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8. Foot and Ankle MCQs

Practice Set 332 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 6621

Topic: 8. Foot and Ankle

A 45-year-old male sustains an acute Achilles tendon rupture while playing tennis. The rupture occurred in the classic "watershed" region of the tendon, which is known to have a precarious blood supply. Approximately how far proximal to the calcaneal insertion is this hypovascular zone located?

. 0 to 1 cm
. 2 to 6 cm
. 7 to 10 cm
. 11 to 14 cm
. At the musculotendinous junction

Correct Answer & Explanation

. 2 to 6 cm

Explanation

Correct Answer: 2 to 6 cmThe Achilles tendon is the largest and strongest tendon in the body, but it is highly susceptible to rupture, most commonly occurring in a specific hypovascular zone. This "watershed" area is located approximately 2 to 6 cm proximal to the tendon's insertion on the calcaneus. The blood supply to the tendon comes from the musculotendinous junction proximally and the osseotendinous junction distally, leaving this mid-substance region relatively ischemic and prone to degenerative changes and subsequent acute rupture during eccentric loading.

Question 6622

Topic: 8. Foot and Ankle

A 24-year-old male is struck by a motor vehicle, sustaining a highly comminuted fracture of the proximal fibula. He subsequently develops a foot drop and numbness over the dorsum of his foot. Which of the following muscles will most likely demonstrate normal strength on physical examination?

. Tibialis anterior
. Extensor hallucis longus
. Peroneus brevis
. Tibialis posterior
. Extensor digitorum longus

Correct Answer & Explanation

. Tibialis posterior

Explanation

Correct Answer: D (Tibialis posterior)The patient has sustained an injury to the common peroneal nerve, which wraps around the fibular neck and is highly susceptible to injury in proximal fibula fractures. The common peroneal nerve bifurcates into the deep and superficial peroneal nerves. The deep peroneal nerve innervates the anterior compartment of the leg (tibialis anterior, extensor hallucis longus, extensor digitorum longus), responsible for ankle dorsiflexion. The superficial peroneal nerve innervates the lateral compartment (peroneus longus and brevis), responsible for ankle eversion. The tibialis posterior is located in the deep posterior compartment of the leg and is innervated by the tibial nerve. Therefore, its function (plantarflexion and inversion) will remain intact.

Question 6623

Topic: 8. Foot and Ankle

A 45-year-old male presents with severe lower back pain radiating down the lateral aspect of his left leg to the dorsum of his foot. MRI reveals a large paracentral disc extrusion at the L4-L5 level. Physical examination is most likely to reveal weakness in which of the following actions, and a diminished reflex in which tendon?

. Weakness in ankle plantarflexion; diminished Achilles reflex
. Weakness in great toe extension; normal reflexes
. Weakness in knee extension; diminished patellar reflex
. Weakness in hip flexion; normal reflexes
. Weakness in ankle eversion; diminished Achilles reflex

Correct Answer & Explanation

. Weakness in great toe extension; normal reflexes

Explanation

Correct Answer: B (Weakness in great toe extension; normal reflexes)In the lumbar spine, a paracentral disc herniation typically impinges on the traversing nerve root. Therefore, an L4-L5 paracentral herniation will compress the L5 nerve root. The L5 nerve root provides motor innervation primarily to the extensor hallucis longus (EHL), responsible for great toe extension, and the tibialis anterior (ankle dorsiflexion). Sensory loss would be noted over the first dorsal web space. Unlike the L4 root (patellar reflex) and the S1 root (Achilles reflex), there is no reliable primary deep tendon reflex associated with the L5 nerve root; thus, reflexes typically remain normal.

Question 6624

Topic: 8. Foot and Ankle

A 30-year-old football player sustains a hyperplantarflexion injury to his midfoot. Weight-bearing radiographs demonstrate widening of the space between the bases of the first and second metatarsals. The primary stabilizing ligament injured in this scenario connects which two osseous structures?

. Medial cuneiform and base of the first metatarsal
. Medial cuneiform and base of the second metatarsal
. Middle cuneiform and base of the second metatarsal
. Navicular and medial cuneiform
. Cuboid and base of the fourth metatarsal

Correct Answer & Explanation

. Medial cuneiform and base of the second metatarsal

Explanation

The Lisfranc ligament is a stout intra-articular ligament that connects the medial cuneiform to the base of the second metatarsal. Disruption of this ligament causes instability of the tarsometatarsal joint complex.

Question 6625

Topic: 8. Foot and Ankle
A 24-year-old football player sustains a knee dislocation (KD-III) following a high-velocity tackle. The knee is reduced in the emergency department. His foot is warm, and palpable dorsalis pedis and posterior tibial pulses are present. The Ankle-Brachial Index (ABI) is measured at 0.85. What is the most appropriate next step in the vascular evaluation of this patient?
. Discharge with closely monitored outpatient follow-up
. Perform serial ABI measurements every 4 hours for 24 hours
. Obtain a CT angiogram of the lower extremity
. Proceed immediately to the operating room for vascular exploration
. Perform a duplex ultrasound of the lower extremity

Correct Answer & Explanation

. Obtain a CT angiogram of the lower extremity

Explanation

In the setting of a knee dislocation, an Ankle-Brachial Index (ABI) of less than 0.90 is a strong indicator of a potential arterial injury, even if distal pulses are palpable. A CT angiogram is the gold standard next step to definitively evaluate for popliteal artery compromise.

Question 6626

Topic: 8. Foot and Ankle

A 28-year-old professional basketball player sustains an acute ankle inversion injury. He presents with severe pain and swelling over the lateral ankle. On examination, there is tenderness over the anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL). Anterior drawer test is positive, and the talar tilt test is positive. An MRI reveals a complete rupture of the ATFL and CFL. What is the recommended management?

. Immediate surgical repair of both ligaments
. Controlled ankle motion (CAM) boot immobilization for 6 weeks followed by physical therapy
. Casting for 2 weeks, then gradual weight-bearing
. Platelet-rich plasma (PRP) injection followed by immobilization
. Surgical reconstruction with a graft due to high demand

Correct Answer & Explanation

. Controlled ankle motion (CAM) boot immobilization for 6 weeks followed by physical therapy

Explanation

For most acute lateral ankle ligament ruptures, even complete tears involving both the ATFL and CFL, non-operative management with a period of immobilization followed by aggressive rehabilitation yields excellent results. A CAM boot allows for controlled motion and early weight-bearing as tolerated. Surgical repair or reconstruction is typically reserved for chronic instability after failed non-operative treatment, or in rare cases, highly demanding athletes with persistent instability. PRP injection lacks strong evidence for superior outcomes in acute ligament tears. Casting for only 2 weeks might be insufficient immobilization.

Question 6627

Topic: 8. Foot and Ankle

A 40-year-old male sustains a Lisfranc injury after a motor vehicle accident. Radiographs and CT scans confirm a homolateral Lisfranc dislocation with diastasis between the first and second metatarsal bases. There is no open wound. What is the optimal treatment for this injury?

. Closed reduction and casting for 6-8 weeks
. Open reduction and internal fixation (ORIF) with screw fixation across the first and second cuneiforms and metatarsal bases
. Primary arthrodesis of the tarsometatarsal joints
. Excision of the accessory navicular
. Immobilization in a walking boot with delayed weight-bearing

Correct Answer & Explanation

. Open reduction and internal fixation (ORIF) with screw fixation across the first and second cuneiforms and metatarsal bases

Explanation

For unstable Lisfranc injuries, particularly those with significant diastasis and dislocation, open reduction and internal fixation (ORIF) is the treatment of choice. Accurate anatomical reduction and rigid fixation are paramount to restore the arch and prevent post-traumatic arthritis. Screws are typically placed from the medial cuneiform to the second metatarsal base (Lisfranc screw) and potentially other intercuneiform or metatarsal base screws depending on the specific pattern. Closed reduction and casting alone are insufficient for unstable injuries. Primary arthrodesis may be considered for severe comminuted injuries or after failed ORIF, but ORIF is preferred initially. Excision of an accessory navicular is unrelated. Immobilization in a walking boot is inadequate.

Question 6628

Topic: 8. Foot and Ankle

A 60-year-old active male sustains an acute rupture of his Achilles tendon. Physical examination reveals a palpable gap and a positive Thompson test. He is otherwise healthy. What is the most appropriate management approach to minimize the risk of re-rupture while maintaining functional outcome?

. Long leg cast immobilization for 8 weeks in equinus.
. Immediate surgical repair followed by early protected mobilization.
. Non-weight bearing with crutches for 2 weeks, then walking boot.
. Platelet-rich plasma (PRP) injection and immobilization for 4 weeks.
. Gradual weight-bearing and aggressive physical therapy without immobilization.

Correct Answer & Explanation

. Immediate surgical repair followed by early protected mobilization.

Explanation

For active patients who sustain an acute Achilles tendon rupture, surgical repair followed by early protected mobilization has generally demonstrated lower re-rupture rates compared to non-operative treatment, especially in high-demand individuals. Early protected mobilization protocols typically involve a controlled ankle motion (CAM) boot with progressive plantarflexion to neutral. Non-operative management can be successful, but typically involves a prolonged period of immobilization, and carries a higher re-rupture risk. PRP injection lacks strong evidence for superior outcomes. Long leg cast for 8 weeks is too restrictive and would lead to significant stiffness and atrophy. Immediate aggressive physical therapy without immobilization would risk re-rupture.

Question 6629

Topic: Ankle Trauma & Sports

Which ligament is critical for maintaining the stability of the distal tibiofibular syndesmosis?

. Anterior talofibular ligament (ATFL)
. Posterior talofibular ligament (PTFL)
. Deltoid ligament
. Anterior inferior tibiofibular ligament (AITFL)
. Calcaneofibular ligament (CFL)

Correct Answer & Explanation

. Anterior inferior tibiofibular ligament (AITFL)

Explanation

The anterior inferior tibiofibular ligament (AITFL) is a primary stabilizer of the distal tibiofibular syndesmosis, along with the posterior inferior tibiofibular ligament (PITFL) and the interosseous ligament. Injuries to these ligaments result in syndesmotic (high ankle) sprains. The ATFL, PTFL, and CFL are components of the lateral ankle collateral ligaments, stabilizing the talocrural joint. The deltoid ligament is the medial collateral ligament of the ankle.

Question 6630

Topic: 8. Foot and Ankle

What is the primary function of the deltoid ligament in the ankle?

. Preventing posterior talar translation.
. Resisting excessive inversion of the ankle.
. Resisting excessive eversion of the ankle.
. Stabilizing the distal tibiofibular syndesmosis.
. Limiting dorsiflexion of the ankle.

Correct Answer & Explanation

. Resisting excessive eversion of the ankle.

Explanation

The deltoid ligament is the strong medial collateral ligament complex of the ankle. Its primary function is to resist excessive eversion of the talus and valgus stress at the ankle joint. It consists of multiple fascicles (tibionavicular, tibiocalcaneal, posterior tibiotalar, and anterior tibiotalar). The lateral collateral ligaments (ATFL, CFL, PTFL) resist inversion. The syndesmotic ligaments stabilize the tibiofibular joint. The PTL prevents posterior talar translation, and the ATFL prevents anterior talar translation. The Achilles tendon limits dorsiflexion.

Question 6631

Topic: 8. Foot and Ankle

A 12-year-old female presents with pain and swelling over the medial aspect of her right foot, just distal to the navicular. A palpable prominence is noted, and radiographs show an accessory navicular bone. What is the most common cause of symptoms associated with an accessory navicular?

. Direct impingement on the talus
. Fracture of the accessory navicular
. Inflammation of the synchondrosis between the accessory navicular and the main navicular, exacerbated by posterior tibial tendon pull
. Compression of the medial plantar nerve
. Rupture of the tibialis posterior tendon

Correct Answer & Explanation

. Inflammation of the synchondrosis between the accessory navicular and the main navicular, exacerbated by posterior tibial tendon pull

Explanation

An accessory navicular (os naviculare accessorium) is an extra bone on the medial side of the navicular. Symptoms, when present, are most commonly caused by inflammation or disruption of the synchondrosis (fibrocartilaginous joint) between the accessory navicular and the main navicular, particularly due to the pull of the posterior tibial tendon, which inserts into this region. Overuse or trauma can exacerbate this. It often presents during adolescence when ossification centers are active. Direct impingement, fracture, or nerve compression are less common causes of pain from this condition, and rupture of the posterior tibial tendon is a more severe, distinct pathology.

Question 6632

Topic: 8. Foot and Ankle

A 25-year-old runner presents with heel pain that is worse in the morning and after periods of rest, improving with activity. Examination reveals tenderness at the plantar fascial insertion on the medial calcaneal tuberosity. What is the most appropriate initial treatment?

. Corticosteroid injection into the plantar fascia.
. Night splint and plantar fascia stretching exercises.
. Surgical release of the plantar fascia.
. Custom orthotics with arch support and heel cup.
. Extracorporeal shockwave therapy (ESWT).

Correct Answer & Explanation

. Night splint and plantar fascia stretching exercises.

Explanation

The patient's symptoms are classic for plantar fasciitis. The most appropriate initial treatment for plantar fasciitis is a conservative regimen that includes night splints (to keep the foot in dorsiflexion, stretching the fascia), plantar fascia stretching exercises, calf stretching, appropriate footwear, and activity modification. Corticosteroid injections provide short-term relief but can weaken the fascia. Surgical release is a last resort for refractory cases. Custom orthotics and ESWT are often considered after initial conservative measures fail. Initial management should focus on non-invasive therapies.

Question 6633

Topic: 8. Foot and Ankle

A 22-year-old man sustains the midfoot injury shown in the radiograph. The injury involves disruption of the Lisfranc ligament complex. Which of the following best describes the anatomic attachments of the primary, strongest band of the Lisfranc ligament?

. From the medial cuneiform to the base of the first metatarsal
. From the medial cuneiform to the base of the second metatarsal
. From the middle cuneiform to the base of the second metatarsal
. From the lateral cuneiform to the base of the third metatarsal
. From the cuboid to the base of the fourth metatarsal

Correct Answer & Explanation

. From the medial cuneiform to the base of the second metatarsal

Explanation

Correct Answer: BThe radiograph demonstrates a Lisfranc injury (tarsometatarsal fracture-dislocation). The Lisfranc ligament is a critical stabilizing structure of the midfoot. Its primary, strongest, and most important band (the interosseous Lisfranc ligament) attaches from the lateral aspect of the medial cuneiform to the medial aspect of the base of the second metatarsal. There is no direct ligamentous connection between the first and second metatarsal bases.

Question 6634

Topic: 8. Foot and Ankle

A 38-year-old woman presents with severe, sharp pain in the third webspace of her foot, 18 months after undergoing a dorsal neurectomy for a Morton's neuroma. Examination reveals a positive Mulder's click and exquisite tenderness on the plantar aspect. If surgical intervention is chosen, what is the most reliable approach and procedure?

. Dorsal approach with revision neurectomy
. Plantar approach with revision neurectomy to a more proximal level
. Dorsal approach with deep transverse metatarsal ligament release
. Plantar condylectomy of the adjacent metatarsal heads
. Percutaneous radiofrequency ablation

Correct Answer & Explanation

. Plantar approach with revision neurectomy to a more proximal level

Explanation

Correct Answer: BRecurrent Morton's neuroma is typically due to a stump neuroma located in the weight-bearing area resulting from an initial resection that was too distal. The most reliable surgical treatment is a revision neurectomy to resect the nerve more proximally, moving the stump out of the weight-bearing zone. A plantar approach is preferred for revision surgery as it allows excellent visualization of the nerve proximal to the deep transverse metatarsal ligament and avoids the dorsal scar tissue from the index procedure.

Question 6635

Topic: 8. Foot and Ankle

A 24-year-old rugby player sustains an axial loading injury to his plantarflexed foot. Weight-bearing radiographs demonstrate widening of the space between the medial and middle cuneiforms. The key ligament disrupted in this injury (the Lisfranc ligament) connects which two osseous structures?

. Medial cuneiform to the base of the first metatarsal
. Medial cuneiform to the base of the second metatarsal
. Middle cuneiform to the base of the second metatarsal
. Navicular to the medial cuneiform
. 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 a strong interosseous ligament extending from the lateral aspect of the medial cuneiform to the medial aspect of the base of the second metatarsal. Its disruption is a hallmark of Lisfranc fracture-dislocations.

Question 6636

Topic: 8. Foot and Ankle

During tibial lengthening over a nail (LON) using a circular fixator, a patient develops a progressive equinus contracture despite daily physical therapy. Which of the following is the most appropriate initial management?

. Immediate operative Achilles tendon lengthening
. Stopping or decreasing the lengthening process and intensifying physical therapy
. Botulinum toxin injection to the gastrocnemius
. Distal tibia-fibula syndesmotic screw fixation
. Open gastrocnemius recession

Correct Answer & Explanation

. Stopping or decreasing the lengthening process and intensifying physical therapy

Explanation

The initial management for an equinus contracture during distraction osteogenesis is to decrease or halt the rate of distraction while increasing aggressive stretching and splinting. Operative intervention is reserved for refractory cases.

Question 6637

Topic: 8. Foot and Ankle

During an acute correction of a severe valgus deformity of the proximal tibia using a closing wedge osteotomy, the patient develops a foot drop postoperatively. Which structure is most likely compromised?

. Tibial nerve
. Common peroneal nerve
. Deep peroneal nerve alone
. Saphenous nerve
. Sural nerve

Correct Answer & Explanation

. Common peroneal nerve

Explanation

Acute correction of genu valgum stretches the lateral structures, placing the common peroneal nerve at high risk for traction neurapraxia or palsy. Prophylactic peroneal nerve decompression is often considered in severe acute varus-producing corrections.

Question 6638

Topic: 8. Foot and Ankle

During distraction osteogenesis using an external fixator for a 5 cm tibial lengthening, a patient develops an equinus contracture. What is the most appropriate initial management?

. Immediate Achilles tendon lengthening
. Stopping distraction completely
. Aggressive physical therapy and night splinting
. Botulinum toxin injection to the gastrocnemius
. Compressing the fixator to starting length

Correct Answer & Explanation

. Aggressive physical therapy and night splinting

Explanation

Soft tissue contractures, particularly equinus during tibial lengthening, are common complications. Initial management involves aggressive physical therapy, dynamic splinting, and sometimes slowing the distraction rate before considering surgical release.

Question 6639

Topic: 8. Foot and Ankle

A 30-year-old male presents with acute onset, excruciating low back pain and right leg pain following a motor vehicle accident. He has a foot drop on the right side and diminished sensation in the web space between the first and second toes. His patellar and ankle reflexes are normal. Which nerve root is most likely affected?

. L3
. L4
. L5
. S1
. S2

Correct Answer & Explanation

. L5

Explanation

The patient's symptoms (foot drop, diminished sensation in the web space between the first and second toes) are classic for an L5 radiculopathy. The L5 nerve root innervates muscles responsible for ankle dorsiflexion (tibialis anterior, extensor hallucis longus) and provides sensation to the dorsum of the foot, including the first web space. L5 radiculopathy typically does not affect the patellar (L4) or ankle (S1) reflexes. L4 affects the quadriceps and patellar reflex. S1 affects plantarflexion and the ankle jerk reflex. L3 affects the adductors and knee sensation.

Question 6640

Topic: 8. Foot and Ankle

A 14-year-old girl presents with a painful hallux valgus deformity. Radiographs demonstrate an increased first-second intermetatarsal angle, a congruent metatarsophalangeal joint, and an abnormal distal metatarsal articular angle. Which of the following surgical strategies is most appropriate to correct all of these specific radiographic abnormalities?

. Distal soft-tissue realignment alone
. Proximal first metatarsal osteotomy with distal soft-tissue realignment
. Distal first metatarsal osteotomy with distal soft-tissue realignment
. Proximal and distal first metatarsal osteotomy
. Arthrodesis of the first metatarsophalangeal joint

Correct Answer & Explanation

. Proximal and distal first metatarsal osteotomy

Explanation

Correct Answer: DIn juvenile hallux valgus, the presence of an increased intermetatarsal angle combined with an abnormal distal metatarsal articular angle (DMAA) and a congruent joint requires a double osteotomy. A proximal osteotomy is needed to correct the intermetatarsal angle, while a distal osteotomy is required to correct the abnormal DMAA. Soft-tissue realignment alone or single osteotomies will fail to address both components of the deformity, leading to a high risk of recurrence or joint incongruency.

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