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8. Foot and Ankle MCQs

Practice Set 184 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 3661

Topic: 8. Foot and Ankle

A 14-year-old boy with Charcot-Marie-Tooth (CMT) disease presents with a progressive bilateral cavovarus foot deformity. Which specific muscle imbalance is the primary driver of the plantarflexed first ray commonly seen in this condition?

. A strong peroneus longus overpowering a weak tibialis anterior
. A strong tibialis anterior overpowering a weak peroneus longus
. A strong peroneus brevis overpowering a weak tibialis posterior
. Extensor digitorum longus weakness relative to the flexor digitorum longus
. Isolated gastrocnemius spasticity

Correct Answer & Explanation

. A strong peroneus longus overpowering a weak tibialis anterior

Explanation

In Charcot-Marie-Tooth disease, the hallmark cavovarus deformity is largely driven by a strong peroneus longus muscle overpowering a weakened tibialis anterior. This specific imbalance forces the first metatarsal into fixed plantarflexion.

Question 3662

Topic: 8. Foot and Ankle

A 65-year-old active male with end-stage post-traumatic ankle osteoarthritis is considering surgical intervention. He has well-aligned hindfoot joints and good bone stock. Compared to ankle arthrodesis, what is the primary biomechanical advantage of performing a Total Ankle Arthroplasty (TAA)?

. Higher rate of successful return to high-impact contact sports
. Preservation of sagittal plane motion, which reduces stress on adjacent hindfoot joints
. Significantly lower rate of secondary reoperation at 10 years
. Superior outcomes in patients with underlying severe sensory neuropathy
. Complete elimination of postoperative activity restrictions

Correct Answer & Explanation

. Preservation of sagittal plane motion, which reduces stress on adjacent hindfoot joints

Explanation

Total Ankle Arthroplasty (TAA) preserves sagittal plane motion, which improves gait kinematics and effectively reduces the biomechanical stress transferred to adjacent joints (e.g., subtalar, talonavicular). This theoretically protects adjacent joints from the development or progression of secondary osteoarthritis.

Question 3663

Topic: 8. Foot and Ankle

A patient who has recalcitrant medial plantar heel pain and pain directly over the medial side of the heel undergoes open release of the plantar fascia. After releasing a portion of the plantar fascia, the deep fascia of the abductor hallucis muscle is released to relieve pressure on which of the following structures?

. Lateral plantar artery
. Tibial nerve
. First branch of the lateral plantar nerve
. Sural nerve
. Flexor hallucis brevis muscle

Correct Answer & Explanation

. First branch of the lateral plantar nerve

Explanation

The deep fascia of the abductor hallucis muscle is released to relieve pressure on the first branch of the lateral plantar nerve. The tibial nerve lies more proximal to this area. The medial plantar nerve has already passed dorsally and medially, while the sural nerve lies on the lateral side of the foot. The flexor hallucis brevis muscle lies deep to the plantar fascia, not the abductor fascia. Baxter DE, Pfeffer GB: Treatment of chronic heel pain by surgical release of the first branch of the lateral plantar nerve. Clin Orthop 1992;279:229-236.

Question 3664

Topic: 8. Foot and Ankle

A 24-year-old athlete sustains an axial load injury to a plantarflexed foot. Radiographs demonstrate widening of the interval between the 1st and 2nd metatarsal bases without associated fracture. What is the most appropriate surgical treatment for this purely ligamentous Lisfranc injury?

. Closed reduction and percutaneous pinning
. Open reduction and internal fixation with transarticular screws
. Primary arthrodesis of the 1st, 2nd, and 3rd tarsometatarsal joints
. Dorsal spanning external fixation
. Excision of the Lisfranc ligament and primary closure

Correct Answer & Explanation

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

Explanation

Current evidence demonstrates that primary arthrodesis for purely ligamentous Lisfranc injuries provides superior functional outcomes and lower reoperation rates compared to open reduction and internal fixation.

Question 3665

Topic: 8. Foot and Ankle

When comparing operative versus non-operative management of acute Achilles tendon ruptures utilizing modern early functional rehabilitation protocols, operative treatment is most strongly associated with:

. Significantly higher re-rupture rates
. Decreased time to achieve full plantarflexion strength
. Higher rates of infection and soft tissue complications
. Lower rates of deep vein thrombosis
. Significantly improved long-term clinical outcome scores

Correct Answer & Explanation

. Higher rates of infection and soft tissue complications

Explanation

Early functional rehabilitation protocols yield similar re-rupture rates and functional outcomes between operative and non-operative groups. However, operative management consistently carries a higher risk of soft tissue complications and infection.

Question 3666

Topic: Midfoot & Hindfoot

A 35-year-old sustains a lateral subtalar dislocation that is irreducible by closed means in the emergency department. Which anatomic structure is most commonly interpositioned, blocking reduction?

. Tibialis posterior tendon
. Extensor digitorum brevis
. Peroneus brevis tendon
. Flexor hallucis longus tendon
. Sural nerve

Correct Answer & Explanation

. Tibialis posterior tendon

Explanation

In lateral subtalar dislocations, the tibialis posterior tendon is the most frequent structure to block closed reduction. In medial dislocations, the extensor digitorum brevis or talonavicular capsule typically blocks reduction.

Question 3667

Topic: 8. Foot and Ankle

During fixation of a pronation-external rotation ankle fracture, the syndesmosis is found to be unstable. Which of the following statements regarding modern syndesmotic screw fixation is most accurate?

. Screws must routinely be removed prior to weight-bearing to prevent breakage
. Fixation with 3 cortical threads provides equivalent clinical outcomes to 4 cortical threads
. The ankle must be held in maximal plantarflexion during screw insertion
. Rigid screw fixation yields superior clinical scores compared to suture button constructs
. Screws should be inserted from posterior to anterior to match the fibular bow

Correct Answer & Explanation

. Fixation with 3 cortical threads provides equivalent clinical outcomes to 4 cortical threads

Explanation

Biomechanical and clinical studies demonstrate no significant difference in outcomes or stability between engaging 3 versus 4 cortices with syndesmotic screws. Additionally, routine screw removal is no longer mandatory unless symptomatic.

Question 3668

Topic: 8. Foot and Ankle

A patient undergoes open reduction and internal fixation of a displaced intra-articular calcaneus fracture via an extensile lateral approach. Which nerve is at greatest risk of iatrogenic injury during the flap elevation?

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

Correct Answer & Explanation

. Sural nerve

Explanation

The sural nerve courses along the lateral aspect of the hindfoot and is particularly vulnerable during the extensile lateral approach to the calcaneus. The incision must be meticulously planned to protect it.

Question 3669

Topic: 8. Foot and Ankle

A 55-year-old patient with severe, poorly controlled diabetes and profound peripheral neuropathy sustains a displaced bimalleolar ankle fracture. What specific modification to surgical technique is recommended?

. Avoiding all internal fixation to reduce the risk of deep infection
. Using bioabsorbable plates and screws
. Enhancing construct rigidity with multiple syndesmotic screws or a hindfoot nail
. Routine primary below-knee amputation
. Encouraging immediate full weight-bearing postoperatively

Correct Answer & Explanation

. Enhancing construct rigidity with multiple syndesmotic screws or a hindfoot nail

Explanation

Neuropathic diabetic patients are at high risk for Charcot arthropathy and hardware failure after ankle fractures. Augmenting standard fixation with multiple syndesmotic screws or tibiotalocalcaneal nailing is highly recommended.

Question 3670

Topic: 8. Foot and Ankle

A skier presents with posterolateral ankle swelling after a forced dorsiflexion and inversion injury. Radiographs show a small flake of bone avulsed from the posterolateral aspect of the fibula. This 'fleck sign' is pathognomonic for:

. A complete tear of the Achilles tendon
. Avulsion of the calcaneofibular ligament
. Superior peroneal retinaculum avulsion with peroneal tendon subluxation
. Syndesmotic disruption
. Fracture of the lateral process of the talus

Correct Answer & Explanation

. Superior peroneal retinaculum avulsion with peroneal tendon subluxation

Explanation

A cortical avulsion from the posterolateral ridge of the distal fibula (fleck sign) indicates avulsion of the superior peroneal retinaculum. This injury is highly associated with subluxation or dislocation of the peroneal tendons.

Question 3671

Topic: 8. Foot and Ankle

A 28-year-old snowboarder presents with lingering lateral ankle pain after a heavy landing. Plain radiographs are read as normal, but clinical tenderness is focused just anterior and inferior to the lateral malleolus. Which occult fracture should be highly suspected?

. Cuboid compression fracture
. Fracture of the lateral process of the talus
. Anterior process of the calcaneus fracture
. Sustentaculum tali fracture
. Avulsion of the base of the fifth metatarsal

Correct Answer & Explanation

. Fracture of the lateral process of the talus

Explanation

Fracture of the lateral process of the talus is the classic 'snowboarder's fracture'. It is easily missed on initial plain radiographs and often requires a CT scan for definitive diagnosis and surgical planning.

Question 3672

Topic: Midfoot & Hindfoot

In a 45-year-old patient with a purely ligamentous Lisfranc injury, primary arthrodesis of the 1st, 2nd, and 3rd tarsometatarsal joints compared to open reduction and internal fixation (ORIF) offers which of the following advantages?

. Lower rate of planned reoperation
. Decreased operative time
. Higher rate of return to pre-injury sports
. Better preservation of midfoot motion
. Decreased risk of deep infection

Correct Answer & Explanation

. Lower rate of planned reoperation

Explanation

Primary arthrodesis for purely ligamentous Lisfranc injuries leads to comparable functional outcomes but significantly lowers the rate of planned hardware removal and secondary salvage arthrodesis compared to ORIF.

Question 3673

Topic: 8. Foot and Ankle

When utilizing an extensile lateral approach for a displaced intra-articular calcaneus fracture, what is the most common postoperative complication?

. Sural nerve injury
. Superficial peroneal nerve injury
. Wound edge necrosis
. Peroneal tendon subluxation
. Flexor hallucis longus entrapment

Correct Answer & Explanation

. Wound edge necrosis

Explanation

The extensile lateral approach to the calcaneus has a high rate of wound complications (up to 25%), particularly wound edge necrosis or dehiscence. Careful, full-thickness flap elevation and subperiosteal dissection are required to minimize this risk.

Question 3674

Topic: Midfoot & Hindfoot

According to Level I evidence, which of the following is a primary advantage of primary arthrodesis over open reduction internal fixation (ORIF) for purely ligamentous Lisfranc injuries?

. Decreased rate of secondary surgeries
. Faster return to pre-injury sports
. Lower rate of wound complications
. Improved range of motion of the midfoot
. Decreased incidence of deep vein thrombosis

Correct Answer & Explanation

. Decreased rate of secondary surgeries

Explanation

Primary arthrodesis of the first, second, and third tarsometatarsal joints for purely ligamentous Lisfranc injuries has similar functional outcomes to ORIF but significantly decreases the need for planned hardware removal and secondary salvage arthrodesis.

Question 3675

Topic: Midfoot & Hindfoot

A 25-year-old male sustains a closed lateral subtalar dislocation. Closed reduction in the emergency department is unsuccessful. Which of the following anatomic structures is most likely blocking the reduction?

. Extensor digitorum brevis
. Tibialis posterior tendon
. Extensor retinaculum
. Flexor hallucis longus tendon
. Peroneus brevis tendon

Correct Answer & Explanation

. Tibialis posterior tendon

Explanation

Lateral subtalar dislocations represent about 15% of subtalar dislocations and occur when the talar head is forced medially. An irreducible lateral subtalar dislocation is most commonly blocked by the interposition of the tibialis posterior tendon.

Question 3676

Topic: 8. Foot and Ankle

During operative fixation of a Weber C ankle fracture with an associated syndesmotic rupture, what is the recommended position of the ankle during syndesmotic screw placement based on recent evidence?

. Maximum plantarflexion to ensure maximum fibular length
. Maximum dorsiflexion to prevent postoperative stiffness
. Neutral position; position has not been shown to affect clinical outcome
. Inversion to tension the lateral ligaments
. Eversion to reduce the medial clear space

Correct Answer & Explanation

. Neutral position; position has not been shown to affect clinical outcome

Explanation

Historically, surgeons advocated placing the ankle in maximal dorsiflexion during syndesmosis fixation due to the wider anterior talar dome. However, recent biomechanical and clinical evidence demonstrates that ankle position during fixation does not affect postoperative range of motion or clinical outcomes.

Question 3677

Topic: 8. Foot and Ankle

A 28-year-old male presents with lateral ankle pain after landing a jump while snowboarding. Radiographs appear normal, but a CT scan reveals a displaced, 1.5 cm fracture of the lateral process of the talus. What is the most appropriate treatment?

. Non-weight bearing cast for 6 weeks
. Weight bearing in a CAM boot for 4 weeks
. Open reduction and internal fixation
. Excision of the fragment
. Subtalar arthrodesis

Correct Answer & Explanation

. Open reduction and internal fixation

Explanation

"Snowboarder's fractures" involving the lateral process of the talus that are displaced (>2 mm) or involve a large intra-articular fragment should be treated with open reduction and internal fixation to restore the subtalar joint surface.

Question 3678

Topic: 8. Foot and Ankle

Which of the following areas of the tarsal navicular is at the highest risk for a stress fracture due to its unique vascular supply?

. Central third
. Medial tuberosity
. Plantar pole
. Dorsal ridge
. Lateral third

Correct Answer & Explanation

. Central third

Explanation

The central third of the tarsal navicular is a relative avascular watershed zone, receiving its blood supply from a network of dorsal and plantar vessels. This relative ischemia makes it highly susceptible to stress fractures in running and jumping athletes.

Question 3679

Topic: 8. Foot and Ankle

When comparing functional rehabilitation (non-operative with early mobilization) to operative repair for acute Achilles tendon ruptures, how do the complication profiles differ?

. Operative management has a higher re-rupture rate
. Non-operative management has a higher rate of deep infection
. Operative management has a higher rate of sural nerve injury and wound complications
. Non-operative management results in significantly greater plantarflexion strength
. There is no difference in the overall complication rates

Correct Answer & Explanation

. Operative management has a higher rate of sural nerve injury and wound complications

Explanation

Modern functional rehabilitation protocols for Achilles tendon ruptures have similar re-rupture rates to operative repair. Operative repair, however, carries a significantly higher risk of surgical site infections, wound healing issues, and sural nerve injury.

Question 3680

Topic: Ankle Trauma & Sports

On an AP radiograph of an ankle fracture, you note a transverse fracture of the medial malleolus and a short oblique fracture of the fibula originating at the joint line and extending posterosuperiorly. According to Lauge-Hansen, what was the mechanism of injury?

. Supination-External Rotation
. Supination-Adduction
. Pronation-External Rotation
. Pronation-Abduction
. Plantarflexion-Inversion

Correct Answer & Explanation

. Supination-External Rotation

Explanation

A Supination-External Rotation (SER) injury typically presents with an oblique or spiral fibular fracture starting at the level of the syndesmosis (anterior-inferior to posterior-superior). A transverse medial malleolus fracture represents the stage 4 avulsion injury in this sequence.

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