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 201
Topic: 8. Foot and Ankle
A 3-month-old infant presents with a rigid rocker-bottom foot. Radiographs demonstrate a dorsally displaced navicular that does not reduce on a maximum plantar flexion lateral view. Which of the following is the most likely diagnosis?
Correct Answer & Explanation
. Congenital vertical talus
Explanation
Congenital vertical talus is characterized by a rigid rocker-bottom deformity and a dorsally dislocated navicular on the talus. Irreducibility of the talonavicular joint on a forced plantar flexion lateral radiograph confirms the diagnosis.
Question 202
Topic: 8. Foot and Ankle
A 13-year-old boy presents with recurrent ankle sprains and rigid flatfeet. Radiographs reveal a 'C-sign' on the lateral view. Which of the following represents the most likely anatomical location of the anomaly?
Correct Answer & Explanation
. Talocalcaneal
Explanation
The 'C-sign' on a lateral radiograph is highly indicative of a talocalcaneal (subtalar) coalition, representing a continuous bony bridge between the talar dome and the sustentaculum tali. Calcaneonavicular coalitions typically present with an 'anteater' sign.
Question 203
Topic: Midfoot & Hindfoot
A 6-year-old boy presents with a limp and midfoot pain. Radiographs demonstrate sclerosis and flattening of the navicular bone without signs of infection. What is the most appropriate treatment?
Correct Answer & Explanation
. Short-leg walking cast for 4-6 weeks
Explanation
The diagnosis is Kohler disease, an idiopathic avascular necrosis of the navicular bone. It is a self-limiting condition; severe pain is best treated with a short-leg walking cast for symptomatic relief while awaiting spontaneous revascularization.
Question 204
Topic: 8. Foot and Ankle
A 10-year-old boy presents with insidious onset of hindfoot pain and recurrent ankle sprains. Examination shows a rigid flatfoot with restricted subtalar motion and peroneal muscle spasm. Which tarsal coalition is most likely present given the patient's age and presentation?
Correct Answer & Explanation
. Calcaneonavicular
Explanation
Calcaneonavicular coalitions typically ossify and become symptomatic between 8 and 12 years of age, presenting with a rigid flatfoot and peroneal spasticity. Talocalcaneal coalitions typically ossify and become symptomatic slightly later, between 12 and 16 years of age.
Question 205
Topic: 8. Foot and Ankle
In an infant with an untreated idiopathic clubfoot, the talus exhibits which of the following primary anatomical abnormalities?
Correct Answer & Explanation
. Plantar and medial deviation of the talar neck
Explanation
In idiopathic clubfoot (CTEV), the primary bony deformity involves the talus, which is smaller than normal, with its neck shortened and deviated medially and plantarly. The calcaneus, navicular, and cuboid are rotated medially around this deformed talus.
Question 206
Topic: 8. Foot and Ankle
A 2-year-old girl is evaluated for bilateral genu varum. Radiographs reveal a metaphyseal-diaphyseal angle (Drennan's angle) of 18 degrees and medial physeal beaking. What is the recommended management?
Correct Answer & Explanation
. Knee-ankle-foot orthoses (KAFOs)
Explanation
The clinical and radiographic findings (metaphyseal-diaphyseal angle > 16 degrees) are highly suggestive of infantile Blount disease. Bracing with KAFOs is the standard initial treatment for stages I and II in children under 3 years of age.
Question 207
Topic: 8. Foot and Ankle
In a patient with congenital vertical talus, which of the following is the hallmark radiographic finding on a lateral radiograph in maximum plantarflexion?
Correct Answer & Explanation
. The navicular remains dorsally dislocated on the talus
Explanation
Congenital vertical talus is defined by a rigid dorsal dislocation of the navicular on the talus. This dislocation does not reduce on a maximum plantarflexion lateral radiograph, distinguishing it from an oblique talus.
Question 208
Topic: 8. Foot and Ankle
A 12-year-old boy complains of vague lateral hindfoot pain and frequent ankle sprains. Radiographs show a "C sign" on the lateral view. Which interpositional material is most appropriate after surgical resection of this anomaly?
Correct Answer & Explanation
. Autologous fat graft
Explanation
The "C sign" indicates a talocalcaneal coalition. After surgical resection, an autologous fat graft is the preferred interpositional material to prevent recurrence of this specific coalition.
Question 209
Topic: 8. Foot and Ankle
A 9-year-old boy presents with a painful rigid flatfoot. Radiographs confirm a calcaneonavicular coalition. Which non-operative management strategy is generally considered the most appropriate initial treatment?
Correct Answer & Explanation
. Short leg walking cast immobilization for 4 to 6 weeks
Explanation
Initial conservative management for a symptomatic tarsal coalition usually involves rigid immobilization in a short leg walking cast for 4 to 6 weeks to reduce joint inflammation and peroneal muscle spasms. Orthotics are often poorly tolerated in a rigid flatfoot.
Question 210
Topic: 8. Foot and Ankle
A 13-year-old boy complains of recurrent ankle sprains and lateral foot pain. Examination reveals rigid flatfeet and pain with subtalar motion. Oblique radiographs of the foot demonstrate an "anteater nose" sign. What is the most likely diagnosis?
Correct Answer & Explanation
. Calcaneonavicular coalition
Explanation
The "anteater nose" sign on an oblique radiograph of the foot represents an elongated anterior process of the calcaneus, diagnostic of a calcaneonavicular coalition. Talocalcaneal coalitions are typically identified by the "C-sign" on a lateral radiograph.
Question 211
Topic: 8. Foot and Ankle
There are no internal moments in the lower extremity during which phase of gait:
Correct Answer & Explanation
. Preswing
Explanation
Preswing is the only phase of gait in which all muscle groups are silent in the ipsilateral lower extremity. In the next phase (initial swing), internal moments are generated at the hip and ankle to initiate swing.
Question 212
Topic: Midfoot & Hindfoot
Which of the following findings is typical in patients with Marfan syndrome as opposed to patients with Ehlers-Danlos syndrome:
Correct Answer & Explanation
. Lens dislocation
Explanation
All of the findings presented, with the exception of lens dislocation, are seen in both syndromes at a frequency that exceeds the general population. Lens dislocation is common in patients with Marfan syndrome but not those with Ehlers-Danlos syndrome.
Question 213
Topic: 8. Foot and Ankle
A 4-year-old boy with macrodactyly of the foot has involvement of the second and third rays. He undergoes debulking of the soft tissues of the phalanges and amputation of the distal phalanges. Two years later, he returns with a dramatic increase in the width and length of the involved regions. You recommend:
Correct Answer & Explanation
. Ray resection of one of the involved rays with further debulking
Explanation
The increase in width of the involved regions can be handled only by ray resection. Additional proximal levels of amputation are not required.
Question 214
Topic: 8. Foot and Ankle
An 8-year-old patient with cerebral palsy has an equinovarus foot on the right side. The varus is worse during push-off. He also holds his right upper extremity stiffly when he walks. He is developing a pressure callus on the lateral side of his foot in the region of the calcaneocuboid joint. Passively, the foot can be corrected to a neutral position of varus-valgus but lacks 12° from neutral dorsiflexion. Your recommendation is:
Correct Answer & Explanation
. Lengthening of the triceps surae and split posterior tibial tendon transfer
Explanation
An equinovarus foot is commonly found in patients with hemiplegic cerebral palsy. The varus aspect is difficult to brace. In this patient with fixed equinus, an AFO would not be a successful treatment option. A lengthening of the triceps surae would be indicated, and it could be done at the level of the Achilles tendon or by a gastrocnemius-soleus recession, depending on the clinical examination. In addition, another procedure is necessary to deal with the varus. The best way to accomplish this would be by split posterior tibial tendon transfer. This patient is too young for a triple arthrodesis, as this procedure is appropriate in patients at or near skeletal maturity with rigid deformity.
Question 215
Topic: Midfoot & Hindfoot
A diabetic patient presents with a swollen, erythematous, but painless foot. Radiographs show extensive bone fragmentation, subluxation, and joint debris without significant sclerosis. According to the Eichenholtz classification, what stage of Charcot arthropathy does this represent?
Correct Answer & Explanation
. Stage 1 (Development/Fragmentation)
Explanation
Eichenholtz Stage 1 (Development) is characterized by acute inflammation, joint laxity, subluxation, bone fragmentation, and debris formation. Stage 2 (Coalescence) shows absorption of fine debris and early sclerosis.
Question 216
Topic: Midfoot & Hindfoot
According to the Eichenholtz classification of Charcot arthropathy, which of the following radiographic findings characterizes the Coalescence stage (Stage II)?
Correct Answer & Explanation
. Absorption of fine debris and fusion of large fragments
Explanation
Stage II (Coalescence) is characterized by the absorption of fine bone debris, early fusion of larger fragments, and sclerosis. Stage I is fragmentation, and Stage III is consolidation and remodeling.
Question 217
Topic: 8. Foot and Ankle
Before any intervention, which of the following statements is true regarding the walking gait of a diplegic patient who has an equinus gait:
Correct Answer & Explanation
. Ankle plantarflexion increases during single-limb stance.
Explanation
In patients with spastic diplegia, ankle plantarflexion increases during single-limb stance, contrary to the normal pattern.
Question 218
Topic: Ankle Trauma & Sports
A 13-year-old boy sustains a juvenile Tillaux fracture. Which of the following ligaments is primarily responsible for the avulsion of this specific fracture fragment?
Correct Answer & Explanation
. Anterior inferior tibiofibular ligament (AITFL)
Explanation
A juvenile Tillaux fracture is a Salter-Harris III fracture of the anterolateral distal tibial epiphysis. It is caused by an avulsion force from the anterior inferior tibiofibular ligament (AITFL) as the medial physis closes before the lateral physis.
Question 219
Topic: 8. Foot and Ankle
A 10-year-old boy sustains a minor ankle sprain. Radiographs reveal an incidental 2-cm eccentric, cortically based, radiolucent lesion with a thin sclerotic margin in the distal tibial metaphysis. He has no pain at the site. What is the most appropriate management?
Correct Answer & Explanation
. Observation
Explanation
The radiographic description is classic for a non-ossifying fibroma (NOF) or fibrous cortical defect. Since it is small, asymptomatic, and incidental, the standard of care is observation, as the vast majority undergo spontaneous ossification and resolve by adulthood.
Question 220
Topic: 8. Foot and Ankle
A 13-year-old boy complains of recurrent ankle sprains and lateral foot pain. Examination shows a rigid flatfoot and peroneal spasticity. Computed tomography demonstrates a talocalcaneal coalition. Which facet is most commonly involved?
Correct Answer & Explanation
. Middle facet
Explanation
Talocalcaneal coalitions most frequently involve the middle facet of the subtalar joint. This presents as a rigid, painful flatfoot in early adolescence.
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