AAOS & ABOS Orthopedic MCQs (Set 1): Ankle, Foot & Gait Biomechanics | 2026 Board Prep

Key Takeaway
This high-yield question set for AAOS/ABOS exams provides focused MCQs on ankle and foot orthopedics. Topics include gait cycle biomechanics, acute ligamentous injuries like subtalar dislocation, pediatric foot conditions such as Sever's disease, and surgical management of chronic ankle instability.
Comprehensive 100-Question Exam
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Question 1
A 31-year-old woman has a history of a painful ankle that has failed to respond to conservative management. She has associated night pain that is relieved with nonsteroidal anti-inflammatory drugs. MRI and technetium Tc 99m scans are consistent with an osteoid osteoma. Management should now consist of
Explanation
Question 2
A 32-year-old man has an open comminuted humeral shaft fracture. Examination reveals absence of sensation in the first web space and he is unable to fully extend the thumb, fingers, and wrist. What is the recommended treatment following irrigation and debridement of the fracture?

Explanation
Question 3
What type of injury is considered the major mechanism of cervical fracture, dislocation, and quadriplegia in contact sports and diving?

Explanation
Question 4 High Yield
An otherwise healthy 26-year-old woman is involved in a high speed motor vehicle accident and sustains the injury shown in Figure 54 to her dominant right arm. Appropriate treatment of this injury complex includes

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Question 5High Yield
A patient who has had neck pain radiating down the arm for the past 4 weeks reports that the pain was excruciating during the first week. Management consisting of anti-inflammatory drugs and physical therapy has decreased the neck and arm symptoms from 10/10 to 3/10. He remains neurologically intact. MRI and CT scans are shown in Figures 5a and 5b. The best course of action should be

Explanation
Question 6
Acute redislocation of the glenohumeral joint is a complication that occurs following a first-time dislocation. This is most often seen with
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Question 7
A sagittal T1-weighted MRI scan of the knee joint is shown in Figure 23. What structure is identified by the arrow?

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Question 8
A 27-year-old woman has a bilateral C5-C6 facet dislocation and quadriparesis after being involved in a motor vehicle accident. Initial management consisted of reduction with traction, but she remains a Frankel A quadriplegic. To facilitate rehabilitation, surgical stabilization and fusion is planned. From a biomechanical point of view, which of the following techniques is the LEAST stable method of fixation?
Explanation
Question 9 High Yield
Based on the findings shown in Figures 22a and 22b, corrective surgery to obtain maximal safe correction and optimal instrumentation fixation should be performed at which of the following locations?

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Question 10High Yield
A 20-year-old man sustains the injury shown in Figures 1a and 1b in a motorcycle accident. In addition to a prompt closed reduction, his outcome might be optimized by

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Question 11
What complication is most likely to develop after right total hip arthroplasty in the patient shown in Figure 5?

Explanation
Question 12High Yield
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
Question 13
A 16-year-old high school pitcher notes acute pain on the medial side of his elbow during a pitch. Examination that day reveals medial elbow tenderness, pain with valgus stress, mild swelling, and loss of extension. Plain radiographs show closed physes and no fracture. Which of the following diagnostic studies will best reveal his injury?

Explanation
Question 14 High Yield
Figure 26 shows the radiograph of a 48-year-old woman who has right arm pain and hematuria. A bone scan reveals increased uptake in the left ribs and thoracic spine. A needle biopsy specimen shows that the lesion is highly keratin positive and composed primarily of clear cells. What is the best course of action?

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Question 15 High Yield
A 34-year-old man has had a 13-month history of an equinovarus deformity of the foot and ankle after a motorcycle accident. His foot and ankle are flexible, but bracing has become uncomfortable. Active dorsiflexion and eversion are absent. What is the most appropriate treatment?

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Question 16
A 77-year-old woman with osteoporosis who underwent cemented total hip arthroplasty 12 years ago fell down a flight of stairs. A radiograph is shown in Figure 15. What is the best option for treating this fracture?

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Question 17 High Yield
Which of the following statements best describes synovial fluid?
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Question 18
A 78-year-old woman undergoes her third lumbar decompression and fusion from L3 to L5 without complication. On the morning of postoperative day 3, examination reveals painless, flaccid weakness of both lower extremities. She also has an absent bulbocavernous reflex and a mild saddle paresthesia. MRI scans of the lumbar spine are shown in Figures 26a and 26b. What is the most appropriate management at this time?

Explanation
Question 19 High Yield
A 52-year-old woman slips in her bathroom and strikes her right hand on a cabinet. She notes swelling, ecchymosis, and pain with attempted motion. There are no open wounds. Radiographs are shown in Figures 5a through 5c. What is the most appropriate treatment?

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Question 20 High Yield
Which of the following is considered a risk factor for the development of low back pain?
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Question 21High Yield
In Figure 2, which of the following structures is the primary stabilizer in preventing valgus instability of the elbow?

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Question 22
When harvesting an iliac crest bone graft from the posterior approach, what anatomic structure is at greatest risk for injury if a Cobb elevator is directed too caudal?
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Question 23
A right-handed 24-year-old woman underwent an arthroscopic Bankart repair for recurrent anterior dislocations 9 months ago. Despite extensive physical therapy for 8 months, the patient has very limited range of motion (elevation to 130 degrees and external rotation to 10 degrees with the arm at the side). Shoulder radiographs are normal. The next step in management should consist of

Explanation
Question 24
A 33-year-old man reports an enlarging painful soft-tissue mass in his right forearm. A radiograph and MRI scans are shown in Figures 45a through 45c. Treatment should consist of

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Question 25 High Yield
A 26-year-old woman sustained a nondisplaced femoral neck fracture and treatment consisted of use of percutaneous cannulated screws. At her 3-month follow-up visit, she reports hip pain and is unable to ambulate. A radiograph is shown in Figure 1. What is the next most appropriate treatment?

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Question 26
A patient who sustained a knife wound to the axilla 4 months ago now has profound interosseous wasting and generalized hand weakness. A brachial plexus injury is likely at which of the following locations in Figure 29?

Explanation
Question 27 High Yield
An 18-year-old gymnast has had a 1-year history of foot pain. Examination reveals medial midfoot tenderness without swelling. Non-weight-bearing in a cast for 6 weeks has failed to provide relief. An axial CT scan of the midfoot is shown in Figure 20. What is the optimal treatment for this condition?

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Question 28
A 21-year-old basketball player inverts his foot during practice. Examination reveals obvious deformity of the hindfoot with a prominence of the talar head dorsolaterally and medial displacement of the forefoot. A radiograph is shown in Figure 17. What is the most likely obstacle to closed reduction?

Explanation
Question 29
A 35-year-old laborer who sustained a forefoot injury 10 years ago has returned to work but reports a progressively painful deformity of the hallux and continued midfoot pain that is aggravated by weight-bearing activities. Shoe wear modifications have failed to provide relief. Direct palpation reveals no pain at the first metatarsocuneiform joint. A radiograph is shown in Figure 11. What is the next most appropriate step in management?

Explanation
Question 30
A 9-year-old boy has a painless enlarged mass on the dorsum of his hand. Figures 14a through 14d show the clinical photograph, radiographs, and biopsy specimen. What is the most likely diagnosis?

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Question 31High Yield
The recurrent motor branch of the median nerve innervates which of the following muscles?

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Question 32 High Yield
What is the most likely long-term sequela of the injury shown in Figures 47a and 47b?

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Question 33 High Yield
A 15-year-old female field hockey player sustains a blow to the mouth from a hockey stick. Three front teeth are knocked out and shown in Figure 4. In addition to calling a dentist immediately, what is the next best step in management?

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Question 34
In the anterior forearm approach to the distal radius (Henry approach), the radial artery is located between what two structures?

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Question 35High Yield
Stiffness can occur following total knee arthroplasty. What is the most appropriate management for a patient who has deteriorating arc of motion after undergoing a revision knee arthroplasty 9 months ago?

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Question 36High Yield
Which of the following is considered an advantage of arthroscopic distal clavicle excision compared with open distal clavicle excision?

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Question 37
What is the most likely type of pathology seen in Figure 16?

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Question 38High Yield
Figure 11 shows the radiograph of an otherwise healthy 22-year-old man who sustained a midfoot injury in a motor vehicle accident 9 days ago. Treatment should consist of

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Question 39
Figures 5a and 5b show the radiographs of an active 52-year-old man who has increasing knee pain and progressive varus deformity after undergoing total knee arthroplasty 7 years ago. Examination reveals a small effusion, but he has good motion and stability. What is the most likely diagnosis?

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Question 40
For halo traction, what is the preferred site for anterior pin placement?
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Question 41
Pacinian corpuscles are lamellated nerve endings that are responsible for providing the perception of

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Question 42
Radiographs of an 80-year-old woman with back pain reveal a compression fracture. Which of the following imaging studies best evaluates the acuity of the fracture?
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Question 43 High Yield
A healthy 64-year-old man just underwent an uncomplicated shoulder arthroplasty for severe glenohumeral osteoarthritis. Intraoperatively, 60 degrees of external rotation was obtained. Postoperatively, he starts on a range-of-motion program. What limitations are recommended?

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Question 44High Yield
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
Question 45High Yield
A 13-year-old boy has knee pain after sustaining a mild twisting injury while playing basketball 4 weeks ago. Radiographs and MRI scans are shown in Figures 24a through 24d, and biopsy specimens are shown in Figures 24e and 24f. Treatment should consist of

Explanation
Question 46
Figure 43 shows the lateral radiograph of a 12-year-old boy with mild osteogenesis imperfecta who injured his left elbow after pushing his brother. Treatment should consist of

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Question 47
Which of the following anatomic changes is observed as part of the normal aging process of the adult spine?

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Question 48
A 67-year-old man is requesting revision surgery because of continued pain in the knee after undergoing a total knee replacement 2 years ago. Examination reveals that the knee is not warm, the incision is well-healed, and the skin has normal coloration and hair formation. No varus or valgus instability is noted, and knee range of motion is 5 degrees to 100 degrees. Laboratory studies show an erythrocyte sedimentation rate of 15 mm/h and a WBC of 5,000/mm3. Aspiration of the knee reveals clear fluid that shows no growth on culture. Radiographs reveal an appropriately positioned cruciate-retaining cemented total knee arthroplasty that is well-fixed. What is the probability that the patient's pain will be improved with revision surgery?

Explanation
Question 49
A 3-year-old boy with severe cerebral palsy is unable to sit independently and does not crawl. Examination reveals a 40-degree hip flexion contracture by the Thomas test and 25 degrees of passive abduction. A radiograph of the pelvis shows subluxation of both hips, with a migration index of 30%. Management should consist of
Explanation
Question 50High Yield
A 36-year-old woman has neck pain in the upper cervical region and occipital discomfort after being involved in a motor vehicle accident. Examination reveals no forehead or scalp lacerations. The neurologic examination is normal. A CT scan shows no evidence of bony injury. Figures 39a and 39b show a lateral radiograph and an MRI scan. Management should consist of

Explanation
Question 51
Analysis of primary total hip arthroplasty using press-fit acetabular components without supplementary screw fixation reveals that screw fixation
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Question 52High Yield
A patient notes pain under the first metatarsophalangeal joint following a soccer injury. The MRI scans shown in Figures 27a and 27b reveal what pathologic finding?

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Question 53
A 35-year-old man sustained a 1-inch stab incision in his proximal forearm while trying to use a screwdriver 2 weeks ago. The laceration was routinely closed, and no problems about the incision site were noted. He now reports that he has been unable to straighten his fingers or thumb completely since the injury. Clinical photographs shown in Figures 30a and 30b show the man passively flexing the wrist. What is the most appropriate management?

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Question 54High Yield
The arrow in the axial T1-weighted MRI scan shown in Figure 18 is pointing to which of the following structures?

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Question 55
A 38-year-old man who is an avid tennis player has had persistent pain over the medial aspect of his knee for the past 6 years. He notes that the pain occurs on a daily basis with any significant activity. Nonsteroidal anti-inflammatory drugs have failed to provide relief. Radiographs are shown in Figures 22a and 22b. What is the best course of action?

Explanation
Question 56 High Yield
A 70-year-old man underwent primary total knee arthroplasty 3 months ago. Figures 7a and 7b show the radiograph and clinical photograph following incision and drainage of the wound 1 week ago. Aspiration of the joint reveals methicillin-sensitive Staphylococcus aureus. What is the next most appropriate step in management?

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Question 57
During primary total knee arthroplasty, the trial components are in place. The extensor space is tight, but the flexion space is normal. What is the best gap balancing solution?

Explanation
Question 58
Figure 13a shows the radiograph of a 9-year-old girl who sustained complete transverse fractures of the radial and ulnar shafts while in-line skating. A manipulative closed reduction is performed, and the result is seen in Figure 13b. What is the next most appropriate step in management?

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Question 59
Figures 22a and 22b show the radiographs of a patient who reports stiffness of the hip and associated pain. Management should consist of

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Question 60
A 36-year-old skier sustains a grade III posterior cruciate ligament (PCL) tear. Where will increased contact pressures develop over time?
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Question 61 High Yield
What root is most commonly involved with a segmental root level palsy after laminoplasty?

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Question 62
A 29-year-old woman reports dysesthesias and burning after undergoing bunion surgery that consisted of a proximal crescentic first metatarsal osteotomy 6 months ago. Examination reveals a positive Tinel's sign at the proximal aspect of the healed incision. What injured nerve is responsible for her continued symptoms?
Explanation
Question 63High Yield
With the increasing availability of total hip arthroplasty (THA) to younger patients with hip osteoarthritis, there has been increased use of alternative bearing surfaces. Compared to a ceramic-on-ceramic articulation, which of the following is a specific advantage of a metal-on-metal bearing surface?
Explanation
Question 64
A superior labrum anterior and posterior (SLAP) lesion doubles the strain in which of the following stabilizing structures?
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Question 65High Yield
A previously asymptomatic 14-year-old girl sustained a twisting injury to her ankle. Radiographs are shown in Figures 2a and 2b. Management should consist of

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Question 66
A 70-year-old woman has a preoperative anterior interscalene block prior to undergoing a total shoulder arthroplasty. After seating her in the beach chair position, she becomes acutely hypotensive. What is the most likely cause for the hypotension?
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Question 67
A 58-year-old woman sustained a ruptured Achilles tendon 1 year ago, and management consisted of an ankle-foot orthosis. She now reports increasing difficulty with ambulation and increasing pain. An MRI scan shows a 6-cm defect in the right Achilles tendon. Management should now consist of
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Question 68 High Yield
In the spine, osteoblastomas usually originate in the

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Question 69
A 12-year-old girl with juvenile rheumatoid arthritis (JRA) has had chronic pain and synovitis about the knee that is now well-controlled medically. Examination reveals 20 degrees of valgus at the knee. Knee range of motion shows 10 degrees to 90 degrees of flexion. Treatment should consist of
Explanation
Question 70
A 28-year-old woman who is an avid runner reports pain about the left hip with activities. Nonsurgical management has failed to provide relief. An MRI arthrogram is shown in Figure 47. What is the most likely diagnosis?

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Question 71High Yield
What postoperative complication occurs at a significantly higher rate in patients undergoing bilateral simultaneous total knee arthroplasty than in patients undergoing unilateral total knee arthroplasty?
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Question 72
A patient with diabetic peripheral neuropathy undergoes a partial first ray amputation for a chronic ulcer beneath the first metatarsal head. The insertion of the anterior tibialis is preserved. The patient has 10 degrees of passive dorsiflexion at the ankle and no other foot deformities or ulcers. Which of the following is considered appropriate shoe wear for this patient?
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Question 73
Figures 3a and 3b show the inversion stress radiographs of a patient's ankle. What is the most likely ligament injury pattern?

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Question 74High Yield
A 33-year-old man had his foot run over by a forklift 1 hour ago. Examination reveals that the head of the fifth metatarsal is extruded through the plantar aspect of the foot. The foot is severely swollen and pale, there is no sensation in the toes, and the pulses are not palpable. Radiographs are shown in Figures 42a and 42b. Emergent management should consist of

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Question 75
Figure 48 shows the initial AP chest radiograph of a 21-year-old motorcycle rider who sustained multiple injuries after striking a telephone pole at high speed. What is the most significant radiographic finding leading to a diagnosis?

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Question 76 High Yield
When performing an arthroscopic subacromial decompression, bleeding can be encountered when dividing the coracoacromial ligament because of injury to what artery?
Detailed Explanation
Question 77High Yield
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

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Question 78
Which of the following factors is most commonly associated with mechanical failure of a cemented total hip arthroplasty?

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Question 79
An otherwise healthy 65-year-old man reports thigh pain of insidious onset. He states that the pain is increased with weight bearing and also occurs at night. He denies any history of cancer. Radiographs are shown in Figures 22a and 22b. A bone scan shows an isolated lesion. CT scans of the chest and abdominal are negative for any other lesions. Initial management should consist of

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Question 80High Yield
In a retroperitoneal approach to the lumbar spine, what nerve is commonly found on the psoas muscle?
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Question 81High Yield
A patient who underwent primary total hip arthroplasty 7 years ago that resulted in excellent pain relief and a normal gait now reports pain and a limp. Postoperative and current AP radiographs are shown in Figures 2a and 2b. What is the most likely cause of the pathology seen?

Explanation
Question 82High Yield
A 64-year-old man with a history of diabetes mellitus underwent open reduction and internal fixation of a displaced ankle fracture 8 weeks ago. Examination now reveals recent onset erythema, warmth, and swelling of the midfoot. Radiographs are shown in Figures 23a through 23d. What is the most likely reason for the swelling of the foot?

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Question 83High Yield
A 17-year-old high school football player reports wrist pain after being tackled. Radiographs are shown in Figures 22a through 22c. What is the recommended intervention?

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Question 84High Yield
Figures 25a and 25b show the radiographs of a 66-year-old man who has had a long history of bilateral painful flatfoot deformities. Examination reveals that his foot is partially correctable passively, albeit with discomfort, and he has an Achilles tendon contracture. An ankle-foot orthosis has failed to provide relief. Treatment should now consist of

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Question 85
The photomicrograph in Figure 37 shows a repaired dural tear 4 days after surgery. The material interposed between the dural edges (D) is composed of

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Question 86
What structure is marked Q in the diagram of the brachial plexus shown in Figure 22?

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Question 87
Figure 16 shows the lateral radiograph of a patient who is scheduled to undergo an anterior cruciate ligament (ACL) reconstruction. If the graft is tensioned at 20 degrees of flexion and the femoral tunnel is created by passing a reamer over the guide wire marked "A," the resulting ligament reconstruction will excessively

Explanation
Question 88
A 42-year-old woman sustained a closed, displaced talar neck fracture in a motor vehicle accident. Which of the following is an avoidable complication of surgical treatment?
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Question 89
Figures 34a and 34b show the radiographs of a 28-year-old man who fell on his outstretched arm with significant force while mountain biking. The nerve deficit most likely to occur would result in weakness of

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Question 90High Yield
Figures 32a and 32b show the radiographs of an active 13-year-old boy who has persistent left thigh pain and a limp despite a trial of protected weight bearing. Management should consist of

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Question 91 High Yield
Figures 46a through 46e show the radiographs of a 22-year-old man who injured his wrist in a motorcycle accident. He has no other injuries. What is the best course of action?

Detailed Explanation
Question 92
Osteonecrosis of the humeral head is a rare complication seen after dislocation of the glenohumeral joint in skeletally immature patients. When this complication is encountered, treatment should consist of

Explanation
Question 93High Yield
During total knee arthroplasty using a posterior cruciate-retaining design, excessive tightness in flexion is noted, while the extension gap is felt to be balanced. Which of the following actions will effectively balance the knee?

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Question 94High Yield
A 24-year-old woman has a spleen laceration and hypotension. Radiographs reveal a pulmonary contusion and a displaced mid-diaphyseal fracture of the femur. The trauma surgeon clears her for stabilization of the femoral fracture. What technique will offer the least potential for initial complications?

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Question 95
The plate seen in Figure 48a was applied to the fracture seen in Figure 48b, and is functioning in what capacity?

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Question 96
Which of the following imaging modalities is most accurate in locating a toothpick in the plantar arch of the foot?

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Question 97
Which of the following nerves is most likely responsible for symptoms associated with plantar fasciitis?

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Question 98
Ganglion cysts about the wrist most commonly arise from what structure?
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Question 99High Yield
Figure 2 shows the AP radiograph of an 18-year-old woman with progressive and severe right hip pain. Nonsteroidal anti-inflammatory drugs no longer control her pain. What is the next most appropriate step in management?

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Question 100
During total shoulder replacement for rheumatoid arthritis, fracture of the humeral shaft occurs. An intraoperative radiograph shows a displaced short oblique fracture at the tip of the prosthesis. At this point, the surgeon should

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