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8. Foot and Ankle MCQs

Practice Set 223 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 4441

Topic: Midfoot & Hindfoot
A 32-year-old man sustains a Hawkins type III talar neck fracture following a fall from a height. Which of the following statements regarding this specific injury is most accurate?
. It involves subtalar subluxation with the tibiotalar and talonavicular joints remaining intact.
. The rate of avascular necrosis (AVN) of the talar body approaches 100%.
. The presence of a Hawkins sign on radiographs at 6 to 8 weeks post-injury indicates impending AVN.
. It involves a fracture of the talar neck with dislocation of both the subtalar and tibiotalar joints.
. Non-operative management with a non-weight-bearing cast for 12 weeks is the standard of care.

Correct Answer & Explanation

. It involves a fracture of the talar neck with dislocation of both the subtalar and tibiotalar joints.

Explanation

In the Hawkins classification of talar neck fractures: Type I is nondisplaced; Type II involves subtalar subluxation/dislocation; Type III involves dislocation of both the subtalar and tibiotalar joints; and Type IV additionally involves talonavicular subluxation/dislocation. The risk of AVN for Type III fractures is high (often cited as 50-90%), whereas Type IV approaches 100%. The 'Hawkins sign' (subchondral radiolucency in the talar dome at 6-8 weeks) is a positive prognostic indicator, signifying intact vascularity and bone resorption, which rules out AVN.

Question 4442

Topic: 8. Foot and Ankle
A 42-year-old roofer falls from a ladder and sustains a displaced, intra-articular calcaneus fracture (Sanders type III). He has a heavy smoking history (2 packs per day) and poorly controlled type 2 diabetes mellitus (HbA1c 9.5%). Which of the following treatment approaches is most appropriate for this patient?
. Open reduction and internal fixation via an extensile lateral approach once the wrinkle sign appears
. Primary subtalar arthrodesis via an extensile lateral approach
. Non-operative management with a removable boot, early range of motion, and non-weight-bearing
. Open reduction and internal fixation via a limited medial approach
. Immediate Ilizarov frame application for closed reduction

Correct Answer & Explanation

. Non-operative management with a removable boot, early range of motion, and non-weight-bearing

Explanation

The extensile lateral approach for calcaneus fractures carries a significant baseline risk of wound necrosis and deep infection. Heavy smoking and poorly controlled diabetes are absolute or strong relative contraindications to this approach due to an unacceptably high rate of catastrophic wound complications, osteomyelitis, and secondary amputation. Despite the intra-articular displacement, non-operative management is the safest and most appropriate course for this high-risk patient.

Question 4443

Topic: 8. Foot and Ankle
A 55-year-old man falls from a ladder and sustains a displaced, intra-articular calcaneus fracture (Sanders Type III). He has a medical history significant for smoking one pack of cigarettes per day and poorly controlled type 2 diabetes mellitus (HbA1c 9.5%). Which of the following surgical approaches minimizes the high risk of wound complications in this specific patient while still allowing for articular reduction?
. Extensile lateral approach
. Medial approach
. Posterior Achilles-splitting approach
. Sinus tarsi approach
. Plantar approach

Correct Answer & Explanation

. Sinus tarsi approach

Explanation

Patients with a history of smoking and poorly controlled diabetes are at an exceptionally high risk for wound necrosis and deep infection following the classic extensile lateral approach for calcaneus fractures. The sinus tarsi approach is a minimally invasive lateral approach that significantly reduces the incidence of soft-tissue complications while still providing adequate visualization for the reduction and fixation of the posterior facet.

Question 4444

Topic: Midfoot & Hindfoot
A 32-year-old snowboarder sustains a high-energy forced dorsiflexion injury to his right ankle. Radiographs and CT imaging reveal a Hawkins type III fracture of the talar neck. Based on the Hawkins classification, what does a type III fracture specifically indicate?
. Undisplaced fracture of the talar neck
. Displaced talar neck fracture with subtalar subluxation or dislocation
. Displaced talar neck fracture with subtalar and tibiotalar dislocations
. Displaced talar neck fracture with subtalar, tibiotalar, and talonavicular dislocations
. Osteochondral fracture of the talar dome

Correct Answer & Explanation

. Displaced talar neck fracture with subtalar and tibiotalar dislocations

Explanation

The Hawkins classification for talar neck fractures is: Type I (nondisplaced), Type II (displaced with subtalar joint subluxation/dislocation), Type III (displaced with both subtalar and tibiotalar joint dislocations), and Type IV (Type III plus talonavicular joint dislocation). Type III injuries carry a very high risk of avascular necrosis (AVN) of the talar body.

Question 4445

Topic: 8. Foot and Ankle
A 50-year-old roofer falls 15 feet, landing squarely on his heels. He sustains a closed, displaced intra-articular calcaneus fracture (Sanders type III). If the surgeon elects to proceed with open reduction and internal fixation via an extensile lateral approach, which of the following is the most frequent and significant complication associated with this specific surgical approach?
. Sural nerve transection
. Wound healing complications and deep infection
. Deep vein thrombosis
. Peroneal tendon subluxation
. Tarsal tunnel syndrome

Correct Answer & Explanation

. Wound healing complications and deep infection

Explanation

The extensile lateral approach for calcaneus fractures relies on a full-thickness fasciocutaneous flap. It is notorious for a high rate of wound complications (up to 25%), including edge necrosis, dehiscence, and deep infection. The risk is significantly increased by smoking, diabetes, and performing surgery before soft tissue swelling has adequately subsided (positive wrinkle test).

Question 4446

Topic: 8. Foot and Ankle
A 31-year-old snowboarder sustains a Hawkins Type III fracture of the talar neck. Despite prompt open reduction and internal fixation, the patient is counseled regarding a high risk of developing avascular necrosis (AVN) of the talar body. Which of the following blood vessels provides the predominant blood supply to the body of the talus, which is typically disrupted in this injury?
. Artery of the tarsal canal
. Artery of the tarsal sinus
. Deltoid branch of the posterior tibial artery
. Dorsalis pedis artery
. Perforating branch of the peroneal artery

Correct Answer & Explanation

. Artery of the tarsal canal

Explanation

The talar body receives its blood supply from a rich extraosseous anastomotic ring. The artery of the tarsal canal, which is a branch of the posterior tibial artery, provides the predominant blood supply to the body of the talus. A Hawkins Type III fracture involves a talar neck fracture with dislocation of both the subtalar and tibiotalar joints, disrupting the extraosseous blood supply (including the artery of the tarsal canal, artery of the tarsal sinus, and deltoid branches) and leading to a very high rate of avascular necrosis.

Question 4447

Topic: 8. Foot and Ankle
A 25-year-old snowboarder sustains a forced dorsiflexion injury to his right ankle. Radiographs reveal a displaced fracture of the talar neck with subluxation of the subtalar joint, while the tibiotalar joint remains concentrically reduced. According to the Hawkins classification, what is the approximate historical risk of developing avascular necrosis (AVN) of the talar body in this patient?
. 0-10%
. 15-20%
. 20-50%
. 75-100%
. 100%

Correct Answer & Explanation

. 20-50%

Explanation

This injury represents a Hawkins Type II talar neck fracture, defined as a talar neck fracture with subluxation or dislocation of the subtalar joint but a reduced ankle joint. The historical risk of avascular necrosis (AVN) of the talar body for a Type II fracture is between 20% and 50%. Type I (non-displaced) fractures have a 0-10% risk, Type III (subtalar and tibiotalar dislocation) have a >50% (often up to 90%) risk, and Type IV (Type III plus talonavicular dislocation) approaches a 100% risk.

Question 4448

Topic: 8. Foot and Ankle

A 45-year-old roofer falls 15 feet, landing squarely on both heels. He has severe bilateral heel pain, swelling, and ecchymosis extending into the plantar arch (Mondor's sign). Lateral radiographs of the right foot demonstrate an intra-articular calcaneus fracture. What specific radiographic finding is classically diagnostic of depression of the posterior facet in this injury?

. An increase in Bohler's angle > 40 degrees
. A decrease in the critical angle of Gissane < 90 degrees
. A decrease in Bohler's angle < 20 degrees
. Widening of the medial clear space
. Dorsal subluxation of the talonavicular joint

Correct Answer & Explanation

. A decrease in Bohler's angle < 20 degrees

Explanation

Bohler's angle is formed by a line drawn from the highest point of the anterior process to the highest point of the posterior facet, and a line drawn from the highest point of the posterior facet to the superior edge of the calcaneal tuberosity. The normal angle is 20 to 40 degrees. In a depressed intra-articular calcaneus fracture, the posterior facet is driven inferiorly, resulting in a flattening or decrease of Bohler's angle to less than 20 degrees. The critical angle of Gissane typically increases (not decreases) when the posterior facet is depressed.

Question 4449

Topic: 8. Foot and Ankle
A 45-year-old male construction worker falls from a roof and sustains a displaced intra-articular calcaneus fracture (Sanders Type III). He is scheduled for open reduction and internal fixation via an extensile lateral approach. To minimize the risk of wound sloughing and necrosis, the surgeon should ensure that the full-thickness soft tissue flap protects the vascular supply from which of the following arteries?
. Medial plantar artery
. Lateral plantar artery
. Lateral calcaneal artery
. Dorsalis pedis artery
. Sural artery

Correct Answer & Explanation

. Lateral calcaneal artery

Explanation

The extensile lateral approach to the calcaneus carries a notorious risk of wound-healing complications. The large L-shaped soft tissue flap relies entirely on the lateral calcaneal artery, a terminal branch of the peroneal artery. To preserve this precarious blood supply, the flap must be raised as a single, full-thickness ('no touch') subperiosteal layer.

Question 4450

Topic: 8. Foot and Ankle

A 22-year-old football player sustains a high-energy knee dislocation, which is closed reduced in the emergency department. His ankle-brachial index (ABI) is measured at 0.85 on the injured leg. Dorsalis pedis and posterior tibial pulses are palpable but asymmetrical compared to the contralateral limb. What is the next most appropriate step in management?

. Immediate exploration of the popliteal artery
. CT angiography of the lower extremity
. Serial physical examinations and ABI measurements every 4 hours
. Discharge home with non-weight-bearing instructions and follow-up in 1 week
. Application of a long-leg cast in full extension

Correct Answer & Explanation

. CT angiography of the lower extremity

Explanation

In a patient with a knee dislocation, vascular injury is a major concern. An ABI < 0.9, abnormal pulses, or an asymmetrical pulse exam are absolute indications for further advanced vascular imaging. CT angiography is the standard non-invasive diagnostic modality of choice to definitively assess for popliteal artery injury before surgical intervention.

Question 4451

Topic: 8. Foot and Ankle
A 45-year-old man falls from a roof and sustains a closed, displaced intra-articular calcaneus fracture (Sanders Type III). He is a current smoker (1 pack/day) and has poorly controlled diabetes mellitus (HbA1c = 9.5%). Which of the following management options minimizes his risk of soft-tissue complications while addressing the fracture?
. Immediate open reduction and internal fixation via an extensile lateral approach
. Open reduction and internal fixation via a medial approach
. Primary subtalar arthrodesis with a structural bone graft
. Closed management with early range of motion or minimally invasive percutaneous fixation
. Application of an external fixator across the ankle joint

Correct Answer & Explanation

. Closed management with early range of motion or minimally invasive percutaneous fixation

Explanation

Extensile lateral approaches for calcaneus fractures carry a high risk of wound breakdown, deep infection, and flap necrosis, particularly in patients with significant risk factors such as active smoking and poorly controlled diabetes. In such cases, non-operative management or minimally invasive/percutaneous fixation techniques are strongly preferred to avoid catastrophic soft-tissue complications.

Question 4452

Topic: 8. Foot and Ankle
A 28-year-old roofing contractor falls 15 feet, sustaining a closed, displaced intra-articular calcaneus fracture (Sanders type III). He undergoes open reduction and internal fixation via an extensile lateral approach. To minimize the risk of wound edge necrosis, surgical dissection relies on preserving the primary vascular supply to the full-thickness lateral flap. Which of the following arteries provides this critical blood supply?
. Lateral tarsal artery
. Lateral calcaneal artery
. Sural artery
. Anterior lateral malleolar artery
. Dorsalis pedis artery

Correct Answer & Explanation

. Lateral calcaneal artery

Explanation

The primary blood supply to the tip (apex) of the extensile lateral flap used for calcaneus fracture fixation is the lateral calcaneal artery, a terminal branch of the peroneal artery. To preserve this vascular supply, the vertical limb of the incision must be placed carefully—typically midway between the posterior margin of the fibula and the lateral border of the Achilles tendon—and the entire flap must be elevated as a full-thickness subperiosteal layer.

Question 4453

Topic: 8. Foot and Ankle

A 42-year-old woman presents to the emergency department with the sudden onset of bilateral perineal numbness, loss of voluntary bowel control, and symmetric distal lower extremity weakness (bilateral foot drop). On examination, her patellar reflexes are 2+ (normal) bilaterally, but her Achilles reflexes are absent. She also reports acute sexual dysfunction. Given her symmetric presentation and mixed upper/lower motor neuron-like signs, the pathology is most likely compressing which anatomical level of the neural axis?

. T8-T9
. T12-L1
. L3-L4
. L5-S1
. S3-S4

Correct Answer & Explanation

. T12-L1

Explanation

The clinical picture describes Conus Medullaris Syndrome, which typically localizes to the T12-L1 vertebral level where the spinal cord terminates. Hallmarks of conus medullaris syndrome include sudden onset, bilateral and symmetric symptoms, early and prominent sphincter (bowel/bladder) dysfunction, saddle anesthesia, and a mix of upper and lower motor neuron signs (e.g., preserved knee jerks from intact L4 roots above the lesion, but absent ankle jerks from affected sacral segments). In contrast, Cauda Equina Syndrome (typically L2-sacrum) presents with gradual onset, asymmetric/unilateral radicular pain, and late sphincter dysfunction with purely lower motor neuron signs.

Question 4454

Topic: Midfoot & Hindfoot
A 55-year-old female presents with progressive flatfoot deformity. Examination shows she is unable to perform a single-leg heel raise, has flexible hindfoot valgus, and forefoot abduction covering >40% of the talar head. What is the most appropriate surgical management?
. Spring ligament repair alone
. Flexor digitorum longus transfer and medial displacement calcaneal osteotomy
. Flexor digitorum longus transfer, medial displacement calcaneal osteotomy, and lateral column lengthening
. Triple arthrodesis
. Tibiotalocalcaneal arthrodesis

Correct Answer & Explanation

. Flexor digitorum longus transfer, medial displacement calcaneal osteotomy, and lateral column lengthening

Explanation

Stage IIb posterior tibial tendon dysfunction involves flexible pes planovalgus with significant forefoot abduction (>40% talonavicular uncoverage). Management requires a lateral column lengthening (e.g., Evans osteotomy) to correct abduction, along with FDL transfer and medial calcaneal displacement.

Question 4455

Topic: 8. Foot and Ankle

A 24-year-old football player sustains a plantarflexion injury to his foot. Non-weight-bearing radiographs are normal, but he has pain with midfoot pronation and abduction. What is the next best step to evaluate for a subtle Lisfranc injury?

. CT scan of the foot without contrast
. MRI of the midfoot
. Weight-bearing radiographs of the foot
. Diagnostic injection of the tarsometatarsal joints
. Bone scan

Correct Answer & Explanation

. Weight-bearing radiographs of the foot

Explanation

Subtle Lisfranc injuries may present with normal non-weight-bearing radiographs. Weight-bearing radiographs are the initial next step to evaluate for diastasis between the first and second metatarsal bases before proceeding to advanced imaging.

Question 4456

Topic: 8. Foot and Ankle

A 30-year-old man sustains a displaced fracture of the talar neck. During surgical approach and fixation, preserving the major blood supply to the talar body is critical. Which artery provides the dominant blood supply to the talar body?

. Artery of the tarsal canal
. Artery of the tarsal sinus
. Deltoid branch of the posterior tibial artery
. Dorsalis pedis artery
. Peroneal artery

Correct Answer & Explanation

. Artery of the tarsal canal

Explanation

The artery of the tarsal canal, a branch of the posterior tibial artery, provides the dominant blood supply to the talar body. Disruption of this supply significantly increases the risk of avascular necrosis following displaced talar neck fractures.

Question 4457

Topic: 8. Foot and Ankle

A 45-year-old recreational athlete sustains an acute Achilles tendon rupture. In comparing operative versus non-operative management with early functional rehabilitation, which of the following statements is true based on current evidence?

. Operative management has a lower re-rupture rate but a higher soft-tissue complication rate
. Non-operative management with cast immobilization has equal re-rupture rates to operative treatment
. Operative management has a higher risk of sural nerve injury but lower deep infection risk
. Early functional rehabilitation increases re-rupture rates in non-operative groups
. Operative management provides superior peak plantarflexion strength at 5 years

Correct Answer & Explanation

. Operative management has a lower re-rupture rate but a higher soft-tissue complication rate

Explanation

Operative management of Achilles ruptures provides a slightly lower re-rupture rate but carries a higher risk of soft-tissue complications compared to non-operative management. Early functional rehabilitation mitigates the re-rupture risk in non-operative patients to near-surgical levels.

Question 4458

Topic: 8. Foot and Ankle

A 22-year-old sustains an ankle syndesmotic injury requiring fixation. Which of the following is considered a primary advantage of dynamic suture-button fixation over static syndesmotic screw fixation?

. Lower implant cost
. Rigid anatomic maintenance of the distal tibiofibular joint without micromotion
. Decreased rate of secondary implant removal
. Lower risk of superficial infection
. Eliminates the need for postoperative non-weight-bearing protocols

Correct Answer & Explanation

. Decreased rate of secondary implant removal

Explanation

Dynamic suture-button fixation allows for physiologic motion at the syndesmosis and avoids the need for routine hardware removal. This significantly decreases the rates of secondary surgeries compared to static screw fixation, which often requires removal due to pain or breakage.

Question 4459

Topic: Midfoot & Hindfoot

A 60-year-old patient with poorly controlled diabetes presents with a swollen, erythematous, and warm foot. Radiographs reveal fragmentation and periarticular debris at the tarsometatarsal joints without ulceration. What is the most appropriate initial management?

. Intravenous antibiotics and surgical debridement
. Total contact casting and non-weight-bearing
. Open reduction and internal fixation of the midfoot
. Arthrodesis of the midfoot with external fixation
. Charcot Restraint Orthotic Walker (CROW) boot and weight-bearing as tolerated

Correct Answer & Explanation

. Total contact casting and non-weight-bearing

Explanation

The patient is in the acute fragmentation phase (Eichenholtz Stage 1) of Charcot arthropathy. The gold standard initial treatment to prevent progressive deformity is immobilization with a total contact cast and strict non-weight-bearing until the acute phase resolves.

Question 4460

Topic: Forefoot

A 55-year-old man presents with dorsal midfoot pain and limited dorsiflexion of the great toe. Radiographs show a dorsal osteophyte on the first metatarsal head and joint space narrowing involving less than 50% of the joint. What is the preferred surgical treatment if conservative measures fail?

. First metatarsophalangeal joint arthrodesis
. Keller resection arthroplasty
. Cheilectomy with or without Moberg osteotomy
. Total joint arthroplasty of the first MTP
. Lapidus procedure

Correct Answer & Explanation

. Cheilectomy with or without Moberg osteotomy

Explanation

For mild-to-moderate hallux rigidus (Grade 1 or 2) with dorsal impingement and preserved plantar joint space, a cheilectomy is the preferred surgical option. First MTP arthrodesis is generally reserved for advanced, end-stage disease.

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