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8. Foot and Ankle MCQs

Practice Set 231 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 4601

Topic: Forefoot

A 45-year-old female presents with symptomatic hallux valgus that has failed nonoperative management. Weight-bearing radiographs demonstrate an intermetatarsal angle (IMA) of 18 degrees and a hallux valgus angle (HVA) of 42 degrees. There is no evidence of first tarsometatarsal hypermobility or osteoarthritis. Which of the following surgical options is most appropriate?

. Distal chevron osteotomy
. Proximal crescentic osteotomy with distal soft tissue procedure
. Akin osteotomy alone
. Keller resection arthroplasty
. First metatarsophalangeal arthrodesis

Correct Answer & Explanation

. Proximal crescentic osteotomy with distal soft tissue procedure

Explanation

A severe hallux valgus deformity (IMA > 13-15 degrees, HVA > 40 degrees) requires a proximal metatarsal osteotomy (e.g., proximal crescentic or Ludloff) or a Lapidus procedure, combined with a distal soft tissue release to achieve adequate correction. A distal chevron osteotomy cannot provide sufficient translation for large IMA corrections. First MTP arthrodesis is typically reserved for severe deformity with concomitant arthritis or rheumatoid arthritis.

Question 4602

Topic: 8. Foot and Ankle

A 24-year-old skier presents with lateral ankle pain and a palpable snapping sensation behind the lateral malleolus after a forced dorsiflexion and eversion injury. On examination, the peroneal tendons subluxate anterior to the posterior cortex of the fibula with resisted ankle eversion. Injury to which of the following anatomic structures is the primary cause of this condition?

. Anterior talofibular ligament
. Calcaneofibular ligament
. Superior peroneal retinaculum
. Inferior peroneal retinaculum
. Peroneus brevis tendon

Correct Answer & Explanation

. Superior peroneal retinaculum

Explanation

Peroneal tendon subluxation or dislocation is caused by an injury to the superior peroneal retinaculum (SPR). The mechanism usually involves forced dorsiflexion and eversion, which causes a violent contraction of the peroneal muscles that strips, avulses, or tears the SPR from its attachment on the posterolateral fibula.

Question 4603

Topic: 8. Foot and Ankle

A 27-year-old soccer player sustains an external rotation injury to his ankle. Radiographs show a proximal fibular fracture (Maisonneuve fracture). Intraoperatively, after placing a syndesmotic screw, fluoroscopic evaluation is performed. Which of the following radiographic parameters is considered the most reliable indicator of syndesmotic reduction on a standard AP and Mortise view?

. Talar tilt angle less than 10 degrees
. Tibiofibular clear space less than 5 mm on both the AP and mortise views
. Tibiofibular overlap greater than 5 mm on the mortise view
. Medial clear space less than 6 mm on the mortise view
. Anterior translation of the talus on the lateral view

Correct Answer & Explanation

. Tibiofibular clear space less than 5 mm on both the AP and mortise views

Explanation

The tibiofibular clear space (measured 1 cm proximal to the tibial plafond) is the most reliable radiographic parameter for assessing syndesmotic integrity, as it is relatively unaffected by foot rotation. It should be less than 5 mm on both the AP and Mortise views. Tibiofibular overlap is highly dependent on the internal rotation of the foot, making it less reliable. The medial clear space should normally be less than 4 mm.

Question 4604

Topic: Midfoot & Hindfoot

A 55-year-old poorly controlled diabetic male presents with a red, hot, swollen right foot. Radiographs reveal fragmentation of the navicular and cuneiforms with a collapse of the medial longitudinal arch. Laboratory markers show a normal white blood cell count and a mildly elevated ESR. He is diagnosed with acute Eichenholtz stage I Charcot arthropathy. What is the most appropriate initial management?

. Urgent surgical debridement and external fixation
. Intravenous antibiotics and bone biopsy
. Total contact casting and non-weight-bearing
. Midfoot arthrodesis with robust internal fixation
. Corticosteroid injection into the midfoot joints

Correct Answer & Explanation

. Total contact casting and non-weight-bearing

Explanation

Acute (Eichenholtz stage I) Charcot arthropathy presents with erythema, edema, and warmth, often mimicking an infection. Treatment in the acute phase is strict immobilization with total contact casting and non-weight-bearing to prevent further deformity until the active inflammatory phase resolves. Surgery is generally contraindicated in the acute phase due to severe osteopenia and the high risk of hardware failure, unless there is severe instability threatening the soft tissue envelope or an associated deep infection.

Question 4605

Topic: Forefoot

A 45-year-old female presents with progressive foot pain and a bunion deformity. Weight-bearing radiographs show a hallux valgus angle of 45 degrees, an intermetatarsal angle (IMA) of 18 degrees, and evidence of hypermobility at the first tarsometatarsal (TMT) joint. Which of the following surgical interventions is most appropriate to minimize the risk of recurrence?

. Distal chevron osteotomy
. Proximal crescentic osteotomy with distal soft tissue procedure
. First tarsometatarsal joint arthrodesis (Lapidus procedure)
. First metatarsophalangeal joint arthrodesis
. Keller resection arthroplasty

Correct Answer & Explanation

. First tarsometatarsal joint arthrodesis (Lapidus procedure)

Explanation

The Lapidus procedure (first TMT arthrodesis) is indicated for severe hallux valgus (IMA > 15-20 degrees), especially when associated with first ray hypermobility. Distal osteotomies are suitable for mild to moderate deformities. Proximal osteotomies can correct larger deformities but do not address TMT hypermobility, leading to a high recurrence rate in these specific patients. A first MTP arthrodesis is an excellent option for severe deformity, but is typically reserved for cases with associated severe osteoarthritis.

Question 4606

Topic: Midfoot & Hindfoot
A 32-year-old male sustains a severe hyperdorsiflexion injury to his right ankle in a motor vehicle collision. Radiographs reveal a displaced talar neck fracture with subluxation of the subtalar joint, but the ankle mortise and talonavicular joints remain congruent. According to the Hawkins classification, what is the approximate risk of developing avascular necrosis (AVN) of the talar body?
. 0 - 15%
. 20 - 50%
. 70 - 100%
. 100%

Correct Answer & Explanation

. 20 - 50%

Explanation

The patient has a Hawkins Type II fracture, defined as a talar neck fracture with subtalar subluxation or dislocation. The risk of AVN for Type I (nondisplaced) is 0-15%. For Type II, it increases to 20-50%. For Type III (subtalar and tibiotalar dislocation), it is 70-100%. Type IV (addition of talonavicular dislocation) also carries a near 100% risk of AVN.

Question 4607

Topic: 8. Foot and Ankle

A 28-year-old professional soccer player sustains a twisting injury to his ankle. Examination reveals tenderness over the anterior inferior tibiofibular ligament (AITFL) and a positive external rotation stress test. Weight-bearing radiographs show widening of the medial clear space and decreased tibiofibular overlap. What is the most reliable intraoperative method to confirm accurate syndesmotic reduction?

. Anteroposterior fluoroscopy comparing the injured and uninjured sides
. Direct open visualization of the anterior inferior tibiofibular ligament
. Computed tomography (CT) scan
. The cotton test (lateral hook test)
. Intraoperative mortise view

Correct Answer & Explanation

. Computed tomography (CT) scan

Explanation

Malreduction of the syndesmosis is a major cause of poor functional outcomes in ankle fractures. Standard intraoperative fluoroscopy (AP and Mortise views) is notoriously unreliable for detecting subtle syndesmotic malreductions. Postoperative or intraoperative CT scan is the most sensitive and reliable method to definitively assess the accuracy of syndesmotic reduction.

Question 4608

Topic: 8. Foot and Ankle

A 22-year-old football player presents with midfoot pain and an inability to bear weight after a competitor fell on his plantarflexed foot. Radiographs show a 2 mm widening between the base of the 1st and 2nd metatarsals. An MRI confirms a complete rupture of the Lisfranc ligament with no associated fractures (purely ligamentous injury). What is the recommended operative treatment to maximize his long-term functional outcome?

. Primary arthrodesis of the 1st, 2nd, and 3rd tarsometatarsal joints
. Open reduction and internal fixation (ORIF) with transarticular screws
. Closed reduction and percutaneous pinning
. Dorsal bridge plating spanning the tarsometatarsal joints
. Suture-button suspensionplasty alone

Correct Answer & Explanation

. Primary arthrodesis of the 1st, 2nd, and 3rd tarsometatarsal joints

Explanation

Purely ligamentous Lisfranc injuries have a poorer prognosis with ORIF compared to bony fracture-dislocations due to poor ligament healing capacity and late arch collapse or post-traumatic arthritis. Multiple landmark studies have shown that primary arthrodesis for purely ligamentous Lisfranc injuries provides better functional outcomes and fewer return trips to the operating room for hardware removal or salvage procedures compared to ORIF.

Question 4609

Topic: 8. Foot and Ankle

A 14-year-old boy presents with frequent ankle sprains and a rigid, painful flatfoot. Clinical examination demonstrates markedly decreased subtalar motion and peroneal spasticity. Lateral radiographs demonstrate an elongation of the anterior process of the calcaneus, known as the 'anteater sign'. Which condition is most likely present?

. Talocalcaneal coalition
. Calcaneonavicular coalition
. Talonavicular coalition
. Cubonavicular coalition
. Accessory navicular syndrome

Correct Answer & Explanation

. Calcaneonavicular coalition

Explanation

The 'anteater sign' on a lateral radiograph refers to the elongation of the anterior process of the calcaneus, which is pathognomonic for a calcaneonavicular coalition. This is best visualized on a 45-degree internal oblique radiograph. Talocalcaneal coalitions (often involving the middle facet) present with a 'C-sign' and a 'talar beak' on lateral radiographs.

Question 4610

Topic: 8. Foot and Ankle

A 60-year-old female presents with medial ankle pain and a progressive flatfoot deformity. She is unable to perform a single-limb heel rise. Weight-bearing radiographs show an uncovered talonavicular joint and plantarflexion of the talus. She is diagnosed with Stage II posterior tibial tendon dysfunction (PTTD). What is the primary functional role of the spring ligament, which is often attenuated in this condition?

. Resists dorsiflexion of the first metatarsal
. Supports the medial longitudinal arch by connecting the calcaneus to the cuboid
. Supports the talar head and resists plantarflexion and medial deviation of the talus
. Acts as the primary dynamic stabilizer of the subtalar joint
. Prevents lateral translation of the calcaneus relative to the talus

Correct Answer & Explanation

. Supports the talar head and resists plantarflexion and medial deviation of the talus

Explanation

The spring ligament complex (plantar calcaneonavicular ligament) forms a hammock under the talar head, connecting the sustentaculum tali of the calcaneus to the navicular. It provides critical static support to the medial longitudinal arch by resisting plantarflexion and medial deviation of the talar head. Its attenuation or rupture is a key pathophysiological feature of adult acquired flatfoot deformity (PTTD).

Question 4611

Topic: 8. Foot and Ankle

A 45-year-old female presents with pain and medial deviation of her great toe 6 months after a chevron osteotomy and distal soft tissue release for hallux valgus. On physical examination, she has a flexible hallux varus deformity. Radiographs demonstrate a negative intermetatarsal angle and medial subluxation of the first metatarsophalangeal (MTP) joint. Which of the following intraoperative technical errors is most likely responsible for this complication?

. Under-resection of the medial eminence of the first metatarsal
. Excessive release of the lateral joint capsule and adductor hallucis
. Inadequate release of the medial sesamoid apparatus
. Plantarflexion malunion of the metatarsal head
. Failure to perform an Akin osteotomy

Correct Answer & Explanation

. Excessive release of the lateral joint capsule and adductor hallucis

Explanation

Hallux varus is a known complication following hallux valgus corrective surgery, characterized by medial deviation of the great toe. Iatrogenic causes include excessive release of the lateral structures (lateral capsule, adductor hallucis tendon), over-resection of the medial eminence ('staking' the metatarsal head), over-tightening of the medial capsule, and excessive lateral translation of the capital fragment causing a negative intermetatarsal angle. Under-resection or inadequate release typically leads to recurrence of hallux valgus, not varus.

Question 4612

Topic: Midfoot & Hindfoot
A 35-year-old male is involved in a high-speed motor vehicle collision and sustains a displaced talar neck fracture. Radiographs show a fracture of the talar neck with subluxation of the subtalar joint, while the tibiotalar and talonavicular joints remain concentrically reduced. According to the Hawkins classification, what is the grade of this injury and the approximate historically reported risk of developing avascular necrosis (AVN) of the talar body?
. Hawkins I; 0-10%
. Hawkins II; 20-50%
. Hawkins III; 80-100%
. Hawkins IV; 100%
. Hawkins II; 80-100%

Correct Answer & Explanation

. Hawkins II; 20-50%

Explanation

The Hawkins classification is used for talar neck fractures. Type I is non-displaced (0-10% AVN risk). Type II involves subtalar subluxation or dislocation with a reduced ankle joint (historically 20-50% AVN risk). Type III involves dislocation of both the subtalar and tibiotalar joints (historically >80% AVN risk). Type IV (added by Canale and Kelly) involves subtalar, tibiotalar, and talonavicular dislocation (nearly 100% AVN risk). The scenario describes a Type II fracture.

Question 4613

Topic: Midfoot & Hindfoot
A 55-year-old female presents with progressive flattening of her left foot, medial arch pain, and an inability to perform a single-leg heel raise. Examination reveals a flexible flatfoot deformity with notable forefoot abduction. Weight-bearing radiographs reveal greater than 40% uncovering of the talonavicular joint on the AP view. Non-operative management has failed. Which of the following surgical strategies is most appropriate?
. Isolated posterior tibial tendon debridement
. Flexor digitorum longus (FDL) transfer to the navicular and medial displacement calcaneal osteotomy (MDCO)
. FDL transfer, MDCO, and lateral column lengthening
. Isolated triple arthrodesis
. Isolated talonavicular arthrodesis

Correct Answer & Explanation

. FDL transfer, MDCO, and lateral column lengthening

Explanation

The patient has Stage IIb adult acquired flatfoot deformity (AAFD) / posterior tibial tendon dysfunction. Stage II indicates a flexible deformity. Stage IIb is distinguished from IIa by the presence of significant forefoot abduction (typically >30-40% talonavicular uncoverage on AP radiograph). Surgical management for Stage IIb requires addressing the transverse plane deformity (forefoot abduction) through a lateral column lengthening (e.g., Evans osteotomy) in addition to an FDL transfer and MDCO. Triple arthrodesis is reserved for Stage III (rigid) deformity.

Question 4614

Topic: 8. Foot and Ankle
A 62-year-old male with poorly controlled type 2 diabetes and profound peripheral neuropathy presents with a swollen, erythematous, and warm right foot. He denies any prior trauma or systemic symptoms. Inflammatory markers are mildly elevated. Radiographs demonstrate periarticular debris, fragmentation of the tarsometatarsal joints, and subluxation, but no soft tissue gas or focal osteomyelitis. Which of the following is the most appropriate initial management?
. Intravenous antibiotics and urgent surgical debridement
. Total contact casting and strict non-weight-bearing
. Open reduction and internal fixation of the TMT joints
. Primary midfoot arthrodesis with a medial column plate
. Prescription of custom accommodative orthotic footwear

Correct Answer & Explanation

. Total contact casting and strict non-weight-bearing

Explanation

This patient presents with acute (Eichenholtz Stage I) Charcot neuroarthropathy. The presentation of a warm, swollen, red foot in a diabetic patient must be differentiated from infection; however, the classic radiographic findings of fragmentation and subluxation without systemic signs or ulceration strongly point to acute Charcot. The mainstay of treatment in the acute fragmentation phase is strict immobilization (total contact casting) and offloading to prevent further deformity. Surgical reconstruction is generally contraindicated in the acute inflammatory phase unless there is severe instability or impending ulceration that cannot be managed non-operatively. Custom footwear is appropriate for Eichenholtz Stage III (consolidation) once the foot is stable.

Question 4615

Topic: 8. Foot and Ankle
A 68-year-old male with end-stage post-traumatic ankle osteoarthritis is being evaluated for surgical management. Which of the following conditions is considered an ABSOLUTE contraindication to performing a total ankle arthroplasty (TAA)?
. Patient age greater than 65 years
. Concomitant severe subtalar osteoarthritis
. Active Charcot neuroarthropathy of the ankle
. Coronal plane tibiotalar deformity of 10 degrees
. History of a prior bimalleolar ankle fracture managed with ORIF

Correct Answer & Explanation

. Active Charcot neuroarthropathy of the ankle

Explanation

Absolute contraindications to total ankle arthroplasty (TAA) include active infection, active Charcot neuroarthropathy (due to complete lack of protective sensation and progressive bone destruction), avascular necrosis involving a significant portion (>50%) of the talar body, and severe uncorrectable malalignment. Concomitant subtalar arthritis is an indication for combined procedures (TAA + subtalar fusion) but not a contraindication. Mild coronal plane deformities (up to 15-20 degrees) can often be corrected during the procedure. Age > 65 is actually a preferred demographic for TAA due to lower functional demands compared to young patients.

Question 4616

Topic: 8. Foot and Ankle

A 22-year-old collegiate basketball player sustains a fracture at the metaphyseal-diaphyseal junction of the fifth metatarsal (Zone 2). He is counseled on the high rate of nonunion in this region, which is primarily attributed to a vascular watershed area. This watershed area exists between the metaphyseal blood supply and which of the following arterial structures?

. Dorsalis pedis artery
. Intramedullary diaphyseal nutrient artery
. Lateral tarsal artery
. Medial plantar artery
. Metatarsal perforating arteries

Correct Answer & Explanation

. Intramedullary diaphyseal nutrient artery

Explanation

A Jones fracture occurs at the metaphyseal-diaphyseal junction of the fifth metatarsal (Zone 2). This area is notorious for delayed union and nonunion because it represents a vascular watershed zone. The blood supply to the fifth metatarsal comes from the metaphyseal vessels proximally and the intramedullary nutrient artery distally, which enters the medial cortex in the proximal third of the diaphysis. The watershed area between these two blood supplies leaves Zone 2 relatively avascular.

Question 4617

Topic: 8. Foot and Ankle

A 45-year-old distance runner presents with chronic, recalcitrant heel pain. The pain is maximal at the medial aspect of the heel and radiates into the plantar-lateral foot. Physical exam reveals point tenderness over the medial calcaneal tuberosity and pain exacerbation with eversion and dorsiflexion of the ankle. Electromyography (EMG) reveals isolated denervation of the abductor digiti minimi muscle. Entrapment of which of the following nerves is the most likely diagnosis?

. Medial plantar nerve
. First branch of the lateral plantar nerve
. Medial calcaneal nerve
. Sural nerve
. Deep peroneal nerve

Correct Answer & Explanation

. First branch of the lateral plantar nerve

Explanation

The patient is presenting with Baxter's nerve entrapment. The first branch of the lateral plantar nerve (Baxter's nerve) can become entrapped between the deep fascia of the abductor hallucis and the medial head of the quadratus plantae. It provides motor innervation to the abductor digiti minimi and sensory innervation to the calcaneal periosteum. Denervation of the abductor digiti minimi on EMG or fatty atrophy on MRI is pathognomonic for this entrapment syndrome.

Question 4618

Topic: 8. Foot and Ankle

A 35-year-old construction worker falls from a height and sustains a displaced, joint-depression type intra-articular calcaneus fracture. Surgical fixation is planned via an extensile lateral approach. During the development of the full-thickness flap, which of the following neurologic structures is at greatest risk of iatrogenic injury?

. Sural nerve
. Superficial peroneal nerve
. Deep peroneal nerve
. Tibial nerve
. Saphenous nerve

Correct Answer & Explanation

. Sural nerve

Explanation

The extensile lateral approach to the calcaneus involves creating a full-thickness subperiosteal flap. The sural nerve courses along the lateral aspect of the hindfoot, posterior to the lateral malleolus, and is at significant risk during the vertical and horizontal limbs of the incision. Retracting the full-thickness flap protects the nerve if it is correctly elevated within the flap, but it remains the most commonly injured neurologic structure during this specific surgical approach.

Question 4619

Topic: 8. Foot and Ankle

A 40-year-old recreational athlete sustains an acute, complete mid-substance rupture of the Achilles tendon. He is discussing operative versus non-operative management with his surgeon. Based on recent high-level randomized controlled trials and meta-analyses, which of the following statements is true regarding non-operative management utilizing an early functional rehabilitation protocol compared to surgical repair?

. Non-operative management carries a significantly higher rate of deep vein thrombosis (DVT).
. Surgical repair has a drastically lower rate of re-rupture regardless of the rehabilitation protocol.
. Non-operative management has a similar re-rupture rate when early functional weight-bearing is utilized.
. Surgical repair leads to significantly better long-term plantarflexion strength and return to sport.
. Non-operative management results in a higher rate of sural nerve injury.

Correct Answer & Explanation

. Non-operative management has a similar re-rupture rate when early functional weight-bearing is utilized.

Explanation

Historically, non-operative management of Achilles tendon ruptures was associated with a higher re-rupture rate. However, modern high-level evidence (such as the study by Willits et al. and subsequent meta-analyses like Soroceanu et al.) has demonstrated that when early functional rehabilitation (early weight-bearing in a functional brace and early range of motion) is employed, the re-rupture rates between operative and non-operative management are statistically similar. Operative management is associated with a higher risk of complications such as infection and sural nerve injury. Long-term functional outcomes and strength are generally similar between the two groups.

Question 4620

Topic: 8. Foot and Ankle

A 55-year-old patient with long-standing, poorly controlled diabetes mellitus presents with a unilaterally swollen, warm, and erythematous right foot. The patient denies any trauma and has no open wounds or ulcers. Pedal pulses are bounding. Plain radiographs demonstrate periarticular fragmentation, debris, and subluxation at the tarsometatarsal joints. Laboratory markers including CRP and ESR are mildly elevated. What is the most appropriate initial management for this condition?

. Prompt surgical debridement and intravenous antibiotics
. Open reduction and internal fixation of the midfoot
. Non-weight bearing in a total contact cast
. Ankle-foot orthosis and weight-bearing as tolerated
. Below-knee amputation

Correct Answer & Explanation

. Non-weight bearing in a total contact cast

Explanation

The clinical presentation of a red, hot, swollen foot in a diabetic patient with intact pulses and no ulceration strongly suggests acute Charcot neuroarthropathy (Eichenholtz stage I). The radiographic findings of fragmentation, debris, and subluxation confirm this diagnosis. The mainstay of initial treatment for acute, active Charcot arthropathy is strict offloading and immobilization, most effectively achieved with a total contact cast. Surgery in the acute phase is typically contraindicated due to severe osteopenia, active inflammation, and a high risk of failure.

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