoulder dislocation with loss of approximately half of the humeral head. Hemiarthroplasty or osteochondral allograft to fill the defect would be required. Given the time since injury, the remaining native head and articular surface may have lost structural integrity, making hemiarthroplasty the preferred choice. The implant should be placed close to the patient's natural version, which normally is in the range of 20 to 30 degrees of retroversion. Excessive anteversion is not recommended to avoid repeat posterior dislocation. Closed reduction is highly unlikely to achieve a reduction and may cause displacement of an unrecognized humeral surgical neck fracture. Open reduction and lesser tuberosity transfer is best suited for smaller head defects and a less chronic dislocation. Glenoid integrity is not affected, thus a glenoid implant is unnecessary.

Full Question & Answer Text (for Search Engines)

Question 1:

03 The sagittal oblique MRI scan shown in Figure 70 reveals a lesion in the shoulder that typically affects what neurologic structure?

Options:

– Axillary nerve
– Musculocutaneous nerve
– Long thoracic nerve
– Suprascapular nerve to the infraspinatus muscle
– Suprascapular nerve to the supraspinatus muscle back answer Question 199.03

Correct Answer: – Suprascapular nerve to the infraspinatus muscle

Explanation:

Question 2:

Options:

Medial femoral circumflex
Obturator
Iliac circumflex
Femoral

Correct Answer: Femoral

Explanation:

DISCUSSION
Video 182 for reference
The femoral artery crosses the hip joint anterior to the anterior hip capsule. The medial femoral circumflex artery enters the joint along the route of the obturator externus. The obturator artery enters the hip joint beneath the transverse acetabular ligament. The iliac circumflex vessel arises superior to the hip joint.
RESPONSES FOR QUESTIONS 183 THROUGH 188
For each clinical scenario described below, identify the corresponding anteroposterior pelvic radiographic image shown above.

Question 3:

Options:

supportive immobilization until the patient is pain-free.
coracoclavicular ligament repair.
open reduction and internal fixation of the acromioclavicular dislocation.
resection of the distal clavicle and Weaver and Dunn reconstruction.
open biopsy of the calcific mass.

Correct Answer: supportive immobilization until the patient is pain-free.

Explanation:

Question 4:

Options:

Spiral groove of the humerus
Midshaft of the radius
Radial neck
Anatomic neck of the humerus
Surgical neck of the humerus

Correct Answer: Radial neck

Explanation:

DISCUSSION: In this patient, the radial nerve is most likely injured at the level of the radial neck. The radial nerve emerges from the posterior cord of the brachial plexus and travels along the spiral groove of the humerus. At the level of the lateral humeral condyle, the radial nerve branches into the posterior interosseous nerve after giving off two cutaneous branches, the superficial radial and the posterior cutaneous. The posterior interosseous nerve travels through the supinator muscle and winds around the radial neck. At this level, the posterior interosseous nerve is vulnerable to injury, particularly following fracture or penetrating trauma.
REFERENCES: Netter F: The Ciba Collection of Medical Illustrations: The Musculoskeletal System, Part 1: Anatomy, Physiology and Metabolic Disorders. West Caldwell, NJ, Ciba-Geigy Corporation, 1987, vol 8, p 53.
Hollinshead W: Anatomy for Surgeons: The Back and Limbs, ed 3. Philadelphia, PA, Harper and Row, 1982, vol 3, pp 428-429.

Question 5:

Options:

Open reduction and internal fixation (ORIF) of the fracture
Removal of the current stem, femur ORIF, and insertion of a longer revision stem
Femur ORIF with cables and strut graft, leaving the current stem in situ
Femur ORIF combined with reimplantation of the primary component

Correct Answer: Removal of the current stem, femur ORIF, and insertion of a longer revision stem

Explanation:

Question 6:

Options:

Repeated measures analysis of variance
F test
Power analysis
Analysis of variance
Kruskal-Wallis test

Correct Answer: Power analysis

Explanation:

Question 7:

Figures 1 and 2 are the CT and MRI scans of a patient with shoulder instability. Contrasting these two imaging techniques for decision making in shoulder instability would suggest

Options:

Both CT and MRI have equivalent cost for the patient.
Both CT and MRI have equivalent safety for the patient.
Associated soft-tissue damage can be more reliably shown on CT scans.
Two-dimensional CT scans represent better definition of bone loss than two-dimensional MRI scans. Two-dimensional CT scan is generally accepted as a superior imaging modality for evaluating bone loss in shoulder instability than two-dimensional MRI scan. This advantage is offset by the relatively high radiation dose. Although CT in most situations is less costly, MRI can provide more data regarding associated soft-tissue damage that can be associated with recurrent instability. It should be noted that three-dimensional MRI has recently been shown as equivalent to three-dimensional CT in its ability to identify glenoid bone loss.

Correct Answer: Two-dimensional CT scans represent better definition of bone loss than two-dimensional MRI scans. Two-dimensional CT scan is generally accepted as a superior imaging modality for evaluating bone loss in shoulder instability than two-dimensional MRI scan. This advantage is offset by the relatively high radiation dose. Although CT in most situations is less costly, MRI can provide more data regarding associated soft-tissue damage that can be associated with recurrent instability. It should be noted that three-dimensional MRI has recently been shown as equivalent to three-dimensional CT in its ability to identify glenoid bone loss.

Explanation:

A 43-year-old woman is involved in a motor vehicle collision. She sustains the isolated injury shown in the radiograph in Figure 1. Her neurovascular examination is compromised. What is the most likely deficit?
A. Inability to flex the distal interphalangeal joint of the index finger
B. Positive Froment’s sign
C. Weakness with wrist extension
D. Decreased capillary refill

Question 8:

Options:

revision L5-S1 hemilaminotomy.
L5-S1 total disk arthroplasty.
L5 Gill laminectomy.
posterior foraminal decompression and fusion at L5-S1 with instrumentation and bone graft.
stand-alone posterior lumbar interbody fusion.

Correct Answer: posterior foraminal decompression and fusion at L5-S1 with instrumentation and bone graft.

Explanation:

DISCUSSION: The patient has a grade I isthmic spondylolisthesis at L5-S1. He has an L5 radiculopathy with foraminal stenosis. Any further treatment needs to include an arthrodesis and foraminal decompression. Isolated interbody fusion is contraindicated in patients with spondylolisthesis, as is total disk arthroplasty. Therefore, the best procedure is a posterior fusion with instrumentation and bone graft along with a foraminal decompression.
REFERENCES: Spivak JM, Connolly PJ (eds): Orthopaedic Knowledge Update: Spine 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, pp 311-317.
Moller H, Hedlund R: Instrumented and noninstrumented posterolateral fusion in adult spondylolisthesis: A prospective randomized study: Part 2. Spine 2000;25:1716-1721.

Question 9:

Options:

surgical exploration and tendon reinsertion of the flexor digitorum profundis.
surgical exploration and tendon reinsertion of the flexor digitorum superficialis.
steroids and physical therapy.
surgical release of the anterior interosseous nerve.
surgical release of the median nerve.

Correct Answer: surgical exploration and tendon reinsertion of the flexor digitorum profundis.

Explanation:

DISCUSSION: The patient has an avulsion of the flexor digitorum profundus. Treatment should include surgical exploration and tendon reinsertion. This is not an avulsion of the flexor digitorum superficialis because the patient’s deficiency is the inability to flex the distal interphalangeal joint, not the proximal interphalangeal joint. Surgical release of the anterior interosseous nerve is not indicated because the flexor digitorum profundus of the ring finger is innervated by the ulnar nerve. A median nerve contusion causes wrist pain and/or numbness and tingling in the median nerve distribution.
REFERENCES: Strickland JW: Flexor tendons: Acute injuries, in Green DP, Hotchkiss RN, Pederson WC (eds): Green’s Operative Hand Surgery, ed 4. Philadelphia, PA, 1999,
pp 1851-1897.
Leddy JP: Avulsions of the flexor digitorum profundus. Hand Clin 1985;1:77-83.

Question 10:

The direct anterior (Smith-Peterson) approach to hip arthroplasty is most commonly associated with injury to what nerve?

Options:

Lateral femoral cutaneous
Sciatic
Pudendal
Superior gluteal

Correct Answer: Lateral femoral cutaneous

Explanation:

Question 11:

Options:

Longer femoral tunnel
More anatomic graft placement
A more vertically oriented graft
Diminished risk of posterior tunnel wall violation ("blowout")
Diminished risk to lateral femoral articular cartilage and subchondral bone posteriorly

Correct Answer: More anatomic graft placement

Explanation:

Question 12:

Decreased risk of shoulder and elbow injury in a throwing athlete has been demonstrated with which of the following? Review Topic

Options:

Rotator cuff strengthening
Superior labral repair
Posterior capsular stretching
Periscapular muscle strengthening
Repair of partial-thickness rotator cuff tears

Correct Answer: Posterior capsular stretching

Explanation:

Question 13:

Options:

Electromyography and nerve conduction velocity studies
MRI
CT
Bone scan
Psychiatric evaluation

Correct Answer: MRI

Explanation:

Question 14:

Options:

UCL repair and nighttime elbow extension splinting
UCL repair with ulnar nerve decompression in situ
Allograft UCL reconstruction with interference screws
Autograft UCL reconstruction with ulnar nerve transposition
Autograft UCL reconstruction using a docking technique

Correct Answer: Autograft UCL reconstruction with ulnar nerve transposition

Explanation:

DISCUSSION: High-level pitchers with symptomatic UCL tears require reconstruction, with autograft being the best studied graft selection. With concomitant ulnar nerve symptoms, a simultaneous ulnar nerve transposition provides good results. Ligament “repairs” and allograft reconstructions have not shown good long-term results.
REFERENCES: Azar FM, Andrews JR, Wilk KE, et al: Operative treatment of ulnar collateral ligament injuries of the elbow in athletes. Am J Sports Med 2000;28:16-23.
Ciccotti MG, Jobe FW: Medial collateral ligament instability and ulnar neuritis in the athlete’s elbow. Instr Course Lect 1999;48:383-391.

Question 15:

The newborn foot deformity seen in Figures 64a and 64b should initially treated with

Options:

observation with possible stretching.
serial casting.
medial surgical release.
posterior medial surgical release.
dynamic ankle-foot orthosis.

Correct Answer: serial casting.

Explanation:

DISCUSSION: Mild to moderate metatarsus adductus is best treated with observation and possible passive stretching exercises because most of these feet will self correct. Numerous types of shoes, braces, and splints have been devised but the efficacy of these have not been determined. Serial casting is reserved for severe metatarsus adductus in the infant, although a medial surgical release may be indicated if the deformity is symptomatic and persists beyond age 4 years.
REFERENCES: Abel MF (ed): Orthopaedic Knowledge Update: Pediatrics 3. Rosemont, IL, American Academ
A
y
L-
o
M
f
ad
O
en
r
a
th
C
o
o
p
p
a
y
edic Surgeons, 2006, pp 240-241.
Farsetti P, Weinstein SL, Ponseti IV: The Long-term functional and radiographic outcomes of untreated
and non-operatively treated metatarsus adductus. J Bone Joint Surg Am 1994;76:257-265. Question 65
A 4-year-old girl has been limping for the past 2 months. There is no history of trauma, previous injury, fever, or other systemic complaints. Examination reveals a moderate right knee effusio n with a 10-degree knee flexion contracture. What is the next most appropriate step in evaluation?
Arthroscopy
Antinuclear antibody
MRI
Bone scan
HLA-B27
DISCUSSION: The patient presents with juvenile idiopathic arthritis manifestations. The American College of Rheumatology defines this as one or more joints involved with swelling of 6 weeks or longer. A positive antinuclear antibody test would be diagnostic. Consideration should be made to have the patient see an ophthalmologist for evaluation of possible uveitis. Although the patient could have Lyme disease, that choice is not an option. The presence of an elevated antinuclear antibody by itself should not necessarily be used for diagnosing arthritis; however, the test does have clinical utility as a screening test. The frequency of a positive antinuclear antibody test is greatest in younger girls with oligoarticular disease and carries an increased risk for anterior uveitis. Arthroscopy might be indicated if this patient was presenting with a discoid meniscus, but there is no history of clicking, which is often one of the classic signs of discoid meniscus. MRI would not be used to diagnose juvenile idiopathic arthritis, but
MRI would be useful to help diagnose discoid meniscus. A bone scan would show increased uptake in the patient’s knee but again, this would not help diagnose her condition. HLA-B27 has no role in diagnosing juvenile idiopathic arthritis, especially in females.
REFERENCES: Iesaka K, Kubiak EN, Bong LR, et al: Orthopaedic surgical management of hip and knee involvement in patients with juvenile rheumatoid arthritis. Am J Orthop 2006;35:67-73.
Wright DA: Juvenile idiopathic arthritis, in Morrissey RT, Weinstein SL (eds): Love
l
and Winter’s Pediatric Orthopaedics, ed 6. Philadelphia PA, Lippincott Williams and Wilkins, 2006, pp 405-438. Question 66
An 18-month-old girl is brought in by her parents because of concerns about intoeing, bowlegs, and tripping and fa
l
ing. Prenatal and birth history are otherwise unremarkable. The child’s growth and
development appear to be normal and she has a normal neurologic exam, a straight spine with no defects, and the hips are stable. Examination reveals hip internal rotation of 40 degrees and hip external rotation of 60 degrees. The thigh-foot angle is internal 30 degrees. Feet are straight and supple. Gait is characterized by intoeing with occasional tripping and falling. Based on these findings, what is the most appropriate action?
No treatment because internal tibial torsion slowly resolves on its own
Immediate treatment with a Denis-Browne bar
Distal tibial osteotomies
Proximal femoral derotational osteotomies
Treatment with twister cables PREFERRED RESPONSE: 1
DISCUSSION: The child has classic internal tibial torsion that is very commonly seen in younger children who are just beginning to walk. The normal outcome is for slow resolution of this problem and it seldom requires any treatment. Treatment with a Denis-Browne bar or with twister cables has not been proven to be effective. Surgical treatment at this point is premature and clearly not indicated.
REFERENCES: Lincoln TL, Suen PW: Common rotational variations in children. J Am Acad Orthop Surg 2003;11:312-320.
Staheli LT, Corbett M, Wyss C, et al: Lower-extremity rotational problems in children: Normal values to guide management. J Bone Joint Surg Am 1985;67:39-47.

Question 16:

A 28-year-old construction worker sustains the closed injury shown in Figures A and B after a fall from a height. He is taken to the operating room. What is the next best step?

Options:

Locked anterior tibial plating and fibular plating
Locked medial tibial plating and fibular plating
Reamed intramedullary nailing without fibular plating
Unreamed intramedullary nailing and fibular plating
Reamed intramedullary nailing and fibular plating

Correct Answer: Unreamed intramedullary nailing and fibular plating

Explanation:

Question 17:

- The Magnetic resonance imaging signal characteristics of a high-grade soft-tissue sarcoma are best described as

Options:

T1-low, T2-low.
T1-low, T2-high.
T1-moderate, T2-low.
T1-high, T2-low.
T1-high, T2-high.

Correct Answer: T1-low, T2-high.

Explanation:

Question 18:

What spinal nerves in the cauda equina are primarily responsible for innervation of the bladder?

Options:

L1, L2, and L3
L4 and L5
L5 and S1
S2, S3, and S4
Filum terminale

Correct Answer: S2, S3, and S4

Explanation:

Question 19:

When performing a saline load test to evaluate for a traumatic arthrotomy of the knee, a mininum of how much saline should be utilized?

Options:

30 mL
50 mL
75 mL
100 mL
155 mL

Correct Answer: 30 mL

Explanation:

Question 20:

The scoring system for impending pathologic fractures devised by Mirels involves assessment of which of the following factors?

Options:

Lesion location, amount of pain, lesion type, lesion size (lucent/blastic)
Patient’s functional status, lesion location, amount of pain, lesion size
Lesion type (lucent/blastic), patient’s functional status, lesion location, amount of pain
Lesion size, lesion type (lucent/blastic), lesion location, patient’s functional status
Amount of pain, patient’s functional status, lesion type (lucent/blastic), lesion size

Correct Answer: Lesion location, amount of pain, lesion type, lesion size (lucent/blastic)

Explanation:

DISCUSSION: The scoring system published by Mirels in 1989 is based on the following characteristics: the location of the lesion, the amount of pain the patient is experiencing, the type of lesion (either lucent, mixed, or blastic), and the lesion size. The tumor is scored from 1 to 3 in each category and a total score is obtained that correlates to fracture risk. Prophylactic fixation is advised for lesions with scores of higher than 8, and consideration for stabilization should be strongly considered for scores of 8. The Mirels scoring system can be useful as an adjunct to clinical decision making.
REFERENCES: Mirels H: Metastatic disease in long bones: A proposed scoring system for diagnosing impending pathologic fractures. 1989. Clin Orthop Relat Res 2003;415:S4-S13.
Damron TA, Morgan H, Prakash D, et al: Critical evaluation of Mirels’ rating system for impending pathologic fractures. Clin Orthop Relat Res 2003;415:S201-S207.

Question 21:

A 30-year-old woman has pain in her right hand. The radiograph, CT scan, and biopsy specimen are seen in Figures 38a through 38c. What is the most likely diagnosis?

Options:

Enchondroma
Giant cell tumor
Metastatic carcinoma
Degenerative cyst
Eosinophilic granuloma

Correct Answer: Enchondroma

Explanation:

Question 22:

Options:

marked osteoporosis.
reduced contact area of a unicompartmental knee arthroplasty for load transmission.
excessive medial placement of the tibial component of the unicompartmental knee arthroplasty.
multiple drill holes that violate the medial cortex.
osteonecrosis of the medial tibial plateau.

Correct Answer: multiple drill holes that violate the medial cortex.

Explanation:

DISCUSSION: While all of the above may contribute to the etiology of a tibial plateau fracture following unicompartmental knee arthroplasty, the recent literature has clearly noted that pin placement for fixation of tibial resection guides is the most critical factor associated with a tibial plateau fracture following unicompartmental knee arthroplasty. Vince and Cyran suggest that fractures associated with unicompartmental knee arthroplasty might be avoidable by limiting the number and paying attention to the location of the pin holes that are created to secure the tibial resection guides. Brumby and associates suggest avoiding multiple guide pin holes in the proximal tibia for unicompartmental knee arthroplasty. They currently recommend the use of one centrally placed pin and an ankle clamp to stabilize the resection guide. Yang and associates note that a medial tibial plateau fracture in association with minimally invasive unicompartmental knee arthroplasty can be eliminated by avoiding fixation pins close to the medial tibial cortex.
REFERENCES: Brumby SA, Carrington R, Zayontz S, et al: Tibial plateau stress fracture: A complication of unicompartmental knee arthroplasty using 4 guide pinholes. J Arthroplasty 2003;18:809-812.
Yang KY, Yeo SJ, Lo NN: Stress fracture of the medial tibial plateau after minimally invasive unicompartmental knee arthroplasty: A report of 2 cases. J Arthroplasty 2003;18:801-803.
Vince KG, Cyran LT: Unicompartmental knee arthroplasty: New indications, more complications? J Arthroplasty 2004;19:9-16.

Question 23:

Options:

Synovial sarcoma
Malignant fibrous histiocytoma
Chondrosarcoma
Ewing's sarcoma
Osteosarcoma

Correct Answer: Osteosarcoma

Explanation:

Question 24:

Options:

chemotherapy.
radiation therapy.
marginal excision.
wide excision.
above-knee amputation.

Correct Answer: marginal excision.

Explanation:

Question 25:

.What is the most appropriate treatment if instability is present at the time of evaluation?

Options:

TEA
Distal humeral replacement arthroplasty
Arthroscopic release with debridement
Soft-tissue interposition arthroplasty DISCUSSION.. The radiographs reveal ulnohumeral arthrosis with relative sparing of the radiocapitellar articulation secondary to underlying osteoarthritis. Arthrosis of the elbow joint in this young and active patient presents a treatment dilemma for the surgeon. Interposition arthroplasty allows for improved function with pain relief and no weight-lifting restrictions, as required with TEA. This option is an intermediate procedure that preserves bone stock and allows for conversion to a TEA if necessary. Conventional TEA would provide pain relief with improved range of motion, but activity limitation and lifetime weight restrictions make this an undesirable option. Arthroscopic debridement is not an option, considering the previous failure from this modality. Contraindications for soft-tissue interposition arthroplasty include elbow instability, active infection, and pain without motion loss. Common complications associated with this procedure include instability, infection, ulnar neuropathy, bone resorption, and heterotopic bone formation.

Correct Answer: Soft-tissue interposition arthroplasty DISCUSSION.. The radiographs reveal ulnohumeral arthrosis with relative sparing of the radiocapitellar articulation secondary to underlying osteoarthritis. Arthrosis of the elbow joint in this young and active patient presents a treatment dilemma for the surgeon. Interposition arthroplasty allows for improved function with pain relief and no weight-lifting restrictions, as required with TEA. This option is an intermediate procedure that preserves bone stock and allows for conversion to a TEA if necessary. Conventional TEA would provide pain relief with improved range of motion, but activity limitation and lifetime weight restrictions make this an undesirable option. Arthroscopic debridement is not an option, considering the previous failure from this modality. Contraindications for soft-tissue interposition arthroplasty include elbow instability, active infection, and pain without motion loss. Common complications associated with this procedure include instability, infection, ulnar neuropathy, bone resorption, and heterotopic bone formation.

Question 26:

Options:

spinal manipulations.
posterior spinal fusion.
anterior/posterior spinal fusion.
spine staples placed thorascopically.
changing to a ‘spine-core’ flexible brace.

Correct Answer: posterior spinal fusion.

Question 27:

Options:

Open biopsy followed by curettage and bone grafting
MRI, whole-body bone scan, CT of the chest, followed by incisional biopsy
Allow the fracture to heal with nonsurgical management and serial radiographs
Open biopsy followed by wide resection and reconstruction with osteoarticular allograft
Open biopsy followed by wide resection and endoprosthetic replacement

Correct Answer: Allow the fracture to heal with nonsurgical management and serial radiographs

Explanation:

DISCUSSION: This radiolucent lesion with a “fallen leaf sign” is typical for a unicameral bone cyst(UBC). The most appropriate treatment is to allow the fracture to heal with clinical and radiographic observation. Curettage and bone grafting is not the best initial management for UBC. Wide resection is not indicated for UBC. The proximal humerus is the most common site for UBC. While staging studies consisting of MRI, bone scan, and CT of the chest are appropriate for lesions suspected of being malignant, the classical appearance of this UBC is such that this work-up is not necessary initially. Following fracture healing, aspiration and injection of the cyst may be indicated.
REFERENCES: Dormans JP, Pill SG: Fractures through bone cysts: Unicameral bone cysts, aneurysmal bone cysts, fibrous cortical defects, and nonossifying fibromas. Instr Course Lect 2002;51:457-467.
Deyoe L, Woodbury DF: Unicameral bone cyst with fracture. Orthopedics 1985;8:529-531.

Question 28:

Options:

Acetabular revision, with placement of a custom triflange acetabular component and femoral head exchange
Removal of the femoral and acetabular components and placement of an antibiotic spacer, with 6 weeks of intravenous antibiotics
Head and liner exchange and retention of the femoral and acetabular implants with acetabular bone grafting
Nonsurgical management with the initiation of bisphosphonates and referral to pain management

Correct Answer: Acetabular revision, with placement of a custom triflange acetabular component and femoral head exchange

Explanation:

Question 29:

Which of the following parameters is considered most important when assessing an acetabular fracture for surgical indications?

Options:

Age of the patient
Failure to maintain reduction of the head under the dome without traction
Presence of a femoral head impaction lesion
Direction of the femoral head displacement
Fragmentation of the fracture

Correct Answer: Failure to maintain reduction of the head under the dome without traction

Explanation:

Question 30:

Options:

Continued nonsurgical management to include long-acting narcotic analgesics
Referral for vertebral axial decompression
Referral to interventional pain management for a spinal cord stimulator
Intradiskal electrothermal therapy (IDET) at L5-S1
Lumbar spinal fusion at L5-S1

Correct Answer: Lumbar spinal fusion at L5-S1

Explanation:

DISCUSSION: The MRI scans reveal advanced degenerative disk disease at L5-S1. Nonsurgical management has failed to provide relief and the patient is quite debilitated as a result of her back pain. Fritzell and associates demonstrated that in a well-informed and selected group of patients with severe low back pain, lumbar fusion can diminish pain and decrease disability more efficiently than commonly used nonsurgical treatments. In a recent updated Cochrane Review of surgery for degenerative lumbar spondylosis, it was noted that while Fritzell and associates appeared to provide strong evidence in favor of fusion, a more recent trial by Brox and associates demonstrated no difference between those patients undergoing lumbar fusion compared to those receiving cognitive intervention and exercise. The Cochrane Review suggests that this may reflect a difference between the control groups. Fritzell and associates compared lumbar fusion to standard 1990s “usual care,” whereas Brox and associates compared lumbar fusion to a “modern rehabilitation program.” Bear in mind that this patient is a certified athletic trainer and runs a hospital health fitness department; therefore, at least for purposes of this question, it can be assumed that she has participated in a “modern rehabilitation program.” The Cochrane Review goes on to state that preliminary results of three small trials of intradiskal electrotherapy suggest that it is ineffective and that preliminary data from three trials of disk arthroplasty do not permit firm conclusions.
REFERENCES: Gibson JN, Waddell G: Surgery for degenerative lumbar spondylosis: Updated Cochrane Review. Spine 2005;30:2312-2320.
Fritzell P, Hagg O, Wessberg P, et al: 2001 Volvo Award Winner in Clinical Studies: Lumbar fusion versus nonsurgical treatment for chronic low back pain: A multicenter randomized controlled trial from the Swedish Lumbar Spine Study Group. Spine 2001;26:2521-2532.
Brox JI, Sorensen R, Friis A, et al: Randomized clinical trial of lumbar instrumented fusion and cognitive intervention and exercises in patients with chronic low back pain and disc degeneration. Spine 2003;28:1913-1921.

Question 31:

What is the most common complication following distal biceps tendon repair?

Options:

Posterior interosseous nerve palsy
Rerupture of the repair
Lateral antebrachial cutaneous neuropraxia
Superficial radial sensory neuropathy

Correct Answer: Lateral antebrachial cutaneous neuropraxia

Explanation:

DISCUSSION
The distal biceps tendon is commonly torn with an eccentric contraction of the biceps when the elbow is taken into extension. Patients treated nonsurgically will note loss of at least 50% supination strength and may develop discomfort with resistive activities. The video shows the squeeze test to evaluate the integrity of the biceps tendon. The test is similar to the Thompson test in the evaluation of an Achilles tendon rupture. The distal arm is squeezed with the elbow flexed 60 to 80 degrees and the forearm pronated. By shortening the musculotendinous unit, the intact biceps tendon will lead to forearm supination. If the biceps is torn, the forearm will not supinate as shown in the video. The maneuver is performed with the elbow in flexion to minimize tension on the brachialis muscle and isolate the biceps. Ruland and associates evaluated 25 patients with suspected distal biceps ruptures and correctly diagnosed all but 1 false-positive result that involved a partial tear. The lacertus fibrosus is not evaluated with this maneuver.
When considering a repair, a 1- or 2-incision technique may be performed. Chavan and associates performed a systematic review comparing the 2 techniques and reported similar complication rates. The 2-incision technique was associated with more instances of significant loss of forearm rotation and more unsatisfactory clinical results. The 1-incision technique is associated with a higher incidence of lateral antebrachial cutaneous neuropathy likely attributable to retraction. The biceps insertion is a thin semilunar area on the posterior/ulnar aspect of the radial tuberosity centered at approximately 30 degrees anterior to the lateral/coronal plane with the arm fully supinated. Forthman and associates used CT scan to asses 30 cadaveric specimens and noted that the biceps tuberosity orientation would prohibit an anatomic repair in 35% of arms for which the 1-incision technique was used.
Mazzocca and associates reported the highest load to failure of the Endobutton (440 newton (N)) compared to fixation with suture anchor (381 N), Wartenberg syndrome (310 N), and an interference screw (232 N). Greenberg and associates noted greater load to failure for the Endobutton (584 N) compared to suture anchor (254 N) and transosseous tunnel (178 N) constructs. Spang and associates reported comparable strength of the Endobutton repair when compared to suture anchors. Fifty N of force is required to hold the elbow flexed at 90 degrees against gravity, which is well below the strength of the repairs studied.
Neuropraxia of the lateral antebrachial cutaneous nerve branch is the most common complication associated with distal biceps repair, with a reported incidence as high as 40%. The nerve branch lies between the biceps and brachialis as it crosses the surgical field in the antecubital fossa. The neuropathy may be related to aggressive retraction, particularly when using the 1-incision technique, and often resolves with time. Cain and associates reported minor complications were common (but major complications uncommon) following distal biceps repair. Reported complications are lateral antebrachial cutaneous paresthesia (26%), radial sensory nerve paresthesia (6%), posterior interosseous nerve injury (4%), and rerupture (2%).
RECOMMENDED READINGS
Ruland RT, Dunbar RP, Bowen JD. The biceps squeeze test for diagnosis of distal biceps tendon ruptures. Clin Orthop Relat Res. 2005 Aug;(437):128-31. PubMed PMID: 16056039.
Forthman CL, Zimmerman RM, Sullivan MJ, Gabel GT. Cross-sectional anatomy of the bicipital tuberosity and biceps brachii tendon insertion: relevance to anatomic tendon repair. J Shoulder Elbow Surg. 2008 May-Jun;17(3):522-6. doi: 10.1016/j.jse.2007.11.002. Epub 2008 Mar 6. PubMed PMID: 18325797.
Chavan PR, Duquin TR, Bisson LJ. Repair of the ruptured distal biceps tendon: a systematic review. Am J Sports Med. 2008 Aug;36(8):1618-24. doi: 10.1177/0363546508321482. Review. PubMed PMID: 18658024.
Mazzocca AD, Burton KJ, Romeo AA, Santangelo S, Adams DA, Arciero RA. Biomechanical evaluation of 4 techniques of distal biceps brachii tendon repair. Am J Sports Med. 2007 Feb;35(2):252-

Question 32:

Iliosacral screws placed for stabilization of posterior pelvic ring injuries (eg, sacroiliac dislocation) that exit the sacrum anteriorly are most likely to injure which of the following structures?

Options:

L4 nerve root
L5 nerve root
S1 nerve root
Internal iliac artery
External iliac artery

Correct Answer: L5 nerve root

Explanation:

Question 33:

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

Options:

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

Correct Answer: Recurrence of the hallux valgus

Explanation:

Question 34:

Options:

CT scan
Hybrid external fixation
Ankle-spanning external fixation
Open reduction and internal fixation within 6 to 8 hours
Open reduction and internal fixation within 2 to 3 days

Correct Answer: Ankle-spanning external fixation

Explanation:

Question 35:

Options:

Ceramic-on-ceramic
Ceramic-on-highly cross-linked polyethylene (HXPE)
Metal-on-HXPE
Metal-on-metal

Correct Answer: Metal-on-metal

Explanation:

Question 36:

Options:

repair of the rotator cuff.
rehabilitation of the shoulder
replacement of the humeral head.
arthroscopic acromioplasty and debridement.
immobilization is a sling until pain resolves.

Correct Answer: rehabilitation of the shoulder

Explanation:

Question 37:

Options:

proximal biceps tenodesis.
application of a sling for 3 weeks, followed by physical therapy.
anterior capsulolabral reconstruction.
repair of the subscapularis tendon.
repair of the pectoralis major tendon.

Correct Answer: repair of the pectoralis major tendon.

Explanation:

Question 38:

Options:

Resection arthroplasty
Single-stage revision total elbow arthroplasty
Two-stage revision elbow arthroplasty
Aggressive arthroscopic debridement and retention of components

Correct Answer: Two-stage revision elbow arthroplasty

Explanation:

Question 39:

Options:

proximal clavicle and sternocostal margin.
proximal humerus.
coracoid process.
distal clavicle and acromion.
anterior scapula.

Correct Answer: proximal clavicle and sternocostal margin.

Explanation:

Question 40:

A patient has a C6 spinal cord injury. Following stabilization of the spine, the patient should be advised that their expected maximum level of function

Options:

An electric wheelchair with puffer control
An electric wheelchair with hand controls
A manual wheelchair and sliding board transfers
A manual wheelchair and independent transfers
Crutches with long leg braces for short distance ambulation

Correct Answer: A manual wheelchair and sliding board transfers

Explanation:

Question 41:

Options:

Decreased rate of postoperative infection
Decreased rate of nonunion
Decreased rate of primary wound healing problems
Decreased rate of reoperation
Increased rate of bone healing

Correct Answer: Decreased rate of primary wound healing problems

Explanation:

DISCUSSION: The mainstay of early treatment of open fractures includes irrigation and debridement. Prior to the development of antibiotics, this was traditionally accomplished with some form of detergent irrigation. Antibiotic irrigation has been in favor more recently but has mixed scientific results related to its use. Results of at least one major study show the use of a nonsterile liquid soap additive (castile soap) is at least as effective as the use of bacitracin with regards to the rate of postoperative infection and fracture healing, and shows a significant decrease in problems with soft-tissue healing.
REFERENCE: Anglen JO: Comparison of soap and antibiotic solutions for irrigation of lower-limb open fracture wounds: A prospective, randomized study. J Bone Joint Surg Am 2005;87:1415-1422.

Question 42:

Following total knee arthroplasty, a patient is noted to have asymmetrical absent pulses and poor capillary refill. What is the next most appropriate step in management?

Options:

Observation of the limb for 4 hours to see if the arterial spasm resolves
Measurement of lower leg compartment pressures
Magnetic resonance angiogram
Emergent return to the operating room for wound exploration while the patient anesthesia
Return to the operating room, obtain a vascular surgery consultation, and intraoperative arteriogram

Correct Answer: Return to the operating room, obtain a vascular surgery consultation, and intraoperative arteriogram

Explanation:

Question 43:

The use of nonsteroidal anti-inflammatory drugs following femoral nailing has been associated with which of the following?

Options:

Increased rate of nonunion
Decreased narcotic requirements
Faster time to union
Increased rate of heterotopic ossification
Decreased rate of revision surgery

Correct Answer: Increased rate of nonunion

Explanation:

Question 44:

Options:

spinal accessory nerve, causing shoulder elevation with the scapula translated and the inferior angle rotated medially.
spinal accessory nerve, causing shoulder depression with the scapula translated laterally and the inferior angle rotated laterally.
long thoracic nerve, causing shoulder elevation with the scapula translated medially and the inferior angle rotated medially.
long thoracic nerve, causing shoulder depression with the scapula translated laterally and the inferior angle rotated laterally.
thoracodorsal nerve, causing shoulder depression with the scapula translated laterally and the inferior angle rotated laterally.

Correct Answer: spinal accessory nerve, causing shoulder depression with the scapula translated laterally and the inferior angle rotated laterally.

Explanation:

Question 45:

A tendon repair is thought to be weakest during which phase of tendon healing?

Options:

Inflammatory
Proliferation
Maturation
Remodeling

Correct Answer: Inflammatory

Explanation:

Question 46:

What is the primary indication for performing a total wrist arthroplasty in a patient with painful rheumatoid arthritis?

Options:

Ipsilateral total elbow arthroplasty
Contralateral wrist arthrodesis
Type III degenerative changes of the wrist
Age older than 55 years
Less than 30 degrees of wrist flexion/extension

Correct Answer: Contralateral wrist arthrodesis

Explanation:

Question 47:

Options:

neoadjuvant chemotherapy followed by surgical resection and reconstruction.
chemotherapy followed by radiation therapy.
IV antibiotics for 4 weeks, followed by oral antibiotics for 4 weeks.
surgical resection and reconstruction followed by chemotherapy.
radiation therapy alone.

Correct Answer: neoadjuvant chemotherapy followed by surgical resection and reconstruction.

Explanation:

DISCUSSION: The imaging studies and histology are consistent with high-grade osteosarcoma. The standard treatment for osteosarcoma is neoadjuvant chemotherapy combined with wide surgical resection that can be performed with amputation or limb salvage depending on characteristics unique to each tumor and each patient. In most patients, limb salvage surgery can be performed with reconstruction using allografts and/or megaprostheses. Osteosarcoma is poorly responsive to radiation therapy. Chemotherapy alone, in the absence of appropriate surgery, has not proven effective.
REFERENCES: Simon MA, Springfield DS: Surgery for Bone and Soft-Tissue Tumors. Philadelphia, PA, Lippincott-Raven, 1998, pp 265-274.
Gibbs CP, Weber K, Scarborough MT: Malignant bone tumors. Instr Course Lect 2002;51:413-428.

Question 48:

Options:

open fixation of the SLAP lesion with a screw that can be removed later.
arthroscopic repair of the SLAP lesion with suture anchors.
arthroscopic repair of the SLAP lesion with suture anchors with a thermal capsular shift.
arthroscopic repair of the SLAP lesion with suture anchors and a rotator cuff interval closure.
arthroscopic repair of the SLAP lesion with suture anchors and an arthroscopic capsular placation.

Correct Answer: arthroscopic repair of the SLAP lesion with suture anchors.

Explanation:

Question 49:

Options:

Electrode placement
Stimulation failure
Anesthetic effect
Cord ischemia from retraction
Cerebral ischemia from retraction

Correct Answer: Cerebral ischemia from retraction

Explanation:

Question 50:

Options:

a program of stretching exercises and rotator cuff strengthening exercises.
a series of six cortisone injections.
arthroscopic acromioplasty.
arthroscopic acromioplasty and laser capsulorrhaphy.
open acromioplasty.

Correct Answer: a program of stretching exercises and rotator cuff strengthening exercises.

Explanation:

Question 51:

Options:

An MRI scan of the shoulder
An MRI scan of the cervical spine
Electromyographic and nerve conduction velocity studies
Immobilization in a sling and early passive range of motion exercises
Immediate return to the operating room for exploration of the brachial plexus

Correct Answer: Immobilization in a sling and early passive range of motion exercises

Explanation:

Question 52:

It is important to avoid which of the following exercises in the immediate postoperative period after humeral head replacement for an acute four-part fracture?

Options:

Pendulum exercises
External rotation with a stick
Passive forward elevation
Active forward elevation
Active range of motion of the elbow, wrist, and hand

Correct Answer: Active forward elevation

Explanation:

Question 53:

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 54:

The anterior portal of a hip arthroscopy places what structure at greatest risk for injury?

Options:

Ascending branch of the lateral circumflex femoral artery
Ascending branch of the medial circumflex femoral artery
Femoral nerve
Lateral femoral cutaneous nerve
Superior gluteal nerve

Correct Answer: Lateral femoral cutaneous nerve

Explanation:

DISCUSSION: The average location of the anterior portal is 6.3 cm distal to the anterior superior iliac spine. The lateral femoral cutaneous nerve typically has divided into three or more branches at the level of the anterior portal. The portal usually passes within several millimeters of the most medial branch. Injury to the nerve can lead to meralgia paresthetica. The femoral nerve lies an average minimum distance of 3.2 cm from the anterior portal. The ascending branch of the lateral circumflex artery lies approximately 3.7 cm inferior to the anterior portal. Neither the ascending branch of the medial circumflex artery nor the superior gluteal nerve are
at risk.
REFERENCES: Byrd JWT: Operative Hip Arthroscopy. New York, NY, Thieme Medical Publishers, 1998, pp 83-91.
Arendt EA (ed): Orthopaedic Knowledge Update: Sports Medicine 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 281-289.

Question 55:

Options:

The flexor digitorum longus tendon is ruptured.
The posterior tibial tendon has a normal appearance.
The posterior tibial tendon has a physiologic amount of fluid in its sheath.
The posterior tibial tendon is completely ruptured and retracted (type III tear).
The posterior tibial tendon has a chronic longitudinal split with enlargement (type II tear).

Correct Answer: The posterior tibial tendon has a chronic longitudinal split with enlargement (type II tear).

Explanation:

Question 56:

Options:

Pulmonary embolism
Fat embolism syndrome
Sepsis
Pneumonia
Pneumothorax

Correct Answer: Fat embolism syndrome

Explanation:

Question 57:

What significant structure is most at risk during a posterior approach of the Achilles tendon near its musculotendinous junction?

Options:

Saphenous vein
Saphenous nerve
Posterior tibial nerve
Sural nerve
Plantaris muscle

Correct Answer: Sural nerve

Explanation:

Question 58:

Options:

Nonsteroidal anti-inflammatory drugs
MRI of the spine
CT myelography
Flexion-extension plain films

Correct Answer: MRI of the spine

Explanation:

DISCUSSION
Patients with ankylosing spondylitis are at high risk for occult fractures after low-energy injuries. Although radiographs and a CT scan do not demonstrate a spinal fracture in this patient, high risk for an unstable occult fracture necessitates further imaging with MRI to ensure that no fractures are missed. Although a CT scan is typically the primary imaging modality for workup of spine injuries in similar patients, CT and MRI complement each other and each detects fractures that are missed using the other modality. A CT myelogram might detect cord or root compression but would not aid in the diagnosis of an occult fracture. Nonsteroidal anti-inflammatory drugs are first-line treatment for idiopathic low-back pain. In a patient with ankylosing spondylitis at high risk for fracture, further workup is needed to rule out an occult fracture. Flexion and extension radiographs of the spine are inferior to MRI for evaluating occult fractures and ligamentous injuries. The primary concern for this patient remains an unstable spinal fracture, which necessitates an MRI of the spine before initiating a workup for other possible causes of his back pain.
RECOMMENDED READINGS
Duane TM, Cross J, Scarcella N, Wolfe LG, Mayglothling J, Aboutanos MB, Whelan JF, Malhotra AK, Ivatury RR. Flexion-extension cervical spine plain films compared with MRI in the diagnosis of ligamentous injury. Am Surg. 2010 Jun;76(6):595-8. PubMed PMID: 20583514.
View Abstract at PubMed
Hitchon PW, From AM, Brenton MD, Glaser JA, Torner JC. Fractures of the thoracolumbar spine complicating ankylosing spondylitis. J Neurosurg. 2002 Sep;97(2 Suppl):218-22. PubMed PMID: 12296682.
View Abstract at PubMed
Koivikko MP, Koskinen SK. MRI of cervical spine injuries complicating ankylosing spondylitis. Skeletal Radiol. 2008 Sep;37(9):813-9. doi: 10.1007/s00256-008-0484-x. Epub 2008 Apr

Question 59:

Figure 12 shows the radiograph of a patient who has anterior knee pain. History reveals a femoral fracture at age 5 years. What is the most likely cause of the deformity?

Options:

Osgood-Schlatter disease
Patellar tendon rupture
Posterior cruciate ligament rupture
Overlengthened hamstrings
Tibial tubercle growth arrest

Correct Answer: Tibial tubercle growth arrest

Explanation:

Question 60:

Options:

Metastatic bone disease
Multiple myeloma
Lymphoma
Chondrosarcoma
Malignant fibrous histiocytoma The biopsy specimen shows round, epithelial-like cells that are grouped in clusters. The cells are arranged in a fibrous background. The diagnosis is metastatic bone disease. The treatment of metatastic bone disease is either internal fixation with postoperative external beam irradiation or external beam irradiation alone. In this case, there is extensive destruction and fracture is imminent. The treatment of choice is acetabular reconstruction followed by external beam irradiation.

Correct Answer: Malignant fibrous histiocytoma The biopsy specimen shows round, epithelial-like cells that are grouped in clusters. The cells are arranged in a fibrous background. The diagnosis is metastatic bone disease. The treatment of metatastic bone disease is either internal fixation with postoperative external beam irradiation or external beam irradiation alone. In this case, there is extensive destruction and fracture is imminent. The treatment of choice is acetabular reconstruction followed by external beam irradiation.

Explanation:

Slide 1 Slide 2 Slide 3 Slide 4
A 50-year-old woman has had severe hip pain for 4 months. Her plain radiographs (Slide 1), technetium bone scan (Slide 2), computerized tomography scan (Slide 3), and coronal T1- and T2-weighted magnetic resonance images (Slide 4) are presented. The most likely diagnosis based upon the radiographs would be:

Question 61:

Where does the median nerve pass in the proximal forearm?

Options:

Through the pronator teres and deep to the flexor digitorum superficialis
Deep to the pronator teres and superficial to the flexor digitorum superficialis
Deep to the pronator teres and deep to the flexor digitorum superficialis
Adjacent to the ulnar artery
Superficial to the pronator teres and flexor digitorum superficialis

Correct Answer: Through the pronator teres and deep to the flexor digitorum superficialis

Explanation:

Question 62:

Options:

Flexion
Extension
Axial rotation
Left lateral bending
Right lateral bending

Correct Answer: Axial rotation

Explanation:

MRI and CT demonstrate an abnormality in the alantoaxial region (C1-C2). See chart in reference. “C1-C2 -Flexion/Extension 30 degrees - Sidebending 10 degrees - Rotation – 70 degrees”

Question 63:

Options:

infection.
instability.
loosening.
periprosthetic fracture.

Correct Answer: instability.

Explanation:

Question 64:

Options:

distraction interpositional arthroplasty.
elbow arthrodesis.
conversion to a resection arthroplasty.
conversion to semiconstrained elbow arthroplasty.
revision to unconstrained total elbow arthroplasty.

Correct Answer: conversion to semiconstrained elbow arthroplasty.

Explanation:

Question 65:

-Which type of cells has been implicated in the process shown inFigure?

Options:

Monocytes
Histiocytes
Leukocytes
Neutrophils
Macrophages

Correct Answer: Macrophages

Question 66:

Exostoses in which of the following anatomic locations is the most likely to undergo malignant transformation in a patient with multiple hereditary exostosis (MHE)?

Options:

Distal humerus
Distal radius
Distal femur
Lumbar spine
Scapula

Correct Answer: Scapula

Explanation:

Question 67:

Refers to the effectiveness of various antibiotics against a particular microorganism.

Options:

Minimum inhibitory concentration (MIC)
Minimum bactericidal concentration (MBC)
Antiobiotic susceptibility
Antibiograms
Antimicrobial resistance
Spectrum of coverage

Correct Answer: Antiobiotic susceptibility

Explanation:

Question 68:

Options:

Infection
Patellar instability
Aseptic loosening
Progression of tibiofemoral arthritis

Correct Answer: Progression of tibiofemoral arthritis

Explanation:

Question 69:

- An MRI scan of the brain of a patient with spastic diplegia will most likely show

Options:

Microcephaly
A temporal lobe cyst
An Arnold-Chiari type 1 malformation
Periventricular leukomalacia
Agnesis of the corpus callosum

Correct Answer: Periventricular leukomalacia

Explanation:

Question 70:

Options:

an internervous plane between muscles innervated by the deep and superficial peroneal nerves.
an internervous plane between muscles innervated by the deep peroneal and the medial plantar nerves.
an interval between the extensor digitorum longus and the extensor digitorum brevis.
not an internervous plane.

Correct Answer: not an internervous plane.

Explanation:

Question 71:

The subcutaneous nerve most at risk for transection during an anterior surgical exposure of the ankle is the

Options:

dorsal cutaneous branch of the sural nerve.
deep peroneal nerve.
medial plantar nerve.
medial branch of the superficial peroneal nerve.

Correct Answer: medial branch of the superficial peroneal nerve.

Explanation:

Question 72:

Options:

Osteomyelitis
Tuberculosis
Osteosarcoma
Ewing’s sarcoma
Malignant fibrous histiocytoma (MFH)

Correct Answer: Ewing’s sarcoma

Explanation:

DISCUSSION: The imaging studies and histology are most consistent with Ewing’s sarcoma. Tuberculosis can show small round blue cells on histology (lymphocytes associated with chronic infection) but would more typically involve the knee joint and periarticular bone. Osteosarcoma and MFH do not have small round blue cells histologically.
REFERENCES: Sissons HA, Murray RO, Kemp HBS: Orthopaedic Diagnosis. Berlin, Springer-Verlag, 1984, pp 254-256.
Wafa H, Grimer RJ: Surgical options and outcomes in bone sarcoma. Expert Rev Anticancer Ther 2006;6:239-248.

Question 73:

Options:

Lumbrical plus deformity
Intrinsic tightness
Quadrigia effect
Proximal interphalangeal joint contracture

Correct Answer: Quadrigia effect

Explanation:

EXPLANATION:
The quadrigia effect can occur due to over-advancement of the FDP tendon during repair (usually greater than 1 cm), development of FDP tendon adhesions, and (as in this case) "over the top" repair of the FDP tendon to the extensor tendon after amputation at the distal phalanx level. All of these conditions result in a functionally shortened FDP tendon of the injured digit. Because the FDP tendons of the long, ring, and small digits share a common muscle belly, excursion of the combined tendons is equal to the shortest tendon. Therefore, the uninjured digits will not have full excursion of their respective FDP tendons and will not be able to close into a full fisting position. Treatment of this condition is most commonly release
of the injured FDP tendon. A lumbrical plus deformity can occur in amputations distal to the flexor digitorum superficialis insertion through the middle phalanx. The FDP tendon retracts and increases tension on the lumbrical muscle, which leads to paradoxical interphalangeal (IP) joint extension with attempted flexion. Intrinsic tightness and interphalangeal joint contractures can be caused by hand trauma
but would not lead to the clinical condition this patient has.

Question 74:

Which of the following is a long-term complication of ankle arthrodesis for posttraumatic arthritis?

Options:

Progressive limb-length discrepancy
Contralateral ankle arthritis
Ipsilateral hindfoot and midfoot arthritis
Ipsilateral knee arthritis
Talar osteonecrosis

Correct Answer: Ipsilateral hindfoot and midfoot arthritis

Explanation:

Question 75:

Options:

Patellofemoral syndrome
Bipartite patella
Stress fracture of the distal femur
Patella alta
Patella baja

Correct Answer: Patellofemoral syndrome

Explanation:

Question 76:

Options:

Rupture of the biceps femoris at the myotendinous junction
Rupture of the biceps femoris muscle belly
Avulsion of the common hamstring origin from the ischium
Complete rupture of the semimembranosus muscle belly
Complete tear of all hamstring muscles

Correct Answer: Rupture of the biceps femoris at the myotendinous junction

Explanation:

Question 77:

Options:

observation and splinting.
local wound drainage under local anesthesia.
incision and drainage, deep wound cultures, removal of the plates and screws, and cast application.
incision and drainage, deep wound cultures, and removal of the fixation only if it is loose.
incision and drainage, deep wound cultures, and bone grafting.

Correct Answer: incision and drainage, deep wound cultures, and removal of the fixation only if it is loose.

Explanation:

Question 78:

Options:

application of a femoral traction pin.
intramedullary nailing of the femur and tibia.
surgical irrigation and debridement.
external fixation of the femoral fracture.
reduction of the femoral head.

Correct Answer: reduction of the femoral head.

Explanation:

Question 79:

Options:

Vertebrectomy of L5
Posterior spinal fusion with or without instrumentation from L4 to S1
Posterior spinal fusion without instrumentation from L5 to S1
Anterior spinal fusion from L4 to L5
Direct repair of the spondylolysis defect

Correct Answer: Posterior spinal fusion with or without instrumentation from L4 to S1

Explanation:

DISCUSSION: The patient has a grade 4 spondylolisthesis. Optimal surgical management is posterior spinal fusion from L4 to the sacrum. The use of instrumentation is controversial. Vertebrectomy is typically reserved for spondylo-optosis (grade 5) cases. Spinal fusion from
L5 to S1 usually is not successful for a slip that is greater than 50%. Isolated anterior spinal fusion has not been successful, and direct repair of the pars defect is only useful for spondylolysis without spondylolisthesis.
REFERENCES: Lenke LG, Bridwell KH: Evaluation and surgical treatment of high-grade isthmic dysplastic spondylolisthesis. Instr Course Lect 2003;52:525-532.
Ginsburg GM, Bassett GS: Back pain in children and adolescents: Evaluation and differential diagnosis. J Am Acad Orthop Surg 1997:5:67-78.

Question 80:

What is the most common cause for poor outcomes in patients who undergo total shoulder arthroplasty?

Options:

Loosening of the humeral component
Loosening of the glenoid component
Infection
Brachial plexus injury
Rotator cuff tear

Correct Answer: Rotator cuff tear

Explanation:

DISCUSSION: In an article in the Journal of Shoulder and Elbow, 431 total shoulder arthroplasties were performed with a cemented all-polyethylene glenoid component between 1990 and 2000. Follow-up averaged 4.2 years. In total, 53 surgical complications occurred in 53 patients (12%). Of these, 32 were major complications (7.4%), with 17 of these requiring reoperation. Index complications in order of frequency included rotator cuff tearing, postoperative glenohumeral instability, and periprosthetic humeral fracture. Notably, glenoid and humeral component loosening requiring reoperation occurred in only one shoulder. Data from the contemporary patient group suggest that there are fewer complications of shoulder arthroplasty and less need for reoperation. Especially striking is the near absence of component revision because of loosening or other mechanical factors. Complications involving the brachial plexus have been reported following total shoulder arthroplasty but are not as common of a cause for failure.
REFERENCES: Chin PY, Sperling JW, Cofield RH, et al: Complications of total shoulder arthroplasty: Are they fewer or different? J Shoulder Elbow Surg 2006;15:19-22.
Hasan SS, Leith JM, Campbell B, et al: Characteristics of unsatisfactory shoulder arthroplasties. J Shoulder Elbow Surg 2002;11:431-441.

Question 81:

-What gene is implicated in spinal muscular atrophy?

Options:

Survival motor neuron I (SMN-I)
Peripheral myelin protein 22 (PMP22)
Dystrophin
Androgen receptor DISCUSSION-Deletions in the SMN-I gene are found in 95% to 98% of patients with spinal muscular atrophy. Genetic testing is typically part of the diagnostic workup for spinal muscular atrophy. A positive test result is diagnostic, and, in most cases, eliminates the need for muscle biopsy. The other choices are not associated with spinal muscular atrophy. Defects in PMP22 are the cause of 70% to 80% of cases of Charcot-Marie-Tooth disease. Mutations in the dystrophin gene cause Duchenne muscular dystrophy, and mutations in the androgen receptor cause spinobulbar muscular atrophy (Kennedy’s disease).

Correct Answer: Survival motor neuron I (SMN-I)

Question 82:

The swelling pressure in cartilage is predominantly due to the association of exchangeable water with which of the following substances? Review Topic

Options:

Biglycan
Type II collagen
Type IX collagen
Aggrecan
Versican

Correct Answer: Aggrecan

Explanation:

Question 83:

Options:

immobilization for 3 weeks, followed by rehabilitation.
open biceps tenodesis.
arthroscopy with revision stabilization.
arthroscopy with repair of the superior labrum.
subscapularis repair.

Correct Answer: subscapularis repair.

Explanation:

Question 84:

Vertebral fractures are common in the thoracolumbar spine. What is the most important factor that determines the strength of the cancellous bone in the vertebral body?

Options:

Mineral content
Rate of loading
Anatomic level of the vertebra
Apparent density
Trabecular number

Correct Answer: Apparent density

Explanation:

Question 85:

Options:

Alcoholism
Drug abuse
Down syndrome
Diabetes mellitus
Idiopathic scoliosis

Correct Answer: Diabetes mellitus

Explanation:

DISCUSSION: The history, physical examination, and radiographic findings are consistent with type IV sacral agenesis or caudal regression syndrome. These children are born with no lumbar spine or sacrum. The T12 vertebra is often prominent posteriorly. Popliteal webbing and knee flexion contractures are common with this diagnosis. There is a higher incidence of this diagnosis when the mother has diabetes mellitus. Maternal drug abuse and alcoholism can produce phenotypically unique children but without the findings described here. Maternal idiopathic scoliosis is not associated with caudal regression syndrome.
REFERENCES: Chan BW, Chan KS, Koide T, et al: Maternal diabetes increases the risk of caudal regression caused by retinoic acid. Diabetes 2002;51:2811-2816.
Zaw W, Stone DG: Caudal regression syndrome in twin pregnancy with type II diabetes.
J Perinatol 2002;22:171-174.

Question 86:

Options:

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

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

Explanation:

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

Question 87:

Options:

Ulnar
Musculocutaneous
Radial
Median
Axillary

Correct Answer: Ulnar

Explanation:

Question 88:

Figure 42 shows the sagittal T2-weighted MRI scan of a patient’s right knee. These findings are most commonly seen with a complete tear of the

Options:

patellar tendon.
lateral collateral ligament.
medial collateral ligament.
posterior cruciate ligament.
anterior cruciate ligament.

Correct Answer: lateral collateral ligament.

Explanation:

DISCUSSION: The MRI scan reveals disruption of the lateral capsule and ligaments with
fluid in the soft tissues laterally. Additionally, there is a large bone bruise on the medial
femoral condyle. This combination indicates injury to the posterolateral complex. These injuries often have coexisting anterior and/or posterior cruciate ligament injuries. Failure to recognize the posterolateral corner injury can lead to failure of anterior or posterior cruciate ligament reconstructions.
REFERENCES: LaPrade RF, Gilbert TJ, Bollom TS, et al: The magnetic resonance imaging appearance of individual structures of the posterolateral knee: A prospective study of normal knees and knees with surgically verified grade III injuries. Am J Sports Med 2000;28:191-199.
Ross G, Chapman AW, Newberg AR, et al: Magnetic resonance imaging for the evaluation of acute posterolateral complex injuries of the knee. Am J Sports Med 1997;25:444-448.

Question 89:

Options:

His younger brother’s hip pain is almost certainly attributable to some other cause
His younger brother’s hip pain likely represents established osteoarthritis of the hip
His younger brother’s hip pain may be related to FAI
There is no known genetic influence in the etiology of FAI

Correct Answer: His younger brother’s hip pain may be related to FAI

Explanation:

DISCUSSION
Evidence suggests that FAI is more common in siblings of patients with FAI, particularly those with a CAM deformity. It is unlikely this patient has well-established osteoarthritis, even in the presence of FAI.
CLINICAL SITUATION FOR QUESTIONS 145 THROUGH 147
Figures 145a and 145b are the radiographs of a 56-year-old man who has had persistent pain in his right groin since undergoing primary total hip surgery 11 months ago. His erythrocyte sedimentation rate (ESR) is 38 mm/h (reference range [rr], 0-20 mm/h) and C-reactive protein (CRP) level is 28 mg/L (rr, 0.08-3.1 mg/L). A hip aspiration performed while the patient was taking antibiotics demonstrated 3200 white blood cells/µL with no growth. Treatment should consist of

Question 90:

The nerve to the abductor digiti quinti, implicated in some patients who have chronic heel pain, is most commonly a branch of what larger nerve?

Options:

Lateral plantar
Lateral calcaneal
Medial plantar
Medial calcaneal
Sural

Correct Answer: Lateral plantar

Explanation:

Question 91:

- A 30-year-old man underwent replantation of his dominant thumb at the metacarpophalangeal joint level 2 days ago. Since replantation, the temperature of the thumb has been between 87.8 F (31 C) and 93.2 F (34 C). The temperature is now 82.4 F (28 C), and there is brisk capillary refill and venous engorgement. Management at this time should include

Options:

Surgical exploration
Application of leeches
Stellate ganglion blocks
Intra-arterial streptokinase
Elevation and reevaluation in 1 hour

Correct Answer: Surgical exploration

Explanation:

Question 92:

Options:

Inadequate graft strength
Failure to restore graft length
Malposition of the femoral tunnel
Malposition of the tibial tunnel

Correct Answer: Malposition of the femoral tunnel

Explanation:

DISCUSSION
The anteromedial bundle originates on the anterior and proximal aspect of the lateral femoral condyle and inserts on the anteromedial aspect of the anterior cruciate ligament (ACL) footprint on the proximal tibia. The posterolateral bundle originates posterior and distal to
63
the anteromedial bundle and inserts on the posterolateral aspect of the tibial footprint. The fibers are parallel when the knee is in an extended position. As the knee moves into flexion,
the fibers of the anteromedial bundle rotate externally with respect to the posterolateral bundle. The anteromedial bundle is tensioned in both flexion and extension. The posteromedial bundle is tensioned in extension, but relaxes as the knee moves into flexion.
The lateral meniscus is more commonly injured with an acute injury to the ACL. The medial meniscus is injured more commonly when the ACL is chronically unstable.
The ACL is an intra-articular and intrasynovial structure. It is innervated by posterior articular branches from the tibial nerve. Innervation of the ACL involves several types of mechanoreceptors (Ruffini, Pacini, Golgi tendon, and free-nerve endings) that may contribute to proprioceptive function of the knee and modulation of quadriceps function.
Injury to the ACL is predominantly associated with instability to anterior translation of the tibia in extension. The ACL plays a secondary role to limit internal rotation of the tibia, and a loss of ACL stability is confirmed by the reduction of the tibia from a position of anterior translation and internal rotation (pivot shift). The radiographs demonstrate anterior placement of the femoral tunnel. The convex shape of the lateral femoral condyle can make it more difficult to visualize the anatomic femoral origin of the ACL. Failure to identify the
anatomic footprint can result in anterior placement of the femoral tunnel. Anterior ACL graft placement can result in its impingement against the posterior cruciate ligament and early limitation of knee flexion. Over time, impingement on the graft may result in stretching of the graft and recurrent knee instability symptoms.
RECOMMENDED READINGS
Duthon VB, Barea C, Abrassart S, Fasel JH, Fritschy D, Ménétrey J. Anatomy of the anterior cruciate ligament. Knee Surg Sports Traumatol Arthrosc. 2006 Mar;14(3):204-13. Epub 2005 Oct 19. Review. PubMed PMID: 16235056.
View
Abstract at PubMed
Zantop T, Petersen W, Sekiya JK, Musahl V, Fu FH. Anterior cruciate ligament anatomy and function relating to anatomical reconstruction. Knee Surg Sports Traumatol Arthrosc. 2006 Oct;14(10):982-92. Epub 2006 Aug 5. Review. PubMed PMID: 16897068.
View Abstract at PubMed

Question 93:

When treating a stable 2-part intertrochanteric hip fracture with a sliding hip screw construct, what is the minimum amount of screw holes that are needed in the side plate for successful fixation?

Options:

One
Two
Three
Four
Five

Correct Answer: One

Explanation:

Question 94:

Options:

Lateral meniscus repair
Corticosteroid injection and physical therapy
Medial meniscus repair
Unloader brace

Correct Answer: Medial meniscus repair

Explanation:

The MRI scan shows a posterior horn medial meniscus root avulsion with bony edema at the tibial root insertion. The radiograph shows no significant degenerative changes. If left untreated, posterior meniscal
root tears lead to progressive degenerative changes as a result of the altered tibiofemoral contact pressures and areas. Nonsurgical treatment including injections, physical therapy, and unloader braces are more
appropriate in the older patient with pre-existing advanced degenerative changes.

Question 95:

Options:

vigorous physical therapy for passive range of motion.
manipulation of the shoulder under anesthesia.
an intra-articular steroid injection.
an axillary radiograph.
MRI.

Correct Answer: an axillary radiograph.

Explanation:

Question 96:

Which repair technique for an osteochondral lesion of the medial talus shoulder produces hyaline cartilage that is similar to native cartilage and will not degrade over time?

Options:

Autologous osteochondral transplantation
Arthroscopic bone marrow stimulation
Chondroplasty
Osteochondral allograft transplantation

Correct Answer: Autologous osteochondral transplantation

Explanation:

DISCUSSION
Autologous osteochondral transplantation (typically involving tubular grafts harvested from the knee) has been shown to replace a talar defect with viable hyaline cartilage. The results over the medium term show good clinical outcomes, and MRI studies reveal cartilage repair similar to native cartilage. Chondroplasty and arthroscopic bone-marrow stimulation are both associated with good clinical results for smaller lesions, but these techniques develop fibrocartilaginous repair tissue composed of type I collagen instead of hyaline cartilage. Osteochondral transplantation of fresh allografts performed less than 14 days after harvest contains high chondrocyte viability. Few clinical studies report long-term results, but radiographic studies demonstrate high rates of collapse and resorption. Joint space narrowing has been noted in 60% of ankles treated with bulk grafts after an average of 44 months. Autologous chondrocyte implantation (both periosteum-covered and matrix-associated techniques) has been shown to create hyaline cartilage in some studies, but fibrocartilage creation has been reported in others.
RECOMMENDED READINGS
Schachter AK, Chen AL, Reddy PD, Tejwani NC. Osteochondral lesions of the talus. J Am Acad Orthop Surg. 2005 May-Jun;13(3):152-8. Review. PubMed PMID: 15938604.
View Abstract
at PubMed
Mitchell ME, Giza E, Sullivan MR. Cartilage transplantation techniques for talar cartilage lesions. J Am Acad Orthop Surg. 2009 Jul;17(7):407-14. Review. PubMed PMID: 19571296.
View Abstract at PubMed
Murawski CD, Kennedy JG. Operative treatment of osteochondral lesions of the talus. J Bone Joint Surg Am. 2013 Jun 5;95(11):1045-54. doi: 10.2106/JBJS.L.00773. Review. PubMed PMID: 23780543.
View Abstract at PubMed

Question 97:

Options:

Flexor hallucis longus
Flexor digitorum longus
Flexor digitorum brevis
Peroneus longus
Split anterior tibial tendon

Correct Answer: Flexor digitorum longus

Explanation:

Question 98:

The histology of the lesion is shown in Figure 101d. What is the most likely complication after treatment of this lesion?

Options:

Arthrofibrosis
Local recurrence
Chondrolysis
Disseminated infection
Metastasis

Correct Answer: Local recurrence

Explanation:

DISCUSSION FOR QUESTIONS 101 THROUGH 103:
The MRI scans show a well-circumscribed inhomogenous mass at the anterior ankle joint consistent with a diagnosis of pigmented villonodular synovitis (PVNS), not an anatomic variant. An inflammatory mass,such as the pannus of rheumatoid arthritis, would reveal moderate signal intensity with relatively uniform signal throughout. The mass is well encapsulated, respecting tissue boundaries and not showing invasive characteristics as malignancies would. The arthroscopic image is also consistent with the reddish-brown frond-like tissue of PVNS. PVNS of the ankle can be treated arthroscopically. If this mode of treatment is chosen, a tissue sample should be sent to pathology for microscopic analysis; débridement should be performed on the remaining tissue. Removal of the instrumentation without débridement will not provide treatment and will result in disease progression. Tourniquet placement does not provide therapeutic benefit.
Brachytherapy has not been described for the treatment of PVNS of the ankle. The histologic image shows multiple multinucleated giant cells, hemosiderin, and very few mitotic figures – consistent with a diagnosis of PVNS. A common complication of PVNS treatment is local recurrence. Arthrofibrosis and chondrolysis are not seen with proper surgical care of these patients. Because this is not an infectious lesion, disseminated infection after treatment is highly unlikely. PVNS rarely metastasizes.
RESPONSES FOR QUESTIONS 104 THROUGH 106
Toe is fused too straight (plantar flexed)
Toe is fused in too much valgus
Toe is fused in too much dorsiflexion
There is a nonunion of the fusion
Excessive shortening of the first metatarsal during preparation for fusion What is the most likely diagnosis for each patient?

Question 99:

Options:

Tenderness over the anterior talofibular and calcaneofibular ligaments
A positive dorsiflexion external rotation test
Loss of passive range of motion
Positive squeeze test
Inability to single leg hop

Correct Answer: Inability to single leg hop

Explanation:

Question 100:

Options:

Closed reduction and application of a shoulder immobilizer
Open reduction and lesser tuberosity transfer
Hemiarthroplasty placed in anatomic version
Hemiarthroplasty placed in anteversion
Total shoulder arthroplasty

Correct Answer: Hemiarthroplasty placed in anatomic version

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

OITE & ABOS Orthopedic Board Review MCQs: Spine, Hip, & Shoulder | Part 20

Key Takeaway

About This Board Review Set

How to Use the Interactive Quiz

Topics Covered in Part 20

Sample Questions from This Set

Why Active MCQ Practice Works

Chapter Index