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8. Foot and Ankle MCQs

Practice Set 163 of 353

This practice set contains high-yield board review questions covering key concepts in 8. Foot and Ankle. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.

Question 3241

Topic: 8. Foot and Ankle

A 24-year-old professional basketball player reports the gradual onset of pain that is poorly localized to the left midfoot for the past 2 months. Examination reveals diffuse tenderness to palpation, full range of motion of the ankle and subtalar joint, and a normal neurovascular examination to the foot. An AP radiograph is shown in Figure 10. Definitive treatment should include

General Orthopedics Board Review 2026: High-Yield MCQs (Set 12) - Figure 40

. a custom-molded orthotic and anti-inflammatory drugs.
. partial weight-bearing ambulation with crutches.
. weight bearing as tolerated with a walking boot.
. casting for 6 weeks with bone stimulation.
. internal fixation.

Correct Answer & Explanation

. internal fixation.

Explanation

The imaging studies reveal a navicular stress fracture. This condition is secondary to chronic overuse (often running on hard surfaces) and results in vague, ill-defined pain in the midfoot. These fractures can be missed on radiographs but are well-defined on CT or MRI. Tarsal navicular fractures are typically oriented in the sagittal plane. Surgery is typically indicated for the high-level athlete because of the high risk for nonunion and persistent symptoms following nonsurgical management. Internal fixation is the treatment of choice. Torg JS, Pavlov H, Cooley JH, et al: Stress fractures of the tarsal navicular. J Bone Joint Surg Am 1982;64:700-712.

Question 3242

Topic: 8. Foot and Ankle

A 30-year-old man has chronic pain, joint stiffness, and symmetrical polyarthropathy but no significant synovitis. Examination reveals enlargement of the second and third metatarsal heads. Radiographs show chondrocalcinosis of the ankles and bony enlargement of the midfoot; no marginal erosions are evident at the metatarsophalangeal level. What is the most likely diagnosis?

. Osteoarthritis
. Rheumatoid arthritis
. Hemochromatosis
. Reiter's syndrome
. Pseudogout (calcium pyrophosphate deposition disease)

Correct Answer & Explanation

. Hemochromatosis

Explanation

The patient's clinical picture is considered the classic presentation for hemochromatosis. Osteoarthritis and pseudogout more commonly affect an older age group. Rheumatoid arthritis is more common in women and is not commonly associated with chondrocalcinosis. The radiographic appearance of the forefoot in Reiter's syndrome is one of a pencil in cup deformity of the metatarsophalangeal joint, not enlargement. Stevens FM, Edwards C: Recognizing and managing hemochromatosis and hemochromatosis arthropathy. J Musculoskeletal Med 2004;4:212-225.

Question 3243

Topic: 8. Foot and Ankle
A 28-year-old man is involved in a high-speed motor vehicle collision. Radiographs and computed tomography (CT) scan reveal a displaced talar neck fracture with subluxation of the subtalar joint, but an intact tibiotalar joint. According to the Hawkins classification, what is the approximate expected rate of avascular necrosis (AVN) of the talar body for this injury?
. 0% to 10%
. 20% to 50%
. 70% to 100%
. 100%
. Risk is entirely dependent on the time to surgical reduction

Correct Answer & Explanation

. 20% to 50%

Explanation

This injury describes a Hawkins Type II talar neck fracture (displaced fracture of the talar neck with subluxation or dislocation of the subtalar joint, but an intact ankle joint). The blood supply to the talar body is disrupted primarily from the artery of the tarsal canal. The risk of AVN for a Hawkins Type II fracture is traditionally taught to be between 20% and 50%. Hawkins Type I (nondisplaced) has a 0-10% risk, Type III (subtalar and tibiotalar dislocation) has a 70-100% risk, and Type IV (Type III plus talonavicular subluxation/dislocation) has a near 100% risk of AVN.

Question 3244

Topic: 8. Foot and Ankle

A 22-year-old collegiate football player sustains a violent axial load to a plantar-flexed foot during a tackle.

Weight-bearing radiographs of the foot demonstrate a 3.5 mm diastasis between the base of the first and second metatarsals. There are no associated fractures visible. What is the most appropriate definitive management?

. Rigid carbon-fiber orthosis and weight-bearing as tolerated
. Non-weight-bearing in a short leg cast for 6 weeks
. Open reduction and internal fixation (ORIF) or primary arthrodesis
. Closed reduction and percutaneous pinning
. Corticosteroid injection into the TMT joint and return to play in 1 week

Correct Answer & Explanation

. Open reduction and internal fixation (ORIF) or primary arthrodesis

Explanation

This scenario describes a purely ligamentous Lisfranc injury (disruption of the tarsometatarsal articulation). A diastasis of greater than 2 mm between the bases of the first and second metatarsals on weight-bearing radiographs indicates instability. Nonoperative management leads to midfoot collapse, chronic pain, and post-traumatic arthritis. Therefore, surgical stabilization via ORIF or primary arthrodesis (increasingly preferred for purely ligamentous injuries due to lower rates of hardware failure and midfoot arthritis) is the standard of care.

Question 3245

Topic: Ankle Trauma & Sports

A 30-year-old athlete sustains a supination-external rotation (Weber B) ankle fracture. Intraoperatively, after anatomic fixation of the lateral malleolus, the surgeon utilizes a 'hook test' to assess the integrity of the syndesmosis under fluoroscopy. Which of the following radiographic parameters during the stress maneuver most reliably indicates syndesmotic instability necessitating fixation?

. Tibiofibular clear space > 5 mm on the AP view
. Tibiofibular overlap < 10 mm on the AP view
. Medial clear space > 4 mm on the mortise view
. Talar tilt > 5 degrees on the mortise view
. Tibiofibular clear space > 2 mm on the lateral view

Correct Answer & Explanation

. Medial clear space > 4 mm on the mortise view

Explanation

Intraoperative assessment of the syndesmosis is performed using the hook test (lateral pull on the fibula) or external rotation stress. The most reliable and clinically relevant indicator of syndesmotic incompetence (and deep deltoid ligament rupture) during these maneuvers is the asymmetric widening of the medial clear space, typically greater than 4-5 mm on the mortise view.

Question 3246

Topic: 8. Foot and Ankle

A 28-year-old man sustains an anterior knee dislocation following a motorcycle crash. The knee is successfully reduced in the trauma bay. Distal pulses are palpable and symmetric to the uninjured side. However, an Ankle-Brachial Index (ABI) is measured at 0.8.

What is the most appropriate next step in management?

. Observation with serial vascular examinations every 4 hours
. Immediate computed tomography (CT) angiography of the lower extremity
. Emergent surgical exploration of the popliteal fossa
. Application of a spanning external fixator and discharge with close follow-up
. Application of a long leg cast in 15 degrees of flexion

Correct Answer & Explanation

. Immediate computed tomography (CT) angiography of the lower extremity

Explanation

In the setting of a knee dislocation, an Ankle-Brachial Index (ABI) of less than 0.9 is highly predictive of an arterial injury, even in the presence of palpable distal pulses. An intimal tear may permit sufficient flow to maintain a pulse but reduces the pressure index. The most appropriate next step is advanced vascular imaging, typically CT angiography, to identify the injury before thrombosis or critical ischemia occurs.

Question 3247

Topic: 8. Foot and Ankle
A 25-year-old snowboarder sustains a Hawkins Type III fracture of the talar neck after a high-energy landing. Which of the following accurately describes the anticipated rate of avascular necrosis (AVN) of the talar body for this specific injury pattern?
. Less than 10%
. 15 to 30%
. 40 to 50%
. 75 to 100%
. It approaches 0% if anatomic reduction is achieved within 24 hours

Correct Answer & Explanation

. 75 to 100%

Explanation

A Hawkins Type III talar neck fracture involves displacement of the talar body from both the subtalar and tibiotalar joints. This displacement typically ruptures the major blood supplies to the talar body (artery of the tarsal canal, branches of the deltoid artery, and dorsal pedis supply). The reported rate of avascular necrosis (AVN) for a Type III injury is very high, historically cited between 75% and 100%.

Question 3248

Topic: Midfoot & Hindfoot

A 22-year-old collegiate athlete sustains a hyperplantarflexion injury to his midfoot. Weight-bearing radiographs demonstrate widening of the first and second intermetatarsal space with no evidence of fracture on CT.

Based on prospective randomized data, what is the recommended surgical management for this purely ligamentous injury?

. Closed reduction and percutaneous K-wire fixation
. Open reduction and internal fixation with temporary transarticular screws
. Primary arthrodesis of the involved medial column joints
. Application of a non-weight bearing cast for 8 weeks without surgery
. Suture-button suspensionplasty of the Lisfranc complex

Correct Answer & Explanation

. Primary arthrodesis of the involved medial column joints

Explanation

For purely ligamentous Lisfranc injuries, prospective randomized studies (most notably Ly and Coetzee, JBJS 2006) have demonstrated that primary arthrodesis yields better functional outcomes, a higher rate of return to pre-injury activity levels, and fewer reoperations compared to open reduction and internal fixation (ORIF). ORIF remains the standard of care for primarily bony Lisfranc fracture-dislocations.

Question 3249

Topic: 8. Foot and Ankle

A 24-year-old collegiate football player presents with severe midfoot pain and inability to bear weight after his foot was axially loaded in plantar flexion. Physical examination reveals midfoot swelling and pathognomonic plantar ecchymosis. Anteroposterior radiographs demonstrate a 'fleck sign' in the space between the medial and middle cuneiforms.

This avulsion fracture indicates disruption of a critical stabilizing ligament. From which anatomical structure does this specific bone fragment typically originate?

. Base of the first metatarsal
. Base of the second metatarsal
. Medial aspect of the intermediate cuneiform
. Plantar aspect of the navicular
. Dorsal aspect of the cuboid

Correct Answer & Explanation

. Base of the second metatarsal

Explanation

The patient has a Lisfranc injury, indicated by the mechanism, plantar ecchymosis, and radiographic 'fleck sign'. The Lisfranc ligament is an interosseous ligament that originates from the lateral aspect of the medial cuneiform and inserts on the medial aspect of the base of the second metatarsal. The 'fleck sign' represents an avulsion fracture of the ligament's insertion at the base of the second metatarsal.

Question 3250

Topic: 8. Foot and Ankle

A 24-year-old professional football player sustains an axial load to a plantar-flexed foot. Radiographs and subsequent MRI confirm a purely ligamentous Lisfranc injury with 3 mm of diastasis between the base of the first and second metatarsals. What is the most appropriate definitive management for this patient?

. Non-weight-bearing cast for 6 weeks
. Closed reduction and percutaneous pinning
. Open reduction and internal fixation with screws
. Primary arthrodesis of the medial column (1st, 2nd, and 3rd tarsometatarsal joints)
. Rigid orthotic shoe insert and immediate weight-bearing

Correct Answer & Explanation

. Primary arthrodesis of the medial column (1st, 2nd, and 3rd tarsometatarsal joints)

Explanation

Purely ligamentous Lisfranc injuries have a significantly higher rate of failure, hardware breakage, loss of reduction, and post-traumatic arthritis when treated with open reduction and internal fixation (ORIF) compared to primarily bony avulsion injuries. Current evidence strongly supports primary arthrodesis of the medial column over ORIF for purely ligamentous Lisfranc injuries, especially in young, active patients or athletes, to provide a stable, durable outcome.

Question 3251

Topic: 8. Foot and Ankle

A 35-year-old male sustains a high-energy motor vehicle collision. Radiographs demonstrate a displaced talar neck fracture with subluxation of the subtalar joint (Hawkins type II). Regarding the vascular supply to the talus and the risk of osteonecrosis, which of the following statements is true?

. The artery of the tarsal canal is a direct branch of the dorsalis pedis artery.
. The deltoid branch of the posterior tibial artery may provide the only remaining blood supply and must be preserved during medial surgical approaches.
. Immediate surgical fixation (within 6 hours) significantly reduces the rate of osteonecrosis compared to delayed fixation.
. Osteonecrosis occurs in greater than 90% of all Hawkins type II fractures.
. The artery of the sinus tarsi provides the primary blood supply to the body of the talus.

Correct Answer & Explanation

. The deltoid branch of the posterior tibial artery may provide the only remaining blood supply and must be preserved during medial surgical approaches.

Explanation

The talus has a precarious blood supply. The primary blood supply to the talar body is the artery of the tarsal canal, a branch of the posterior tibial artery. In displaced talar neck fractures (Hawkins II-IV), the major blood supply is often disrupted. The deltoid branch of the posterior tibial artery is consistently preserved as long as the deltoid ligament is intact; therefore, preserving the deltoid ligament during a medial approach is critical to avoid devascularizing the remaining bone. Recent literature shows that the incidence of osteonecrosis is dictated by the initial displacement (trauma) rather than the timing of surgical fixation. Osteonecrosis rates for Hawkins II fractures are historically around 20-50%, not >90%.

Question 3252

Topic: 8. Foot and Ankle

A 30-year-old male sustains a severe midfoot sprain while playing American football. Weight-bearing radiographs demonstrate a 3 mm diastasis between the base of the first and second metatarsals. The primary ligamentous structure injured in this pattern originates from which bone and inserts onto which bone?

. Medial cuneiform to the base of the second metatarsal
. Middle cuneiform to the base of the second metatarsal
. Medial cuneiform to the base of the first metatarsal
. Lateral cuneiform to the base of the third metatarsal
. Cuboid to the base of the fourth metatarsal

Correct Answer & Explanation

. Medial cuneiform to the base of the second metatarsal

Explanation

The Lisfranc ligament is an intra-articular ligament that provides critical stability to the midfoot. It originates on the lateral aspect of the medial cuneiform and inserts onto the medial aspect of the base of the second metatarsal. There is no direct ligamentous connection between the first and second metatarsal bases, making the Lisfranc ligament the primary stabilizer preventing lateral subluxation of the lesser metatarsals.

Question 3253

Topic: 8. Foot and Ankle

A 32-year-old male sustains a twisting injury to his midfoot while playing soccer. He has swelling, plantar ecchymosis, and tenderness over the tarsometatarsal joints. Weight-bearing radiographs demonstrate a 3 mm diastasis between the base of the first and second metatarsals. What is the most appropriate definitive management?

. Rigid walking boot for 6 weeks
. Short leg cast non-weight-bearing for 6 weeks
. Closed reduction and casting
. Open reduction and internal fixation
. Primary arthrodesis of the transverse tarsal joint

Correct Answer & Explanation

. Open reduction and internal fixation

Explanation

A diastasis of >2 mm between the first and second metatarsal bases on weight-bearing radiographs is diagnostic of an unstable Lisfranc injury. The standard of care for displaced or unstable Lisfranc injuries in an active patient is anatomical reduction and stabilization, typically achieved with open reduction and internal fixation (ORIF). Rigid immobilization alone is reserved for strictly nondisplaced, stable sprains.

Question 3254

Topic: Midfoot & Hindfoot
A 28-year-old man falls from a height and sustains a Hawkins Type III fracture of the talar neck. Which of the following best describes the anatomical displacement associated with this injury?
. Nondisplaced talar neck fracture
. Displaced talar neck fracture with subluxation of the subtalar joint only
. Fracture of the talar head with talonavicular dislocation
. Displaced talar neck fracture with dislocation of both the subtalar and tibiotalar joints
. Displaced talar neck fracture with dislocation of the subtalar, tibiotalar, and talonavicular joints

Correct Answer & Explanation

. Displaced talar neck fracture with dislocation of both the subtalar and tibiotalar joints

Explanation

According to the Hawkins classification for talar neck fractures: Type I is nondisplaced; Type II involves subluxation or dislocation of the subtalar joint; Type III involves dislocation of both the subtalar and tibiotalar (ankle) joints; and Type IV (Canale and Kelly modification) adds talonavicular joint dislocation. Type III fractures are associated with a very high rate of avascular necrosis of the talar body.

Question 3255

Topic: Midfoot & Hindfoot

A 25-year-old male sustains a purely ligamentous Lisfranc injury after a twisting mechanism while playing football. Which of the following fixation constructs has been shown to provide the best long-term clinical outcomes for this specific injury pattern?

. Primary arthrodesis of the medial tarsometatarsal joints
. Open reduction and internal fixation with transarticular screws
. Open reduction and internal fixation with dorsal spanning plates
. Closed reduction and percutaneous pinning
. Cast immobilization and non-weight bearing for 8 weeks

Correct Answer & Explanation

. Primary arthrodesis of the medial tarsometatarsal joints

Explanation

Purely ligamentous Lisfranc injuries have historically demonstrated poor outcomes with ORIF due to the lack of bone-to-bone healing and reliance on ligamentous scar tissue. Prospective randomized controlled trials (such as Ly and Coetzee, JBJS 2006) have shown that primary arthrodesis of the medial two or three rays results in better functional outcomes and a lower rate of planned secondary surgeries compared to ORIF.

Question 3256

Topic: 8. Foot and Ankle

A 28-year-old woman sustains a displaced talar neck fracture following a fall from a height. The surgeon plans an open reduction and internal fixation to restore articular congruity and mitigate the risk of avascular necrosis (AVN). The primary blood supply to the body of the talus, which is at risk in this injury, is derived from the:

. Artery of the tarsal canal
. Artery of the tarsal sinus
. Deltoid artery
. Dorsalis pedis artery
. Anterior tibial artery

Correct Answer & Explanation

. Artery of the tarsal canal

Explanation

The artery of the tarsal canal, which is a branch of the posterior tibial artery, provides the dominant blood supply to the body of the talus. Disruption of this blood supply, along with the other extraosseous vessels, contributes significantly to the high rate of avascular necrosis seen in displaced talar neck fractures.

Question 3257

Topic: 8. Foot and Ankle

A 22-year-old athlete sustains a hyperplantarflexion injury to his midfoot with severe pain and swelling. Radiographs demonstrate widening of the space between the first and second metatarsal bases and a small bony avulsion in this interval ('fleck sign'). The avulsed bone fragment originates from the attachment of the Lisfranc ligament. This ligament connects which of the following structures?

. Medial cuneiform and the base of the second metatarsal
. Middle cuneiform and the base of the second metatarsal
. Medial cuneiform and the base of the first metatarsal
. Lateral cuneiform and the cuboid
. Navicular and the medial cuneiform

Correct Answer & Explanation

. Medial cuneiform and the base of the second metatarsal

Explanation

The Lisfranc ligament is a critical stabilizing intra-articular ligament of the midfoot that connects the lateral aspect of the medial cuneiform to the medial aspect of the base of the second metatarsal. Disruption of this ligament leads to a Lisfranc injury, which often necessitates operative stabilization.

Question 3258

Topic: 8. Foot and Ankle

A 40-year-old construction worker undergoes open reduction and internal fixation of a displaced intra-articular calcaneus fracture via a standard extensile lateral approach. Postoperatively, he complains of numbness and tingling along the lateral aspect of his hindfoot. Which of the following nerves was most likely injured during the surgical approach?

. Superficial peroneal nerve
. Deep peroneal nerve
. Sural nerve
. Saphenous nerve
. Medial plantar nerve

Correct Answer & Explanation

. Sural nerve

Explanation

The sural nerve courses distally along the lateral aspect of the hindfoot and is at significant risk for injury during the extensile lateral approach to the calcaneus. The incision must be carefully planned (typically L-shaped) and full-thickness subperiosteal flaps created to protect the sural nerve and the vascular supply to the lateral skin flap.

Question 3259

Topic: Midfoot & Hindfoot
A 28-year-old roofer falls 15 feet, landing on his feet, and sustains a Hawkins Type III fracture of the talar neck. According to the Hawkins classification, what anatomic disruptions define a Type III fracture, and what is the approximate risk of avascular necrosis (AVN) of the talar body?
. Nondisplaced fracture; 0-10% AVN risk
. Displaced fracture with subtalar joint subluxation; 20-50% AVN risk
. Displaced fracture with dislocation of both the subtalar and tibiotalar joints; near 100% AVN risk
. Displaced fracture with dislocation of the subtalar, tibiotalar, and talonavicular joints; 100% AVN risk
. Comminuted fracture of the talar body; 50% AVN risk

Correct Answer & Explanation

. Displaced fracture with dislocation of both the subtalar and tibiotalar joints; near 100% AVN risk

Explanation

The Hawkins classification describes talar neck fractures. Type I is nondisplaced (0-10% AVN risk). Type II involves subluxation or dislocation of the subtalar joint (20-50% AVN risk). Type III involves dislocation of both the subtalar and tibiotalar (ankle) joints, with the talar body typically extruded posteromedially (near 100% AVN risk). Type IV adds talonavicular dislocation.

Question 3260

Topic: 8. Foot and Ankle

A 22-year-old collegiate football player sustains an anterior knee dislocation which is immediately reduced on the field. In the emergency department, his knee is splinted. His dorsalis pedis and posterior tibial pulses are palpable but diminished compared to the contralateral side. The ankle-brachial index (ABI) is calculated to be 0.82. What is the most appropriate next step in management?

. Immediate transport to the operating room for surgical exploration of the popliteal artery
. Computed tomography angiography (CTA) of the lower extremity
. Admission for serial vascular examinations every 4 hours
. Duplex ultrasonography of the lower extremity veins
. Magnetic resonance imaging (MRI) to assess ligamentous injury

Correct Answer & Explanation

. Computed tomography angiography (CTA) of the lower extremity

Explanation

In the setting of a knee dislocation, vascular status must be carefully assessed. Hard signs of arterial injury (expanding hematoma, absent pulses, pulsatile bleeding, cold/pale limb) mandate immediate surgical exploration. Soft signs, such as diminished pulses or an ABI < 0.9, indicate the need for advanced vascular imaging, most commonly a CTA. Serial examinations are reserved for patients with symmetric normal pulses and an ABI > 0.9.

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