Menu

8. Foot and Ankle MCQs

Practice Set 53 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 1041

Topic: Midfoot & Hindfoot

A 55-year-old diabetic patient presents with an acutely swollen, erythematous, and warm foot but no systemic signs of infection. Radiographs show periarticular debris, fragmentation of the tarsometatarsal joints, and subluxation. According to the Eichenholtz classification, what stage does this represent, and what is the preferred initial management?

. Stage 0; Immediate open reduction internal fixation
. Stage 1; Total contact casting and non-weight-bearing
. Stage 2; Custom orthosis and weight-bearing as tolerated
. Stage 3; Arthrodesis of the midfoot
. Stage 1; Intravenous antibiotics and surgical debridement

Correct Answer & Explanation

. Stage 1; Total contact casting and non-weight-bearing

Explanation

This presentation describes Eichenholtz Stage 1 (development/fragmentation) of Charcot arthropathy. The gold standard initial management is offloading via total contact casting to prevent further deformity while the acute inflammatory phase resolves.

Question 1042

Topic: 8. Foot and Ankle

A 25-year-old collegiate football player sustains a purely ligamentous Lisfranc injury. Weight-bearing radiographs demonstrate 3 mm of widening between the medial cuneiform and the base of the second metatarsal. Based on recent high-level evidence, what is the favored operative management for a purely ligamentous Lisfranc injury to minimize the need for subsequent revision surgery?

. Closed reduction and percutaneous pinning (CRPP)
. Open reduction and internal fixation (ORIF) with transarticular screws
. Open reduction and internal fixation (ORIF) with dorsal bridge plating
. Primary partial tarsometatarsal arthrodesis
. Immobilization in a non-weight-bearing cast for 8 weeks

Correct Answer & Explanation

. Primary partial tarsometatarsal arthrodesis

Explanation

Recent prospective randomized studies indicate that primary arthrodesis of the involved tarsometatarsal joints for purely ligamentous Lisfranc injuries yields superior functional outcomes and a lower revision rate compared to ORIF.

Question 1043

Topic: 8. Foot and Ankle
A 28-year-old male sustains a Hawkins Type III fracture of the talar neck after a fall from a height. Which of the following best describes the expected rate of avascular necrosis (AVN) of the talar body and the mechanism of disrupted blood supply?
. 0-10%, disruption of the artery of the tarsal canal
. 20-50%, disruption of the dorsalis pedis artery branches
. 50-75%, disruption of the artery of the tarsal sinus
. 80-100%, disruption of the artery of the tarsal canal, deltoid branches, and intraosseous network
. 100%, disruption of the posterior tibial artery

Correct Answer & Explanation

. 80-100%, disruption of the artery of the tarsal canal, deltoid branches, and intraosseous network

Explanation

Hawkins Type III fractures involve the talar neck with subtalar and tibiotalar dislocation, disrupting all three major blood supplies to the talar body. The AVN rate approaches 80-100% in these injuries.

Question 1044

Topic: 8. Foot and Ankle

A 40-year-old male weekend warrior sustains an acute Achilles tendon rupture. When discussing operative versus non-operative management in a highly structured board setting, what is the most accurate statement regarding outcomes based on recent prospective randomized trials?

. Operative management has a significantly lower re-rupture rate but higher complication rate, assuming functional rehabilitation is not used
. With early functional rehabilitation, non-operative management has equivalent re-rupture rates to operative management
. Non-operative management results in significantly greater plantarflexion strength at 1 year
. Operative management has a lower risk of sural nerve injury
. Traditional cast immobilization yields better outcomes than early functional rehabilitation

Correct Answer & Explanation

. With early functional rehabilitation, non-operative management has equivalent re-rupture rates to operative management

Explanation

Recent Level I evidence shows that when early functional rehabilitation (early weight-bearing and ROM) is employed, re-rupture rates are not significantly different between operative and non-operative groups. However, surgery continues to carry a higher risk of wound complications.

Question 1045

Topic: 8. Foot and Ankle
A 24-year-old male sustains a displaced Hawkins Type III fracture of the talar neck following a motorcycle accident. Which specific arterial blood supply is considered the dominant contributor to the talar body and is most predictably disrupted in this severe injury pattern?
. Artery of the tarsal canal
. Artery of the tarsal sinus
. Deltoid branch of the posterior tibial artery
. Branches of the dorsalis pedis artery
. Perforating branches of the peroneal artery

Correct Answer & Explanation

. Artery of the tarsal canal

Explanation

The artery of the tarsal canal is a branch of the posterior tibial artery and provides the dominant, most critical blood supply to the talar body. Disruption of this artery, along with others in displaced talar neck fractures, dramatically increases the risk of avascular necrosis.

Question 1046

Topic: 8. Foot and Ankle
A 28-year-old male sustains a Hawkins Type III talar neck fracture following a motor vehicle collision. Based on the classification, what is the approximate risk of developing avascular necrosis (AVN) of the talar body?
. 0-10%
. 15-30%
. 40-50%
. 75-100%
. 100% with immediate subtalar arthritis

Correct Answer & Explanation

. 75-100%

Explanation

A Hawkins Type III talar neck fracture involves subluxation or dislocation of both the subtalar and tibiotalar joints. This severe injury disrupts the major blood supplies to the talus, leading to an AVN risk nearing 75-100%.

Question 1047

Topic: 8. Foot and Ankle

The surgeon plans operative intervention for the displaced, comminuted navicular body fracture. A medial approach is chosen. Which of the following describes the correct anatomical interval for this approach and a critical neurovascular structure at risk?

. A. Between the extensor hallucis longus and tibialis anterior tendons; risk to the deep peroneal nerve.
. B. Between the tibialis anterior and tibialis posterior tendons; risk to the dorsalis pedis artery.
. C. Between the flexor digitorum longus and flexor hallucis longus tendons; risk to the posterior tibial nerve.
. D. Between the tibialis anterior and tibialis posterior tendons; risk to the medial plantar nerve.
. E. Between the peroneus longus and brevis tendons; risk to the superficial peroneal nerve.

Correct Answer & Explanation

. B. Between the tibialis anterior and tibialis posterior tendons; risk to the dorsalis pedis artery.

Explanation

Correct Answer: BExplanation:The case explicitly states, 'I would use a medial approach, between the tibialis anterior and tibialis posterior tendons, preserving the remaining blood supply as much as possible...' The medial approach to the navicular is typically performed through the interval between the tibialis anterior tendon (anteriorly) and the tibialis posterior tendon (posteriorly). The dorsalis pedis artery is a continuation of the anterior tibial artery and runs on the dorsum of the foot. While the primary approach is medial, the blood supply to the navicular relies on the radial arcade of vessels arising from the dorsalis pedis and medial plantar arteries. Injury to these vessels, particularly the dorsalis pedis artery and its branches, can compromise the already tenuous blood supply to the navicular, leading to complications like avascular necrosis (AVN) and non-union, as highlighted in the case.A. Between the extensor hallucis longus and tibialis anterior tendons; risk to the deep peroneal nerve:This interval is more dorsal and lateral, typically used for approaches to the talus or first metatarsal, not the navicular. The deep peroneal nerve is at risk in this region.C. Between the flexor digitorum longus and flexor hallucis longus tendons; risk to the posterior tibial nerve:This interval is on the plantar aspect of the foot, not a standard approach for a navicular body fracture. The posterior tibial nerve is in the tarsal tunnel.D. Between the tibialis anterior and tibialis posterior tendons; risk to the medial plantar nerve:While the medial plantar nerve is present on the medial side of the foot, the primary neurovascular structure at risk for the navicular's blood supply, as discussed in the context of AVN, is the arterial supply (dorsalis pedis and medial plantar arteries). The dorsalis pedis artery is a more direct concern for the navicular's dorsal blood supply.E. Between the peroneus longus and brevis tendons; risk to the superficial peroneal nerve:This interval is on the lateral side of the foot, not a medial approach to the navicular. The superficial peroneal nerve is at risk laterally.

Question 1048

Topic: 8. Foot and Ankle

The examiner asks about the high incidence of non-union and avascular necrosis (AVN) in navicular fractures. The candidate correctly explains that the navicular bone's blood supply is vulnerable. Which specific arterial arcade is primarily responsible for the navicular's blood supply and is most susceptible to injury in these fractures?

. A. Perforating branches of the peroneal artery.
. B. Arcuate artery from the dorsalis pedis artery.
. C. Radial arcade of vessels from the dorsalis pedis and medial plantar arteries.
. D. Lateral tarsal artery from the dorsalis pedis artery.
. E. Medial malleolar artery from the posterior tibial artery.

Correct Answer & Explanation

. C. Radial arcade of vessels from the dorsalis pedis and medial plantar arteries.

Explanation

Correct Answer: CExplanation:The case explicitly states, 'The navicular bone, similar to talus, has a large articular surface area and for the blood supply it relies on the radial arcade of vessels arising from the dorsalis pedis and medial planter arteries and this could be injured either at the time of fracture or during surgery, which could lead to AVN, non-union and/or collapse of the bone resulting in a painful mid-foot.' This directly answers the question. The navicular's blood supply is indeed precarious, primarily derived from a radial arcade formed by branches of the dorsalis pedis artery dorsally and the medial plantar artery plantarly. This dual supply can be compromised by high-energy fractures or surgical dissection, leading to the dreaded complications of AVN and non-union.A. Perforating branches of the peroneal artery:The peroneal artery primarily supplies the lateral compartment of the leg and lateral ankle/hindfoot, not the navicular.B. Arcuate artery from the dorsalis pedis artery:The arcuate artery is a branch of the dorsalis pedis artery that supplies the metatarsals, but it is not the primary or sole supply to the navicular body. The 'radial arcade' is a more comprehensive description of the navicular's supply.D. Lateral tarsal artery from the dorsalis pedis artery:The lateral tarsal artery is a branch of the dorsalis pedis artery that supplies the lateral tarsus, but again, it's not the primary arcade for the navicular body.E. Medial malleolar artery from the posterior tibial artery:The medial malleolar artery supplies the medial malleolus and surrounding ankle structures, not the navicular bone.

Question 1049

Topic: Midfoot & Hindfoot

The candidate discusses the management options for the navicular fracture, stating that operative intervention is favored. However, they also mention a specific scenario where primary fusion of the talonavicular joint might be considered. What is this specific indication for primary fusion, as outlined in the case?

. A. Patient refusal for internal fixation.
. B. Significant soft tissue compromise precluding open reduction.
. C. Severe comminution of the articular surface making anatomical reduction impossible.
. D. Associated Lisfranc injury requiring concurrent fusion.
. E. Presence of pre-existing talonavicular arthritis.

Correct Answer & Explanation

. C. Severe comminution of the articular surface making anatomical reduction impossible.

Explanation

Correct Answer: CExplanation:The case states, 'The principles of management are to restore the articular surface, stabilize and hold the fracture to allow early mobilization. The aim of the treatment is to have a mobile, pain-free and functional joint. However, sometimes that is not possible due to severe comminution of the articular surface, in which case I may consider primary fusion of the talonavicular joint.' This directly indicates that severe comminution of the articular surface, rendering anatomical reduction and restoration of joint congruity unachievable, is the primary indication for considering primary talonavicular fusion.A. Patient refusal for internal fixation:While patient preference is always a factor in consent, it is not aclinicalindication for primary fusion in the context of fracture severity.B. Significant soft tissue compromise precluding open reduction:Soft tissue compromise might delay surgery or influence the approach, but it doesn't directly lead to a decision for primary fusion of the joint unless the soft tissue damage is so severe that it prevents any form of reconstruction or fixation. The case focuses on articular comminution as the reason for fusion.D. Associated Lisfranc injury requiring concurrent fusion:The case describes an 'isolated closed injury of the foot' and does not mention a Lisfranc injury. While a Lisfranc injury might require fusion, it's not the reason for primary talonavicular fusion in this specific navicular fracture scenario.E. Presence of pre-existing talonavicular arthritis:Pre-existing arthritis would certainly make fusion a more attractive option, but the case does not mention this. The indication given in the case is specifically related to the acute fracture's severity.

Question 1050

Topic: 8. Foot and Ankle

During the discussion of potential complications, the candidate lists early complications including nerve injury. Which specific nerve branches are highlighted as being at risk during a medial approach to the navicular?

. A. Sural nerve and its branches.
. B. Saphenous nerve and its infrapatellar branch.
. C. Superficial and deep peroneal nerves and their branches.
. D. Posterior tibial nerve and its calcaneal branches.
. E. Medial plantar nerve and its digital branches.

Correct Answer & Explanation

. C. Superficial and deep peroneal nerves and their branches.

Explanation

Correct Answer: CExplanation:The case states, 'Early complications include infection, nerve injury (branches of superficial and deep peroneal nerves) and vascular injury (dorsalis pedis).' This directly identifies the superficial and deep peroneal nerves as being at risk. While a medial approach is used for the navicular, the deep peroneal nerve runs dorsally and can be at risk during dissection or retraction, especially if the approach extends more dorsally or if there's significant swelling. The superficial peroneal nerve, though more lateral, can also be at risk with extensive dissection or positioning. It's important to consider all major nerves in the vicinity of the surgical field.A. Sural nerve and its branches:The sural nerve is located on the posterolateral aspect of the ankle and foot, not typically at direct risk during a medial navicular approach.B. Saphenous nerve and its infrapatellar branch:The saphenous nerve is a sensory nerve on the medial side of the leg and ankle, but its infrapatellar branch is much higher, around the knee. While the saphenous nerve itself can be at risk more proximally on the medial ankle, the case specifically mentions peroneal nerves.D. Posterior tibial nerve and its calcaneal branches:The posterior tibial nerve is located in the tarsal tunnel on the posteromedial aspect of the ankle, primarily supplying the plantar foot. It is generally not at direct risk during a medial approach to the navicular body.E. Medial plantar nerve and its digital branches:The medial plantar nerve is a terminal branch of the posterior tibial nerve, located on the plantar aspect of the foot. While it's on the medial side, it's deep and plantar, not typically at direct risk during a dorsal or medial approach to the navicular body.

Question 1051

Topic: 8. Foot and Ankle
A 26-year-old male sustains a Hawkins Type III talar neck fracture (fracture with subluxation/dislocation of both the subtalar and tibiotalar joints). What is the estimated rate of avascular necrosis (AVN) of the talar body associated with this injury type?
. Less than 10%
. 15-20%
. 30-40%
. 80-100%
. 0%

Correct Answer & Explanation

. 80-100%

Explanation

Hawkins Type III talar neck fractures involve complete disruption of the blood supply to the talar body (from the deltoid branches, artery of the tarsal canal, and artery of the sinus tarsi). The risk of AVN in Type III fractures is historically cited as nearly 80-100%.

Question 1052

Topic: Ankle Trauma & Sports

A 40-year-old female twists her ankle. Radiographs show a short oblique fracture of the distal fibula at the level of the syndesmosis and a transverse medial malleolus fracture. Based on the Lauge-Hansen classification (Supination-External Rotation), what is the first structure injured in this sequence?

. Medial malleolus
. Anterior inferior tibiofibular ligament (AITFL)
. Posterior inferior tibiofibular ligament (PITFL)
. Deltoid ligament
. Interosseous membrane

Correct Answer & Explanation

. Anterior inferior tibiofibular ligament (AITFL)

Explanation

In the Lauge-Hansen Supination-External Rotation (SER) sequence, the injury progresses from anterior to posterior. Stage 1 is the rupture of the anterior inferior tibiofibular ligament (AITFL).

Question 1053

Topic: 8. Foot and Ankle

A 27-year-old female sustains a Lisfranc injury during a horseback riding fall. She has a 'fleck sign' on her AP foot radiograph. This sign represents a bony avulsion of the Lisfranc ligament from which of the following anatomic locations?

. Plantar base of the first metatarsal
. Medial aspect of the medial cuneiform
. Plantar base of the second metatarsal
. Dorsal aspect of the intermediate cuneiform
. Navicular tuberosity

Correct Answer & Explanation

. Plantar base of the second metatarsal

Explanation

The 'fleck sign' is a pathognomonic radiographic finding for a Lisfranc injury. It represents a bony avulsion of the Lisfranc ligament from the plantar base of the second metatarsal, which normally connects to the medial cuneiform.

Question 1054

Topic: 8. Foot and Ankle

An extensile lateral approach is planned for the operative fixation of a displaced intra-articular calcaneus fracture. To minimize the risk of full-thickness skin flap necrosis, the surgeon must carefully preserve the primary arterial supply to the corner of the flap. Which artery supplies this crucial angiosome?

. Medial calcaneal artery
. Dorsalis pedis artery
. Lateral calcaneal artery
. Sural artery
. Anterior tibial artery

Correct Answer & Explanation

. Lateral calcaneal artery

Explanation

The extensile lateral approach to the calcaneus creates a full-thickness flap whose critical blood supply relies heavily on the lateral calcaneal artery, a branch of the peroneal artery. Careful subperiosteal dissection avoiding “no-touch” retractor techniques helps prevent devastating wound complications.

Question 1055

Topic: 8. Foot and Ankle

A 24-year-old football player sustains an injury to his midfoot. Weight-bearing radiographs show a 3 mm diastasis between the first and second metatarsal bases. The primary ligament injured in this condition connects which two osseous structures?

. Plantar aspect of the medial cuneiform to the base of the second metatarsal
. Dorsal aspect of the middle cuneiform to the base of the second metatarsal
. Plantar aspect of the navicular to the base of the first metatarsal
. Plantar aspect of the cuboid to the base of the fourth metatarsal
. Plantar aspect of the medial cuneiform to the base of the first metatarsal

Correct Answer & Explanation

. Plantar aspect of the medial cuneiform to the base of the second metatarsal

Explanation

The Lisfranc ligament is the largest and strongest ligament of the Lisfranc complex. It originates from the lateral, plantar aspect of the medial cuneiform and inserts onto the medial, plantar base of the second metatarsal.

Question 1056

Topic: 8. Foot and Ankle

A 45-year-old roofer falls from a ladder and sustains a displaced intra-articular calcaneus fracture.

He is indicated for open reduction and internal fixation via an extensile lateral approach. Which complication is most frequently associated with this specific surgical approach?

. Sural nerve injury
. Superficial peroneal nerve injury
. Flexor hallucis longus tendon tethering
. Wound edge necrosis and dehiscence
. Iatrogenic peroneal tendon subluxation

Correct Answer & Explanation

. Wound edge necrosis and dehiscence

Explanation

The extensile lateral approach to the calcaneus is notorious for wound healing complications, including wound edge necrosis and dehiscence, which occur in up to 10-25% of cases. Meticulous soft tissue handling and adhering to a "no-touch" technique for the skin flap are critical.

Question 1057

Topic: 8. Foot and Ankle

A 30-year-old male sustains a Lisfranc injury after a fall from height. Radiographs show diastasis between the medial cuneiform and the base of the second metatarsal.

What is the most critical component of surgical fixation for an unstable Lisfranc injury?

. Rigid fixation of all metatarsal-cuneiform joints
. Anatomic reduction and rigid fixation of the first and second tarsometatarsal (TMT) joints
. Fusion of the naviculocuneiform joint
. Flexible fixation of all TMT joints to allow motion
. Early weight-bearing to promote healing

Correct Answer & Explanation

. Anatomic reduction and rigid fixation of the first and second tarsometatarsal (TMT) joints

Explanation

Correct Answer: BThe Lisfranc joint complex includes the tarsometatarsal joints. The stability of the midfoot is largely dependent on the integrity of the Lisfranc ligament and the stability of the first and second tarsometatarsal (TMT) joints. Anatomic reduction and rigid internal fixation, typically with screws, of the first and second TMT joints are paramount to restore the arch, maintain stability, and prevent post-traumatic arthritis. While other TMT joints may be involved, stable fixation of the first and second TMT joints is the most critical for overall midfoot stability. Fusion is generally reserved for chronic instability or arthritis. Flexible fixation and early weight-bearing are inappropriate for acute, unstable Lisfranc injuries, as they can lead to loss of reduction and poor outcomes.

Question 1058

Topic: 8. Foot and Ankle

During open reduction and internal fixation of a displaced intra-articular calcaneus fracture via a lateral extensile approach, the surgeon utilizes the "constant fragment" as the foundation for reconstruction. Which anatomical structure is securely attached to this fragment?

. Achilles tendon
. Plantar fascia
. Spring ligament and deltoid ligament
. Bifurcate ligament
. Peroneus brevis tendon

Correct Answer & Explanation

. Spring ligament and deltoid ligament

Explanation

The "constant fragment" is the anteromedial fragment, which includes the sustentaculum tali. It remains relatively undisplaced due to the strong attachments of the deltoid and spring ligaments, serving as the foundation to which the remaining fragments are reduced.

Question 1059

Topic: 8. Foot and Ankle
A 32-year-old male sustains a Hawkins Type III fracture of the talar neck. Which of the following vessels provides the primary blood supply to the talar body and is most at risk in this injury?
. Anterior tibial artery
. Artery of the tarsal sinus
. Artery of the tarsal canal
. 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. In a Hawkins Type III injury, involving fracture of the talar neck with subtalar and tibiotalar dislocation, this vascular supply is highly compromised.

Question 1060

Topic: 8. Foot and Ankle
A 42-year-old roofer falls and sustains a closed, displaced, intra-articular calcaneus fracture (Sanders Type III). Open reduction and internal fixation via an extensile lateral approach is planned. Which of the following structures is at greatest risk during the creation of the full-thickness flap?
. Posterior tibial artery
. Sural nerve
. Deep peroneal nerve
. Medial plantar nerve
. Flexor hallucis longus tendon

Correct Answer & Explanation

. Sural nerve

Explanation

The sural nerve is highly vulnerable during the extensile lateral approach to the calcaneus. The full-thickness flap must be elevated in a 'no-touch' subperiosteal plane to protect the sural nerve and preserve the delicate soft tissue vascularity.

Test Yourself

Switch to an interactive, timed exam simulation to truly master this topic.

On this Page