Arthroplasty, Trauma, Sports Orthopedic MCQs - Part 111

About This Board Review Set

This is Part 111 of the comprehensive OITE and AAOS Orthopedic Surgery Board Review series authored by Dr. Mohammed Hutaif, Consultant Orthopedic & Spine Surgeon.

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

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Topics Covered in Part 111

This module focuses heavily on: Arthroplasty, Fracture, Knee, Ligament, Shoulder.

Sample Questions from This Set

Sample Question 1: Second impact syndrome (SIS) after head injury is characterized by which of the following?...

Sample Question 2: Figure 21 shows the tomogram of a 26-year-old woman who sustained an axial load injury to her neck in a fall off a horse. What ligament is injured?...

Sample Question 3: An 18-year-old man was in a motor vehicle accident and sustained a closed head injury, right displaced scapular body and glenoid fractures, a right proximal humeral fracture, fractures of ribs one through three, facial fractures, and bilate...

Sample Question 4: Reverse total shoulder arthroplasty with a latissimus dorsi transfer would be the most appropriate treatment for which of the following patients? Review Topic...

Sample Question 5: A 28-year-old man reports knee stiffness, swelling, and a constant ache that is worse with activity. Examination reveals an effusion, global tenderness, and warmth to the touch. Flexion is limited to 110 degrees. Figures 48a through 48d sho...

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

Comprehensive 100-Question Exam

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Question 1

Second impact syndrome (SIS) after head injury is characterized by which of the following?

Explanation

DISCUSSION: SIS is a devastating but preventable complication of head injury. It occurs when return to activities is allowed prior to complete resolution of the symptoms of the first head injury. A second, sometimes trivial, head injury can lead to a devastating series of events that can result in sudden death. The symptoms tend to progress rapidly and often involve the brain stem. The prognosis is poor.
REFERENCES: Cantu RC: Second-impact syndrome. Clin Sports Med 1998;17:37-44.
Saunders RL, Harbaugh RE: Second impact in catastrophic contact-sports head trauma. JAMA 1984;252:538-539.
Stevenson KL, Adelson PD: Pediatric sports-related head injuries, in Delee JC, Drez D (eds): Orthopaedic Sports Medicine: Principles and Practice, ed 2. Philadelphia, PA, WB Saunders, 2003, vol 1, p 781.

Question 2

Figure 21 shows the tomogram of a 26-year-old woman who sustained an axial load injury to her neck in a fall off a horse. What ligament is injured?

Explanation

DISCUSSION: Levine and Edwards, in their description of the classic C1 burst (Jefferson) fracture, noted that spread of the lateral masses of more than 7 mm is indicative of a transverse ligament rupture. Long-term C1-C2 instability, however, has not been described with this fracture pattern. Although long-term traction followed by halo vest immobilization has been described as the best technique for achieving an ideal result, treatment of this injury remains somewhat controversial.
REFERENCES: Levine AM, Edwards CC: Fractures of the atlas. J Bone Joint Surg Am 1991;73:680-691.
Kurz LT: Fractures of the first cervical vertebra, in Clark CR (ed): The Cervical Spine, ed 3. Philadelphia, PA, Lippincott Raven, 1998, pp 409-413.

Question 3

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

Explanation

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

Question 4

Reverse total shoulder arthroplasty with a latissimus dorsi transfer would be the most appropriate treatment for which of the following patients? Review Topic

Explanation

Reverse total shoulder arthroplasty with a latissimus dorsi transfer would be most appropriate in a patient with failed shoulder hemiarthroplasty and the inability to perform active external rotation with the arm abducted
R-TSA has become the mainstay treatment for rotator cuff arthropathy. In the presence of severe loss of active elevation and external rotation, combined latisimus dorsi transfer and reverse total shoulder arthroplasty can restore elevation and external rotation, respectively. This may be used in the primary or revision setting.
Frankle et al. report the results of sixty patients with rotator cuff deficiency and glenohumeral arthritis who were followed for a minimum of two years. All were
treated with R-TSA. Their study showed that forward flexion increased from 55 to
105 degrees, and abduction increased from 41 to 102 degrees.
Boileau et al. followed 45 patients with severe cuff tear arthropathy and advanced atrophy/fatty infiltration of the infraspinatus or teres minor muscles. All patients were treated with R-TSA and a modified L'Episcopo procedure (latissimus dorsi and teres major transfer). Mean active elevation increased from 74 degrees preoperatively to
149 postoperatively, and external rotation increased from -21 to 13 degrees.
Illustrations A and B show the classic findings of rotator cuff arthropathy. There is significant acromial acetabularization and femoralization of humeral head. Other features include: asymmetric superior glenoid wear, osteopenia, "snowcap sign" due to subchondral sclerosis and anterosuperior escape. Illustration C shows a left shoulder after conversion from hemiarthroplasty to reverse total shoulder arthropathy.
Incorrect Answers:

Question 5

A 28-year-old man reports knee stiffness, swelling, and a constant ache that is worse with activity. Examination reveals an effusion, global tenderness, and warmth to the touch. Flexion is limited to 110 degrees. Figures 48a through 48d show sagittal T 1 -weighted, sagittal T 2 -weighted, axial T 1 -weighted fat-saturated gadolinium, and axial gradient echo MRI scans. Based on these findings, what is the most likely diagnosis?

Explanation

DISCUSSION: The MRI scans show multiple low-signal intensity lesions scattered throughout the knee, extending posteriorly inferior to the tibial plateau. The low-signal intensity on both the T₁- and T₂-weighted images, the modest vascularity noted on the gadolinium image, and the “blooming” noted on the gradient echo image (ferrous-laden tissue) are all strongly suggestive of diffuse PVNS. Whereas synovial chondromatosis can present as diffuse masses in the knee, they present as nodule masses that have low T₁- and high T₂-weighted signal characteristics.
REFERENCES: Resnick D (ed): Diagnosis of Bone and Joint Disorders. Philadelphia, PA,

WB Saunders, 2002, pp 4241-4252.
Sanders TG, Parsons TW: Radiographic imaging of musculoskeletal neoplasia. Cancer Control 2001;8:1-11.

Question 6

9 degress Celsius, serum WBC is 14,000, and his C-reactive protein is elevated. He reports that he uses IV heroin. A coronal 3D CT scan of the left clavicle is shown in Figure B. Joint aspiration shows many grams stain positive organisms. Which of the following organisms is the most likely pathogen?

Explanation

Tibial eminence fracture
Sagittal plane fracture of the medial femoral condyle
Schatzker I tibia plateau fracture
Coronal plane fracture of the lateral femoral condyle
Axial plane fracture through the medial femoral condyle Correct answer: 4
The "Hoffa fracture" is a coronal plane fracture of the femoral condyle that is often missed on plain radiographs of supracondylar and intercondylar femur fractures. It involves the lateral condyle more frequently than the medial.
Identification is important as it may impact operative planning and likely require screw fixation in the anteroposterior plane.
Nork et al. reviewed 202 supracondylar-intercondylar distal femoral fractures and found a 38% prevalence of associated coronal plane fractures. The authors recommend CT scan imaging of all supracondylar and intercondylar fractures.
Ostermann et al reported on 24 unicondylar fractures of the distal femur treated with open reduction internal fixation with a screw construct. Twenty-
three patients acheived satisfactory results at 5 year follow-up. Illustrations A and B are another example of a supracondylar femur fracture with an associated Hoffa fracture identified on CT scan.

A 35-year-old woman presents with an elbow injury which includes a coronoid fracture involving more than 50%, a comminuted
radial head fracture, and an elbow dislocation. What is the most appropriate treatment?
closed reduction and early range of motion
radial head resection and lateral collateral ligament reconstruction
radial head resection and coronoid open reduction internal fixation
radial head arthroplasty and coronoid open reduction internal fixation
radial head arthroplasty, coronoid open reduction internal fixation, and lateral collateral ligament repair
A terrible triad of the elbow includes dislocation of the elbow with associated fractures of the radial head and the coronoid process. Ring et al. stressed that these injuries are prone to complications and advised against resection of the radial head due to instability, and instead recommended a radial head replacement if too comminuted for ORIF. Coronoid fractures compromise elbow stability as well and require open reduction and internal fixation as with the lateral collateral ligament. McKee et al. showed stable elbows in 34/36 with mean Mayo elbow score of 88 when the standard protocol of coronoid ORIF, radial head repair/replacement, and LCL repair were employed.
The talocrural angle of an ankle mortise x-ray is formed between a line perpendicular to the tibial plafond and a line drawn:
perpendicular to the medial clear space
parallel to the talar body
between the tips of the malleoli
perpendicular to the shaft of the fibular
parallel to the subtalar joint Correct answer: 3
The talocrural angle is formed by the intersection of a line perpendicular to the plafond with a line drawn between the malleoli (average = 83+/-4deg). When the lateral malleolus is shortened secondary to fracture, this can lead to increased talocrural angle. This malunion leads to lateral tilt of the talus.
Phillips et al looked at 138 patients with a closed grade-4 supination-external rotation or pronation-external rotation ankle fracture. Although the conclusions were limited due to poor follow up, they found the difference in the talocrural angle between the injured and normal sides was a statistically significant radiographic indicator of a good prognosis.
Pettrone et al looked at a series of 146 displaced ankle fractures, and the effect of open or closed treatment, and internal fixation of one or both malleoli. They found open reduction proved superior to closed reduction, and in bimalleolar fractures open reduction of both malleoli was better than fixing only the medial side.
Illustrations A and B are demonstrations of the talocrural angle.

A 33-year-old male sustains the injury shown in Figure A. He is initially treated with a spanning external fixator followed by definitive open reduction internal fixation of the tibia and fibula. His wounds healed without infection or other complications. Two years following surgery, which of the following parameters will most likely predict a poor clinical outcome and inability to return to work?

Joint line restoration
Degree of fracture displacement
Time before definitive ORIF
Open fracture
Lower level of education Correct answer: 5
Lower level of education is the parameter that correlated most closely with a poor clinical outcome and inability to return to work.
To determine what fracture- and patient-specific variables affect outcome, Williams et al evaluated 29 patients with 32 tibial plafond fractures at a minimum of 2 years from the time of injury. Outcome was assessed by four independent measures: a radiographic arthrosis score, a subjective ankle score, the Short Form-36 (SF-36), and the patient’s ability to return to work. The four outcome measures did not correlate with each other. Radiographic arthrosis was predicted best by severity of injury and accuracy of reduction. However, these variables did not show any significant relationship to the clinical ankle score, the SF-36, or return to work. These outcome measures were more influenced by patient-specific socioeconomic factors. Higher ankle
scores were seen in patients with college degrees and lower scores were seen in patients with a work-related injury. The ability to return to work was affected by the patient’s level of education.
Pollak et al performed a retrospective cohort analysis of pilon fractures. Patient, injury, and treatment characteristics were recorded. The primary outcomes that were measured included general health, walking ability, limitation of range of motion, pain, and stair-climbing ability. A secondary outcome measure was employment status. Multivariate analyses revealed that presence of two or more comorbidities, being married, having an annual personal income of less than $25,000, not having attained a high-school diploma, and having been treated with external fixation with or without limited internal fixation were significantly related to poorer results as reflected by at least two of the five primary outcome measures.
What is the most appropriate treatment for a 17-year-old boy who sustained a gunshot wound to his forearm from a handgun with a muzzle-velocity of 1000 feet/second if he is neurovascularly intact and radiographs reveal no fracture?
Irrigation and local wound care in the emergency department
Emergent irrigation and debridement in the operating room with vacuum-assisted wound closure
Emergent irrigation and debridement in the operating room with 7 days of intravenous antibiotics
Wound closure in the emergency department with follow-up wound check in 1 week
Exploration and removal of all bullet fragments in the emergency department and 10 day course of oral antibiotics
The question refers to appropriate management of a gunshot wound to the forearm. The first question that must be answered when evaluating gunshot injuries is whether the gunshot is low velocity or high velocity. Low-velocity wounds are less severe, are more common in the civilian population, and are typically attributed to bullets with muzzle velocities below 1,000 to 2,000 feet per second. Tissue damage is usually more substantial with higher-velocity (greater than 2,000 to 3,000 fps) military and hunting weapons. In this question, a muzzle velocity of 1,000 ft/sec is provided. Low velocity injuries with stable, non-operative fractures can be treated with local wound care.
The two referenced articles offer guidance for treating low-velocity gunshot injuries with stable, non-operative fracture patterns. The first article by Geissler et al is a retrospective study comparing 25 patients that prospectively received local irrigation and debridement, tetanus prophylaxis and a long acting cephalosporin intramuscularly to a random retrospective sample of 25 patients with similar ballistic-induced fractures and wounds managed by local debridement and 48h of intravenous antibiotics. One infection occurred in each group, requiring further therapy. It was concluded that patients with low-velocity gunshot induced fractures can be managed without the use of short-term intravenous antibiotics with no increased risk of infection.
In the second study, Dickey et al evaluated the efficacy of an outpatient management protocol for patients with a gunshot-induced fracture with a stable, non-operative configuration. 41 patients with a grade I or II open, nonoperative fracture secondary to a low-velocity bullet were treated with 1gm of cefazolin administered in the emergency room and a 7-day course of oral cephalexin. No patient developed a deep infection. Thus, local I&D, tetanus, and oral antibiotics for 2-3 days is adequate for low velocity gunshot wounds.
Which clinical sign is the most sensitive for the diagnosis of compartment syndrome in a child with a supracondylar humerus fracture?
pulselessness
pallor
paresthesia
paralysis
increasing analgesia requirement Correct answer: 5
Although pain, pallor, paresthesia, paralysis, and pulselessness are all possible signs and symptoms of compartment syndrome in children with fractures, studies have shown increasing analgesia requirement is more sensitive.
Bae et al reviewed thirty-six cases of compartment syndrome in 33 pediatric patients. Approximately 75% of these patients developed compartment syndrome in the setting of fracture. "They found pain, pallor, paresthesia, paralysis, and pulselessness were relatively unreliable signs and symptoms of compartment syndrome in these children. An increasing analgesia requirement in combination with other clinical signs, was a more sensitive indicator of
compartment syndrome."
Whitesides et al summarizes the diagnosis and treatment of acute compartment syndrome. They emphasize the need for early diagnosis, as "muscles tolerate 4 hours of ischemia well, but by 6 hours the result is uncertain; after 8 hours, the damage is irreversible." They recommend fasciotomy be performed when tissue pressure rises past 20 mm Hg below diastolic pressure.
A 45-year-old man sustains the injury seen in Figures A and B following a motor vehicle accident. Postoperative radiographs are seen in Figures C and D. Which of the following is the most accurate when comparing outcomes between intramedullary nailing (IMN) and open reduction internal fixation (ORIF) for this injury?

Union rates at one year are higher with ORIF
Infection rates are higher with IMN
Functional shoulder outcomes at one year are equivalent with IMN and ORIF
Iatrogenic radial nerve injury rate is higher with ORIF
Shoulder stiffness rates at one year are equivalent with IMN and ORIF Correct answer: 3
Although shoulder pain and stiffness is increased following IMN compared to ORIF, functional outcome scores at one year have been shown to be equivalent
in both treatment groups.
Diaphyseal humeral shaft fractures outcomes following IMN and ORIF are under further investigation. Diaphyseal humeral shaft fractures have historically been treated with ORIF, however proponents for IMN cite benefits of less periosteal stripping and soft tissue dissection. Recent investigations have shown outcomes with regard to nonunion, infection, re-operation, and nerve palsy appear equivalent between both groups. Rates of shoulder stiffness and shoulder pain have been demonstrated to be higher in IMN compared to ORIF. American Shoulder and Elbow Scores (ASES) have shown no difference at one year post-operatively.
Bhandari et al. performed a meta-anaylsis of 3 prospective randomized trials. They found lower rates of re-operation and shoulder impingement with ORIF of humeral shaft fractures.
Wali et al. performed a prospective randomized study of IMN or ORIF on 50 patients with mid-diaphyseal humeral shaft fractures. They found IMN had shorter operative time, shorter hospital stay, and lower blood loss. They found no difference in union rates, complication, or shoulder functional outcomes scores. They conclude IMN to be an effective option for treating mid-diaphyseal humeral shaft fractures.
Heineman et al. have recently conducted an update on their meta-analysis to include more recent randomized studies. With the inclusion of newer studies the author found a statistically significant increase in total complication rate with the use of IM nailing compared with ORIF. The authors found no significant difference between the two treatment modalities for the secondary outcomes (nonunion, infection, nerve palsy, re-operation).
Figures A and B show a diaphyseal humeral shaft fracture. Figure C and D show postoperative radiographs following intramedullary nailing of a humeral shaft fracture.
Incorrect Answers:
A 25-year-old female presents complaining of progressive anteromedial pain in her left ankle. She underwent operative fixation 5 months prior at an outside hospital. The operative report indicated that, due to anterior fracture blisters, a direct medial incision was utilized, centered over the posterior colliculus of the medial malleolus, without violation of the deltoid ligament. A radiograph and computed tomographic scan of her initial injury are shown in Figures A and B, respectively. On exam, she has well-healed incisions, exhibits no tenderness to palpation over her hardware, but does endorse pain with deep palpation along the anteromedial joint line. Figure C shows an anteroposterior left ankle radiograph taken today. Labs are obtained and reveal a white blood cell count of 9.0 k/uL (reference range 4.5-11.0 k/uL) and a C-reactive protein value of 0.8 mg/dL (<0.9 mg/dL). What is the next best step in managing her problem?

Syndesmotic fixation
Intra-articular corticosteroid injection
Referral to physical therapy
Surgical correction of malunion
Removal of hardware Correct answer: 4
This patient sustained a supination-adduction (SAD) injury with a vertical shear fracture of her medial malleolus and a fibular avulsion fracture. She sustained a medial plafond articular impaction injury that was not addressed at the time of surgery.
In SAD injuries, supination of the foot is combined with inward rotation at the ankle, adduction of the hindfoot, and inversion of the forefoot. This results in the following sequence of events: 1. Talofibular sprain or distal fibular avulsion (equivalent to Weber A). 2. Vertical medial malleolus fracture as the talus strikes the tibia. Associated injuries may include osteochondral damage to the talus and marginal impaction of the medial plafond. It is important to evaluate the medial plafond for articular impaction. When present, an arthrotomy must be performed, typically utilizing an anteromedial incision, with direct visualization of the articular surface to restore the joint line appropriately.
Weber et al. provided a review article on corrective osteotomies for malleolar fracture malunions. They stress that malunions can lead to ankle instability, abnormal load transfer, and post-traumatic arthritis. They conclude that corrective osteotomies that restore anatomical alignment show good results in long-term follow-up.
Perera et al. provided additional commentary on the surgical reconstruction of malunited ankle fractures. The authors emphasize the link between malunion and poor outcomes. They state that successful salvage procedures involve a clear understanding of the deformity, careful preoperative planning, and a solid understanding of reconstructive techniques. They provide several instructive case examples in their review.
McConnell et al. provided a discussion on SAD ankle fractures at their institution and emphasized the importance of recognizing marginal impaction of the tibial plafond when treating these injuries. Of 800 ankle fractures identified over a 5-year period, 44 were SAD injuries, 19 of the 44 displayed a vertical shear fracture of the medial malleolus, and 8 of the 19 demonstrated marginal impaction of the tibial plafond. These 8 impaction injuries were treated with open reduction internal fixation with elevation of the articular impaction; all had good to excellent outcomes without arthritic changes at last
follow-up.
Figure A is an anteroposterior left ankle radiograph demonstrating a SAD injury with a vertical shear fracture of the medial malleolus, a fibular avulsion fracture, and articular impaction of the medial tibial plafond. Figure B is a coronal CT demonstrating articular impaction of the medial plafond. Illustration A is an intra-operative photograph with the medial malleolus retracted allowing inspection of the articular surface; mild anteromedial plafond impaction is present.
Incorrect Answers:

A 90-year-old female slips and falls at home. She is a community ambulator and has no medical problems. She reports right hip pain at this time. Injury radiographs are shown in Figures A & B. Delay of more than 48 hours may result in:

Increased intraoperative time
Increased 30-day mortality
No impact on the rate of postoperative pneumonia
Higher rates of blood transfusion
Increased risk of post-operative infection Correct answer: 2
Figures A & B demonstrate a right, unstable intertrochanteric femur fracture. Surgical stabilization within 48 hours improves short-term and 30-day mortality.
Hip fractures are common and mortality rates vary. In the elderly, mortality rates may reach 10% at 1-month, 20% at 4-months, and 30% at 1-year. Time to surgery has found to be a decisive factor. A pre-operative delay may lead to an increase in mortality and adversely influence other clinical outcomes.
Clinical guidelines recommend immediate operative stabilization, given the patient is medically fit for surgery.
Nyholm et al. performed a retrospective study of the Danish Fracture Database to investigate whether a surgical delay increases 30-day and 90-day mortality rates for patients with proximal femoral fractures. The 30-day and 90-day mortalities were 10.8% and 17.4%, respectively. The risk of 30-day mortality increased with increasing time intervals of more than 12 hours, 24 hours, and more than 48 hours. 90-day mortality increased with a surgical delay of more than 24 hours. They conclude that rapid surgical treatment should be performed by attending orthopaedic surgeons.
Moja et al. performed a meta-analysis and meta-regression to assess the relationship between surgical delay and mortality in elderly patients with a hip fracture. They analyzed 35 independent studies with 191,873 patients and 34,448 deaths. The majority of studies had a cut-off of 48 hours. They report that early hip surgery was associated with a lower risk of death and pressure sores. They conclude that early hip fracture surgery appears to provide a survival benefit compared to later intervention.
Rodriguez-Fernandez et al. performed a study examining 2 groups with hip fractures. The first group was studied retrospectively and had an average delay of surgical treatment of more than 1-week while the second group was studied prospectively, and had surgical treatment within 48 hours. They found a larger number of complications in the group with a delay in surgical treatment. They conclude that elderly patients with hip fractures should be treated as soon as their medical condition permits.
Figures A and B are the AP and lateral radiographs demonstrating a right, unstable intertrochanteric femur fracture. Illustration A is an intertrochanteric femur fracture, stabilized with a cephalomedullary nail.
Incorrect Answers:

A 22-year-old healthy left hand dominant male presents to the ED with left shoulder pain after falling from an ATV. Figure A is the radiograph of his left clavicle. He is neurovascularly intact and there is no evidence of skin tenting or open fracture. Which of the following most predisposes this patient to nonunion?

Diaphyseal fracture
Fracture displacement
Age
Male Gender
Injury involving the dominant extremity Correct answer: 2
Displaced clavicle fractures are associated with higher rates of nonunion.
Nonunion occurs in roughly 5-6% of clavicle fractures and can result in slower functional return, poor cosmesis and muscle fatigability. Clavicle fractures can be sub-classified using the Allman classification into medial, diaphyseal, and lateral injuries (Illustration A). The Neer classification for diaphyseal injuries describes fractures as "nondisplaced" (less than 100% displacement) and "displaced" (greater than 100% displacement).
Robinson et al. performed a prospective cohort study to identify risk factors for nonunion after nonoperative management of clavicle fractures. The overall nonunion rate was 6.2% and was highest in lateral third fractures (11.5%).
Diaphyseal fractures had the lowest nonunion rate (4.5%). Additionally, the authors found that the risk for nonunion was increased by advancing age, female gender, fracture displacement, and comminution.
Jorgensen et al. performed a systemic review of the literature looking for predictors of non-union and malunion in mid shaft clavicle fractures treated non-operatively. They found fracture comminution, displacement, older age, female gender, and the presence of smoking to be his factors for non-union. Of these, displacement was the most likely factor that can be used to predict nonunion.
Figure A demonstrates a displaced left clavicle diaphyseal fracture. Note that the medial fragment is displaced superiorly by the deforming force of the sternocleidomastoid. Illustration A represents the Allman classification.
Illustration B demonstrates the deforming forces acting on the clavicle.
Incorrect Answers:

A 24-year-old male presents with ankle pain after being involved in a motor vehicle accident. His injury radiograph is shown in Figure A. Which of the following has been shown to contribute to the development of post-traumatic arthritis in this injury pattern?

Initial superficial zone cartilage cell death via apoptosis at the fracture margins
Initial superficial zone cartilage cell death via apoptosis remote from the fracture margins
Initial superficial zone cartilage cell death via necrosis remote from the fracture margins
Initial superficial zone cartilage cell death via necrosis at the fracture margins
Delayed superficial zone cartilage cell death via necrosis at the fracture margins
Figure A demonstrates a tibial plafond fracture. Initial superficial zone cartilage cell death via necrosis at the fracture margins has been shown to contribute to post-traumatic arthritis.
Post-traumatic osteoarthritis typically occurs after an intra-articular fracture. Impacted chondrocytes die by either necrosis or apoptosis, which have both been implicated in post-traumatic osteoarthritis. Initial cell death in the superficial cartilage zones at the fracture margins occurs by necrosis. Apoptosis occurs in a delayed fashion and is mitigated by several bioactive agents.
Apoptosis also affects the superficial cartilage zones near the fracture margins. Deep cartilaginous zones and areas away from the fracture margins do not seem to be involved in these processes.
McKinley et al. performed a review of the basic science of intra-articular fractures and posttraumatic osteoarthritis. They report that initial damage to the cartilage in combination with the ensuing pathomechanical and pathobiologic response of the cartilage after a fracture contribute to posttraumatic arthritis. Chronic abnormal joint loading is also thought to contribute to this process as well. They conclude that the relative contribution of each is unknown.
Tochigi et al. performed a study to determine the distribution and progression of chondrocyte damage after intra-articular ankle fractures. They harvested 7 normal human ankles and subjected them to impaction. They found that immediate superficial zone chondrocyte death was greater in fracture-edge regions than on-fracture regions. Subsequent cell death over the next 48 hours was significantly higher in fracture-edge regions as well. They conclude that cartilage damage in intra-articular fractures was characterized by chondrocyte death at fracture margins.
Figure A is an ankle mortise radiograph demonstrating an intra-articular tibial plafond fracture.
Incorrect Answers:
A 35-year-old male presents with left knee pain after sustaining the injury seen in Figure A. He is neurovascularly intact and can perform a straight leg raise, but has pain with passive range of motion. Figures B and C show an anteroposterior and lateral radiograph of the left knee, respectively. 175 cc of saline is injected into the superolateral quadrant with no egress of fluid from the inferolateral
laceration. What percentage of traumatic arthrotomies would be detected with this test?

Question 7

Figure 1 depicts an intraoperative photograph obtained following proximal row carpectomy. The black dot denotes the capitate. The top of the figure is radial and the bottom of the figure is ulnar. Surgical disruption of the structure identified by the forceps would result in

Explanation

EXPLANATION:
The structure identified by the forceps is the radioscaphocapitate ligament. During a proximal row carpectomy, it is very important to identify and protect this ligament. Compromise of the ligament would result in ulnar translocation of the carpus and early failure of the proximal row carpectomy procedure. If the ligament is injured during surgery, immediate repair should be performed. Green and associates discuss the importance of the radioscaphocapitate ligament in stabilizing the carpus after this procedure is performed. Nakamura and associates compared 3-mm, 6-mm, and 10-mm radial styloidectomies, and only the 3-mm styloidectomy subsequently preserved carpal stability. Compromise of the radioscaphocapitate ligament occurred when larger portions of the radial styloid were excised. Distal radioulnar joint instability would result only from the disruption of the distal radioulnar joint stabilizers. Avascular necrosis would not occur, because the capitate receives its blood supply mainly from the palmar vessels. Finally, loss of active thumb IP flexion would not occur, because the flexor pollicis longus tendon would remain intact even if ligament compromise were to occur.

Question 8

03 A 28-year-old man underwent surgical fixation for an intra-articular distal humeral fracture 8 weeks ago now reports progressively restricted elbow motion. Radiographs at the time of union are shown in Figures 13a and 13b. Management should now consist of

Explanation

The radiographs show HO posteriorly in the triceps tendon and also anteriorly in the tendon. The fracture appears well-healed. At this point, oral indomethacin or single dose irradiation would not help as the HO is already there and these are typically used to prevent HO. Option #3 also would not help since there appears to be more of a bony block than soft tissue contracture. This leaves options 4 and 5. In the past, ectopic bone resection was
delayed until the heterotopic ossification was “mature”. This was signified by a cold bone scan and normal serum alk phos, as well as a mature appearance on xray. It was thought that by waiting until the HO was mature, recurrence would be avoided. However, in the cited reference, out of the widely read Journal of Hand Surgery, the authors obtained good results with increased range of motion, resolution of cubital tunnel syndrome and no recurrence of contractures or loss of motion with excision of ectopic bone and elbow release that was performed once bony union of fracture was obtained. They also used a 5 day course of indomethacin post-op.
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Question 9

A 28-year-old man sustained a shoulder dislocation 2 years ago. It remained dislocated for 3 weeks and required an open reduction. He now reports constant pain and has only 60 degrees of forward elevation and 10 degrees of external rotation. He desires to return to some sporting activities. An AP radiograph and intraoperative photograph (a view of the humeral head through a deltopectoral approach) are shown in Figures 31a and 31b. What is the best treatment option to decrease pain and improve function? Review Topic

Explanation

The radiograph and intraoperative photograph show osteonecrosis with near complete head loss/collapse. A stemmed implant is more appropriate in this patient because there is very little bone to support a resurfacing implant. In a younger patient, a glenoid implant should be delayed as long as possible because of the eventual need for revision secondary to glenoid loosening and wear, especially in a young active male. The hemiarthroplasty may be converted to a total shoulder arthroplasty in the future.

Question 10

A 19-year-old female field hockey player sustains a right ankle injury last night during a game. The patient is on crutches and reports that she has not been able to put any weight on her right ankle since the injury. She was running alongside with another player when her right ankle “gave out” and she twisted it, falling to the ground. Physical examination reveals discoloration similar to a hematoma and significant swelling around the lateral ankle area. Pain is elicited during palpation of the anterior talofibular ligament. What test should be performed to aid in this diagnosis?

Explanation

The anterior drawer test is performed with the ankle in 10° of plantar flexion, which results in the greatest amount of translation. The test investigates the integrity of the anterior talofibular ligament with a key distance of translation being 8 to 10 mm. While the patient is sitting and has her knees flexed over the edge of a table or bench, the physician uses one hand to stabilize the distal leg and with the other hand applies an anterior force to the heel in an attempt to gap the talus anteriorly from under the tibia. The anterior talofibular ligament and calcaneofibular ligament are both compromised based on the examination findings. The anterior drawer test result reflects injury to the anterior talofibular ligament and a possible injury to the calcaneofibular ligament. A lateral talar tilt test angle measurement >15° degrees reflects a rupture of both anterior talofibular ligament and calcaneofibular ligaments. The diagnosis is a severe lateral ligament complex sprain. This is optimally managed with early mobilization and a guided rehabilitation program that emphasizes proprioceptive stability.

Question 11

In hybrid arthroplasty, the use of a polymethylmethacrylate (PMMA) precoated femoral component has been shown to result in

Explanation

DISCUSSION: Precoating of the femoral stem with PMMA results in increased bonding of the stem to the cement mantle. However, this has not been shown to result in superior survivorship compared with nonprecoated stems of similar design. In one series, the rate of revision of precoated stems was greater than that of nonprecoated cohorts. The wear and infection rates have not been shown to differ between precoated and nonprecoated stems.
REFERENCES: Sporer SM, Callaghan JJ, Olejniczak JP, Goetz DD, Johnston RC: The effects of surface roughness and polymethylmethacrylate precoating on the radiographic and clinical results of the Iowa hip prosthesis: A study of patients less than fifty years old. J Bone Joint Surg Am 1999;81:481-492.
Schulte KR, Callaghan JJ, Kelley SS, Johnston RC: The outcome of Charnley total hip arthroplasty with cement after a minimum twenty-year follow-up: The results of one surgeon. J Bone Joint Surg Am 1993;75:961-975.

Question 12

A 20-year-old basketball player reports a 6-month history of right groin pain that radiates into his testicles with activities of daily living. He denies any history of trauma. Examination reveals tenderness about the groin, and he has full hip range of motion. The abdomen is soft. Radiographs are normal. Nonsurgical management has consisted of rest and physical therapy, but he continues to have pain. What is the next step in management?

Explanation

DISCUSSION: Sports hernias may be one of the most common causes of groin pain in athletes. Resisted hip adduction is painful in the case of groin disruption. Radiation of pain into the testicles and/or adductor region is often present. Sports hernias are associated with weakening of the posterior inguinal wall. In contrast with sports hernias, traditional or classic hernias can be readily detected on physical examination. Diagnostic imaging studies are not helpful and only serve to help exclude other diagnoses. Systemic high-dose steroids or sacroiliac joint injections have no role in treatment. High success rates have been reported for laparoscopic hernia repair in athletes.
REFERENCES: Kluin J, den Hoed PT, van Linschoten R, et al: Endoscopic evaluation and treatment of groin pain in the athlete. Am J Sports Med 2004;32:944-949.
Genitsaris M, Goulimaris I, Sikas N: Laparoscopic repair of groin pain in athletes. Am J Sports Med 2004;32:1238-1242.
Meyers WC, Foley DP, Garrett WE, et al: Management of severe lower abdominal or inguinal pain in high-performance athletes: PAIN (Performing Athletes with Abdominal or Inguinal Neuromuscular Pain Study Group). Am J Sports Med 2000;28:2-8.

Question 13

Five weeks after the patient completes a 6-week course of antibiotics, his ESR is 24 mm/h and CRP level is 10 mg/L, which is similar to the levels at 6 weeks. What is the most appropriate treatment at this time?

Explanation

DISCUSSION
This patient has both serologic and synovial fluid findings that are concerning for indolent infection. He was taking antibiotics at the time of aspiration. The AAOS clinical practice guideline, The Diagnosis of Periprosthetic Joint Infections of the Hip and Knee, suggests that patients discontinue antibiotics for a minimum of 2 weeks and that a repeat aspiration should be performed in cases of contradictory findings. In this situation, the cell count is elevated
along with an elevated ESR and CRP level. As a result, the appropriate treatment at this time is to reaspirate his hip.
This patient has a periprosthetic joint infection with a draining sinus tract. He has had symptoms for several months and, as a result, irrigation and debridement are not indicated. A single-stage surgery may be performed in some centers for healthy patients with susceptible organisms. However, single-stage reconstructions are generally performed with cemented implants in patients without a draining sinus tract. A 2-stage procedure with an antibiotic spacer is the surgical treatment modality most likely to eradicate this infection.
Serologic findings have significantly improved since the time of the prior surgical procedure. Surgical intervention does not need to be delayed until these values have completely normalized.

Question 14

Figure 1 is the radiograph of a 50-year old woman with lateral-sided left knee pain. She noticed the pain over the last few months and has had no new injury. She had a microfracture performed of her lateral femoral condyle 5 years ago. What is the likely cause of the finding noted on her radiograph?

Explanation

The radiograph reveals bony overgrowth of the microfracture site on the lateral femoral condyle. This occurs from violation of the subchondral plate during aggressive removal of the calcified cartilage layer during the microfracture. It is important during a microfracture to attempt to have a contained lesion and remove the calcified cartilage layer down to the subchondral plate, but avoid aggressively penetrating the plate.

Question 15

A 48-year-old man has recurrent right knee pain. Figure 52a shows the sagittal proton density T2-weighted MRI scan, and Figure 52b shows the sagittal T2-weighted MRI scan at the same level. The arrow is pointing to a

Explanation

DISCUSSION: Meniscal tears have many configurations and locations. The normal medial meniscus has a bow-tie configuration on the two most medial consecutive sagittal views. Toward the center of the joint the anterior and posterior horns have a triangular shape. These images show an abnormal intra-articular low-signal structure located anterior to the intact posterior cruciate ligament. This most likely represents a torn and displaced posterior horn of the medial meniscus, sometimes called “double PCL sign.” A popliteal cyst and ligaments of Wrisberg and Humphry are not visible on these figures.
REFERENCES: Helms CA: MR image of the knee, in Fundamentals of Skeletal Radiology, ed 2. Philadelphia, PA, WB Saunders, 1995, pp 172-191.
Mink JH, Deutsch AL: The knee, in MRI of the Musculoskeletal System, ed 1. New York, NY, Raven Press, 1990, pp 251-387.

Question 16

A 35-year-old female runner reports progressive vague aching pain involving her midfoot. Her pain is most notable when running. She denies specific injury. Examination reveals minimal swelling and localized tenderness over the dorsal medial midfoot and navicular. Radiographs and an MRI scan are shown in Figures 37a through 37c. What is the most appropriate management?

Explanation

DISCUSSION: A high index of suspicion is required to identify a possible navicular stress fracture, especially in runners. High pain tolerance in the competitive athlete and often minimal swelling contribute to frequent delays in diagnosis. Localized tenderness over the dorsal navicular (so-called “N spot”) in a running athlete should alert the treating physician. In this patient, the radiographs are negative and the MRI scan shows marrow edema within the navicular. This could represent a stress reaction, stress fracture, or osteonecrosis. Appropriate management should include non-weight-bearing immobilization and obtaining a CT scan to determine if a fracture is present. Early surgical treatment may be considered but only if a fracture is identified.
REFERENCES: Lee A, Anderson R: Stress fractures of the tarsal navicular. Foot Ankle Clin 2004;9:85-104.
Coughlin M: Tarsal navicular stress fractures. Tech Foot Ankle Surg 2002;1:112-122.

Question 17

A 21-year-old college defensive lineman sustains a minimally displaced (less than 1 mm) midthird scaphoid fracture during the first game of the season. Management should consist of

Explanation

DISCUSSION: The union rate for minimally displaced midthird scaphoid fractures is quite high with cast immobilization while allowing a return to sports. Inadequate immobilization results in a much higher nonunion rate. Early fixation and rehabilitation have been proposed for sports or positions that are not amenable to cast immobilization. While immobilization of a nondisplaced fracture results in an acceptably high union rate, there is no advantage to fixation in conjunction with immobilization in the course of healing. With adequate immobilization and protection, play restrictions until healing has occurred are unnecessary.
REFERENCES: Rettig AC, Kollias SC: Internal fixation of acute stable scaphoid fractures in the athlete. Am J Sports Med 1996;24:182-186.
Rettig AC, Weidenbener EJ, Gloyeske R: Alternative management in midthird scaphoid fractures in the athlete. Am J Sports Med 1994;22:711-714.
Riester JN, Baker BE, Mosher JF, Lowe D: A review of scaphoid fracture healing in competitive athletes. Am J Sports Med 1985;13:159-161.

Question 18

Surgical arthroscopy performed 1 week after injury presents increased risk for

Explanation

DISCUSSION
The MR images show injuries to the ACL, PCL, and PLC consistent with a knee dislocation. The optimal timing of surgery after multiligament knee injury remains unclear. Two systematic reviews demonstrated superior clinical outcome scores after early treatment, including higher mean Lysholm scores and a higher percentage of good/excellent International
Knee Documentation Committee scores. Early treatment was associated with increased residual anterior knee instability but no difference in posterior instability, varus laxity, or valgus laxity. Although numbers were limited, the average range of motion and rate of extension loss of at least 5 degrees was similar between groups. More patients in the early-treatment group demonstrated a higher rate of flexion loss of 10 or more degrees and an increased need to undergo a second procedure to address arthrofibrosis, including manipulation under anesthesia and arthrolysis. Return to work did not significantly differ between groups, but return to sports was lower in the early-treatment group. Evidence demonstrates a higher rate of low-energy mechanisms resulting in multiligament knee injury and an increased odds ratio for complications among obese (= 30 degrees kg/m2 patients, including wound complications and neurovascular injury. The complication rate increased 9.2% for every 1-point increase in body mass index. There is no association between complication rate and age, injury mechanism, or timing of surgery. Orthopaedic surgeons performing arthroscopy during the early postinjury period must be mindful of the extensive soft-tissue damage present in these patients, including potential capsular defects. Use of high-pressure irrigation can lead to substantial fluid extravasation into the thigh or lower leg compartments, placing patients at increased risk for compartment syndrome. In addition to avoiding high-pressure irrigation, some orthopaedic surgeons have advocated the creation of generous capsular incisions during portal establishment to allow for ready egress of irrigation fluid from the portal sites rather than into soft tissues.
RESPONSES FOR QUESTIONS 85 THROUGH 88
Excessive medial placement of coracoid autograft
Excessive lateral placement of coracoid autograft
Excessive inferior dissection during the procedure
Excessive retraction and dissection of the medial portion of the conjoint tendon
A 20-year-old right-hand-dominant football player sustained a traumatic shoulder dislocation during a tackle. He has had multiple recurrent dislocations, and radiographs reveal anterior glenoid bone loss. He underwent a Latarjet procedure. Match the most likely complication described below with the surgical error listed above.

Question 19

During spinal deformity surgery, which of the following is the most specific early indicator of an intraoperative injury to the spinal cord? Review Topic

Explanation

Transcranial motor-evoked potentials provide the most specific early indicator of an intraoperative spinal cord injury. Somatosensory-evoked potentials are routinely used but do not have the sensitivity and specificity of motor-evoked potentials. EMG evaluations are routinely used for root evaluation following pedicle screw placement. BAERs are typically used in monitoring brain surgery.

Question 20

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

Explanation

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

Question 21

Which of the following statements best describes the kinematic behavior of the knee during motion from full extension to flexion?

Explanation

DISCUSSION: During normal knee flexion, knee kinematic analysis reveals that the medial tibiofemoral contact point moves very little (translates) in the anterior-posterior direction, whereas the lateral contact point moves much
greater in the anterior-posterior direction (translates), resulting in more lateral translation, rollback, and medial pivoting.
REFERENCE: Churchill DL, Incavo SJ, Johnson CC, et al: The transepicondylar axis approximates the optimal flexion axis of the knee. Clin Orthop Relat Res 1998;356:111-118.
Figure 98c Question 98
A 71-year-old businessman reports medial knee pain recalcitrant to nonsurgical management.
Examination reveals that his body mass index (BMI) is 28 and he has a mild varus deformity with a range of
motion from 5 degrees to 130 degrees of flexion. Anterior drawer and Lachman’s test are negative. Radiographs are shown in Figures 98a through 98c. For cultural and religious reasons, he is concerned about maintaining his range of motion and kneeling ability. Which of the following options is best?
High tibial osteotomy
Unicompartmental knee arthroplasty
Cruciate-retaining total knee arthroplasty with a fixed bearing design
Posterior stabilized total knee arthroplasty with a fixed bearing design
Cruciate-sacrificing total knee arthroplasty with a rotating platform design PREFERRED RESPONSE: 2
DISCUSSION: Unicompartmental arthroplasty of the knee is associated with better range of motion than either total knee arthroplasty or high tibial osteotomy. In a prospective randomized trial of unicompartmental and total knee arthroplasty for patients with medial compartment osteoarthritis, patients with the unicompartmental prosthesis had better range of motion. The literature that compares range of motion in cruciate-retaining as opposed to posterior stabilized and fixed bearing as opposed to mobile- bearing total knees suggests relatively equivalent range of motion between these designs.
REFERENCES: Newman JH, Ackroyd CE, Shah NE: Unicompartmental or total knee replacement? Five- year results of a prospective randomized trial of 102 osteoarthritic knees with unicompartmental arthritis.
J Bone Joint Surg Br 1998;80:862-865.
Barrack RL, Booth RE Jr, Lonner JH, et al (eds): Orthopaedic Knowledge Update: Hip and Knee Reconstruction 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, pp 59-69.

Question 22

A 24-year-old dancer sustains the injury shown in Figure 28. Management should consist of

Explanation

DISCUSSION: The patient has a moderately displaced distal diaphyseal fracture of the fifth metatarsal, and the most appropriate treatment is brief immobilization and symptomatic management. Attempts at closed reduction are unlikely to appreciably alter the position of the fracture. Surgical techniques for either reduction of the fracture or fixation have not been shown to result in improved functional outcomes.
REFERENCES: O’Malley MJ, Hamilton WG, Munyak J: Fractures of the distal shaft of the fifth metatarsal: “Dancer’s Fracture.” Am J Sports Med 1996;24:240-243.
DeLee JC: Fractures and dislocations of the foot, in Mann RA, Coughlin MJ (eds): Surgery of the Foot and Ankle, ed 6. St Louis, MO, CV Mosby, 1993, pp 1465-1703.
Hamilton WG: Foot and ankle injuries in dancers, in Yokum L (ed): Sports Clinics of North America. Philadelphia, PA, Williams and Wilkins, 1988.

Question 23

Based on the radiograph shown in Figure 4, the innervation of what muscle is most at risk with total hip arthroplasty?

Explanation

DISCUSSION: The radiograph reveals a Crowe IV deformity in a patient with developmental dysplasia of the hip. If hip arthroplasty is performed, then some degree of limb lengthening is anticipated. Excessive limb lengthening can result in sciatic nerve palsy in these patients. The peroneal branch of the sciatic nerve is most often affected. Of the muscles listed, only the extensor hallucis longus is innervated by the peroneal branch of the sciatic nerve.
REFERENCES: Eggli S, Hankemayer S, Muller ME: Nerve palsy after leg lengthening in total replacement arthroplasty for developmental dysplasia of the hip. J Bone Joint Surg Br 1999;81:843-845.
Schmalzried TP, Amstutz HC, Dorey FJ: Nerve palsy associated with total hip replacement:

Risk factors and prognosis. J Bone Joint Surg Am 1991;73:1074-1080.

Question 24

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

Explanation

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

Question 25

The clinical photograph in Figure 27 shows a palsy of what nerve/associated muscle? Review Topic

Explanation

The clinical picture reveals medial scapular winging, which involves the serratus anterior muscle, potentially due to an injury to the long thoracic nerve that innervates this muscle. Injury to the long thoracic nerve is usually due to closed trauma, direct compression, traction or stretching injury, a direct blow, or, very rarely, viral infection
such as Parsonage-Turner syndrome. The nerve is easily injured in surgical dissection of the axilla, and is predisposed to injury due to its relatively long course, it is small in diameter, and it has little surrounding connective tissue. If rehabilitation and time are unsuccessful, both nerve and muscle transfers have been described with mixed results.

Question 26

Nonsurgical management of pectoralis major tears is likely to result in weakness of glenohumeral

Explanation

DISCUSSION: Nonsurgical management is considered for proximal tears as well as partial tears in some individuals. Surgical management is often not appropriate in older or sedentary patients. However, patients treated nonsurgically will have a significant cosmetic defect, as well as weakness in adduction and internal rotation.
REFERENCES: Schepsis AA, Grafe MW, Jones HP, et al: Rupture of the pectoralis major muscle: Outcome or repair of acute and chronic injuries: Am J Sports Med 2000;28:9-15.
Petilon J, Carr DR, Sekiya JK, et al: Pectoralis major muscle injuries: Evaluation and management. J Am Acad Orthop Surg 2005;13:59-68.

Question 27

A 34-year- woman has pain at the base of the thumb that worsens é pinching activities. Nonsurgical treatment has failed to provide relief. Examination reveals that the basilar joint is hypermobile, tender and painful when stressed. A radiograph of the trapeziometacarpal joint shows normal contour with widening when compared with the opposite side. Management should consist of

Explanation

Painful instability of the thumb carpometacarpal (CMC) joint as manifested by “idiopathic hypermobility of the basal joint is not uncommon, particularly in women, and would seem to be a significant factor in producing the arthrosis that so frequently afflicts this joint.” “Extra-articular ligament reconstruction to stabilize the thumb carpometacarpal (CMC) (basal) joint by routing a portion of the flexor carpi radialis (FCR) through the base of the thumb metacarpal … is recommended only for patients in stage I and stage II disease (i.e., patient’s having zero to only slight cartilage attrition). With 95 % of stage I and stage II patients having achieved and maintained good or excellent results, (restoration of stability, pain reduction and possibly retarding joint degeneration) … we feel the procedure has proved predictable and durable. Despite limited success in patients with significant articular deterioration (stage III and stage IV), we do not recommend ligament reconstruction alone in such cases. Instead we would recommend articular resurfacing or implant arthroplasty that would depend on the number of trapezium surfaces involved.”

Question 28

The mechanism for the osseous destruction is attributable to

Explanation

DISCUSSION
This scenario is a classic example of the development of Charcot foot. A red, swollen, deformed foot without ulceration suggests neuroarthropathy. Normal inflammatory marker findings, no history of fever or chills, and radiographs demonstrating bone loss support the diagnosis. Limb elevation with dramatic reduction in erythema is also characteristic of this disease process and does not occur with infection. Total-contact casting is the cornerstone of treatment for acute Charcot disease. Hemoglobin A1C is an indicator of glucose averaged over a 3-month period, providing the most reliable indication of a patient's ongoing glucose control. The pathophysiology of bone destruction is believed to be hypervascularity of bone. Infection and Charcot disease may develop simultaneously, but the combination is rare.
RECOMMENDED READINGS
Kaynak G, Birsel O, Güven MF, Ogüt T. An overview of the Charcot foot pathophysiology. Diabet Foot Ankle. 2013 Aug 2;4. doi: 10.3402/dfa.v4i0.21117.Print 2013. PubMed PMID: 23919113.View Abstract at PubMed
Pinzur MS, Lio T, Posner M. Treatment of Eichenholtz stage I Charcot foot arthropathy with a weightbearing total contact cast. Foot Ankle Int. 2006 May;27(5):324-9. PubMed PMID: 16701052. View Abstract at PubMed

Question 29

A woman with a neck and chest tumor has weakness in the biceps and paresthesias in the thumb. Brachioradialis and infraspinatus function are normal. The lesion is affecting which of the following structures?

Explanation

DISCUSSION: The lateral cord terminates as the musculocutaneous nerve and also contributes sensory fibers to the median nerve. Involvement of the C6 root or upper trunk could potentially cause weakness of the infraspinatus and the brachioradialis. The middle trunk and the posterior cord do not contribute motor fibers to the thumb or sensory fibers to the thumb.
REFERENCE: Kline DG, Hudson AR: Nerve Injuries: Operative Results for Major Nerve Injuries, Entrapments and Tumors. Philadelphia, PA, WB Saunders, 1995, p 334.

Question 30

Figure 44 shows the radiograph of an 11-year-old girl who has hip pain. Further diagnostic workup should include

Explanation

DISCUSSION: The patient has severe acetabular protrusio, a condition that is frequently associated with Marfan syndrome. An echocardiogram is necessary to rule out the most serious consequence of this syndrome, aortic root widening, which can lead to aortic valve dysfunction or fatal aortic rupture. An electromyogram may be indicated for Charcot-Marie-Tooth disease, which is associated with acetabular dysplasia, but not protrusio. The renal ultrasound, the MRI scan, and the biopsy would be of no value in this patient. Protrusio can also be seen in patients with osteogenesis imperfecta and juvenile rheumatoid arthritis.
REFERENCES: Steel HH: Protrusio acetabuli: Its occurrence in the completely expressed Marfan syndrome and its musculoskeletal component and a procedure to arrest the course of protrusion in the growing pelvis. J Pediatr Orthop 1996;16:704-718.
Wenger DR, Ditkoff TJ, Herring JA, Mauldin DM: Protrusio acetabuli in Marfan’s syndrome. Clin Orthop 1980;147:134-138.

Question 31

What is the prognosis for ambulation, from best to worst, for patients with an incomplete spinal cord injury?

Explanation

DISCUSSION: Of the incomplete spinal cord injuries, Brown-Sequard syndrome has the best prognosis for ambulation. Central cord syndrome has a variable recovery. Anterior cord syndrome has the worst prognosis, with motor recovery rare below the level of the injury.
REFERENCES: Apple DF: Spinal cord injury rehabilitation, in Herkowitz HN, Garfin SR, Balderston RA, Eismont FJ, Bell GR, Wiesel SW (eds): Rothman-Simeone The Spine, ed 4. Philadelphia, PA, WB Saunders, 1999, pp 1130-1131.
Northrup BE: Evaluation and early treatment of acute injuries to the spine and spinal cord, in Clark CR (ed): The Cervical Spine, ed 3. Philadelphia, PA, Lippincott Raven, 1998, pp 544-545.

Question 32

A 20-year-old-man sustained a scapular fracture after attempting to grab a beam as he fell through a ceiling at a job site 3 months ago. A clinical photograph is shown in Figure 36. He now reports pain in the anterior shoulder and difficulty with overhead activities. What nerve roots make up the involved peripheral nerve?

Explanation

DISCUSSION: The patient sustained an injury to the long thoracic nerve, which supplies the serratus anterior. Branches of C5 and C6 enter the scalenus medius, unite in the muscle, and emerge as a single trunk and pass down the axilla. On the surface of the serratus anterior, the long thoracic nerve is joined by the branch from C7 and descends in front of the serratus anterior, providing segmental innervation to the serratus anterior.
REFERENCE: Leffert RD: Anatomy of the Brachial Plexus in Brachial Plexus Injuries. Churchill Livingstone, New York, NY, 1985.

Question 33

What arterial vessel is most prone to injury during posterior iliac crest bone graft harvest?

Explanation

DISCUSSION: The superior gluteal artery is most at risk with a posterior iliac crest bone graft harvest. The artery leaves the pelvis through the sciatic notch and can be injured by retractors or other sharp instruments entering the sciatic notch area. The deep circumflex iliac, iliolumbar, and fourth lumbar arteries supply the iliacus and iliopsoas muscles and can be damaged during anterior bone graft harvest. The ascending branch of the lateral femoral circumflex artery is at risk during the anterior approach to the hip.
REFERENCES: Guyer RD, Delmarter RB, Fulp T, Small SD: Complications of cervical spine surgery, in Herkowitz HN, Garfin SR, Balderston RA, Eismont FJ, Bell GR, Wiesel SW (eds): Rothman-Simeone The Spine, ed 4. Philadelphia, PA, WB Saunders, 1999, p 547.
Kurz LT, Garfin SR, Booth RE Jr: Iliac bone grafting: Techniques and complications of harvesting, in Garfin SR (ed): Complications of Spine Surgery. Baltimore, MD, Williams and Wilkins, 1989, pp 330-331.
Hoppenfeld S, deBoer P: Surgical Exposures in Orthopaedics: The Anatomic Approach. Philadelphia, PA, JB Lippincott, 1984, pp 297, 331-332.

Question 34

What muscle is most often encountered during surgical approaches to C5-6?

Explanation

DISCUSSION: The omohyoid muscle crosses the surgical field from inferior lateral to anterior superior traveling from the scapula to the hyoid bone and may need to be transected. The posterior digastric crosses the field as well but higher near C3-4. The other muscles run longitudinally.
REFERENCES: Chang U, Lee MC, Kim DH: Anterior approach to the midcervical spine, in Kim DH, Henn JS, Vaccaro AR, et al (eds): Surgical Anatomy and Techniques to the Spine. Philadelphia, PA, Saunders Elsevier, 2006, pp 45-56.
Netter GH: Atlas of Human Anatomy. Summit, NJ, Ciba-Geigy Corporation, 1989.

Question 35

Calcitonin acts as an antiresorptive agent by

Explanation

DISCUSSION: Calcitonin is a hormone that binds to osteoclasts and acts to decrease both osteoclast activity and number. Calcitonin is most effective in reducing vertebral compression fractures in high-turnover osteoporosis. It is also effective in treating regional osteoporosis. Because of its analgesic effect, it is helpful in treating painful acute compression fractures associated with osteoporosis.
REFERENCE: Lane JM, Nydick M: Osteoporosis: Current modes of prevention and treatment. J Am Acad Orthop Surg 1999;7:19-31.

Question 36

A 77-year-old man with diabetes mellitus has had a nonhealing Wagner grade I ulcer under the medial sesamoid for the past 3 months. He smokes tobacco regularly. He has undergone several debridements and total contact casting. Examination reveals no palpable pulses. He has no erythema or purulence, and he is afebrile. Radiographs reveal no abnormalities. What is the best initial diagnostic test to help determine why the ulcer has failed to heal?

Explanation

DISCUSSION: The best initial test for this patient is to assess the vascular supply to the foot. An elderly smoker with diabetes mellitus has a high risk of peripheral vascular disease. Decreased weight bearing has not been successful. Although a bone scan might be helpful, it would take secondary consideration to the patient’s vascular supply, especially in the absence of any acute infection. Monofilament testing would help diagnosis neuropathy, which is a root cause behind the ulcer forming, but does not prevent it from healing. The Thompson’s test is used to diagnosis an Achilles tendon rupture.
REFERENCE: Brodsky JW: Evaluation of the diabetic foot. Instr Course Lect 1999;48:289-303.

Question 37

A 27-year-old man now reports dorsiflexion and inversion weakness after an automobile collision 6 months ago in which compartment syndrome developed isolated to the anterior and deep posterior compartments. Examination reveals the development of a progressive cavovarus deformity, but the ankle and hindfoot remain flexible. In addition to Achilles tendon lengthening, which of the following procedures is most likely to improve the motor balance of his foot and ankle?

Explanation

DISCUSSION: Compartment syndrome of the anterior and deep posterior compartments results in anterior tibialis and posterior tibialis tendon weakness, respectively. Furthermore, the long flexors to the hallux and lesser toes will be weak as well. The intact peroneus longus overpowers the weak anterior tibialis tendon, resulting in plantar flexion of the first metatarsal, cavus, and hindfoot varus. Therefore, transferring the peroneus longus to the dorsolateral midfoot reduces the first metatarsal plantar flexion torque, and possibly augments ankle dorsiflexion torque.
REFERENCES: Hansen ST: Functional Reconstruction of the Foot and Ankle. Philadelphia, PA, Lippincott, Williams & Wilkins, 2000, pp 433-435.
Vienne P, Schoniger R, Helmy N, et al: Hindfoot instability in cavovarus deformity: Static and dynamic balancing. Foot Ankle Int 2007;28:96-102.

Question 38

Figures 63a and 63b show the radiographs of a 38-year-old man who reports low back and bilateral lower extremity pain. The spondylolisthesis is best classified as which of the following? Review Topic

Explanation

Spondylolisthesis can be classified into five types. Type I, dysplastic, occurs at the lumbosacral junction as a result of congenital abnormalities of the upper sacrum and/or the arch of L5. Type II, isthmic, refers to those involving a lesion in the pars interarticularis. Type IIA, lytic, represents fatigue fractures of the pars. Type IIB describes those with elongated, but intact pars. Type IIC describes those that are a result of an acute fracture of the pars. Type III, degenerative spondylolisthesis, results from long-standing intersegmental disease. Type IV, traumatic, refers to those resulting from fractures in regions other than the pars, such as the pedicles. Type V, pathologic, refers to spondylolisthesis resulting from generalized or local bone disease. The radiographs demonstrate type II, isthmic spondylolisthesis.

Question 39

Figures 174a and 174b are the radiograph and clinical photograph of a 64-year-old obese woman (body mass index [BMI] of 48) who has controlled diabetes and hypertension. She has failed nonsurgical treatment and a weight loss program. She is considering total knee arthroplasty (TKA). What is the most significant postsurgical risk for this patient?

Explanation

DISCUSSION
The literature has demonstrated increased risk for complications among obese patients undergoing TKA (10%-30%). An evaluation of TKA among obese patients revealed 3- to 9-fold higher incidence of wound complications and deep-seated infection. Belmont and associates demonstrated that patients with a BMI higher than 40 are at higher risk for overall complications than patients with a BMI lower than 25, with a particularly high risk for developing local wound complications and infection. An increased risk for thromboembolic complications was not shown among obese patients undergoing TKA. Patient-reported outcome scores among obese patients undergoing TKA are equivalent to those of nonobese
patients. There are conflicting data regarding the outcome and survivorship following TKA for obese patients. Although some studies show a difference in patient-reported outcomes at differing postsurgical intervals, most obese patients undergoing TKA are satisfied with the procedure.

Question 40

A 63-year-woman has an elbow flexion contracture. History reveals that she underwent three previous surgeries to remove a malignant fibrous histiocytoma of the forearm. An MRI scan reveals a locally recurrent tumor at the site of the previous surgery. Which of the following is considered the most predictive factor for local recurrence?

Explanation

DISCUSSION: The greatest risk factor for local recurrence is an inadequate surgical margin. The tumor grade, histologic subtype, and size are predictive of systemic relapse. Sarcomas that arise in some anatomic sites, such as the forearm or retroperitoneum, may be more difficult to completely resect compared with other sites. The optimum margin is generally considered to be a cuff of normal tissue beyond the tumor.
REFERENCES: Bell RS, O’Sullivan B, Liu FF, et al: The surgical margin in soft-tissue sarcoma. J Bone Joint Surg Am 1989;71:370-375.
Sadoski C, Suit HD, Rosenberg A, Mankin H, Efird J: Preoperative radiation, surgical margins, and local control of extremity sarcomas of soft tissues. J Surg Oncol 1993;52:223-230.
Wilson AN, Davis A, Bell RS, et al: Local control of soft tissue sarcoma of the extremity: The experience of a multidisciplinary sarcoma group with definitive surgery and radiotherapy. Eur J Cancer 1994;30:746-751.

Question 41

A 66-year-old male undergoes the procedure shown in figures A and B. After 4 years, he develops progressive pain and limitations in his daily function that is refractory to conservative measures. He is indicated for conversion to a total knee replacement with almost complete relief of his symptoms postoperatively. What preoperative factor likely led to the subsequent failure?

Explanation

unicompartmental arthroplasty. The absence of an ACL is a contraindication for mobile-bearing UKA.

OrthoCash 2020
Which of the following is the most common cause of early revision surgery (<20 weeks) following a hip resurfacing arthroplasty?
Periprosthetic fracture
Rupture of abductors
Dislocation
Heterotopic ossification
Post-operative stiffness
Periprosthetic fracture, specifically femoral neck fracture, is the most common cause of early revision less than 20 weeks following surgery.
The rate of femoral neck fractures following hip resurfacing varies, but most literature reports a rate of 1%. A majority of these fractures happen in the early post-operative period and are the most frequent cause of revision surgery within several months following surgery. The cause is usually multifactorial, but placing the femoral implant in varus, osteonecrosis, and notching have been proven risk factors for fracture.
Little el al. report on 377 patients undergoing hip resurfacing. 13 required revision including 8 for fracture of the femoral neck and 3 for loosening of a component. Evidence of osteonecrosis was seen in two of these cases, leading the authors to believe it may contributed to fracture.
Illustration A shows a comparison of a typical total hip replacement and a hip resurfacing arthroplasty. Illustration B shows notching of the femoral neck, a known cause of femoral neck fracture following hip resurfacing. Illustration C shows a femoral neck fracture in a patient with a hip resurfacing.

OrthoCash 2020
A 55-year-old male undergoes a revision total knee arthroplasty of an implant that is only 3 years old. At the time of surgery, the tibial polyethylene liner shows catastrophic delamination and cracking. What is the most likely cause of this extensive, accelerated wear of the polyethylene liner?
Sterilization in ethylene oxide
Gamma irradiation of the polyethylene liner in the presence of air
Gamma irradiation of the polyethylene liner with vacuum packaging
Gamma irradiation of the polyethylene liner in nitrogen
Gamma irradiation of the polyethylene liner in argon Corrent answer: 2
Irradiation of polyethylene in air (i.e. oxygen present) has been shown to be a risk factor for catastrophic failure after total knee replacement.
Free radicals are generated when polyethylene is irradiated in the presence of air. Initially, these free radicals result in cross-linking. However, if the polyethylene is exposed to these free radicals for an extended period of time, delamination, cracking, and catastrophic failure may ensue. The industry has completely abandoned this method of sterilization as a result. Currently, the standard of care is irradiation of polyethylene in an inert gas (e.g. argon, nitrogen or vacuum packaging). The amount of oxidative products when polyethylene is sterilized in the absence of oxygen is much less and does not lead to catastrophic failure.
Sterilization without irradiation is another option (ethylene oxide). When this occurs, there is no cross-linking and thus the increased wear properties are lost. However, since there is no oxidization, you do not have the risk of catastrophic failure as seen in those liners irradiated in the presence of oxygen.
The cited reference by McNulty et al. from Orthopedics discusses the influence of sterilization methods on wear performance. They found that gamma irradiation and storage of the polyethylene components in an essentially oxygen-free environment imparted by gamma irradiation in a vacuum foil pouch (GVF) protects the components from oxidization.
Illustration A shows a polyethylene liner that has undergone catastrophic wear as a result of irradiation in the presence of oxygen.
Incorrect Answers:
catastrophic wear, although wear properties are less than gamma irradiation in the absence of air.

OrthoCash 2020
Which of the following interventions reduces osteolysis around distal portion of the femoral stem when performing a total hip arthroplasty?
Use of an extended offset femoral neck component
Use of a proximal circumferentially coated ingrowth stem
Use of a collared stem
Use of a long femoral stem
Ensuring that the stem fills the diaphysis of the femur Corrent answer: 2
Osteolysis of the femur is caused by activation of macrophages by microscopic polyethylene particles within the "effective joint space", defined as any area where joint fluid can come into contact with bone. This can occur above the acetabular cup, through screw holes, and down the femoral shaft around the prosthetic stem. Ideally, with a cementless stem, both the proximal and metaphyseal femur are well filled by the prosthesis. Collared stems are used to augment poor calcar bone quality or bone loss.
Sinha et al showed in a retrospective review of 101 hips with cementless circumferentially coated femoral stems no distal femur osteolysis occurred, but 82% showed “evidence of proximal femur stress shielding”, though only 38% showed proximal femoral osteolysis.
OrthoCash 2020
During a minimally invasive approach to total hip arthroplasty a femoral periprosthetic fracture occurs. Which of the following steps is crucial to properly treat this complication?
Transitioning to an extensile approach to adequately visualize and reduce the fracture
Limiting post-operative weight bearing
Switching to a cemented femoral stem to avoid the stresses created during press-fit fixation
Delaying the arthroplasty until the fracture has healed
Supplementing the fracture with autograft Corrent answer: 1
Proper treatment of an intraoperative femoral fracture during total hip arthroplasty involves adequate exposure, anatomic reduction, and bypassing the fracture site by 2 cortical diameters of the femur with a long stem. This may involve repositioning the patient on the table if the arthroplasty is performed in the supine position. Minimally invasive surgical techniques have been developed to insert the components through smaller exposures and less soft tissue dissection. The purported advantages include faster rehabilitation, less blood loss, shorter hospital stays, and better cosmesis. However, complications an arise if the surgeon sacrifices surgical exposure and visualization.
Fehring et al review 3 cases of total hip arthroplasty performed through minimally invasive techniques with catastrophic outcomes. Intra-operative fracture, chronic instability, and death were all identified.
OrthoCash 2020
A 70-year-old man underwent total hip arthroplasty 4 months ago and has experienced 3 dislocations. Radiographs reveal no failure of the hardware and an acetabular component that has an abduction
angle of 40 degrees and a version of 10 degrees retroverted. What is the most appropriate treatment for the recurrent dislocations?
hip abduction brace
revision of the acetabular liner to a constrained type
revision of the entire acetabular component
revision of the femoral head to a larger size
revision to an extended offset prosthesis Corrent answer: 3
Per Dorr et al: post-operative hip instability can be caused by several factors: soft tissue imbalance, component malposition, or position. Component malposition, as in this case, should be treated with revision of the offending component. In this case the acetabulum was placed in retroversion when it should have been 15-20 degrees anteverted. None of the other options addresses the cause of the instability. According to Morrey, the most signficant risk factors to instability are prior hip surgery, trochanteric nonunion, and posterior surgical approach. He wrote that the most reliable way to correct instability is to reorient a retroverted acetabular cup.
OrthoCash 2020
In patients with sickle cell disease and asymptomatic osteonecrosis of the femoral head identified with magnetic resonance imaging, what percentage will eventually go on to femoral head collapse?

Question 42

What is the most common behavioral effect of anabolic steroid use in athletes? Review Topic

Explanation

Users of anabolic steroids often display increased feelings of hostility and aggression. Although reports of psychotic, depressive, and manic behavior have been reported with the use of steroids, they are rare. Drug dependence, such as seen with narcotics, is not a feature of steroid use.

Question 43

What is the standard interval for placement of an anterolateral portal in ankle arthroscopy?

Explanation

As with arthroscopy of the knee, the anterolateral (AL) portal is the primary diagnostic portal used for initial placement of the arthroscope. The AL portal is made 5 mm below the joint line just lateral to the extensor tendons. The lateral cutaneous branch of the superficial peroneal nerve lies near this portal region. From this approach, one can visualize the anteromedial (AM), anterocentral (AC), and most of the AL areas of the tibiotalar joint. With the addition of laterally based external distraction instrumentation, the surgeon can usually advance the arthroscope posterocentrally and posterolaterally to visualize most of the articulation and the structures in the central and posterior compartments: the intraarticular aspects and synovium of the distal tibiofibular syndesmosis, the posterior tibiofibular ligament, the transverse ligament, and the synovial plicae that overlie the transverse ligament.

Question 44

A patient has a C6-7 herniated nucleus pulposus. What is the most likely distribution of symptoms? Review Topic

Explanation

Hyperextension
Flexion-distraction
Flexion-compression
Rotational
Pure axial load
Figure A shows a quadrangular fracture pattern of C5. These injuries are observed with flexion-compression loads.
Quadrangular fractures of the cervical spine are considered flexion teardrop fractures. However, they present with a larger anterior lip fragment compared to the classic teardrop fracture pattern. The radiographic findings include a quadrangular-shaped fragment from the anterior one-third of the vertebral body with significant posterior vertebral subluxation, angular kyphosis, and an increased interspinous space with facet subluxation due to disruption of the posterior elements. These are unstable fractures, and almost always require anterior and posterior stabilization.
Moore et al. studied the reliability of Cervical Spine Injury Severity Score to measure stability after cervical spine trauma. The classification system is based on morphologic descriptions and, secondly, on stability based on a quantifiable value. They showed that the Cervical Spine Injury Severity Score had excellent reliability with intra-observer intraclass correlation coefficients (ICC) >0.97 and inter-observer ICC >0.88.
Vaccaro et al. published the subaxial cervical spine injury classification system (SLIC). This systems involves 3 main categories (injury morphology, disco-ligamentous complex, and neurologic status). The overall injury severity score is obtained by summing the scores from each category. They propose that SLIC < 4 can be treated non-operatively.
Allen et al. published a classification system of cervical spine injuries which breaks injuries of the subaxial spine into six phylogenic groups based on mechanism of injury. These include: 1) flexion-compression 2) vertical-compression 3) flexion-
distraction 4) extension-compression 5) extension-distraction 6) lateral flexion. Facet
dislocation
is
caused
by
flexion-distraction
force.
Figure A shows a lateral radiograph of the cervical spine demonstrating a typical flexion-compression fracture with anteriorly displaced quadrangular fragment. Illustration A shows a flexion-compression injury. Illustration B shows the mechanism of injury for a quadrangular fracture of the cervical spine. This unstable fracture pattern is characterized by anterior column failure in flexion/compression and posterior column failure in tension. Illustration C shows an illustration of the fracture morphology according to the Allen and Ferguson classification.
Incorrect Answer 1:
Hyperextension injuries
Flexion-distraction injuries usually result in facet dislocations.

Question 45

Figure 53 shows the MRI scan of a 53-year-old carnival worker who has pain and swelling in the left shoulder as a result of attempting to stop a roller coaster car with his arm. Examination reveals decreased ROM, apprehension, and inability to move the dorsum of his hand away from his back. Treatment should consist of

Explanation

This patient has an acute tear of the subscapularis tendon both by MRI and physical exam. Treatment of choice is open repair. Nonoperative treatment is not indicated.

Question 46

Figure 1 is the MR image of a high school soccer player who sustained a right knee injury during a game while making a cut toward the ball. He felt a pop and his leg gave way. During physical examination, as the knee is moved from full extension into flexion with an internal rotation and valgus force, you notice a "clunk" within the knee. What is the most likely biomechanical basis for the "clunk"?

Explanation

This patient sustained an isolated anterior cruciate ligament (ACL) injury based upon the mechanism described and examination findings. The finding that produces the “clunk” is the pivot-shift maneuver, which is positive in a knee with an incompetent ACL. With an ACL-deficient knee in full extension and internal rotation, the lateral tibial plateau subluxates anteriorly. As the knee is flexed, the lateral tibial plateau slides posteriorly into a reduced position, causing an audible clunk. Response D correctly describes the pathomechanics that result in the audible clunk heard during the pivot-shift maneuver. Responses A and B are incorrect because they describe the medial tibial plateau, which is not part of the pathomechanics of the pivot shift. Response C is incorrect because in extension, the lateral tibial plateau is subluxated, not reduced.

Question 47

In patients without spondylolisthesis or scoliosis undergoing laminectomy for lumbar spinal stenosis, spinal fusion is generally recommended if

Explanation

DISCUSSION: With the notable exception of fusion for degenerative spondylolisthesis and scoliosis, there is a paucity of evidence on the indications for spinal fusion in patients undergoing laminectomy for spinal stenosis. However, it is generally recommended that if the spine is destabilized (for example by removal of one complete facet joint or by an iatrogenic pars fracture), spinal fusion should be considered. Although fusion can be considered for a very long laminectomy, a two-level laminectomy does not represent, by itself, a clear indication for the addition of a spinal fusion. The repair of a dural tear and the use of nicotine by the patient play no role in the determination of whether or not to add fusion to a laminectomy procedure.
REFERENCES: Spivak JM, Connolly PJ (eds): Orthopaedic Knowledge Update: Spine 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, pp 299-409.
Fischgrund JS, Mackay M, Herkowitz HN, et al: 1997 Volvo Award winner in clinical studies. Degenerative lumbar spondylolisthesis with spinal stenosis: A prospective, randomized study comparing decompressive laminectomy and arthrodesis with and without spinal instrumentation. Spine 1997;22:2807-2812.

Question 48

A 32-year-old man notes increasing back pain and progressive paraparesis over the past few weeks. He is febrile, and laboratory studies show a WBC of 12,500/mm3. MRI scans are shown in Figures 6a and 6b. Management should consist of

Explanation

DISCUSSION: Indications for surgery in spinal infections include progressive destruction despite antibiotic treatment, an abscess requiring drainage, neurologic deficit, need for diagnosis, and/or instability. This patient has a progressive neurologic deficit. Debridement performed at the site of the abscess should effect canal decompression. Once the debridement is complete back to viable bone, the defect can be reconstructed with a strut graft. Additional posterior stabilization is used as deemed necessary by the degree of anterior destruction. CT-guided needle aspiration, while occasionally useful in the earliest phases of an infection, produces frequent false-negative results and would provide little useful information in the management of this patient.
REFERENCES: Emery SE, Chan DP, Woodward HR: Treatment of hematogenous pyogenic vertebral osteomyelitis with anterior debridement and primary bone grafting. Spine 1989;14:284-291.
Lifeso RM: Pyogenic spinal sepsis in adults. Spine 1990;15:1265-1271.
Beaty JH (ed): Orthopaedic Knowledge Update 6. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 713-721.

Question 49

The diagnosis of an infection after total knee arthroplasty is most reliably proven based on what single study?

Explanation

DISCUSSION: In a study of 52 patients with infected total knee arthroplasties, Windsor and associates showed that the average leukocyte count was 8,300/mm³ and that aspirated knee fluid was positive in all patients except one. Knee radiographs can be unclear in showing infection, which may be present without radiographic signs of loosening. Technetium Tc 99m and gallium bone scans may not conclusively show the presence of infection, particularly in the first 3 years after knee arthroplasty.
REFERENCES: Windsor RE, Bono JV: Infected total knee replacements. J Am Acad Orthop Surg 1994;2:44-53.
Windsor RE, Insall JN, Urs WK, et al: Two-stage reimplantation for the salvage of total knee arthroplasty complicated by infection: Further follow-up and refinement of indications. J Bone Joint Surg Am 1990;72:272-278.

Question 50

A patient undergoing joint arthroplasty is put on a drug that competitively inhibits the activation of an enzyme that breaks down Factor Ia. The drug is

Explanation

Factor Ia is fibrin. The enzyme that breaks down fibrin is plasmin. Tranexamic acid (TXA) is an antifibrinolytic that prevents the activation of plasmin from the inactive zymogen plasminogen.
Tranexamic acid competitively inhibits the activation of plasminogen to plasmin by binding to specific sites on both plasminogen and plasmin. Tranexamic acid has roughly eight times the antifibrinolytic activity of an older analogue, e-aminocaproic acid. It is used during joint replacement surgery to reduce blood loss and the need for transfusion.
Watts et al. review strategies for minimizing blood loss and transfusion. They recommend 1g of TXA prior to incision, and 1g at wound closure. They also recommend giving fluids for symptoms of anemia, rather than transfusion, as even high risk patients do well with sufficient intravascular volume even with low hemoglobin levels.
Imai et al. evaluated TXA in 107 patients undergoing THA. They found that intraoperative blood loss after preoperative TXA administration was lower than both control and postoperative TXA administration groups. They recommend using 1 g of TXA 10 minutes before surgery and 6 hours after the first administration to best reduce blood loss during THA.
Gillette et al. retrospectively reviewed 2046 patients receiving TXA for THA or TKA together with either aspirin, warfarin or dalteparin. They found that the rates of symptomatic DVT (0.35%, 0.15%, and 0.52%, respectively) and nonfatal PE were similar (0.17%, 0.43%, and 0.26%, respectively) for the 3 drugs respectively. They recommend TXA to decrease blood loss and transfusion.
Illustration A shows the role of tranexamic acid in the fibrinolytic cycle and the
clotting cascade.
Incorrect Answers:

Question 51

A female cross-country runner has an insidious onset of right groin pain. Radiographs of the right hip reveal a tension-side stress fracture. History reveals that she was treated for a “foot” fracture 1 year ago. In addition to performing internal fixation of the femoral neck, which of the following should be obtained?

Explanation

DISCUSSION: Stress fractures in female long distance runners are frequently associated with the Female Athletic Triad. The triad consists of osteoporosis, amenorrhea, and altered eating habits. A thorough menstrual history, including age of menarche, history of amenorrhea, and use of oral contraceptives, is imperative. Amenorrhea leads to osteoporosis and predisposes the athlete to fractures. An MRI of the hip is not necessary because a fracture is evident on the radiograph. Serum calcium levels are normal in osteoporosis, a family history would be noncontributory, and it is highly unlikely that a contralateral hip radiograph will yield useful information.
REFERENCES: Bennell KL, Malcolm SA, Thomas SA, et al: Risk factors for stress fractures in track and field athletes: A twelve-month prospective study. Am J Sports Med 1996;24:810-818.
Barrow GW, Saha H: Menstrual irregularity and stress fractures in collegiate female distance runners. Am J Sports Med 1988;16:209-216.

Question 52

A 20-year-old man is brought to the emergency department after a high-speed motor vehicle accident. His initial blood pressure is 70/40 mm Hg. He is currently receiving intravenous fluids as well as blood. His Focused Assessment with Sonography for Trauma examination did not show any free fluid in his abdomen and his chest radiograph is unremarkable. An AP pelvis radiograph is shown in Figure 15. What is the next most appropriate step in the management of his pelvic injury?

Explanation

DISCUSSION: This hypotensive patient has an obvious open book injury of the pelvic ring on the AP pelvis radiograph and further radiographs are not needed prior to the initiation of treatment. Although angiography may be indicated if he does not respond to stabilization of his pelvis and fluid/blood administration, temporary stabilization of the pelvis with a sheet or binder should be performed first because it is simple, quick, and has been shown to be effective. This patient does not need a laparotomy at this point since the FAST examination did not show any free intra-abdominal fluid and his chest radiograph was unremarkable, leaving the most likely source of bleeding the pelvic fracture. Open reduction with internal fixation of a pelvic injury is not indicated in an acutely ill patient.
REFERENCES: Kreig JC, Mohr M, Ellis TJ, et al: Emergent stabilization of pelvic ring injuries by controlled circumferential compression: A clinical trial. J Trauma 2005;59:659-664.
Croce MA, Magnotti LJ, Savage SA, et al: Emergent pelvic fixation in patients with exsanguinating pelvic fractures. J Am Coll Surg 2007;204:935-942.
Routt ML Jr, Falicov A, Woodhouse E, et al: Circumferential pelvic antishock sheeting:

A temporary resuscitation aid. J Orthop Trauma 2002;16:45-48.

Question 53

Radiographs shown in Figures 1 through 3 show two different prosthetic design variations of the same knee implant. When compared with the design of right knee prosthesis, the left can be expected to have a

Explanation

A 76-year-old woman has had three hip revisions for instability. She presents to the emergency department with another dislocation that occurred while getting up from a low chair. Current radiographs are shown in Figures 1 and 2. Her prior AP pelvis radiograph is shown in Figure 3. ESR and CRP are normal. What is the best plan for definitive treatment?

Question 54

Figure 1 is the MRI scan of a 15-year-old boy who has had knee pain with running for 5 months. Radiographs show an osteochondritis dissecans (OCD) lesion of the medial femoral condyle. What is the most appropriate treatment?

Explanation

OCD is an acquired lesion of the subchondral bone. Patients with OCD initially report nonspecific pain and variable amounts of swelling. Initial radiographs help identify the lesion and establish the status of the physes. An MRI scan is useful for assessing the potential for the lesion to heal with nonsurgical treatment. Nonsurgical treatment is appropriate for small, stable lesions in patients with open physes and focuses on activity restriction for 3 to 9 months. Surgical treatment is necessary for unstable or detached lesions. Stable lesions with intact articular cartilage can be treated with subchondral drilling to stimulate vascular ingrowth, with radiographic healing at an average of 4.4 months. Fixation is indicated for unstable or hinged lesions, and stabilization of the fragment can be achieved using a variety of implants through an arthroscopic or open approach. The fragment should be salvaged and the normal articular surface restored whenever possible.

Question 55

A 27-year-old professional football player complains of acute onset neck and radiating left arm pain after making a tackle. For approximately 1 week after injury his left deltoid strength was 4/5. An MRI is performed, which demonstrates a C4-5 disc herniation without evidence of cord compression. He was treated with a brief course of oral steroids followed by aggressive physical therapy. At this time he is asymptomatic and his neurologic exam is normal. If the patient returns to professional football play, what is his increased risk of sustaining a catastrophic spinal cord injury? Review Topic

Explanation

This patient is a professional football player who likely is suffering from an acute left sided C4-5 cervical disc herniation causing a C5 radiculopathy. After non-operative treatment and return to sport, his likelihood of sustaining a catastrophic spinal cord injury is less than 5%.
A C5 radiculopathy from an acute disc herniation can manifest as pain in the neck and affected arm, as well as weakness in the affected myotome. The natural history of this pathology is symptomatic improvement over time. In professional athletes, there are few studies to guide treatment, but oral methylprednisolone has been shown to improve symptoms and expedite return to play. The risk of sustaining catastrophic spinal cord injury after return to play is considered low, and has been reported to be 0%.
Wong et. al. performed a systematic review of the literature identifying the natural history, clinical course, and prognostic factors of symptomatic cervical disc herniations with radiculopathy. They found substantial symptomatic improvement within the first 4-6 months after onset, with maintained improvements for 2-3 years. No patients in their review developed progressive neurological deficits or myelopathy
at
any
point
during
follow
up.
Meredith et. al. performed a retrospective chart review of 16 professional football players with cervical disc herniations. The authors recommended surgery if patients had MRI with cord compression and signal change within the cord, but otherwise encouraged nonoperative treatment with return to sports after symptoms improved and repeat MRI demonstrated no cord compression. Symptoms generally improved with a course of anti-inflammatory medications including NSAIDs, oral methylprednisolone, and epidural steroid injections. Nine of the 16 patients were able to return to play, and at one year after return to play there were no catastrophic spinal cord injuries among the group.
Incorrect

Question 56

A 12½-year-old boy reports intermittent knee pain and limping that interferes with his ability to participate in sports. He actively participates in football, basketball, and baseball. He denies any history of injury. Examination shows full range of motion without effusion. Radiographs reveal an osteochondritis dissecans (OCD) lesion on the lateral aspect of the medial femoral condyle. MRI scans are shown in Figures 14a and 14b. Initial treatment should consist of Review Topic

Explanation

Agenesis of the anterior cruciate ligament
Thickened medial plica
Grade IV chondral flap
Pigmented villonodular synovitis
Abnormal meniscal morphology
This child presents with an asymptomatic click in the knee. It is associated with widening of the lateral joint space of the knee on X-ray. These features are highly suggestive of a discoid lateral meniscus in this age category.
The principal diagnostic feature of a discoid meniscus is the complaint of snapping or clicking in the knee. Children are usually asymptomatic. Although, less frequently, children may present with pain that is largely secondary to an underlying meniscal tear. MRI scans of the knee have show to have the greatest sensitivity for identifying discoid menisci. The presence of a contiguous central meniscus on three consecutive slices is usually indicative of the diagnosis. Treatment is mostly focused on conservative modalities. Surgical intervention is reserved for symptomatic cases with recurrent locking, swelling or persistent pain is present in older children.
Kramer et al. looked at the presentation of pediatric knee pain. They showed that the lateral meniscus is more commonly affected than the medial meniscus. The majority of discoid tears occur in the posterior or middle aspect of the discoid meniscus.
Figure A shows an AP radiograph of a pediatric knee. There is an increased lateral joint space suggestive of a discoid meniscus.
Illustrations A-C show an MRI of the knee with 3 consecutive coronal cuts showing an abnormal appearing discoid meniscus.
Incorrect Answers:

Question 57

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.The patient undergoes successful primary THA with a metal-on-metal bearing. At 1-year follow-up, she reports no pain and is highly satisfied with the procedure. However, 3 years after the index procedure, she reports atraumatic right hip pain that worsens with activities. Radiographs reveal the implants in good position with no sign of loosening or lysis. An initial laboratory evaluation reveals a normal sedimentation rate and C-reactive protein (CRP) level. The most appropriate next diagnostic step is

Explanation

DISCUSSION:
THA has proven to be durable and reliable for pain relief and improvement of function in 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. Because it offers 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 after the possible 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 work-up of a painful metal-on-metal hip arthroplasty necessitates a systematic approach. Several algorithms have been proposed. Routine laboratory studies including the erythrocyte sedimentation rate, C-reactive protein (CRP) level, and serum cobalt and chromium ion levels should be obtained for all patients with pain. Advanced imaging, including MRI with MARS, 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 a revision of failed metal-on-metal hip replacements.

Question 58

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

Explanation

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

Question 59

At the time of revision knee arthroplasty, a surgeon performs a rectus snip to gain exposure to the knee. When compared with a standard parapatellar approach, what is the expected outcome?

Explanation

DISCUSSION:
Rectus snip during total knee arthroplasty has no effect on motion or strength at long-term follow-up. It has not been associated with extensor mechanism lag.

Question 60

While performing a total shoulder arthroplasty, excessive retraction is placed on the "strap muscles" (short head of biceps and coracobrachialis). Neurovascular examination would reveal weakness of which of the following? Review Topic

Explanation

The musculocutaneous nerve can be as close as 3 cm to the coracoid process; therefore, this relationship is important to keep in mind when performing surgery in
this area. Excessive traction on the musculocutaneous nerve could lead to a neurapraxia with resultant weakness of elbow flexion and forearm supinaton because of the loss of biceps function.

Question 61

Treatment should include

Explanation

DISCUSSION
The MR images show a tear through a discoid lateral meniscus. A discoid meniscus is caused by a failure of apoptosis during development in utero and is considered a congenital abnormality. Discoid menisci are prone to tearing and can be caused by minimal trauma. There is no known genetic cause for this condition. Radiographic findings that may be present in the setting of a discoid meniscus include lateral joint space widening, squaring of the lateral femoral condyle, and cupping of the lateral tibial plateau. Contralateral discoid menisci are noted in 20% of patients. There are no other known associated conditions. Treatment of a symptomatic discoid meniscus should include partial meniscectomy and saucerization or repair.

Question 62

Creatine is currently being used by athletes as a dietary supplement in an attempt to enhance performance. What is the physiologic basis for its use?

Explanation

DISCUSSION: Creatine is currently used as a nutritional supplement in an attempt to enhance athletic performance. The physiologic basis for its use is based on its conversion by CK to PCr, which acts as an energy reservoir in muscle cells for the production of ATP. A number of studies that examined the effect of creatine supplementation on performance concluded that while creatine does not increase peak force production, it can increase the amount of work done in the first few anaerobic short duration, maximal effort trials. The mechanism for this enhancement of work is unknown, but it is most likely secondary to the increase in the available PCr pool.
REFERENCES: Greenhaff PL: Creatine and its application as an ergogenic aid. Int J Sport Nutr 1995;5:S100-S110.
Greenhaff PL, Casey A, Short AH, Harris R, Soderlund K, Hultman E: Influence of oral creatine supplementation on muscle torque during repeated bouts of maximal voluntary exercise in man. Clin Sci 1993;84:565-571.
Trump ME, Heigenhauser GJ, Putman CT, Spriet LL: Importance of muscle phosphocreatine during intermittent maximal cycling. J Appl Physiol 1996;80:1574-1580.
Hultman E, Soderlund K, Timmons JA, Cederblad G, Greenhaff PL: Muscle creatine loading in men. J Appl Physiol 1996;81:232-237.

Question 63

Figure 30 shows the radiograph of a 38-year-old man who reports persistent pain laterally and plantarly about the fifth metatarsal head. Examination reveals calluses dorsolaterally and plantarly about the fifth metatarsal head. Nonsurgical management has failed to provide relief. Surgical treatment should include

Explanation

DISCUSSION: The patient has painful lateral and plantar keratoses with metatarsus quintus valgus deformity. This combination of problems is best addressed with an oblique mid-diaphyseal osteotomy that allows the distal metatarsal to be displaced medially and dorsally. Lateral eminence resection alone will not address the painful plantar keratosis. A distal chevron osteotomy has a more limited ability to address the plantar keratosis (if translated medially and slight dorsally). Proximal diaphyseal osteotomies of the fifth metatarsal are associated with an increased risk of delayed union or nonunion secondary to the relative hypovascularity in the proximal diaphysis. Excision of the fifth metatarsal head can result in a floppy fifth toe and transfer metatarsalgia.
REFERENCES: Coughlin MJ: Treatment of bunionette deformity with longitudinal diaphyseal osteotomy with distal soft tissue repair. Foot Ankle 1991;11:195-203.
Moran MM, Claridge RJ: Chevron osteotomy for bunionette. Foot Ankle Int 1994;15:684-688.

Question 64

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

Explanation

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

Question 65

What is the typical axial plane transverse angulation of the thoracic pedicles?

Explanation

DISCUSSION: Thoracic pedicles typically are angled 25 degrees medially at T₁ so the

starting point is more lateral. T₂ angles about 15 degrees, and then the pedicles average about

5 to 7 degrees down to T10. At T11 and 12, the angulation is minimal.
REFERENCES: Weinstein L: Pediatric Spine Principles and Practice. New York, NY, Raven Press, 1994, pp 1659-1681.
Lenke LG, Orchowski J: Segmental posterior spinal instrumentation: Thoracic spine to sacrum, in Frymoyer JW, Wiesel SW (eds): The Adult and Pediatric Spine, ed 3. Philadelphia, PA, Lippincott Williams and Wilkins, 2004, pp 537-552.

Question 66

Which sterilization method is expected to produce the most degradation of an allograft used for anterior cruciate ligament reconstruction?

Explanation

CLINICAL SITUATION FOR QUESTIONS 43 THROUGH 46
Figures 43a and 43b are the MR arthrogram images of a 16-year-old, right-hand-dominant baseball player who injured his left shoulder 4 weeks ago during a game. He now has pain, weakness, and the inability to swing a bat and can no longer do push-ups. He denies prior injury to his left shoulder. Radiographs are unremarkable.

Question 67

The relocation test is most reliable for diagnosing anterior subluxation of the glenohumeral joint when

Explanation

DISCUSSION: The relocation test is most accurate when true apprehension is produced with the arm in combined abduction and external rotation and then relieved when posterior pressure is placed on the humeral head. Pain with this test is a less specific response and may occur with other shoulder disorders such as impingement.
REFERENCE: Speer KP, Hannafin JA, Altchek DW, Warren RF: An evaluation of the shoulder relocation test. Am J Sports Med 1994;22:177-183.

Question 68

An 19-year-old male presents to the emergency room following an motor vehicle accident as an unrestrained driver. Examination reveals unilateral jugular vein engorgement. Chest and special view radiographs are seen in Figures A and B respectively. Following CT scan of the chest, the next step in management is Review Topic

Explanation

This patient has a right posterior sternoclavicular (SC) dislocation. Management involves closed reduction and bracing. Closed reduction should be performed with a thoracic surgeon available in the event of mediastinal involvement.
The SC joint can dislocate anteriorly or posteriorly. Posterior dislocations are first treated with closed reduction. If closed reduction fails, open reduction is indicated. Early complications of posterior SC dislocation include pneumothorax, laceration/erosion/occlusion of great vessels, esophageal rupture and brachial plexus compression. Late complications include tracheoesophageal fistula, stridor and dysphagia.
Groh et al. reviewed traumatic SC injuries. Reduction maneuvers in posterior SC dislocation include: (1) traction on the arm and slowly bringing it into extension, (2) traction with the arm in adduction and posterior pressure applied to the shoulder, and
(3) pulling anteriorly on a towel clip encircling the medial clavicle. Chronic instability after posterior SC dislocations can be managed with figure-of-8 semitendinosus graft or medial clavicle resection and reattachment of the clavicle to the first rib with dacron tape.
Glass et al. performed a systematic review on SC dislocations. They found mediastinal compression occurred 30% of the time with posterior dislocations.
Figures A and B are radiographs demonstrating asymmetry of the SC joints, characteristic of a right posterior SC dislocation (Figure B is not a serendipity view). Illustration A demonstrates how in POSTERIOR dislocation, the clavicle appears INFERIOR, and in ANTERIOR dislocation, the clavicle appears SUPERIOR on a serendipity view radiograph respectively. Illustration B shows the imaging technique for a serendipity view radiograph. Illustration C is a reconstructed CT image of the patient showing left posterior SC dislocation.
Incorrect Answers:

Question 69

A 45-year-old man underwent unipolar hemiarthroplasty reconstruction using cementless fixation for nontraumatic osteonecrosis of the femoral head 5 years ago. He now reports buttock and groin pain that is associated with loading activities. What is the most likely cause of his pain?

Explanation

DISCUSSION: One of the most common complications of hemiarthroplasty is acetabular cartilage degeneration, resulting in increasing pain. Conversion total hip arthroplasty generally is successful with placement of an acetabular cup. Additionally, many patients with osteonecrosis already have degenerative changes of the acetabular cartilage even though radiographic findings may appear normal.
REFERENCES: Steinberg ME, Corces A, Fallon M: Acetabular involvement in osteonecrosis of the femoral head. J Bone Joint Surg Am 1999;81:60-65.
Dalldorf PG, Banas MP, Hicks DG, Pelligrini VD Jr: Rate of degeneration of human acetabular cartilage after hemiarthroplasty. J Bone Joint Surg Am 1995;77:877-882.

Question 70

A 25-year-old male polytrauma patient undergoes initial temporary external fixation for a femoral shaft fracture. He is converted to a femoral nail at 7 days. This management can be expected to result in

Explanation

DISCUSSION: Recently Harwood and associates investigated the principles of damage control orthopaedics (DCO) as they apply to patients with femoral shaft fractures. When they compared those who underwent initial external fixation of femoral shaft fractures with conversion to an intramedullary nail to those who underwent intramedullary nailing as their initial treatment, they found the following: overall infection rates were comparable in patients receiving DCO versus primary intramedullary fixation; open fracture was an independent risk factor for infection regardless of the treatment method; contamination rates in external fixator pin sites rose considerably when left in place more than 2 weeks and logistic regression analysis suggests that infection rates may increase when conversion to an intramedullary nail occurs after 2 weeks following external fixation; and there was no significant difference in time to union among treatment groups.
REFERENCES: Harwood PJ, Giannoudis PV, Probst C, et al: The risk of local infective complications after damage control procedures for femoral shaft fracture. J Orthop Trauma 2006;20:181-189.
Roberts CS, Pape HC, Jones AL, et al: Damage control orthopaedics: Evolving concepts in the treatment of patients who have sustained orthopaedic trauma. Instr Course Lect

2005;54:447-462.

Question 71

After surgery, this patient continues to experience pain and swelling of the knee with recurrent effusions. He returns to the office with continued pain 2 years after surgery. He describes instability, particularly when descending stairs. Upon examination, there is range of motion from 0 to 120 degrees with no extensor lag. The knee is stable to varus and valgus stress in extension, but there is flexion instability in both the anterior-posterior direction and in the varus-valgus direction. Bracing leads to a slight decrease in symptoms but is not well tolerated. Isokinetic testing demonstrates decreased knee extension velocity at mid push. Radiographs demonstrate well-aligned and fixed knee implants. An infection workup is negative. What is the most appropriate surgical intervention at this time?

Explanation

DISCUSSION

Video 99 for reference
This patient has valgus knee alignment, and, after undergoing appropriate bone resections and soft-tissue balancing, has demonstrated a tight PCL on trial reduction as evidenced by lift-off of the trial insert as described by Scott and Chmell. The appropriate maneuver is PCL recession with partial release of tight (usually anterolateral) PCL fibers. However, for this patient, instability resulted in increased anterior translation. At this stage, the options are to convert to either a deeper-dish insert with increased sagittal conformity or a posterior stabilized insert. The only appropriate choice among the responses is use of an insert with increased sagittal conformity to prevent excessive anterior translation. Increasing the polyethylene could improve stability in flexion, but, considering there is good stability in extension, this likely would lead to an inability to achieve full extension. The patient’s valgus deformity, flexion contracture, correction with release of the iliotibial band, and posterolateral capsule predispose him to increased risk for peroneal nerve palsy. His symptoms at follow-up suggest knee flexion
instability with pain, swelling, and difficulty descending stairs. Considering his history, an incompetent PCL must be considered. Revision of the knee to a posterior stabilized or nonlinked constrained condylar implant depending on the condition of the ligaments likely is needed to address his symptoms. The difference in extension vs flexion stability makes polyethylene exchange a poor option. There is no reason to believe a constrained rotating hinge design is necessary. Repeat use of a PCL-retaining insert is not recommended.

Question 72

A 32-year-old football coach has had a 4-month history of increasing right wrist pain, particularly during blocking exercises, and he reports significant pain with range of motion and gripping activities. He denies any history of trauma. Examination reveals dorsal wrist tenderness and boggy fullness over the dorsum of the wrist. No erythema is noted. Grip strength is 60% compared with the opposite side. Radiographs are shown in Figures 5a and 5b. What is the most likely diagnosis?

Explanation

DISCUSSION: The patient has Kienbock’s disease (osteonecrosis of the lunate), which presents with boggy synovitis of the wrist, decreased range of motion, and often normal radiographs. The patient’s radiographs reveal small fragments from the lunate, with increased density in the lunate body. While a traumatic event may precede the patient’s pain, often an insidious increase in pain is found. Repetitive trauma has been suggested as a possible cause. This disease process is classically associated with an ulnar-negative variant. An MRI scan, revealing a low-intensity signal in the lunate, is the best diagnostic tool for early Kienbock’s disease.
REFERENCES: Green DP, Hotchkiss RN, Pederson WC: Green’s Operative Hand Surgery, ed 4. Philadelphia, PA, Churchill Livingstone, 1999, pp 837-848.
Gerwin M, Weiland AJ: Avascular necrosis of the carpals. Hand Clin 1993, p 761.

Question 73

A patient with severe rheumatoid arthritis reports progressive hip pain. Serial hip radiographs will most likely show which of the following findings?

Explanation

DISCUSSION: Radiographic findings in patients with rheumatoid arthritis include symmetric joint space narrowing, periacetabular and femoral head erosions, and diffuse periarticular osteopenia. In advanced stages, protrusio acetabuli is a common finding. Ranawat and associates have shown a rate of superior femoral head migration of 4.5 mm per year and medial (axial) migration of 2.5 mm per year. Asymmetric joint space narrowing is a classic radiographic finding of degenerative arthrosis. Sacroiliac joint ankylosis commonly occurs in ankylosing spondylitis. Hip synovitis is a pathologic diagnosis, not a radiographic finding.
REFERENCES: Lachiewicz PF: Rheumatoid arthritis of the hip. J Am Acad Orthop Surg 1997;5:332-338.
Stuchin SA, Johanson NA, Lachiewicz PF, Mont MA: Surgical management of inflammatory arthritis of the adult hip and knee, in Zuckerman JS (ed): Instructional Course Lectures 48. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 93-109.

Question 74

Figures 14a and 14b show the clinical photographs of a patient who was stranded in a subzero region for several days. The photographs were taken the morning after arrival in the hospital. The patient is otherwise healthy and fit, and takes no medication. He has no clinical signs of sepsis. He reports burning pain and tingling in both feet. What is the best treatment?

Explanation

DISCUSSION: The patient has no clinical or observed signs of sepsis. The skin just proximal to the gangrenous tissue appears somewhat hyperemic and is clearly viable. These wounds should be managed much like burn wounds. Moist dressings should be used until the tissue clearly demarcates. Much of the insult may simply be superficial and only require late debridement.
REFERENCES: McAdams TR, Swenson DR, Miller RA: Frostbite: An orthopedic perspective.

Am J Orthop 1999;28:21-26.
Taylor MS: Cold weather injuries during peacetime military training. Milit Med 1992;157:602-604.

Question 75

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

Explanation

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

Question 76

Figure 56 is the MR image of a 20-year-old Division I baseball pitcher who has a 1-month history of medial elbow pain in his throwing arm. He also notes a decrease in both control and pitching velocity. An examination reveals tenderness at the medial epicondyle that is exacerbated with valgus elbow stress. The strongest indication for ulnar collateral ligament (UCL) reconstruction is

Explanation

DISCUSSION
All responses represent findings that may be associated with chronic UCL insufficiency. Responses 1 and 3 reflect injury to the UCL itself. In most patients, particularly young patients, UCL reconstruction should not be considered until an appropriate trial of nonsurgical measures has failed. This trial should include, at a minimum, 6 weeks of throwing abstinence followed by rehabilitation to address pitching mechanics and shoulder motion deficits and core strengthening. Although the decision to enter the MLB draft may influence surgical decision making, a pitcher with a 1-month history of elbow symptoms should attempt nonsurgical therapy before making a surgical decision that is not based on clinical data.

Question 77

A 30-year-old woman who runs approximately 30 miles a week has had right hip and groin pain for the past 3 weeks. Examination reveals an antalgic gait, limited motion of the right hip, and pain, especially with internal and external rotation. Plain radiographs are normal, and an MRI scan is shown in Figure 21. Management should consist of

Explanation

DISCUSSION: A stress fracture of the hip is a relatively common problem in endurance sports. These fractures are classified as compression-side, tension-side, and displaced femoral neck fractures. The MRI scan shows a compression-side stress fracture. Compression-side fractures usually occur in the inferior or calcar area of the proximal femur, and non-weight-bearing crutch ambulation for 6 to 7 weeks will most likely result in healing. Once the patient is walking without pain or a limp, activities can be slowly increased. Because tension-side fractures have a high risk of displacement, treatment should consist of immediate internal fixation.
REFERENCES: Griffin LY (ed): Orthopaedic Knowledge Update: Sports Medicine. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1994, pp 239-253.
Fullerton LR Jr, Snowdy HA: Femoral neck stress fractures. Am J Sports Med

1988;16:365-377.

Question 78

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

Explanation

With the arm in the abducted, externally rotated position, the anterior band of the inferior glenohumeral ligament complex moves anteriorly, preventing anterior humeral head translation. Both the coracohumeral ligament and the superior glenohumeral ligament restrain the humeral head to inferior translation of the adducted arm, and to external rotation in the adducted position. The middle glenohumeral ligament is a primary stabilizer to anterior translation with the arm abducted to 45 degrees. The posterior band of the inferior glenohumeral ligament complex resists posterior translation of the humeral head when the arm is internally rotated.

Question 79

Which of the following nerves is most commonly injured during revision surgery following a Bristow procedure?

Explanation

DISCUSSION: Because of the previously transferred bone block of coracoid and short arm flexors, the musculocutaneous nerve often scars along the anteroinferior glenohumeral capsule. Mobilization of this tissue places the nerve at greatest risk. The axillary nerve is also potentially at risk, but this is nonspecific to prior surgery, particularly the Bristow procedure.
REFERENCES: Norris TR: Complications following anterior instability repairs, in Bigliani LU (ed): Complications of Shoulder Surgery. Baltimore, MD, Williams and Wilkins, 1993,

pp 98-116.
Flatow EL, Bigliani LU, April EW: An anatomic study of the musculocutaneous nerve and its relationship to the coracoid process. Clin Orthop 1989;244:166-171.

Question 80

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

Explanation

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

Question 81

Limited weight bearing usually is recommended following open reduction and internal fixation of intra-articular lower extremity fractures. A bone graft, or bone graft substitute is often placed in the metaphyseal void beneath the reduced articular fragments. Which of the following bone grafts or bone graft substitutes will most likely permit earlier weight bearing without subsidence of the articular reduction?

Explanation

Most bone graft substitutes have a low compressive strength, similar to cancellous bone. Calcium phosphate cements, when hardened, have a much higher compressive strength compared to any of the other bone grafts or bone graft substitutes. In a study of 26 patients undergoing open reduction and internal fixation of displaced tibial plateau fractures, calcium phosphate was found to produce good outcomes. Because of the high mechanical strength of the cement, the authors allowed early weight bearing after a mean postoperative period of 4.5 weeks, with a range from 1 to 6 weeks. Despite early weight bearing, only two patients in this series had a partial loss of reduction. In biomechanical studies of displaced tibial plateau fractures, calcium phosphate compared favorably to cancellous bone graft. In one clinical series of patients undergoing open reduction and internal fixation for a calcaneus fracture, those patients whose reductions were supported with calcium phosphate were allowed to begin full weight bearing at 3 weeks and displayed no radiographic evidence of reduction loss. The effectiveness of calcium phosphate to resist deformation with cyclical loading in simulated calcaneal fractures has been confirmed in a biomechanical study.

Question 82

A 14-year-old boy sustained a 100% displaced distal radius Salter-Harris type II fracture. Neurologic examination demonstrates normal motor examination and two-point discrimination. He undergoes fracture reduction to the anatomic position with the application of a long arm cast. Postreduction he reports increasing hand and wrist pain with diminution of two-point discrimination to 10 mm over the index and middle fingers over the next several hours after surgery. The cast is bivalved and the padding released relieving all external pressure over the arm. Reevaluation reveals increasing sensory deficit over the affected area. What is the next most appropriate management intervention?

Explanation

The patient has an evolving acute carpal tunnel syndrome. Initial management for this injury is to relieve all external pressure that may elevate the neural compression. Surgical decompression of the median nerve at the carpal tunnel is the optimal intervention. Further nonsurgical interventions (cast removal or further bivalving) are insufficient to alleviate the neural compression.

Question 83

A 46-year-old woman had an ankle fracture and ORIF 6 years ago. She had subsequent removal of some of the hardware, but her pain has persisted (Figures 44a and 44b).

Explanation

DISCUSSION
Patients younger than 40 years of age who have ankle arthritis pose an ongoing clinical challenge. Nonsurgical treatment should be maximized, although distraction arthroplasty can be used in an effort to delay the need for fusion.
One of the strongest indications for ankle arthroplasty is a preexisting hindfoot fusion with a goal to retain some ankle/hindfoot motion. Ankle fusion is perhaps the most predictable surgical treatment for a relatively young, active patient with ankle arthritis. Moreover, there are concerns regarding implant loosening when performing TAA in active patients.
Outcome after syndesmosis ORIF has been linked to the quality of the reduction at the index procedure. Syndesmotic malreduction that is severe necessitates osteotomy and revision ORIF.
RECOMMENDED READINGS
Sagi HC, Shah AR, Sanders RW. The functional consequence of syndesmotic joint malreduction at a minimum 2-year follow-up. J Orthop Trauma. 2012 Jul;26(7):439-43. doi: 10.1097/BOT.0b013e31822a526a. PubMed PMID: 22357084. View Abstract at PubMed
Smith NC, Beaman D, Rozbruch SR, Glazebrook MA. Evidence-based indications for distraction ankle arthroplasty. Foot Ankle Int. 2012 Aug;33(8):632-6. Review. View Abstract at PubMed
Kim BS, Knupp M, Zwicky L, Lee JW, Hintermann B. Total ankle replacement in association with hindfoot fusion: Outcome and complications. J Bone Joint Surg Br. 2010 Nov;92(11):1540-7. doi: 10.1302/0301-620X.92B11.24452. PubMed PMID: 21037349. View Abstract at PubMed
Daniels TR, Younger AS, Penner M, Wing K, Dryden PJ, Wong H, Glazebrook M. Intermediate-term results of total ankle replacement and ankle arthrodesis: a COFAS multicenter study. J Bone Joint Surg Am. 2014 Jan 15;96(2):135-42. doi: 10.2106/JBJS.L.01597. View Abstract at PubMed

Question 84

Following application of a short leg cast, a patient reports a complete foot drop. A compression injury of the peroneal nerve at the fibular neck is confirmed by electrical studies. Which of the following muscles is expected to be the last to recover function during the ensuing months?

Explanation

DISCUSSION: The recovery process from peroneal nerve palsy may take many months as axonal regrowth occurs. Of the muscles listed, the extensor hallucis is innervated most distally by the peroneal nerve. The flexor digitorum longus is innervated by the tibial nerve.
REFERENCE: Sarrafian SK: Anatomy of the Foot and Ankle, Descriptive, Topographic, Functional, ed 2. Philadelphia, PA, JB Lippincott, 1993, p 364.

Question 85

At revision, the stem is retained and a new head with a polyethylene bearing is selected. The best option for the head is

Explanation

DISCUSSION
Ceramic-on-ceramic is a controversial bearing surface typically reserved for younger patients such as this one. Some studies have suggested that the bearing is more expensive and does not really prolong the service life of the implant, although a recent meta-analysis of high-quality trials showed that there is a decreased revision rate with ceramic-on-ceramic, so its use may be justified. Complications of intraoperative bearing fracture and squeaking are more common than with conventional bearings, but pain and function scores are equivalent. Stripe wear associated with a vertical cup and morbid obesity are related to an increased risk for liner fracture. Concerns about head fractures with a new ceramic head and a damaged trunnion have led investigators to conclude that using a harder bearing than the initial bearing surface with a built-in titanium sleeve is probably the best solution when a stem is retained during revision surgery.

Question 86

A 35-year-old male sustains a closed tibial shaft fracture after falling from 12 feet. Which of the following measurements would be concerning for an evolving compartment syndrome?

Explanation

DISCUSSION: A delta P (diastolic blood pressure minus compartment pressure measurement)of < 30 mmHg is an indication for fasciotomies with the caveat that the diastolic pressure is measured either pre- or postoperatively.
Given the poor outcomes associated with missed compartment syndromes, it is important to obtain both clinical and objective data when determining if a patient needs fasciotomies. Determining if a patient needs fasciotomies in the operating room while a patient is under anesthesia is complicated by the fact that obtaining a clinical exam is impossible, and that the diastolic blood pressure may be falsely decreased compared to normal pre- or postoperative measurements. Currently, it is recommended that intraoperative compartment pressures be compared to preoperative diastolic blood pressures, with delta p < 30 indicating the need for fasciotomies.
Kakar et al. review the preoperative, intraoperative, and postoperative diastolic blood pressure (DBP) in 242 patients with a tibia fracture treated operatively. They found the mean DBP was 18 points lower in the operating room compared to the preoperative measurement. In addition, they found the difference between preoperative and postoperative diastolic blood pressures to be within 2 points, indicating the decrease seen intraoperatively is likely a spurious value induced by anesthetic.
McQueen and Court-Brown prospectively review 116 patients with tibia fractures that had continuous monitoring of their anterior compartment for 24 hours. They found that using an absolute pressure of 30 mmHg would have resulted in 50 patients (43%) treated with unnecessary fasciotomies. They conclude using a differential pressure of
30 mmHg is a more reliable indicator of compartment syndrome.
Incorrect Answers:

Question 87

Five weeks after undergoing a successful L4-L5 diskectomy, with complete relief of his preoperative sciatica, a 36-year-old man has severe, relentless back and buttock pain. Examination and laboratory studies are unremarkable with the exception of an erythrocyte sedimentation rate (ESR) of 90 mm/h. What is the next most appropriate step in management?

Explanation

DISCUSSION: The patient’s history, including the timing and type of symptoms, is typical for postoperative diskitis. The elevated ESR, 5 weeks after surgery, is also consistent with infection; a normal WBC count is not unusual. Management should consist of MRI with gadolinium; if positive, this should be followed by percutaneous biopsy to confirm the organism. Open biopsy may be considered if the percutaneous biopsy is unsuccessful. Anterior debridement and interbody fusion is reserved for the occasional patient that fails to respond to intravenous antibiotics, bed rest, and immobilization.
REFERENCES: Garfin SR, Vaccaro AR (eds): Orthopaedic Knowledge Update: Spine. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, pp 257-271.
Beatty JH (ed): Orthopaedic Knowledge Update 6. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 713-721.

Question 88

Cortical bone demonstrates viscoelastic behavior as its mechanical properties are sensitive to strain rate and duration of applied load. Regarding longitudinal strain in cortical bone, which of the following statements regarding this characteristic is true?

Explanation

As strain rate increases, both elastic modulus and ultimate strength increase.
For LOW strain rates typical of normal activity (physiological strain rates of <0.1/s), bone is ELASTIC and DUCTILE (increasing ultimate strain with increasing strain rate). There is a ductile-to-brittle transition with increasing strain rate from normal to
supranormal rates. For EXTREMELY HIGH supranormal strain rates (>0.1/s, high impact trauma), bone is VISCOELASTIC and BRITTLE (low ultimate strain with increasing strain rate). Bone also becomes stronger and stiffer (higher modulus, steeper slope of stress-strain plot) as strain rate increases. This viscoelastic property helps in damping muscle contracture.
Natali and Meroi reviewed studies examining mechanical properties of bone. Mechanical properties are correlated with moisture, deformation rate, density and region of bone. Mechanical adaptation of bone is affected by strain rate (rate at which bone is deformed), strain mode (tension, compression, shear), strain direction (direction of strain relative to bone surface), strain frequency (cycles/second), stimulus duration (period over which deformation cycles are applied), strain distribution (pattern of strain magnitude across bone section) and strain energy (energy stored during deformation).
Illustration A shows the mechanical properties of bone with increasing strain rates. Incorrect Answers:
increase. During normal activity, as strain rate increases, bone is more ductile. With high impact trauma, bone is more brittle.

Question 89

In patients with neurofibromatosis, what is the most important sign of impending rapid progression of a spinal deformity?

Explanation

DISCUSSION: Neurofibromatosis can progress very rapidly. Rib penciling is the only singular prognostic factor. Significant progression has been observed in 87% of the curves with three or more penciled ribs. The other factors are often present but do not have a high correlation with rapid, severe progression.
REFERENCES: Crawford AH, Schorry EK: Neurofibromatosis in children: The role of the orthopaedist. J Am Acad Orthop Surg 1999;7:217-230.
Durrani AA, Crawford AH, Chouhdry SN, Saifuddin A, Morley TR: Modulation of spinal deformities in patients with neurofibromatosis type 1. Spine 2000;25:69-75.

Question 90

A 6-year-old boy is being treated for acute hematogeneous osteomyelitis of the distal femur with intravenous antibiotics. The best method to determine the success or failure of initial treatment is by serial evaluations of which of the following studies? Review Topic

Explanation

Successful antibiotic treatment of acute osteomyelitis should lead to a rapid decline in the CRP. The CRP is the most sensitive study to follow the treatment of osteomyelitis. The CRP should decline after 48 to 72 hours of appropriate treatment. CBC and ESR are helpful in initial evaluation and diagnosis, but remain abnormal in the early phase of treatment regardless of response. Imaging studies are useful for surgical planning or secondarily if the CRP remains elevated.

Question 91

A 16-year-old high school football player sustains an injury to the left hip. The avulsed fragment identified by the arrow in Figure 34 represents the origin of which of the following structures?

Explanation

DISCUSSION: The avulsed fragment represents the origin of the rectus femoris from the anterior inferior iliac spine and the brim of the acetabulum. Avulsion of the anterior inferior iliac spine is much less common than avulsion of the anterior superior iliac spine with its origin of the sartorius. The origin of the gluteus minimus is from the outer cortex of the iliac wing and has not been reported as a source of bony avulsion. The hip capsule is composed of the ischiofemoral and pubofemoral ligaments, in addition to the iliofemoral ligament. The pelvic attachment of the ischiofemoral ligament is from the ischial part of the acetabulum posteriorly, while the pubofemoral ligament attaches to the pubic portion inferiorly. Technically, ligaments do not have origins and insertions as muscle tendon groups do, but have attachment sites.
REFERENCES: Metzmaker JN, Pappas AM: Avulsion fractures of the pelvis. Am J Sports Med 1985;13:349-358.
Mader TJ: Avulsion of the rectus femoris tendon: An unusual type of pelvic fracture. Pediatr Emerg Care 1990;6:198-199.

Question 92

A 19-year-old running back lands directly on his anterior knee after being tackled. He has mild anterior knee pain, a trace effusion, a 2+ posterior drawer, a grade 1+ stable Lachman, no valgus laxity, and negative dial tests at 30° and 90°. What is the best treatment strategy at this time?

Explanation

This patient has likely sustained an isolated PCL injury. The examination is consistent with a grade II injury to the PCL. In this scenario, the best initial option is nonsurgical treatment and return to play as symptoms subside and strength improves. Physical therapy with a focus on quadriceps strengthening and delayed PCL reconstruction is not the answer because this patient can likely be treated without surgery. The absence of valgus laxity and negative dial testing findings suggest that an injury to the posteromedial and posterolateral corners has not occurred. Initial nonsurgical treatment is indicated for this patient. If he completes rehabilitation and experiences persistent disability with anterior and/or medial knee discomfort or senses the knee is "loose," PCL reconstruction should be considered at that time.

Question 93

Radiotherapy for palliative pain control as the risk for pathological fracture is very small

Explanation

Treatment for musculoskeletal oncology depends on a correct tissue diagnosis, which in this patient requires an open incisional biopsy. Despite the concern that this lesion may represent a metastasis from lung carcinoma, without tissue diagnosis, treatment cannot ensue. Regarding concerns for pathologic fracture, this patient would be best managed with no weight bearing until a diagnosis can be determined. If this lesion is a sarcoma, then despite the patient's pain and risk of pathologic fracture, neo-adjuvant chemotherapy and wide surgical resection will be needed for the best chance at local control and patient survival. While intramedullary nailing of the tibia and sending canal reamings to pathology may either appear appropriate or be performed at
some centers, this procedure may contaminate the entire bone with tumor and make limb salvage nearly impossible if this is a sarcoma. If the incisional biopsy shows carcinoma, then intramedullary nailing with adjuvant radiotherapy would be completely appropriate.

Question 94

Which of the following growth factors binds and activates the lipoprotein receptor-related protein 5/6 (LRP5/6) during bone development? Review Topic

Explanation

Wnt and Hedgehog (Hh) signaling pathways are key regulators of bone formation. Mutations in the Wnt and Hh pathways result in skeletal malformations as well as osteoarthritis. Wnts are a large family of secreted proteins (19 different members in the human genome) that transduce their signal through several pathways. The most studied of these pathways is the Wnt/beta-catenin pathway, in which Wnt protein binds to the LRP5/6 receptor at the cell surface and activates an intracellular cascade. This cascade leads to translocation of beta-catenin into the nucleus to activate transcription of genes that control osteoblast differentiation. Agents that stimulate this pathway are under investigation for treatment of osteoporosis.

Question 95

What is the most common type of malalignment after intramedullary nailing of distal 1/3 tibia fractures?

Explanation

DISCUSSION: Puloski et al determined the incidence and severity of tibial malrotation following reamed intramedullary nail fixation as measured by computerized tomography. Malrotation was defined as an internal/external rotation deformity greater than 10 degrees. They found that 5 (22%) of the tibia were malrotated greater than 10 degrees, and of those 5 tibia, 4 were distal 1/3 fractures.
McKee et al randomized 85 patients undergoing intramedullary tibial nailing using manual traction with the leg draped free versus standard fracture table positioning and traction. They found that manual traction is an effective technique that can save a significant amount of time without sacrificing the quality of reduction or fixation of tibial shaft fractures.

Question 96

A hockey player had a puck hit his foot. Radiographs taken immediately after the game were negative. He still has persistent pain 5 days after the injury and difficulty weight bearing. What is the best next step?

Explanation

Ice hockey injuries demand a thorough assessment because they have the potential to be significant. In hockey players, bone injuries in the foot and ankle can be missed or improperly diagnosed through routine radiographic imaging. MRI can display bone injuries that are not found radiographically; this is because some fractures and contusions involve the medial ankle and midfoot bones.

Question 97

Figure 69 is the radiograph of a 9-year-old who has posterior hindfoot pain while running. What is the most likely diagnosis?

Explanation

DISCUSSION
Sever disease is a traction apophysitis at the Achilles tendon insertion on the calcaneus. Plain radiographs may be unremarkable for this condition. Other osteochondroses of the foot include Kohler disease (tarsal navicular), Freiberg infraction (lesser metatarsal head), and Thiemann disease (great toe phalanx).
RECOMMENDED READINGS
Sullivan RJ. Adolescent foot and ankle conditions. In: Pinzur MD, ED. Orthopaedic Knowledge Update: Foot and Ankle 4. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2008:47-55.
Feldman DS. Osteochondrosis. In: Spivak JM, Di Cesare PE, Feldman Ds, et al, eds. Orthopaedic: A Study Guide. New York, NY: McGraw-Hill; 1999:765-766.
Schantz K, Rasmussen F. Thiemann's finger or toe disease. Follow-up of seven cases. Acta Orthop Scand. 1986 Feb;57(1):91-3. PubMed PMID: 3962642. View Abstract at PubMed

Question 98

Figures 18a and 18b show the radiographs of a patient who has pain with walking. On careful questioning, it is determined that the discomfort occurs at push-off, or when the patient attempts to climb stairs. What nonsurgical option is most likely to ameliorate the symptoms?

Explanation

DISCUSSION: The patient has a malunion of an attempted open reduction of a Lisfranc dislocation. The pain occurs during the terminal stance phase of gait as load is being transferred from the hindfoot to the forefoot. The bending moment can be best neutralized with shoe modification with a cushioned heel and rocker sole, which best unloads the tarsal-metatarsal junction.
REFERENCES: Bono CM, Berberian WS: Orthotic devices: Degenerative disorders of the foot and ankle. Foot Ankle Clin 2001;6:329-340.
Richardson EG (ed): Orthopaedic Knowledge Update: Foot and Ankle 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004, pp 58-63.

Question 99

A 47-year-old woman has an asymptomatic pelvic mass that was discovered on routine gynecologic examination. A radiograph, CT scan, MRI scan, and biopsy specimen are shown in Figures 7a through 7d. Metastatic work-up is negative. Treatment should consist of

Explanation

DISCUSSION: The imaging studies show a chondrosarcoma; therefore, surgical treatment is indicated. There is no role for intralesional treatment of an exophytic lesion, particularly in the pelvis. Even obtaining a biopsy specimen risks intrapelvic contamination, although many surgeons would still perform a biopsy prior to a resection to confirm the diagnosis. Chondrosarcoma is considered resistant to both radiation therapy and chemotherapy; therefore, radiation therapy generally is not used except for unresectable lesions. Chemotherapy would be used only for metastatic disease or in patients with high-grade chondrosarcoma. The grade would not be known until after resection, and in this patient, the histology slide showed a grade I neoplasm. Chemotherapy would not be used preoperatively because a cartilage tumor is unlikely to shrink, and in this patient, the lesion is resectable.
REFERENCES: Springfield DS, Gebhardt MS, Mcguire MH: Chondrosarcoma: A review. J Bone Joint Surg Am 1996;78:141-149.
Marco RA, Gitelis S, Brebach GT, Healey JH: Cartilage tumors: Evaluation and treatment. J Am Acad Orthop Surg 2000;8:292-304.

Question 100

Figure 36 shows the hip arthrogram of a newborn. Which of the following structures is enclosed by the circle?

Explanation

DISCUSSION: The structure enclosed by the circle is the acetabular labrum. It is visible as the white point of tissue outlined by the darkly radiopaque contrast. The appearance of the contrast surrounding the sharp white point of a normal labrum is called the “rose thorn sign.” The limbus is the term reserved for a rounded, infolded labrum seen with arthrography. The pulvinar is the fatty tissue seen in the empty acetabulum when the hip is dislocated. The ligamentum teres is seen as a white stripe outlined by contrast coursing from the central acetabulum to the dislocated femoral head. The transverse acetabular ligament courses across the inferior portion of the acetabulum and is not clearly seen with arthrography.
REFERENCES: Herring JA: Tachdjian’s Pediatric Orthopaedics, ed 3. Philadelphia, PA,

WB Saunders, 2002, vol 1, pp 532-533.
Severin E: Contribution to the knowledge of congenital dislocation of the hip joint.

Acta Chir Scand 1941;84:1.

Full Question & Answer Text (for Search Engines)

Question 1:

Second impact syndrome (SIS) after head injury is characterized by which of the following?

Options:

Gradual progression of neurologic symptoms
Preventable by restricting return to play until symptom-free
Excellent prognosis for full recovery
Rarely involves brain stem compromise
CT rarely shows brain edema

Correct Answer: Preventable by restricting return to play until symptom-free

Explanation:

Question 2:

Figure 21 shows the tomogram of a 26-year-old woman who sustained an axial load injury to her neck in a fall off a horse. What ligament is injured?

Options:

Anterior longitudinal
Posterior longitudinal
Alar
Apical
Transverse

Correct Answer: Transverse

Explanation:

Question 3:

Options:

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

Correct Answer: Evaluation of peripheral pulses

Explanation:

Question 4:

Reverse total shoulder arthroplasty with a latissimus dorsi transfer would be the most appropriate treatment for which of the following patients? Review Topic

Options:

Previous shoulder arthrodesis and complete brachial plexus injury
Humeral head avascular necrosis with partial thickness infraspinatus tear
Failed hemiarthroplasty with the inability to perform active external rotation with the arm abducted
Primary shoulder osteoarthritis with 10 degree of glenoid retroversion
Primary rotator cuff arthropathy with active forward shoulder flexion >100 degrees and external rotation >50 degrees

Correct Answer: Previous shoulder arthrodesis and complete brachial plexus injury

Explanation:

Question 5:

Options:

Infection
Arthritis
Synovial chondromatosis
Pigmented villonodular synovitis (PVNS)
Reactive synovitis

Correct Answer: Pigmented villonodular synovitis (PVNS)

Explanation:

DISCUSSION: The MRI scans show multiple low-signal intensity lesions scattered throughout the knee, extending posteriorly inferior to the tibial plateau. The low-signal intensity on both the T
1
- and T
2
-weighted images, the modest vascularity noted on the gadolinium image, and the “blooming” noted on the gradient echo image (ferrous-laden tissue) are all strongly suggestive of diffuse PVNS. Whereas synovial chondromatosis can present as diffuse masses in the knee, they present as nodule masses that have low T
1
- and high T
2
-weighted signal characteristics.
REFERENCES: Resnick D (ed): Diagnosis of Bone and Joint Disorders. Philadelphia, PA,
WB Saunders, 2002, pp 4241-4252.
Sanders TG, Parsons TW: Radiographic imaging of musculoskeletal neoplasia. Cancer Control 2001;8:1-11.

Question 6:

Options:

Propionibacterium acnes
Staphylococcus aureus
Group B streptococcus
Neisseria gonorrhea
Enterococcus coli

Correct Answer: Enterococcus coli

Explanation:

This patient has sternoclavicular joint septic arthritis with gram positive organisms. Although there is an increased incidence of Pseudomonas aeruginosa infection in IV drug users, S. aureus is still the most common organism.
Ross et al states "Staphylococcus aureus is now the major cause of
sternoclavicular septic arthritis in intravenous drug users. Pseudomonas aeruginosa infection in injection drug users declined dramatically with the end of an epidemic of pentazocine abuse in the 1980s."
The referenced article by Goldin et al is from the New England Journal of Medicine reports that all of their cases of SC joint septic arthritis were in intravenous drug abusers and that P. aeruginosa grew out of 3 patients and S. aureus grew out of 1 patient.
A more recent article by Abu Arab et al reported that Staph aureus was most common even in IV drug users. The review article by Higginbotham and Kuhn note that risk factors for SC joint septic arthritis include hemodialysis, immunocompromise, alcoholism, and HIV. Neisseria gonorrhoeae, fungal, and candida present in HIV patients.
Treatment is I&D and appropriate antibiotics, although aspiration and abx have shown some success too. CT and MRI are useful in diagnosis, and open biopsy or aspiration is recommended for definitive diagnosis.
A 30-year-old man presents with a distal third tibia fracture that has healed in 25 degrees of varus alignment. The patient is at greatest risk of developing which of the following conditions as a result of this malunion?
Degenerative lumbar spine changes
Ipsilateral ankle pain and stiffness
Ipsilateral hip joint degenerative changes
Contralateral hip joint degenerative changes
Ipsilateral medial knee degenerative changes
Correct answer: 2
A significant malunion of the distal tibia has important consequences for patient outcome, including pain, gait changes, and cosmesis.
The first referenced article by Milner et al looked at long-term outcomes of tibial malunions and noted that varus malunion led to increased ankle/subtalar stiffness and pain regardless of the amount of radiographic degenerative changes.
The second referenced article by Puno et al reinforced the concept of decreased functional outcomes of the ankle with tibial malunions, and noted
that other lower extremity joints (ipsilateral and contralateral) do not have increased rates of degeneration from such a malunion.
A 33-year-old man sustains a femur fracture in a motorcycle accident. AP and lateral radiographs are provided in Figure A. Prior to surgery, a CT scan of the knee is ordered for preoperative planning. Which of the following additional findings is most likely to be discovered?
Tibial eminence fracture
Sagittal plane fracture of the medial femoral condyle
Schatzker I tibia plateau fracture
Coronal plane fracture of the lateral femoral condyle
Axial plane fracture through the medial femoral condyle
Correct answer: 4
The "Hoffa fracture" is a coronal plane fracture of the femoral condyle that is often missed on plain radiographs of supracondylar and intercondylar femur fractures. It involves the lateral condyle more frequently than the medial.
Identification is important as it may impact operative planning and likely require screw fixation in the anteroposterior plane.
Nork et al. reviewed 202 supracondylar-intercondylar distal femoral fractures and found a 38% prevalence of associated coronal plane fractures. The authors recommend CT scan imaging of all supracondylar and intercondylar fractures.
Ostermann et al reported on 24 unicondylar fractures of the distal femur treated with open reduction internal fixation with a screw construct. Twenty-
three patients acheived satisfactory results at 5 year follow-up. Illustrations A and B are another example of a supracondylar femur fracture with an associated Hoffa fracture identified on CT scan.
A 35-year-old woman presents with an elbow injury which includes a coronoid fracture involving more than 50%, a comminuted
radial head fracture, and an elbow dislocation. What is the most appropriate treatment?
closed reduction and early range of motion
radial head resection and lateral collateral ligament reconstruction
radial head resection and coronoid open reduction internal fixation
radial head arthroplasty and coronoid open reduction internal fixation
radial head arthroplasty, coronoid open reduction internal fixation, and lateral collateral ligament repair
A terrible triad of the elbow includes dislocation of the elbow with associated fractures of the radial head and the coronoid process. Ring et al. stressed that these injuries are prone to complications and advised against resection of the radial head due to instability, and instead recommended a radial head replacement if too comminuted for ORIF. Coronoid fractures compromise elbow stability as well and require open reduction and internal fixation as with the lateral collateral ligament. McKee et al. showed stable elbows in 34/36 with mean Mayo elbow score of 88 when the standard protocol of coronoid ORIF, radial head repair/replacement, and LCL repair were employed.
The talocrural angle of an ankle mortise x-ray is formed between a line perpendicular to the tibial plafond and a line drawn:
perpendicular to the medial clear space
parallel to the talar body
between the tips of the malleoli
perpendicular to the shaft of the fibular
parallel to the subtalar joint
Correct answer: 3
The talocrural angle is formed by the intersection of a line perpendicular to the plafond with a line drawn between the malleoli (average = 83+/-4deg). When the lateral malleolus is shortened secondary to fracture, this can lead to increased talocrural angle. This malunion leads to lateral tilt of the talus.
Phillips et al looked at 138 patients with a closed grade-4 supination-external rotation or pronation-external rotation ankle fracture. Although the conclusions were limited due to poor follow up, they found the difference in the talocrural angle between the injured and normal sides was a statistically significant radiographic indicator of a good prognosis.
Pettrone et al looked at a series of 146 displaced ankle fractures, and the effect of open or closed treatment, and internal fixation of one or both malleoli. They found open reduction proved superior to closed reduction, and in bimalleolar fractures open reduction of both malleoli was better than fixing only the medial side.
Illustrations A and B are demonstrations of the talocrural angle.
A 33-year-old male sustains the injury shown in Figure A. He is initially treated with a spanning external fixator followed by definitive open reduction internal fixation of the tibia and fibula. His wounds healed without infection or other complications. Two years following surgery, which of the following parameters will most likely predict a poor clinical outcome and inability to return to work?
Joint line restoration
Degree of fracture displacement
Time before definitive ORIF
Open fracture
Lower level of education
Correct answer: 5
Lower level of education is the parameter that correlated most closely with a poor clinical outcome and inability to return to work.
To determine what fracture- and patient-specific variables affect outcome, Williams et al evaluated 29 patients with 32 tibial plafond fractures at a minimum of 2 years from the time of injury. Outcome was assessed by four independent measures: a radiographic arthrosis score, a subjective ankle score, the Short Form-36 (SF-36), and the patient’s ability to return to work. The four outcome measures did not correlate with each other. Radiographic arthrosis was predicted best by severity of injury and accuracy of reduction. However, these variables did not show any significant relationship to the clinical ankle score, the SF-36, or return to work. These outcome measures were more influenced by patient-specific socioeconomic factors. Higher ankle
scores were seen in patients with college degrees and lower scores were seen in patients with a work-related injury. The ability to return to work was affected by the patient’s level of education.
Pollak et al performed a retrospective cohort analysis of pilon fractures. Patient, injury, and treatment characteristics were recorded. The primary outcomes that were measured included general health, walking ability, limitation of range of motion, pain, and stair-climbing ability. A secondary outcome measure was employment status. Multivariate analyses revealed that presence of two or more comorbidities, being married, having an annual personal income of less than $25,000, not having attained a high-school diploma, and having been treated with external fixation with or without limited internal fixation were significantly related to poorer results as reflected by at least two of the five primary outcome measures.
What is the most appropriate treatment for a 17-year-old boy who sustained a gunshot wound to his forearm from a handgun with a muzzle-velocity of 1000 feet/second if he is neurovascularly intact and radiographs reveal no fracture?
Irrigation and local wound care in the emergency department
Emergent irrigation and debridement in the operating room with vacuum-assisted wound closure
Emergent irrigation and debridement in the operating room with 7 days of intravenous antibiotics
Wound closure in the emergency department with follow-up wound check in 1 week
Exploration and removal of all bullet fragments in the emergency department and 10 day course of oral antibiotics
The question refers to appropriate management of a gunshot wound to the forearm. The first question that must be answered when evaluating gunshot injuries is whether the gunshot is low velocity or high velocity. Low-velocity wounds are less severe, are more common in the civilian population, and are typically attributed to bullets with muzzle velocities below 1,000 to 2,000 feet per second. Tissue damage is usually more substantial with higher-velocity (greater than 2,000 to 3,000 fps) military and hunting weapons. In this question, a muzzle velocity of 1,000 ft/sec is provided. Low velocity injuries with stable, non-operative fractures can be treated with local wound care.
The two referenced articles offer guidance for treating low-velocity gunshot injuries with stable, non-operative fracture patterns. The first article by Geissler et al is a retrospective study comparing 25 patients that prospectively received local irrigation and debridement, tetanus prophylaxis and a long acting cephalosporin intramuscularly to a random retrospective sample of 25 patients with similar ballistic-induced fractures and wounds managed by local debridement and 48h of intravenous antibiotics. One infection occurred in each group, requiring further therapy. It was concluded that patients with low-velocity gunshot induced fractures can be managed without the use of short-term intravenous antibiotics with no increased risk of infection.
In the second study, Dickey et al evaluated the efficacy of an outpatient management protocol for patients with a gunshot-induced fracture with a stable, non-operative configuration. 41 patients with a grade I or II open, nonoperative fracture secondary to a low-velocity bullet were treated with 1gm of cefazolin administered in the emergency room and a 7-day course of oral cephalexin. No patient developed a deep infection. Thus, local I&D, tetanus, and oral antibiotics for 2-3 days is adequate for low velocity gunshot wounds.
Which clinical sign is the most sensitive for the diagnosis of compartment syndrome in a child with a supracondylar humerus fracture?
pulselessness
pallor
paresthesia
paralysis
increasing analgesia requirement
Correct answer: 5
Although pain, pallor, paresthesia, paralysis, and pulselessness are all possible signs and symptoms of compartment syndrome in children with fractures, studies have shown increasing analgesia requirement is more sensitive.
Bae et al reviewed thirty-six cases of compartment syndrome in 33 pediatric patients. Approximately 75% of these patients developed compartment syndrome in the setting of fracture. "They found pain, pallor, paresthesia, paralysis, and pulselessness were relatively unreliable signs and symptoms of compartment syndrome in these children. An increasing analgesia requirement in combination with other clinical signs, was a more sensitive indicator of
compartment syndrome."
Whitesides et al summarizes the diagnosis and treatment of acute compartment syndrome. They emphasize the need for early diagnosis, as "muscles tolerate 4 hours of ischemia well, but by 6 hours the result is uncertain; after 8 hours, the damage is irreversible." They recommend fasciotomy be performed when tissue pressure rises past 20 mm Hg below diastolic pressure.
A 45-year-old man sustains the injury seen in Figures A and B following a motor vehicle accident. Postoperative radiographs are seen in Figures C and D. Which of the following is the most accurate when comparing outcomes between intramedullary nailing (IMN) and open reduction internal fixation (ORIF) for this injury?
Union rates at one year are higher with ORIF
Infection rates are higher with IMN
Functional shoulder outcomes at one year are equivalent with IMN and ORIF
Iatrogenic radial nerve injury rate is higher with ORIF
Shoulder stiffness rates at one year are equivalent with IMN and ORIF
Correct answer: 3
Although shoulder pain and stiffness is increased following IMN compared to ORIF, functional outcome scores at one year have been shown to be equivalent
in both treatment groups.
Diaphyseal humeral shaft fractures outcomes following IMN and ORIF are under further investigation. Diaphyseal humeral shaft fractures have historically been treated with ORIF, however proponents for IMN cite benefits of less periosteal stripping and soft tissue dissection. Recent investigations have shown outcomes with regard to nonunion, infection, re-operation, and nerve palsy appear equivalent between both groups. Rates of shoulder stiffness and shoulder pain have been demonstrated to be higher in IMN compared to ORIF. American Shoulder and Elbow Scores (ASES) have shown no difference at one year post-operatively.
Bhandari et al. performed a meta-anaylsis of 3 prospective randomized trials. They found lower rates of re-operation and shoulder impingement with ORIF of humeral shaft fractures.
Wali et al. performed a prospective randomized study of IMN or ORIF on 50 patients with mid-diaphyseal humeral shaft fractures. They found IMN had shorter operative time, shorter hospital stay, and lower blood loss. They found no difference in union rates, complication, or shoulder functional outcomes scores. They conclude IMN to be an effective option for treating mid-diaphyseal humeral shaft fractures.
Heineman et al. have recently conducted an update on their meta-analysis to include more recent randomized studies. With the inclusion of newer studies the author found a statistically significant increase in total complication rate with the use of IM nailing compared with ORIF. The authors found no significant difference between the two treatment modalities for the secondary outcomes (nonunion, infection, nerve palsy, re-operation).
Figures A and B show a diaphyseal humeral shaft fracture. Figure C and D show postoperative radiographs following intramedullary nailing of a humeral shaft fracture.
Incorrect Answers:
A 25-year-old female presents complaining of progressive anteromedial pain in her left ankle. She underwent operative fixation 5 months prior at an outside hospital. The operative report indicated that, due to anterior fracture blisters, a direct medial incision was utilized, centered over the posterior colliculus of the medial malleolus, without violation of the deltoid ligament. A radiograph and computed tomographic scan of her initial injury are shown in Figures A and B, respectively. On exam, she has well-healed incisions, exhibits no tenderness to palpation over her hardware, but does endorse pain with deep palpation along the anteromedial joint line. Figure C shows an anteroposterior left ankle radiograph taken today. Labs are obtained and reveal a white blood cell count of 9.0 k/uL (reference range 4.5-11.0 k/uL) and a C-reactive protein value of 0.8 mg/dL (<0.9 mg/dL). What is the next best step in managing her problem?
Syndesmotic fixation
Intra-articular corticosteroid injection
Referral to physical therapy
Surgical correction of malunion
Removal of hardware
Correct answer: 4
This patient sustained a supination-adduction (SAD) injury with a vertical shear fracture of her medial malleolus and a fibular avulsion fracture. She sustained a medial plafond articular impaction injury that was not addressed at the time of surgery.
In SAD injuries, supination of the foot is combined with inward rotation at the ankle, adduction of the hindfoot, and inversion of the forefoot. This results in the following sequence of events: 1. Talofibular sprain or distal fibular avulsion (equivalent to Weber A). 2. Vertical medial malleolus fracture as the talus strikes the tibia. Associated injuries may include osteochondral damage to the talus and marginal impaction of the medial plafond. It is important to evaluate the medial plafond for articular impaction. When present, an arthrotomy must be performed, typically utilizing an anteromedial incision, with direct visualization of the articular surface to restore the joint line appropriately.
Weber et al. provided a review article on corrective osteotomies for malleolar fracture malunions. They stress that malunions can lead to ankle instability, abnormal load transfer, and post-traumatic arthritis. They conclude that corrective osteotomies that restore anatomical alignment show good results in long-term follow-up.
Perera et al. provided additional commentary on the surgical reconstruction of malunited ankle fractures. The authors emphasize the link between malunion and poor outcomes. They state that successful salvage procedures involve a clear understanding of the deformity, careful preoperative planning, and a solid understanding of reconstructive techniques. They provide several instructive case examples in their review.
McConnell et al. provided a discussion on SAD ankle fractures at their institution and emphasized the importance of recognizing marginal impaction of the tibial plafond when treating these injuries. Of 800 ankle fractures identified over a 5-year period, 44 were SAD injuries, 19 of the 44 displayed a vertical shear fracture of the medial malleolus, and 8 of the 19 demonstrated marginal impaction of the tibial plafond. These 8 impaction injuries were treated with open reduction internal fixation with elevation of the articular impaction; all had good to excellent outcomes without arthritic changes at last
follow-up.
Figure A is an anteroposterior left ankle radiograph demonstrating a SAD injury with a vertical shear fracture of the medial malleolus, a fibular avulsion fracture, and articular impaction of the medial tibial plafond. Figure B is a coronal CT demonstrating articular impaction of the medial plafond. Illustration A is an intra-operative photograph with the medial malleolus retracted allowing inspection of the articular surface; mild anteromedial plafond impaction is present.
Incorrect Answers:
A 90-year-old female slips and falls at home. She is a community ambulator and has no medical problems. She reports right hip pain at this time. Injury radiographs are shown in Figures A & B. Delay of more than 48 hours may result in:
Increased intraoperative time
Increased 30-day mortality
No impact on the rate of postoperative pneumonia
Higher rates of blood transfusion
Increased risk of post-operative infection
Correct answer: 2
Figures A & B demonstrate a right, unstable intertrochanteric femur fracture. Surgical stabilization within 48 hours improves short-term and 30-day mortality.
Hip fractures are common and mortality rates vary. In the elderly, mortality rates may reach 10% at 1-month, 20% at 4-months, and 30% at 1-year. Time to surgery has found to be a decisive factor. A pre-operative delay may lead to an increase in mortality and adversely influence other clinical outcomes.
Clinical guidelines recommend immediate operative stabilization, given the patient is medically fit for surgery.
Nyholm et al. performed a retrospective study of the Danish Fracture Database to investigate whether a surgical delay increases 30-day and 90-day mortality rates for patients with proximal femoral fractures. The 30-day and 90-day mortalities were 10.8% and 17.4%, respectively. The risk of 30-day mortality increased with increasing time intervals of more than 12 hours, 24 hours, and more than 48 hours. 90-day mortality increased with a surgical delay of more than 24 hours. They conclude that rapid surgical treatment should be performed by attending orthopaedic surgeons.
Moja et al. performed a meta-analysis and meta-regression to assess the relationship between surgical delay and mortality in elderly patients with a hip fracture. They analyzed 35 independent studies with 191,873 patients and 34,448 deaths. The majority of studies had a cut-off of 48 hours. They report that early hip surgery was associated with a lower risk of death and pressure sores. They conclude that early hip fracture surgery appears to provide a survival benefit compared to later intervention.
Rodriguez-Fernandez et al. performed a study examining 2 groups with hip fractures. The first group was studied retrospectively and had an average delay of surgical treatment of more than 1-week while the second group was studied prospectively, and had surgical treatment within 48 hours. They found a larger number of complications in the group with a delay in surgical treatment. They conclude that elderly patients with hip fractures should be treated as soon as their medical condition permits.
Figures A and B are the AP and lateral radiographs demonstrating a right, unstable intertrochanteric femur fracture. Illustration A is an intertrochanteric femur fracture, stabilized with a cephalomedullary nail.
Incorrect Answers:
A 22-year-old healthy left hand dominant male presents to the ED with left shoulder pain after falling from an ATV. Figure A is the radiograph of his left clavicle. He is neurovascularly intact and there is no evidence of skin tenting or open fracture. Which of the following most predisposes this patient to nonunion?
Diaphyseal fracture
Fracture displacement
Age
Male Gender
Injury involving the dominant extremity
Correct answer: 2
Displaced clavicle fractures are associated with higher rates of nonunion.
Nonunion occurs in roughly 5-6% of clavicle fractures and can result in slower functional return, poor cosmesis and muscle fatigability. Clavicle fractures can be sub-classified using the Allman classification into medial, diaphyseal, and lateral injuries (Illustration A). The Neer classification for diaphyseal injuries describes fractures as "nondisplaced" (less than 100% displacement) and "displaced" (greater than 100% displacement).
Robinson et al. performed a prospective cohort study to identify risk factors for nonunion after nonoperative management of clavicle fractures. The overall nonunion rate was 6.2% and was highest in lateral third fractures (11.5%).
Diaphyseal fractures had the lowest nonunion rate (4.5%). Additionally, the authors found that the risk for nonunion was increased by advancing age, female gender, fracture displacement, and comminution.
Jorgensen et al. performed a systemic review of the literature looking for predictors of non-union and malunion in mid shaft clavicle fractures treated non-operatively. They found fracture comminution, displacement, older age, female gender, and the presence of smoking to be his factors for non-union. Of these, displacement was the most likely factor that can be used to predict nonunion.
Figure A demonstrates a displaced left clavicle diaphyseal fracture. Note that the medial fragment is displaced superiorly by the deforming force of the sternocleidomastoid. Illustration A represents the Allman classification.
Illustration B demonstrates the deforming forces acting on the clavicle.
Incorrect Answers:
A 24-year-old male presents with ankle pain after being involved in a motor vehicle accident. His injury radiograph is shown in Figure A. Which of the following has been shown to contribute to the development of post-traumatic arthritis in this injury pattern?
Initial superficial zone cartilage cell death via apoptosis at the fracture margins
Initial superficial zone cartilage cell death via apoptosis remote from the fracture margins
Initial superficial zone cartilage cell death via necrosis remote from the fracture margins
Initial superficial zone cartilage cell death via necrosis at the fracture margins
Delayed superficial zone cartilage cell death via necrosis at the fracture margins
Figure A demonstrates a tibial plafond fracture. Initial superficial zone cartilage cell death via necrosis at the fracture margins has been shown to contribute to post-traumatic arthritis.
Post-traumatic osteoarthritis typically occurs after an intra-articular fracture. Impacted chondrocytes die by either necrosis or apoptosis, which have both been implicated in post-traumatic osteoarthritis. Initial cell death in the superficial cartilage zones at the fracture margins occurs by necrosis. Apoptosis occurs in a delayed fashion and is mitigated by several bioactive agents.
Apoptosis also affects the superficial cartilage zones near the fracture margins. Deep cartilaginous zones and areas away from the fracture margins do not seem to be involved in these processes.
McKinley et al. performed a review of the basic science of intra-articular fractures and posttraumatic osteoarthritis. They report that initial damage to the cartilage in combination with the ensuing pathomechanical and pathobiologic response of the cartilage after a fracture contribute to posttraumatic arthritis. Chronic abnormal joint loading is also thought to contribute to this process as well. They conclude that the relative contribution of each is unknown.
Tochigi et al. performed a study to determine the distribution and progression of chondrocyte damage after intra-articular ankle fractures. They harvested 7 normal human ankles and subjected them to impaction. They found that immediate superficial zone chondrocyte death was greater in fracture-edge regions than on-fracture regions. Subsequent cell death over the next 48 hours was significantly higher in fracture-edge regions as well. They conclude that cartilage damage in intra-articular fractures was characterized by chondrocyte death at fracture margins.
Figure A is an ankle mortise radiograph demonstrating an intra-articular tibial plafond fracture.
Incorrect Answers:
A 35-year-old male presents with left knee pain after sustaining the injury seen in Figure A. He is neurovascularly intact and can perform a straight leg raise, but has pain with passive range of motion. Figures B and C show an anteroposterior and lateral radiograph of the left knee, respectively. 175 cc of saline is injected into the superolateral quadrant with no egress of fluid from the inferolateral
laceration. What percentage of traumatic arthrotomies would be detected with this test?

Question 7:

Options:

loss of active thumb interphalangeal (IP) flexion.
distal radioulnar joint instability.
avascular necrosis of the capitate.
ulnar carpal translocation.

Correct Answer: ulnar carpal translocation.

Explanation:

Question 8:

Options:

oral indomethacin.
Irradiation with a single dose of 700 cGy.
Physical therapy with dynamic splinting.
Physical therapy and delayed ectopic bone excision at 12 months.
Immediate elbow release and ectopic bone excision. back answer Question 59.03

Correct Answer: Immediate elbow release and ectopic bone excision. back answer Question 59.03

Explanation:

Question 9:

Options:

Resurfacing hemiarthroplasty
Resurfacing hemiarthroplasty with fascial glenoid resurfacing
Resurfacing hemiarthroplasty with cemented glenoid component
Stemmed hemiarthroplasty
Stemmed total shoulder arthroplasty

Correct Answer: Stemmed hemiarthroplasty

Explanation:

Question 10:

Options:

Thompson test
External rotation stress test
Anterior drawer test
Squeeze test

Correct Answer: Anterior drawer test

Explanation:

Question 11:

In hybrid arthroplasty, the use of a polymethylmethacrylate (PMMA) precoated femoral component has been shown to result in

Options:

increased survivorship compared with nonprecoated stems.
increased bonding of the stem to the cement mantle.
a reduced rate of wear compared with nonprecoated stems.
a reduced rate of revision compared with nonprecoated stems.
a reduced rate of postoperative infection.

Correct Answer: increased bonding of the stem to the cement mantle.

Explanation:

Question 12:

Options:

Bone scan
CT
High-dose steroids
Sacroiliac joint injection
Hernia repair

Correct Answer: Hernia repair

Explanation:

Question 13:

Options:

Delay further surgical intervention until his ESR and CRP level normalize
Delay further surgical intervention until his ESR normalizes
Delay further surgical intervention until his CRP level normalizes
Proceed with surgical intervention if the patient’s condition is medically optimized

Correct Answer: Proceed with surgical intervention if the patient’s condition is medically optimized

Explanation:

Question 14:

Options:

Uncontained cartilage lesion
Removal of the subchondral plate
Removal of the calcified cartilage layer
Failure to remove the calcified cartilage layer

Correct Answer: Removal of the subchondral plate

Explanation:

Question 15:

Options:

popliteal cyst.
posterior cruciate ligament tear.
torn and displaced posterior horn of the medial meniscus.
normal meniscofemoral ligament of Humphry.
normal meniscofemoral ligament of Wrisberg.

Correct Answer: torn and displaced posterior horn of the medial meniscus.

Explanation:

Question 16:

Options:

Non-weight-bearing immobilization and CT
Walking boot and weight bearing as tolerated
Activity restrictions (avoidance of running) and repeat radiographs in 2 to 4 weeks
Activity restrictions and a bone scan
Surgical fixation

Correct Answer: Non-weight-bearing immobilization and CT

Explanation:

DISCUSSION: A high index of suspicion is required to identify a possible navicular stress fracture, especially in runners. High pain tolerance in the competitive athlete and often minimal swelling contribute to frequent delays in diagnosis. Localized tenderness over the dorsal navicular (so-called “N spot”) in a running athlete should alert the treating physician. In this patient, the radiographs are negative and the MRI scan shows marrow edema within the navicular. This could represent a stress reaction, stress fracture, or osteonecrosis. Appropriate management should include non-weight-bearing immobilization and obtaining a CT scan to determine if a fracture is present. Early surgical treatment may be considered but only if a fracture is identified.
REFERENCES: Lee A, Anderson R: Stress fractures of the tarsal navicular. Foot Ankle Clin 2004;9:85-104.
Coughlin M: Tarsal navicular stress fractures. Tech Foot Ankle Surg 2002;1:112-122.

Question 17:

A 21-year-old college defensive lineman sustains a minimally displaced (less than 1 mm) midthird scaphoid fracture during the first game of the season. Management should consist of

Options:

cast immobilization and a return to play as symptoms allow.
cast immobilization and a return to play when union is achieved.
open reduction and internal fixation, followed by early range of motion with a return to play when union is achieved.
open reduction and internal fixation, followed by a return to play with protective casting.
symptomatic treatment, with definitive treatment at the end of the season.

Correct Answer: cast immobilization and a return to play as symptoms allow.

Explanation:

Question 18:

Surgical arthroscopy performed 1 week after injury presents increased risk for

Options:

deep venous thrombosis.
popliteal artery dissection.
complex regional pain syndrome.
compartment syndrome.

Correct Answer: compartment syndrome.

Explanation:

Question 19:

During spinal deformity surgery, which of the following is the most specific early indicator of an intraoperative injury to the spinal cord? Review Topic

Options:

Somatosensory-evoked potentials
Transcranial motor-evoked potential monitoring
Transcutaneous electroencephalogram neuromonitoring
Stimulus-evoked transpedicular electromyography (EMG)
Brainstem auditory-evoked responses (BAERs)

Correct Answer: Transcranial motor-evoked potential monitoring

Explanation:

Question 20:

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

Options:

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

Correct Answer: Cheilctomy of the MTP joint

Explanation:

Question 21:

Which of the following statements best describes the kinematic behavior of the knee during motion from full extension to flexion?

Options:

Both the medial and lateral knee tibiofemoral contact points rotate and translate equally with increasing knee flexion.
The medial femoral condyle translates much less than the lateral femoral condyle with knee flexion.
The lateral femoral condyle translates much less than the medial femoral condyle with knee flexion.
The medial compartment rotates internally whereas the lateral compartment rotates externally.
The lateral compartment rotates internally whereas the medial compartment rotates externally.

Correct Answer: The medial femoral condyle translates much less than the lateral femoral condyle with knee flexion.

Explanation:

Question 22:

A 24-year-old dancer sustains the injury shown in Figure 28. Management should consist of

Options:

closed reduction and application of a well-molded cast.
open reduction and percutaneous pin fixation.
open reduction and internal fixation with a mini fragment plate and screws.
intramedullary screw fixation.
brief immobilization and symptomatic treatment.

Correct Answer: brief immobilization and symptomatic treatment.

Explanation:

Question 23:

Based on the radiograph shown in Figure 4, the innervation of what muscle is most at risk with total hip arthroplasty?

Options:

Quadriceps
Extensor hallucis longus
Lateral gastrocnemius
Adductor magnus
Semitendinosus

Correct Answer: Extensor hallucis longus

Explanation:

DISCUSSION: The radiograph reveals a Crowe IV deformity in a patient with developmental dysplasia of the hip. If hip arthroplasty is performed, then some degree of limb lengthening is anticipated. Excessive limb lengthening can result in sciatic nerve palsy in these patients. The peroneal branch of the sciatic nerve is most often affected. Of the muscles listed, only the extensor hallucis longus is innervated by the peroneal branch of the sciatic nerve.
REFERENCES: Eggli S, Hankemayer S, Muller ME: Nerve palsy after leg lengthening in total replacement arthroplasty for developmental dysplasia of the hip. J Bone Joint Surg Br 1999;81:843-845.
Schmalzried TP, Amstutz HC, Dorey FJ: Nerve palsy associated with total hip replacement:
Risk factors and prognosis. J Bone Joint Surg Am 1991;73:1074-1080.

Question 24:

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

Options:

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

Correct Answer: Posterior fusion of the thoracic curve

Explanation:

Question 25:

The clinical photograph in Figure 27 shows a palsy of what nerve/associated muscle? Review Topic

Options:

Long thoracic/rhomboid
Long thoracic/serratus anterior
Long thoracic/supraspinatus
Dorsal scapular/trapezius
Spinal accessory/trapezius

Correct Answer: Long thoracic/serratus anterior

Explanation:

Question 26:

Nonsurgical management of pectoralis major tears is likely to result in weakness of glenohumeral

Options:

abduction and external rotation.
abduction and internal rotation.
adduction and external rotation.
adduction and internal rotation.
external rotation and forward flexion.

Correct Answer: adduction and internal rotation.

Explanation:

Question 27:

Options:

Trapeziometacarpal arthrodesis
Osteotomy of the thumb metacarpal
Arthrotomy and joint debridement
Ligament reconstruction using one half of the flexor carpi radialis
Trapezium resection, tendon interposition, and reconstruction of the ligament

Correct Answer: Ligament reconstruction using one half of the flexor carpi radialis

Explanation:

Question 28:

The mechanism for the osseous destruction is attributable to

Options:

avascular necrosis.
tumor invasion.
hypervascularity.
infection.

Correct Answer: hypervascularity.

Explanation:

DISCUSSION
This scenario is a classic example of the development of Charcot foot. A red, swollen, deformed foot without ulceration suggests neuroarthropathy. Normal inflammatory marker findings, no history of fever or chills, and radiographs demonstrating bone loss support the diagnosis. Limb elevation with dramatic reduction in erythema is also characteristic of this disease process and does not occur with infection. Total-contact casting is the cornerstone of treatment for acute Charcot disease. Hemoglobin A1C is an indicator of glucose averaged over a 3-month period, providing the most reliable indication of a patient's ongoing glucose control. The pathophysiology of bone destruction is believed to be hypervascularity of bone. Infection and Charcot disease may develop simultaneously, but the combination is rare.
RECOMMENDED READINGS
Kaynak G, Birsel O, Güven MF, Ogüt T. An overview of the Charcot foot pathophysiology. Diabet Foot Ankle. 2013 Aug 2;4. doi: 10.3402/dfa.v4i0.21117.Print 2013. PubMed PMID: 23919113.
View Abstract at PubMed
Pinzur MS, Lio T, Posner M. Treatment of Eichenholtz stage I Charcot foot arthropathy with a weightbearing total contact cast. Foot Ankle Int. 2006 May;27(5):324-9. PubMed PMID: 16701052.
View Abstract at PubMed

Question 29:

Options:

C6
Upper trunk
Middle trunk
Posterior cord
Lateral cord

Correct Answer: Lateral cord

Explanation:

DISCUSSION: The lateral cord terminates as the musculocutaneous nerve and also contributes sensory fibers to the median nerve. Involvement of the C6 root or upper trunk could potentially cause weakness of the infraspinatus and the brachioradialis. The middle trunk and the posterior cord do not contribute motor fibers to the thumb or sensory fibers to the thumb.
REFERENCE: Kline DG, Hudson AR: Nerve Injuries: Operative Results for Major Nerve Injuries, Entrapments and Tumors. Philadelphia, PA, WB Saunders, 1995, p 334.

Question 30:

Figure 44 shows the radiograph of an 11-year-old girl who has hip pain. Further diagnostic workup should include

Options:

a renal ultrasound.
an echocardiogram.
an electromyogram.
an MRI scan of the spine.
an iliac crest biopsy.

Correct Answer: an echocardiogram.

Explanation:

Question 31:

What is the prognosis for ambulation, from best to worst, for patients with an incomplete spinal cord injury?

Options:

Central cord syndrome, anterior cord syndrome, Brown-Sequard syndrome
Central cord syndrome, Brown-Sequard syndrome, anterior cord syndrome
Brown-Sequard syndrome, anterior cord syndrome, central cord syndrome
Brown-Sequard syndrome, central cord syndrome, anterior cord syndrome
Anterior cord syndrome, central cord syndrome, Brown-Sequard syndrome

Correct Answer: Brown-Sequard syndrome, central cord syndrome, anterior cord syndrome

Explanation:

Question 32:

Options:

C3-T1
C4-C5
C5-C7
C6-C8
C8-T1

Correct Answer: C5-C7

Explanation:

Question 33:

What arterial vessel is most prone to injury during posterior iliac crest bone graft harvest?

Options:

Superior gluteal
Deep circumflex iliac
Iliolumbar
Ascending branch of the lateral femoral circumflex
Fourth lumbar

Correct Answer: Superior gluteal

Explanation:

Question 34:

What muscle is most often encountered during surgical approaches to C5-6?

Options:

Omohyoid
Cricohyoid
Splenius capitus
Thyrohyoid
Posterior digastric

Correct Answer: Omohyoid

Explanation:

DISCUSSION: The omohyoid muscle crosses the surgical field from inferior lateral to anterior superior traveling from the scapula to the hyoid bone and may need to be transected. The posterior digastric crosses the field as well but higher near C3-4. The other muscles run longitudinally.
REFERENCES: Chang U, Lee MC, Kim DH: Anterior approach to the midcervical spine, in Kim DH, Henn JS, Vaccaro AR, et al (eds): Surgical Anatomy and Techniques to the Spine. Philadelphia, PA, Saunders Elsevier, 2006, pp 45-56.
Netter GH: Atlas of Human Anatomy. Summit, NJ, Ciba-Geigy Corporation, 1989.

Question 35:

Calcitonin acts as an antiresorptive agent by

Options:

decreasing osteoblast number.
decreasing osteoclast activity and number.
increasing osteoclast activity.
increasing osteoblast activity.
increasing osteoblast number.

Correct Answer: decreasing osteoclast activity and number.

Explanation:

Question 36:

Options:

07 Semmes-Weinstein monofilament
Bone scan
Thompson’s test
CT
Noninvasive vascular studies

Correct Answer: Noninvasive vascular studies

Explanation:

Question 37:

Options:

Anterior tibialis tendon transfer to the dorsolateral midfoot
Posterior tibialis tendon transfer to the dorsolateral midfoot
Peroneus longus tendon transfer to the dorsolateral midfoot
Peroneus brevis tendon transfer to the dorsolateral midfoot
Flexor hallucis longus tendon transfer to the peroneus brevis

Correct Answer: Peroneus longus tendon transfer to the dorsolateral midfoot

Explanation:

DISCUSSION: Compartment syndrome of the anterior and deep posterior compartments results in anterior tibialis and posterior tibialis tendon weakness, respectively. Furthermore, the long flexors to the hallux and lesser toes will be weak as well. The intact peroneus longus overpowers the weak anterior tibialis tendon, resulting in plantar flexion of the first metatarsal, cavus, and hindfoot varus. Therefore, transferring the peroneus longus to the dorsolateral midfoot reduces the first metatarsal plantar flexion torque, and possibly augments ankle dorsiflexion torque.
REFERENCES: Hansen ST: Functional Reconstruction of the Foot and Ankle. Philadelphia, PA, Lippincott, Williams & Wilkins, 2000, pp 433-435.
Vienne P, Schoniger R, Helmy N, et al: Hindfoot instability in cavovarus deformity: Static and dynamic balancing. Foot Ankle Int 2007;28:96-102.

Question 38:

Figures 63a and 63b show the radiographs of a 38-year-old man who reports low back and bilateral lower extremity pain. The spondylolisthesis is best classified as which of the following? Review Topic

Options:

Pathologic
Isthmic
Acquired
Degenerative
Dysplastic

Correct Answer: Isthmic

Explanation:

Question 39:

Options:

Dissatisfaction after TKA
Periprosthetic infection and wound complications
Implant loosening
Thromboembolic disease

Correct Answer: Periprosthetic infection and wound complications

Explanation:

Question 40:

Options:

Tumor grade
Tumor size
Surgical margin
Anatomic site of the tumor
Histologic subtype of the tumor

Correct Answer: Surgical margin

Explanation:

Question 41:

Options:

ACL reconstruction 20 years ago
Spontaneous osteonecrosis of the knee involving the medial compartment
A history of inflammatory arthritis
Body weight of 80kg
degree varus deformity Corrent answer: 3 Inflammatory arthritides are considered contraindications for a partial knee replacement due to the likely progression of arthritis in the native compartments. Unicompartmental arthroplasty (UKA) is generally considered an excellent procedure provided that appropriate surgical indications are used for patient selection. Classic indications for UKA include unicompartmental disease in patients older than 60 with relatively low activity demands. Additionally, the patients should weigh less than 82 kg, have minimal pain at rest, have motion >90 degrees, varus deformity <10 degrees, and flexion contractures <10 degrees. While most of these classic indications are still used today, recent studies are showing excellent results in younger, heavier, and more active patients. Inflammatory arthropathy is a contra-indication to unicompartmental knee replacement due to the high risk of continued arthritis progression in the other compartments. These patients should undergo total knee replacement instead. Heyse et al. retrospectively reviewed the results of unicompartmental arthroplasty for spontaneous osteonecrosis of the knee (SONK). 75.7% of patients were "very satisfied" with the procedure and 21.6% were "satisfied." At 15 years, 90.6% of unicompartmental arthroplasties had not been revised. Overall, the authors feel it is an excellent procedure for SONK. Price et al. reviewed 682 medial Oxford UKA knees for 20-year survival. They found the all-cause revision survival rate was 91%. 29 revision procedures occurred at a mean time of 3.3 years postoperatively. The most common cause of revision was lateral arthrosis (34%), followed closely by component loosening (31%). They concluded that Oxford medial UKA has good survival even into the second decade postoperatively. Figure A and B show AP and lateral images of a left knee status post medial unicompartmental knee arthroplasty. Specifically, this is the Oxford UKA system. Illustration A is a T2-weighted MRI demonstrating SONK. Incorrect Answers:

Correct Answer: degree varus deformity Corrent answer: 3 Inflammatory arthritides are considered contraindications for a partial knee replacement due to the likely progression of arthritis in the native compartments. Unicompartmental arthroplasty (UKA) is generally considered an excellent procedure provided that appropriate surgical indications are used for patient selection. Classic indications for UKA include unicompartmental disease in patients older than 60 with relatively low activity demands. Additionally, the patients should weigh less than 82 kg, have minimal pain at rest, have motion >90 degrees, varus deformity <10 degrees, and flexion contractures <10 degrees. While most of these classic indications are still used today, recent studies are showing excellent results in younger, heavier, and more active patients. Inflammatory arthropathy is a contra-indication to unicompartmental knee replacement due to the high risk of continued arthritis progression in the other compartments. These patients should undergo total knee replacement instead. Heyse et al. retrospectively reviewed the results of unicompartmental arthroplasty for spontaneous osteonecrosis of the knee (SONK). 75.7% of patients were "very satisfied" with the procedure and 21.6% were "satisfied." At 15 years, 90.6% of unicompartmental arthroplasties had not been revised. Overall, the authors feel it is an excellent procedure for SONK. Price et al. reviewed 682 medial Oxford UKA knees for 20-year survival. They found the all-cause revision survival rate was 91%. 29 revision procedures occurred at a mean time of 3.3 years postoperatively. The most common cause of revision was lateral arthrosis (34%), followed closely by component loosening (31%). They concluded that Oxford medial UKA has good survival even into the second decade postoperatively. Figure A and B show AP and lateral images of a left knee status post medial unicompartmental knee arthroplasty. Specifically, this is the Oxford UKA system. Illustration A is a T2-weighted MRI demonstrating SONK. Incorrect Answers:

Explanation:

unicompartmental arthroplasty. The absence of an ACL is a contraindication for mobile-bearing UKA.
OrthoCash 2020
Which of the following is the most common cause of early revision surgery (<20 weeks) following a hip resurfacing arthroplasty?
Periprosthetic fracture
Rupture of abductors
Dislocation
Heterotopic ossification
Post-operative stiffness
Periprosthetic fracture, specifically femoral neck fracture, is the most common cause of early revision less than 20 weeks following surgery.
The rate of femoral neck fractures following hip resurfacing varies, but most literature reports a rate of 1%. A majority of these fractures happen in the early post-operative period and are the most frequent cause of revision surgery within several months following surgery. The cause is usually multifactorial, but placing the femoral implant in varus, osteonecrosis, and notching have been proven risk factors for fracture.
Little el al. report on 377 patients undergoing hip resurfacing. 13 required revision including 8 for fracture of the femoral neck and 3 for loosening of a component. Evidence of osteonecrosis was seen in two of these cases, leading the authors to believe it may contributed to fracture.
Illustration A shows a comparison of a typical total hip replacement and a hip resurfacing arthroplasty. Illustration B shows notching of the femoral neck, a known cause of femoral neck fracture following hip resurfacing. Illustration C shows a femoral neck fracture in a patient with a hip resurfacing.
OrthoCash 2020
A 55-year-old male undergoes a revision total knee arthroplasty of an implant that is only 3 years old. At the time of surgery, the tibial polyethylene liner shows catastrophic delamination and cracking. What is the most likely cause of this extensive, accelerated wear of the polyethylene liner?
Sterilization in ethylene oxide
Gamma irradiation of the polyethylene liner in the presence of air
Gamma irradiation of the polyethylene liner with vacuum packaging
Gamma irradiation of the polyethylene liner in nitrogen
Gamma irradiation of the polyethylene liner in argon
Corrent answer: 2
Irradiation of polyethylene in air (i.e. oxygen present) has been shown to be a risk factor for catastrophic failure after total knee replacement.
Free radicals are generated when polyethylene is irradiated in the presence of air. Initially, these free radicals result in cross-linking. However, if the polyethylene is exposed to these free radicals for an extended period of time, delamination, cracking, and catastrophic failure may ensue. The industry has completely abandoned this method of sterilization as a result. Currently, the standard of care is irradiation of polyethylene in an inert gas (e.g. argon, nitrogen or vacuum packaging). The amount of oxidative products when polyethylene is sterilized in the absence of oxygen is much less and does not lead to catastrophic failure.
Sterilization without irradiation is another option (ethylene oxide). When this occurs, there is no cross-linking and thus the increased wear properties are lost. However, since there is no oxidization, you do not have the risk of catastrophic failure as seen in those liners irradiated in the presence of oxygen.
The cited reference by McNulty et al. from Orthopedics discusses the influence of sterilization methods on wear performance. They found that gamma irradiation and storage of the polyethylene components in an essentially oxygen-free environment imparted by gamma irradiation in a vacuum foil pouch (GVF) protects the components from oxidization.
Illustration A shows a polyethylene liner that has undergone catastrophic wear as a result of irradiation in the presence of oxygen.
Incorrect Answers:
catastrophic wear, although wear properties are less than gamma irradiation in the absence of air.
OrthoCash 2020
Which of the following interventions reduces osteolysis around distal portion of the femoral stem when performing a total hip arthroplasty?
Use of an extended offset femoral neck component
Use of a proximal circumferentially coated ingrowth stem
Use of a collared stem
Use of a long femoral stem
Ensuring that the stem fills the diaphysis of the femur
Corrent answer: 2
Osteolysis of the femur is caused by activation of macrophages by microscopic polyethylene particles within the "effective joint space", defined as any area where joint fluid can come into contact with bone. This can occur above the acetabular cup, through screw holes, and down the femoral shaft around the prosthetic stem. Ideally, with a cementless stem, both the proximal and metaphyseal femur are well filled by the prosthesis. Collared stems are used to augment poor calcar bone quality or bone loss.
Sinha et al showed in a retrospective review of 101 hips with cementless circumferentially coated femoral stems no distal femur osteolysis occurred, but 82% showed “evidence of proximal femur stress shielding”, though only 38% showed proximal femoral osteolysis.
OrthoCash 2020
During a minimally invasive approach to total hip arthroplasty a femoral periprosthetic fracture occurs. Which of the following steps is crucial to properly treat this complication?
Transitioning to an extensile approach to adequately visualize and reduce the fracture
Limiting post-operative weight bearing
Switching to a cemented femoral stem to avoid the stresses created during press-fit fixation
Delaying the arthroplasty until the fracture has healed
Supplementing the fracture with autograft
Corrent answer: 1
Proper treatment of an intraoperative femoral fracture during total hip arthroplasty involves adequate exposure, anatomic reduction, and bypassing the fracture site by 2 cortical diameters of the femur with a long stem. This may involve repositioning the patient on the table if the arthroplasty is performed in the supine position. Minimally invasive surgical techniques have been developed to insert the components through smaller exposures and less soft tissue dissection. The purported advantages include faster rehabilitation, less blood loss, shorter hospital stays, and better cosmesis. However, complications an arise if the surgeon sacrifices surgical exposure and visualization.
Fehring et al review 3 cases of total hip arthroplasty performed through minimally invasive techniques with catastrophic outcomes. Intra-operative fracture, chronic instability, and death were all identified.
OrthoCash 2020
A 70-year-old man underwent total hip arthroplasty 4 months ago and has experienced 3 dislocations. Radiographs reveal no failure of the hardware and an acetabular component that has an abduction
angle of 40 degrees and a version of 10 degrees retroverted. What is the most appropriate treatment for the recurrent dislocations?
hip abduction brace
revision of the acetabular liner to a constrained type
revision of the entire acetabular component
revision of the femoral head to a larger size
revision to an extended offset prosthesis
Corrent answer: 3
Per Dorr et al: post-operative hip instability can be caused by several factors: soft tissue imbalance, component malposition, or position. Component malposition, as in this case, should be treated with revision of the offending component. In this case the acetabulum was placed in retroversion when it should have been 15-20 degrees anteverted. None of the other options addresses the cause of the instability. According to Morrey, the most signficant risk factors to instability are prior hip surgery, trochanteric nonunion, and posterior surgical approach. He wrote that the most reliable way to correct instability is to reorient a retroverted acetabular cup.
OrthoCash 2020
In patients with sickle cell disease and asymptomatic osteonecrosis of the femoral head identified with magnetic resonance imaging, what percentage will eventually go on to femoral head collapse?

Question 42:

What is the most common behavioral effect of anabolic steroid use in athletes? Review Topic

Options:

Increased aggression
Psychosis
Drug dependence
Depression
Mania

Correct Answer: Increased aggression

Explanation:

Question 43:

What is the standard interval for placement of an anterolateral portal in ankle arthroscopy?

Options:

Peroneus brevis to peroneus longus
Peroneus tertius to extensor hallucis longus
Peroneus tertius to superficial peroneal nerve
Extensor hallucis longus to deep peroneal nerve
Extensor hallucis longus to extensor digitorum longus

Correct Answer: Peroneus tertius to superficial peroneal nerve

Explanation:

Question 44:

A patient has a C6-7 herniated nucleus pulposus. What is the most likely distribution of symptoms? Review Topic

Options:

Pain in the posterior neck and scapula, numbness over the clavicle, and weakness of the head and neck extensors
Pain in the shoulder, numbness over the lateral shoulder, weakness of the deltoid
Pain at the elbow, numbness over the thumb and index finger, weakness of the biceps and wrist extensors
Pain at the forearm and hand, numbness of the middle finger, weakness of the triceps and finger extensors
Pain at the wrist, numbness in the little and ring fingers, weak finger flexors

Correct Answer: Pain at the wrist, numbness in the little and ring fingers, weak finger flexors

Explanation:

A C6-7 herniated nucleus pulposus is most likely to produce a C7 radiculopathy resulting in pain at the forearm and hand, numbness of the middle finger, and weakness of the triceps and finger extensors. Alternative answers represent sequelae of symptomatic disk herniations at C3-C4 (1), C4-C5 (2), C5-C6 (3), and C7-T1 (5), respectively.
(SBQ12SP.27) A 24-year-old male sustains the injury shown in Figure A. What was the most likely mechanism of injury?
Review Topic
Hyperextension
Flexion-distraction
Flexion-compression
Rotational
Pure axial load
Figure A shows a quadrangular fracture pattern of C5. These injuries are observed with flexion-compression loads.
Quadrangular fractures of the cervical spine are considered flexion teardrop fractures. However, they present with a larger anterior lip fragment compared to the classic teardrop fracture pattern. The radiographic findings include a quadrangular-shaped fragment from the anterior one-third of the vertebral body with significant posterior vertebral subluxation, angular kyphosis, and an increased interspinous space with facet subluxation due to disruption of the posterior elements. These are unstable fractures, and almost always require anterior and posterior stabilization.
Moore et al. studied the reliability of Cervical Spine Injury Severity Score to measure stability after cervical spine trauma. The classification system is based on morphologic descriptions and, secondly, on stability based on a quantifiable value. They showed that the Cervical Spine Injury Severity Score had excellent reliability with intra-observer intraclass correlation coefficients (ICC) >0.97 and inter-observer ICC >0.88.
Vaccaro et al. published the subaxial cervical spine injury classification system (SLIC). This systems involves 3 main categories (injury morphology, disco-ligamentous complex, and neurologic status). The overall injury severity score is obtained by summing the scores from each category. They propose that SLIC < 4 can be treated non-operatively.
Allen et al. published a classification system of cervical spine injuries which breaks injuries of the subaxial spine into six phylogenic groups based on mechanism of injury. These include: 1) flexion-compression 2) vertical-compression 3) flexion-
distraction 4) extension-compression 5) extension-distraction 6) lateral flexion. Facet
dislocation
is
caused
by
flexion-distraction
force.
Figure A shows a lateral radiograph of the cervical spine demonstrating a typical flexion-compression fracture with anteriorly displaced quadrangular fragment. Illustration A shows a flexion-compression injury. Illustration B shows the mechanism of injury for a quadrangular fracture of the cervical spine. This unstable fracture pattern is characterized by anterior column failure in flexion/compression and posterior column failure in tension. Illustration C shows an illustration of the fracture morphology according to the Allen and Ferguson classification.
Incorrect Answer 1:
Hyperextension injuries
Flexion-distraction injuries usually result in facet dislocations.

Question 45:

Options:

open acromioplasty
open Bankart repair
open subscapularis tendon repair
inferior capsular shift
a supervised physical therapy program

Correct Answer: open subscapularis tendon repair

Explanation:

This patient has an acute tear of the subscapularis tendon both by MRI and physical exam. Treatment of choice is open repair. Nonoperative treatment is not indicated.

Question 46:

Options:

In extension with internal rotation/valgus force, the medial tibial plateau is subluxated; with flexion, the medial tibial plateau reduces.
In extension with internal rotation/valgus force, the medial tibial plateau is reduced; with flexion, the medial tibial plateau subluxates.
In extension with internal rotation/valgus force, the lateral tibial plateau is reduced; with flexion, the lateral plateau subluxates.
In extension with internal rotation/valgus force, the lateral tibial plateau is subluxated; with flexion, the lateral plateau reduces.

Correct Answer: In extension with internal rotation/valgus force, the lateral tibial plateau is subluxated; with flexion, the lateral plateau reduces.

Explanation:

Question 47:

In patients without spondylolisthesis or scoliosis undergoing laminectomy for lumbar spinal stenosis, spinal fusion is generally recommended if

Options:

a dural tear is repaired.
more than one level requires decompression.
less than one half of each facet is removed bilaterally.
the pars interarticularis is fractured.
the patient is a smoker.

Correct Answer: the pars interarticularis is fractured.

Explanation:

DISCUSSION: With the notable exception of fusion for degenerative spondylolisthesis and scoliosis, there is a paucity of evidence on the indications for spinal fusion in patients undergoing laminectomy for spinal stenosis. However, it is generally recommended that if the spine is destabilized (for example by removal of one complete facet joint or by an iatrogenic pars fracture), spinal fusion should be considered. Although fusion can be considered for a very long laminectomy, a two-level laminectomy does not represent, by itself, a clear indication for the addition of a spinal fusion. The repair of a dural tear and the use of nicotine by the patient play no role in the determination of whether or not to add fusion to a laminectomy procedure.
REFERENCES: Spivak JM, Connolly PJ (eds): Orthopaedic Knowledge Update: Spine 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, pp 299-409.
Fischgrund JS, Mackay M, Herkowitz HN, et al: 1997 Volvo Award winner in clinical studies. Degenerative lumbar spondylolisthesis with spinal stenosis: A prospective, randomized study comparing decompressive laminectomy and arthrodesis with and without spinal instrumentation. Spine 1997;22:2807-2812.

Question 48:

Options:

CT-guided needle aspiration and organism-appropriate antibiotics.
laminectomy and postoperative bracing.
posterior fusion with instrumentation and IV antibiotics.
anterior debridement and strut graft, with possible posterior instrumentation.
posterior extracavitary decompression alone.

Correct Answer: anterior debridement and strut graft, with possible posterior instrumentation.

Explanation:

Question 49:

The diagnosis of an infection after total knee arthroplasty is most reliably proven based on what single study?

Options:

Leukocyte count and C-reactive protein
Radiographs
Technetium Tc 99m and gallium bone scans
Aspiration of joint fluid
MRI

Correct Answer: Aspiration of joint fluid

Explanation:

DISCUSSION: In a study of 52 patients with infected total knee arthroplasties, Windsor and associates showed that the average leukocyte count was 8,300/mm
3
and that aspirated knee fluid was positive in all patients except one. Knee radiographs can be unclear in showing infection, which may be present without radiographic signs of loosening. Technetium Tc 99m and gallium bone scans may not conclusively show the presence of infection, particularly in the first 3 years after knee arthroplasty.
REFERENCES: Windsor RE, Bono JV: Infected total knee replacements. J Am Acad Orthop Surg 1994;2:44-53.
Windsor RE, Insall JN, Urs WK, et al: Two-stage reimplantation for the salvage of total knee arthroplasty complicated by infection: Further follow-up and refinement of indications. J Bone Joint Surg Am 1990;72:272-278.

Question 50:

A patient undergoing joint arthroplasty is put on a drug that competitively inhibits the activation of an enzyme that breaks down Factor Ia. The drug is

Options:

Dabigatran
Tranexamic acid
Rivaroxaban
Fondaparinux
Heparin

Correct Answer: Heparin

Explanation:

Question 51:

Options:

Menstrual history
Family history
Serum calcium level
MRI of the hip
Contralateral hip radiograph

Correct Answer: Menstrual history

Explanation:

Question 52:

Options:

Inlet and outlet views of the pelvis to better delineate the injury
Angiography
Laparotomy
Open reduction and internal fixation of the pelvis
Placement of a pelvic binder around the patient

Correct Answer: Placement of a pelvic binder around the patient

Explanation:

DISCUSSION: This hypotensive patient has an obvious open book injury of the pelvic ring on the AP pelvis radiograph and further radiographs are not needed prior to the initiation of treatment. Although angiography may be indicated if he does not respond to stabilization of his pelvis and fluid/blood administration, temporary stabilization of the pelvis with a sheet or binder should be performed first because it is simple, quick, and has been shown to be effective. This patient does not need a laparotomy at this point since the FAST examination did not show any free intra-abdominal fluid and his chest radiograph was unremarkable, leaving the most likely source of bleeding the pelvic fracture. Open reduction with internal fixation of a pelvic injury is not indicated in an acutely ill patient.
REFERENCES: Kreig JC, Mohr M, Ellis TJ, et al: Emergent stabilization of pelvic ring injuries by controlled circumferential compression: A clinical trial. J Trauma 2005;59:659-664.
Croce MA, Magnotti LJ, Savage SA, et al: Emergent pelvic fixation in patients with exsanguinating pelvic fractures. J Am Coll Surg 2007;204:935-942.
Routt ML Jr, Falicov A, Woodhouse E, et al: Circumferential pelvic antishock sheeting:
A temporary resuscitation aid. J Orthop Trauma 2002;16:45-48.

Question 53:

Options:

higher incidence of patellar clunk and similar implant survivorship.
higher incidence of patellar clunk and superior implant survivorship.
lower incidence of patellar clunk and superior implant survivorship.
lower incidence of patellar clunk and similar implant survivorship. The images show a left posterior stabilized knee prosthesis and a right cruciate sacrificing (ultracongruent / dished type) knee prosthesis. Posterior stabilized designs have a risk of patellar clunk due to the presence of the femoral box with some designs, such as the one shown, exhibiting higher rates. Clinical outcomes are similar between cruciate-retaining, cruciate- sacrificing and posterior stabilized designs.

Correct Answer: higher incidence of patellar clunk and similar implant survivorship.

Explanation:

Question 54:

Options:

Arthroscopic or open reduction and internal fixation
Arthroscopic loose body removal
Activity restriction for up to 9 months
Subchondral drilling

Correct Answer: Arthroscopic or open reduction and internal fixation

Explanation:

Question 55:

Options:

There is no increased risk for spinal cord injury.
10%
25%
35%
Greater than 50%

Correct Answer: There is no increased risk for spinal cord injury.

Explanation:

Question 56:

Options:

activity modification
arthroscopic evaluation of fragment stability.
transarticular drilling of the lesion with 0.045 Kirschner wire.
arthroscopic excision of the fragment and microfracture of underlying cancellous bone.
excision of the fragment and mosaicplasty.

Correct Answer: activity modification

Explanation:

This skeletally immature patient has a small OCD lesion that appears stable, and he has not undergone any treatment. Therefore, a trial of activity modification and limited weight bearing until pain resolves is the best initial choice.
Cessation of sport activities for 4 to 6 months may allow healing of the lesion. Surgical treatment of juvenile OCD lesions is reserved for unstable lesions, patients
who have not shown radiographic evidence of healing and are still symptomatic after
6 months of nonsurgical management, or patients who are approaching skeletal maturity. Good results with stable in situ lesions that have failed to respond to nonsurgical management have been reported with both transarticular and retroarticular drilling. Results after excision alone are poor at 5-year follow-up, and it is unclear if microfracture will improve the long-term outcome. Mosaicplasty may be the next best option for patients who remain or become symptomatic after excision of the fragment and microfracture.
Wall et al. reviewed juvenile OCD. They state that JOCD has better potential for healing than adult OCD, but several series have shown up to a 50% failure to heal with nonsurgical techniques. The presence of a loose body is an indication for surgical fixation, drilling or regenerative procedures, depending on the presence/extent of subchondral bone sclerosis and the surgeon's experience.
Figure A and B are coronal MRI images showing a stable appearing JOCD lesion of the medial femoral condyle.
Incorrect
in the first
(SBQ13PE.9) A 6-year-old boy complains of a 'clunking' sensation in his left knee. He has no associated pain and denies trauma. He can elicit the sensation when moving his knee from flexion into full extension. He is otherwise healthy, with no birth or developmental issues. On examination, there is a palpable clunk felt over the anterior knee through range of motion. There is no obvious instability or tenderness and he had normal patellar tracking. An AP radiograph of the knee is shown in Figure A. What would be the most likely diagnosis?
Review
Topic
Agenesis of the anterior cruciate ligament
Thickened medial plica
Grade IV chondral flap
Pigmented villonodular synovitis
Abnormal meniscal morphology
This child presents with an asymptomatic click in the knee. It is associated with widening of the lateral joint space of the knee on X-ray. These features are highly suggestive of a discoid lateral meniscus in this age category.
The principal diagnostic feature of a discoid meniscus is the complaint of snapping or clicking in the knee. Children are usually asymptomatic. Although, less frequently, children may present with pain that is largely secondary to an underlying meniscal tear. MRI scans of the knee have show to have the greatest sensitivity for identifying discoid menisci. The presence of a contiguous central meniscus on three consecutive slices is usually indicative of the diagnosis. Treatment is mostly focused on conservative modalities. Surgical intervention is reserved for symptomatic cases with recurrent locking, swelling or persistent pain is present in older children.
Kramer et al. looked at the presentation of pediatric knee pain. They showed that the lateral meniscus is more commonly affected than the medial meniscus. The majority of discoid tears occur in the posterior or middle aspect of the discoid meniscus.
Figure A shows an AP radiograph of a pediatric knee. There is an increased lateral joint space suggestive of a discoid meniscus.
Illustrations A-C show an MRI of the knee with 3 consecutive coronal cuts showing an abnormal appearing discoid meniscus.
Incorrect Answers:

Question 57:

Options:

MRI with metal artifact reduction sequence (MARS) only. B. serum cobalt only.
serum cobalt and chromium levels.
serum cobalt and chromium levels and MRI with MARS.

Correct Answer: MRI with metal artifact reduction sequence (MARS) only. B. serum cobalt only.

Explanation:

Question 58:

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

Options:

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

Correct Answer: Cathepsin K

Explanation:

Question 59:

At the time of revision knee arthroplasty, a surgeon performs a rectus snip to gain exposure to the knee. When compared with a standard parapatellar approach, what is the expected outcome?

Options:

Improvement in range of motion
Reduction in range of motion
Increase in extensor mechanism lag
No differences in motion and strength

Correct Answer: No differences in motion and strength

Explanation:

DISCUSSION:
Rectus snip during total knee arthroplasty has no effect on motion or strength at long-term follow-up. It has not been associated with extensor mechanism lag.

Question 60:

Options:

Shoulder abduction
Shoulder external rotation
Shoulder internal rotation
Elbow extension
Forearm supination

Correct Answer: Forearm supination

Explanation:

Question 61:

Treatment should include

Options:

anterior cruciate ligament reconstruction with lateral meniscus repair.
partial lateral meniscectomy with saucerization.
lateral meniscus transplant.
protected weight bearing with referral for genetic testing.

Correct Answer: partial lateral meniscectomy with saucerization.

Explanation:

Question 62:

Creatine is currently being used by athletes as a dietary supplement in an attempt to enhance performance. What is the physiologic basis for its use?

Options:

Assists in carbohydrate metabolism and glycogen synthesis by producing adenosine diphosphate (ADP) to enhance aerobic activities
Converts to phosphocreatine (PCr), which acts as an energy reservoir for adenosine triphosphate (ATP) in muscle tissue
Converts to PCr, which enhances the production of ADP and promotes the metabolism of triglycerides as an energy source
Converts to PCr, which enhances the production of ADP and promotes the metabolism of proteins as an energy source
Converts to ADP by creatine kinase (CK) providing an energy reservoir for the production of ATP

Correct Answer: Converts to phosphocreatine (PCr), which acts as an energy reservoir for adenosine triphosphate (ATP) in muscle tissue

Explanation:

Question 63:

Options:

simple lateral eminence resection.
distal chevron osteotomy of the fifth metatarsal.
oblique mid-diaphyseal osteotomy of the fifth metatarsal.
proximal diaphyseal osteotomy of the fifth metatarsal.
excision of the fifth metatarsal head.

Correct Answer: oblique mid-diaphyseal osteotomy of the fifth metatarsal.

Explanation:

Question 64:

Options:

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

Correct Answer: symptomatic relief with anti-inflammatory drugs.

Explanation:

Question 65:

What is the typical axial plane transverse angulation of the thoracic pedicles?

Options:

5 degrees medial at T 1 and T 2 ; 10 degrees from T3 to T10
5 degrees lateral at T 1 ; neutral at T 2 ; 5 degrees medial from T3 to T12
10 degrees medial from T1 to T10; 15 degrees medial at T11 and T12
10 degrees medial from T 1 to T12
25 degrees medial at T 1 ; 15 degrees at T 2 ; and 10 degrees medial from T3 to T10

Correct Answer: 25 degrees medial at T 1 ; 15 degrees at T 2 ; and 10 degrees medial from T3 to T10

Explanation:

DISCUSSION: Thoracic pedicles typically are angled 25 degrees medially at T
1
so the
starting point is more lateral. T
2
angles about 15 degrees, and then the pedicles average about
5 to 7 degrees down to T10. At T11 and 12, the angulation is minimal.
REFERENCES: Weinstein L: Pediatric Spine Principles and Practice. New York, NY, Raven Press, 1994, pp 1659-1681.
Lenke LG, Orchowski J: Segmental posterior spinal instrumentation: Thoracic spine to sacrum, in Frymoyer JW, Wiesel SW (eds): The Adult and Pediatric Spine, ed 3. Philadelphia, PA, Lippincott Williams and Wilkins, 2004, pp 537-552.

Question 66:

Which sterilization method is expected to produce the most degradation of an allograft used for anterior cruciate ligament reconstruction?

Options:

Deep freezing
Supercritical CO2 treatment
Gamma irradiation with 1.2 Mrad
Chlorhexidine gluconate 4% cleansing

Correct Answer: Supercritical CO2 treatment

Explanation:

DISCUSSION
A biomechanical study compared unprocessed, irradiated (2.0 Mrad-2.8 Mrad), and supercritical CO2-treated soft-tissue allografts and demonstrated a 27% to 36% decrease in stiffness of the supercritical CO2-treated grafts. No significant difference was found between the irradiated and untreated soft-tissue allografts. Low-dose (1.0 Mrad-1.2 Mrad) gamma irradiation of bone-patellar-tendon-allograft has been shown to produce a 20% decrease in graft stiffness. Deep freezing or cleansing with 4% chlorhexidine gluconate does not appear to adversely affect the biomechanical properties of the allograft tissue.
CLINICAL SITUATION FOR QUESTIONS 43 THROUGH 46
Figures 43a and 43b are the MR arthrogram images of a 16-year-old, right-hand-dominant baseball player who injured his left shoulder 4 weeks ago during a game. He now has pain, weakness, and the inability to swing a bat and can no longer do push-ups. He denies prior injury to his left shoulder. Radiographs are unremarkable.

Question 67:

The relocation test is most reliable for diagnosing anterior subluxation of the glenohumeral joint when

Options:

posterior pressure placed on the humeral head results in increased pain.
external rotation with the arm in 90 degrees of abduction produces apprehension that is relieved by posterior pressure on the humeral head.
external rotation with the arm in 90 degrees of abduction produces pain that is relieved by posterior pressure on the humeral head.
external rotation with the arm in 90 degrees of abduction produces no symptoms, but posterior pressure on the humeral head produces pain and apprehension.
external rotation with the arm in 90 degrees of abduction produces no symptoms, but posterior pressure on the humeral head produces apprehension.

Correct Answer: external rotation with the arm in 90 degrees of abduction produces apprehension that is relieved by posterior pressure on the humeral head.

Explanation:

Question 68:

Options:

Nonsurgical management and follow-up CT scan in 6 weeks
Closed reduction in the emergency room under sedation
Closed reduction in the operating room under general anesthesia with thoracic surgery on standby, followed by figure-of-8 clavicle strap immobilization for 4 weeks
Closed reduction in the operating room under general anesthesia with thoracic surgery on standby, followed by compression plating
Open reduction in the operating room under general anesthesia, followed by transarticular pinning with K-wires

Correct Answer: Closed reduction in the emergency room under sedation

Explanation:

Question 69:

Options:

Infection
Stem loosening
Acetabular osteonecrosis
Acetabular cartilage degeneration
Referred pain from the lumbar spine

Correct Answer: Acetabular cartilage degeneration

Explanation:

Question 70:

Options:

higher infection rates.
higher nonunion rates.
equal union and infection rates.
higher rate of ARDS.
higher mortality rate.

Correct Answer: equal union and infection rates.

Explanation:

DISCUSSION: Recently Harwood and associates investigated the principles of damage control orthopaedics (DCO) as they apply to patients with femoral shaft fractures. When they compared those who underwent initial external fixation of femoral shaft fractures with conversion to an intramedullary nail to those who underwent intramedullary nailing as their initial treatment, they found the following: overall infection rates were comparable in patients receiving DCO versus primary intramedullary fixation; open fracture was an independent risk factor for infection regardless of the treatment method; contamination rates in external fixator pin sites rose considerably when left in place more than 2 weeks and logistic regression analysis suggests that infection rates may increase when conversion to an intramedullary nail occurs after 2 weeks following external fixation; and there was no significant difference in time to union among treatment groups.
REFERENCES: Harwood PJ, Giannoudis PV, Probst C, et al: The risk of local infective complications after damage control procedures for femoral shaft fracture. J Orthop Trauma 2006;20:181-189.
Roberts CS, Pape HC, Jones AL, et al: Damage control orthopaedics: Evolving concepts in the treatment of patients who have sustained orthopaedic trauma. Instr Course Lect
2005;54:447-462.

Question 71:

Options:

Tibial polyethylene exchange
Revision of the femoral and tibial components and conversion to a posterior stabilized insert
Revision of femoral and tibial components to a constrained rotating hinge prosthesis
Isolated femoral component revision and upsizing the femoral implant with a new PCL-retaining polyethylene insert

Correct Answer: Revision of the femoral and tibial components and conversion to a posterior stabilized insert

Explanation:

DISCUSSION
Video 99 for reference
This patient has valgus knee alignment, and, after undergoing appropriate bone resections and soft-tissue balancing, has demonstrated a tight PCL on trial reduction as evidenced by lift-off of the trial insert as described by Scott and Chmell. The appropriate maneuver is PCL recession with partial release of tight (usually anterolateral) PCL fibers. However, for this patient, instability resulted in increased anterior translation. At this stage, the options are to convert to either a deeper-dish insert with increased sagittal conformity or a posterior stabilized insert. The only appropriate choice among the responses is use of an insert with increased sagittal conformity to prevent excessive anterior translation. Increasing the polyethylene could improve stability in flexion, but, considering there is good stability in extension, this likely would lead to an inability to achieve full extension. The patient’s valgus deformity, flexion contracture, correction with release of the iliotibial band, and posterolateral capsule predispose him to increased risk for peroneal nerve palsy. His symptoms at follow-up suggest knee flexion
instability with pain, swelling, and difficulty descending stairs. Considering his history, an incompetent PCL must be considered. Revision of the knee to a posterior stabilized or nonlinked constrained condylar implant depending on the condition of the ligaments likely is needed to address his symptoms. The difference in extension vs flexion stability makes polyethylene exchange a poor option. There is no reason to believe a constrained rotating hinge design is necessary. Repeat use of a PCL-retaining insert is not recommended.

Question 72:

Options:

Scapholunate dissociation
Triangular fibrocartilage tear
Scaphoid fracture
Perilunate dislocation
Kienbock’s disease

Correct Answer: Kienbock’s disease

Explanation:

Question 73:

A patient with severe rheumatoid arthritis reports progressive hip pain. Serial hip radiographs will most likely show which of the following findings?

Options:

Asymmetric joint space narrowing
Sacroiliac joint ankylosis
Progressive superior and lateral migration of the femoral head
Periarticular osteopenia
Hip synovitis

Correct Answer: Periarticular osteopenia

Explanation:

Question 74:

Options:

Moist dressings and continued observation
Debridement of the necrotic tissue
Amputation at the metatarsophalangeal level with open wound management
Closed forefoot amputation
Guillotine transtibial amputation

Correct Answer: Moist dressings and continued observation

Explanation:

DISCUSSION: The patient has no clinical or observed signs of sepsis. The skin just proximal to the gangrenous tissue appears somewhat hyperemic and is clearly viable. These wounds should be managed much like burn wounds. Moist dressings should be used until the tissue clearly demarcates. Much of the insult may simply be superficial and only require late debridement.
REFERENCES: McAdams TR, Swenson DR, Miller RA: Frostbite: An orthopedic perspective.
Am J Orthop 1999;28:21-26.
Taylor MS: Cold weather injuries during peacetime military training. Milit Med 1992;157:602-604.

Question 75:

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

Options:

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

Correct Answer: Reduction and internal fixation

Explanation:

Question 76:

Options:

progressive ulnar neuropathy.
a decision to enter the Major League Baseball (MLB) draft.
pain with resisted wrist flexion.
failure to improve after prolonged nonsurgical treatment.

Correct Answer: failure to improve after prolonged nonsurgical treatment.

Explanation:

Question 77:

Options:

immediate internal fixation of the right femoral neck stress fracture.
non-weight-bearing crutch ambulation until symptoms resolve, followed by a gradual resumption of activities.
ultrasound therapy to promote fracture healing.
a metabolic work-up.
a bone scan to look for other stress fractures.

Correct Answer: non-weight-bearing crutch ambulation until symptoms resolve, followed by a gradual resumption of activities.

Explanation:

Question 78:

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

Options:

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

Correct Answer: Anterior band of the inferior glenohumeral ligament complex

Explanation:

Question 79:

Which of the following nerves is most commonly injured during revision surgery following a Bristow procedure?

Options:

Dorsal scapular
Suprascapular
Axillary
Musculocutaneous
Ulnar

Correct Answer: Musculocutaneous

Explanation:

DISCUSSION: Because of the previously transferred bone block of coracoid and short arm flexors, the musculocutaneous nerve often scars along the anteroinferior glenohumeral capsule. Mobilization of this tissue places the nerve at greatest risk. The axillary nerve is also potentially at risk, but this is nonspecific to prior surgery, particularly the Bristow procedure.
REFERENCES: Norris TR: Complications following anterior instability repairs, in Bigliani LU (ed): Complications of Shoulder Surgery. Baltimore, MD, Williams and Wilkins, 1993,
pp 98-116.
Flatow EL, Bigliani LU, April EW: An anatomic study of the musculocutaneous nerve and its relationship to the coracoid process. Clin Orthop 1989;244:166-171.

Question 80:

Options:

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

Correct Answer: Reverse shoulder arthroplasty

Explanation:

Question 81:

Options:

Autogenous iliac crest bone graft
Calcium phosphate
Calcium sulfate
Tricalcium phosphate
Coralline hydroxyapatite blocks

Correct Answer: Calcium phosphate

Explanation:

Question 82:

Options:

Cast removal and measurement of carpal canal pressure
Immediate carpal tunnel release and pinning of the fracture
Continued observation
Surgical reduction and pinning of the fracture
Electromyography/nerve conduction velocity studies

Correct Answer: Immediate carpal tunnel release and pinning of the fracture

Explanation:

Question 83:

A 46-year-old woman had an ankle fracture and ORIF 6 years ago. She had subsequent removal of some of the hardware, but her pain has persisted (Figures 44a and 44b).

Options:

Tibial and/or fibular osteotomy with open reduction and internal fixation (ORIF)
Ankle distraction arthroplasty
Ankle fusion
Total ankle arthroplasty (TAA)

Correct Answer: Tibial and/or fibular osteotomy with open reduction and internal fixation (ORIF)

Explanation:

DISCUSSION
Patients younger than 40 years of age who have ankle arthritis pose an ongoing clinical challenge. Nonsurgical treatment should be maximized, although distraction arthroplasty can be used in an effort to delay the need for fusion.
One of the strongest indications for ankle arthroplasty is a preexisting hindfoot fusion with a goal to retain some ankle/hindfoot motion. Ankle fusion is perhaps the most predictable surgical treatment for a relatively young, active patient with ankle arthritis. Moreover, there are concerns regarding implant loosening when performing TAA in active patients.
Outcome after syndesmosis ORIF has been linked to the quality of the reduction at the index procedure. Syndesmotic malreduction that is severe necessitates osteotomy and revision ORIF.
RECOMMENDED READINGS
Sagi HC, Shah AR, Sanders RW. The functional consequence of syndesmotic joint malreduction at a minimum 2-year follow-up. J Orthop Trauma. 2012 Jul;26(7):439-43. doi: 10.1097/BOT.0b013e31822a526a. PubMed PMID: 22357084.
View Abstract at PubMed
Smith NC, Beaman D, Rozbruch SR, Glazebrook MA. Evidence-based indications for distraction ankle arthroplasty. Foot Ankle Int. 2012 Aug;33(8):632-6. Review.
View Abstract at PubMed
Kim BS, Knupp M, Zwicky L, Lee JW, Hintermann B. Total ankle replacement in association with hindfoot fusion: Outcome and complications. J Bone Joint Surg Br. 2010 Nov;92(11):1540-7. doi: 10.1302/0301-620X.92B11.24452. PubMed PMID: 21037349.
View Abstract at PubMed
Daniels TR, Younger AS, Penner M, Wing K, Dryden PJ, Wong H, Glazebrook M. Intermediate-term results of total ankle replacement and ankle arthrodesis: a COFAS multicenter study. J Bone Joint Surg Am. 2014 Jan 15;96(2):135-42. doi: 10.2106/JBJS.L.01597.
View Abstract at PubMed

Question 84:

Options:

Extensor digitorum longus
Flexor digitorum longus
Peroneus longus
Extensor hallucis longus
Tibialis anterior

Correct Answer: Extensor digitorum longus

Explanation:

DISCUSSION: The recovery process from peroneal nerve palsy may take many months as axonal regrowth occurs. Of the muscles listed, the extensor hallucis is innervated most distally by the peroneal nerve. The flexor digitorum longus is innervated by the tibial nerve.
REFERENCE: Sarrafian SK: Anatomy of the Foot and Ankle, Descriptive, Topographic, Functional, ed 2. Philadelphia, PA, JB Lippincott, 1993, p 364.

Question 85:

At revision, the stem is retained and a new head with a polyethylene bearing is selected. The best option for the head is

Options:

ceramic with a metal sleeve.
ceramic alone.
metal with a metal sleeve.
metal alone.

Correct Answer: ceramic with a metal sleeve.

Explanation:

Question 86:

A 35-year-old male sustains a closed tibial shaft fracture after falling from 12 feet. Which of the following measurements would be concerning for an evolving compartment syndrome?

Options:

Preoperative anterior compartment measurement of 29, with diastolic pressure 58
Preoperative anterior compartment measurement of 25, with diastolic pressure of 60
Intraoperative anterior compartment measurement of 25, with intraoperative diastolic pressure of 54
Intraoperative anterior compartment measurement of 28, with intraoperative diastolic pressure of 72
Preoperative anterior compartment measurement of 22, with mean arterial pressure of 70

Correct Answer: Intraoperative anterior compartment measurement of 28, with intraoperative diastolic pressure of 72

Explanation:

Question 87:

Options:

Broad-spectrum intravenous antibiotics
AP, lateral, and flexion-extension lateral radiographs
MRI with gadolinium
Open biopsy of the surgical disk space
Anterior debridement and interbody fusion

Correct Answer: MRI with gadolinium

Explanation:

Question 88:

Options:

As strain rate increases, both elastic modulus and ultimate strength increase
As strain rate increases, elastic modulus remains unchanged but ultimate strength increases
As strain rate increases, elastic modulus increases but ultimate strength decreases
As strain rate increases, both elastic modulus and ultimate strength decrease
As strain rate increases, elastic modulus increases but ultimate strength remains unchanged

Correct Answer: As strain rate increases, both elastic modulus and ultimate strength increase

Explanation:

Question 89:

In patients with neurofibromatosis, what is the most important sign of impending rapid progression of a spinal deformity?

Options:

Apical curve rotation
Anterior vertebral body erosions
Cervical spine involvement
Penciling of three or more ribs
Curve magnitude of greater than 50 degrees

Correct Answer: Penciling of three or more ribs

Explanation:

Question 90:

Options:

Radiographs
MRI
Erythrocyte sedimentation rate (ESR)
CBC with differential
C-reactive protein (CRP)

Correct Answer: C-reactive protein (CRP)

Explanation:

Question 91:

A 16-year-old high school football player sustains an injury to the left hip. The avulsed fragment identified by the arrow in Figure 34 represents the origin of which of the following structures?

Options:

Ischiofemoral ligament
Pubofemoral ligament
Rectus femoris
Sartorius
Gluteus minimus

Correct Answer: Rectus femoris

Explanation:

Question 92:

Options:

Physical therapy with a focus on quadriceps strengthening
Physical therapy and delayed posterior cruciate ligament (PCL) reconstruction
PCL reconstruction
PCL and posterolateral corner reconstruction

Correct Answer: Physical therapy with a focus on quadriceps strengthening

Explanation:

Question 93:

Radiotherapy for palliative pain control as the risk for pathological fracture is very small

Options:

Open incisional biopsy
Chemotherapy and surgical stabilization with intramedullary nailing of the tibia
Radiotherapy and surgical stabilization with intramedullary nailing of the tibia

Correct Answer: Radiotherapy and surgical stabilization with intramedullary nailing of the tibia

Explanation:

Question 94:

Which of the following growth factors binds and activates the lipoprotein receptor-related protein 5/6 (LRP5/6) during bone development? Review Topic

Options:

Transforming growth factor-beta
Platelet-derived growth factor
Parathyroid hormone
Bone morphogenetic protein
Wnt protein

Correct Answer: Wnt protein

Explanation:

Question 95:

What is the most common type of malalignment after intramedullary nailing of distal 1/3 tibia fractures?

Options:

Varus
Valgus
Translational
Rotational
Apex anterior

Correct Answer: Varus

Explanation:

Question 96:

Options:

Repeat radiographs
Full clearance to return to play
Bone scan
MRI scan

Correct Answer: MRI scan

Explanation:

Ice hockey injuries demand a thorough assessment because they have the potential to be significant. In hockey players, bone injuries in the foot and ankle can be missed or improperly diagnosed through routine radiographic imaging. MRI can display bone injuries that are not found radiographically; this is because
some fractures and contusions involve the medial ankle and midfoot bones.

Question 97:

Figure 69 is the radiograph of a 9-year-old who has posterior hindfoot pain while running. What is the most likely diagnosis?

Options:

Kohler disease
Thiemann disease
Freiberg infraction
Sever disease

Correct Answer: Sever disease

Explanation:

Question 98:

Options:

Neutral posted rigid custom foot orthosis
Custom rigid UCBL foot orthosis
Ankle-foot orthosis with the ankle locked at 90 degrees
Shoe modification with a cushioned heel and rocker sole
Metal hinged/leather short ankle “Arizona” orthosis

Correct Answer: Shoe modification with a cushioned heel and rocker sole

Explanation:

DISCUSSION: The patient has a malunion of an attempted open reduction of a Lisfranc dislocation. The pain occurs during the terminal stance phase of gait as load is being transferred from the hindfoot to the forefoot. The bending moment can be best neutralized with shoe modification with a cushioned heel and rocker sole, which best unloads the tarsal-metatarsal junction.
REFERENCES: Bono CM, Berberian WS: Orthotic devices: Degenerative disorders of the foot and ankle. Foot Ankle Clin 2001;6:329-340.
Richardson EG (ed): Orthopaedic Knowledge Update: Foot and Ankle 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004, pp 58-63.

Question 99:

Options:

observation.
primary wide resection.
intralesional curettage.
radiation therapy.
preoperative chemotherapy.

Correct Answer: primary wide resection.

Explanation:

Question 100:

Figure 36 shows the hip arthrogram of a newborn. Which of the following structures is enclosed by the circle?

Options:

Limbus
Pulvinar
Ligamentum teres
Transverse acetabular ligament
Acetabular labrum

Correct Answer: Acetabular labrum

Explanation:

DISCUSSION: The structure enclosed by the circle is the acetabular labrum. It is visible as the white point of tissue outlined by the darkly radiopaque contrast. The appearance of the contrast surrounding the sharp white point of a normal labrum is called the “rose thorn sign.” The limbus is the term reserved for a rounded, infolded labrum seen with arthrography. The pulvinar is the fatty tissue seen in the empty acetabulum when the hip is dislocated. The ligamentum teres is seen as a white stripe outlined by contrast coursing from the central acetabulum to the dislocated femoral head. The transverse acetabular ligament courses across the inferior portion of the acetabulum and is not clearly seen with arthrography.
REFERENCES: Herring JA: Tachdjian’s Pediatric Orthopaedics, ed 3. Philadelphia, PA,
WB Saunders, 2002, vol 1, pp 532-533.
Severin E: Contribution to the knowledge of congenital dislocation of the hip joint.
Acta Chir Scand 1941;84:1.

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

Orthopedic Surgery Board Review MCQs: Arthroplasty, Trauma & Sports Medicine | Part 111

Key Takeaway

About This Board Review Set

How to Use the Interactive Quiz

Topics Covered in Part 111

Sample Questions from This Set

Why Active MCQ Practice Works

Chapter Index