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 2901
Topic: Ankle Trauma & Sports
The strongest and most important ligamentous stabilizer of the distal tibiofibular syndesmosis is the:
While the anterior inferior tibiofibular ligament (AITFL) is typically the first to tear in a syndesmotic injury, biomechanical studies demonstrate that the posterior inferior tibiofibular ligament (PITFL) provides the greatest proportion of strength (approximately 42%) to the syndesmosis, making it the strongest stabilizer.
Question 2902
Topic: 8. Foot and Ankle
In the evaluation of a suspected Lisfranc injury, which radiographic finding on a weight-bearing AP view of the foot is considered a primary indicator of disruption?
Correct Answer & Explanation
. Malalignment of the medial border of the second metatarsal with the medial border of the middle cuneiform
Explanation
A classic and pathognomonic finding of a Lisfranc injury on an AP radiograph is any step-off or malalignment of the medial border of the second metatarsal base with the medial border of the middle cuneiform. They should form a perfectly continuous line in a normal foot.
Question 2903
Topic: 8. Foot and Ankle
A 24-year-old professional football player sustains a high-energy axial load injury to a plantarflexed foot. Radiographs demonstrate widening of the midfoot spaces.
The critical interosseous Lisfranc ligament connects which of the following two osseous structures?
Correct Answer & Explanation
. Medial cuneiform to the base of the second metatarsal
Explanation
The Lisfranc ligament is a strong interosseous ligament critical for the stability of the tarsometatarsal joint complex. It originates from the lateral aspect of the medial cuneiform and inserts onto the medial aspect of the base of the second metatarsal. There is no direct ligamentous connection between the bases of the first and second metatarsals, making the Lisfranc ligament the primary restraint to lateral displacement of the lesser metatarsals.
Question 2904
Topic: 8. Foot and Ankle
A 58-year-old male with long-standing, poorly controlled diabetes presents with a unilaterally swollen, warm, and erythematous foot without ulceration. Radiographs reveal osseous fragmentation, debris, and joint subluxation in the midfoot, but no significant sclerosis or osteophyte formation. According to the Eichenholtz classification of Charcot neuroarthropathy, what stage does this represent?
Correct Answer & Explanation
. Stage 1 (Development/Fragmentation)
Explanation
The Eichenholtz classification describes the radiographic progression of Charcot neuroarthropathy. Stage 0 is clinically swollen and warm with normal radiographs. Stage 1 (Development/Fragmentation) features bony debris, fragmentation, joint subluxation/dislocation, and loss of joint space. Stage 2 (Coalescence) is marked by absorption of fine debris, early fusion of fragments, and sclerosis. Stage 3 (Reconstruction) shows consolidation of fractures, remodeling, and mature osteophyte formation.
Question 2905
Topic: 8. Foot and Ankle
A 28-year-old male sustains a low-energy twisting injury to his midfoot. Initial weight-bearing radiographs show a subtle 2 mm widening between the base of the first and second metatarsals. If this Lisfranc injury is missed and goes untreated, which muscle acts as the primary deforming force leading to dorsal displacement of the first metatarsal?
Correct Answer & Explanation
. Tibialis anterior
Explanation
In a Lisfranc injury, the critical ligamentous disruption occurs between the medial cuneiform and the base of the second metatarsal. The tibialis anterior inserts onto the medial cuneiform and the base of the first metatarsal. Its unantagonized pull in the setting of instability acts as a primary deforming force, pulling the first metatarsal and medial cuneiform dorsally and medially. The peroneus longus, which inserts plantarly on the lateral aspect of the first metatarsal base and medial cuneiform, exerts a plantar and lateral force.
Question 2906
Topic: 8. Foot and Ankle
A 2-week-old infant is being treated for idiopathic congenital talipes equinovarus using the Ponseti method. According to the CAVE sequence, which deformity is corrected first, and what is the specific manipulation required to achieve this correction?
Correct Answer & Explanation
. Cavus, corrected by depressing the first ray to pronate the forefoot.
Explanation
The Ponseti method follows the CAVE sequence: Cavus, Adductus, Varus, Equinus. The cavus deformity is the first to be addressed. It is driven by relative pronation of the forefoot in relation to the hindfoot. Correction is achieved by elevating the first ray, effectively supinating the forefoot to align it with the hindfoot. Subsequent casts correct adductus and varus simultaneously by abducting the foot around the head of the talus, and equinus is corrected last (often requiring a percutaneous Achilles tenotomy).
Question 2907
Topic: 8. Foot and Ankle
A 56-year-old male with poorly controlled diabetes presents with a swollen, erythematous, and warm right foot. Radiographs demonstrate fragmentation, bone debris, and periarticular subluxation at the tarsometatarsal joints. According to the Eichenholtz classification, this patient is in the Development stage (Stage I) of Charcot arthropathy. What is the primary pathophysiological process mediating the acute bone destruction in this phase?
Correct Answer & Explanation
. Intense osteoclastic resorption mediated by pro-inflammatory cytokines and RANKL
Explanation
Acute Charcot neuroarthropathy (Eichenholtz Stage I / Development phase) is characterized by an exaggerated inflammatory response. The loss of sympathetic regulation leads to bounding pulses (neurotraumatic theory) and a massive release of pro-inflammatory cytokines (TNF-α, IL-1). These cytokines upregulate the RANKL pathway, leading to intense, uncontrolled osteoclastic bone resorption, which causes the severe fragmentation, osteopenia, and destruction seen on radiographs. Avascular necrosis, fibrous sclerosis, and pannus do not define the acute Charcot phase.
Question 2908
Topic: 8. Foot and Ankle
During surgical reconstruction of a subtle Lisfranc injury in a collegiate athlete, the surgeon must address the critical Lisfranc ligament complex. Which of the following accurately describes the anatomic orientation of the proper (intra-osseous) Lisfranc ligament?
Correct Answer & Explanation
. It connects the medial cuneiform to the base of the second metatarsal.
Explanation
The Lisfranc ligament is an intra-osseous ligament that connects the lateral aspect of the medial cuneiform to the medial base of the second metatarsal. It is the largest and strongest ligament of the Lisfranc complex and is crucial for stabilizing the tarsometatarsal joint, particularly because there is no direct transverse ligament connecting the first and second metatarsal bases.
Question 2909
Topic: 8. Foot and Ankle
A 24-year-old football player sustains a hyperplantarflexion injury to his midfoot. Weight-bearing radiographs show a 3 mm diastasis between the base of the first and second metatarsals. An MRI confirms an isolated, complete rupture of the Lisfranc ligament. Which of the following correctly describes the anatomical attachments of this critically stabilizing ligament?
Correct Answer & Explanation
. Base of the 2nd metatarsal and medial cuneiform
Explanation
The Lisfranc ligament is an intra-articular ligament that originates from the lateral aspect of the medial cuneiform and attaches to the medial base of the second metatarsal. It is the strongest of the ligaments stabilizing the second metatarsal base and is critical for maintaining the structural integrity of the midfoot arch. There is no direct ligamentous connection between the base of the first and second metatarsals.
Question 2910
Topic: 8. Foot and Ankle
A 55-year-old male with long-standing, poorly controlled type 2 diabetes presents with a warm, erythematous, and swollen right foot and ankle. He denies any systemic symptoms like fevers or chills. Radiographs reveal fragmentation of the tarsal bones, periarticular debris, and subluxation of the tarsometatarsal joints. According to the Eichenholtz classification of Charcot arthropathy, which stage does this patient's clinical and radiographic picture represent?
Correct Answer & Explanation
. Stage I (Development/Fragmentation)
Explanation
The Eichenholtz classification characterizes the radiographic progression of Charcot arthropathy. Stage I (Development/Fragmentation) is characterized by acute inflammation, osseous fragmentation, periarticular debris, and joint subluxation/dislocation. Stage II (Coalescence) shows decreased inflammation with absorption of fine debris and early fusion. Stage III (Reconstruction) shows rounded bone ends, sclerosis, and stable arthrosis. Stage 0 (added later by Shibata) describes the clinical acute inflammatory phase before distinct radiographic changes occur.
Question 2911
Topic: 8. Foot and Ankle
A 25-year-old male sustained a foot injury in a motor vehicle accident.
Radiographs demonstrate a 'fleck sign' in the first intermetatarsal space and widening between the bases of the first and second metatarsals. What are the anatomic attachments of the ligament most likely ruptured in this injury?
Correct Answer & Explanation
. Medial cuneiform to the base of the second metatarsal
Explanation
The Lisfranc ligament is a strong interosseous ligament that connects the medial cuneiform to the base of the second metatarsal. It is the critical stabilizer of the second tarsometatarsal joint complex. Rupture typically results in lateral subluxation of the second through fifth metatarsals.
Question 2912
Topic: 8. Foot and Ankle
A 55-year-old male with a 15-year history of poorly controlled type 2 diabetes presents with a swollen, erythematous, warm, and painless right foot.
Radiographs show early fragmentation and debris at the tarsometatarsal joints. Inflammatory markers are mildly elevated, but there are no open wounds or ulcers. What is the most appropriate initial management?
Correct Answer & Explanation
. Immobilization in a total contact cast and non-weight bearing
Explanation
This is a classic presentation of acute Charcot neuroarthropathy (Eichenholtz Stage I: fragmentation/dissolution). The joint is hot, swollen, and red, often mimicking infection. In the absence of an ulcer, deep infection is highly unlikely. The gold standard initial treatment to halt progression and prevent severe deformity is strict offloading and immobilization, most effectively achieved with a Total Contact Cast (TCC).
Question 2913
Topic: 8. Foot and Ankle
A 24-year-old football player sustains a hyperplantarflexion injury to his midfoot. Radiographs demonstrate widening of the space between the base of the first and second metatarsals.
Which of the following best describes the anatomy of the primary ligament disrupted in this injury?
Correct Answer & Explanation
. A plantar ligament extending from the medial cuneiform to the base of the second metatarsal
Explanation
The Lisfranc ligament is an interosseous ligament located plantarly. It extends from the lateral aspect of the medial cuneiform to the medial aspect of the base of the second metatarsal. It is the largest and strongest of the ligaments supporting the first tarsometatarsal articulation, and its disruption is the hallmark of a Lisfranc injury. There is no direct intermetatarsal ligament between the bases of the first and second metatarsals.
Question 2914
Topic: 8. Foot and Ankle
A 2-week-old infant is undergoing the Ponseti method for the treatment of idiopathic clubfoot. The deformity consists of cavus, adductus, varus, and equinus. In the Ponseti casting technique, the correction of the cavus deformity is achieved first. Which of the following maneuvers is mechanically correct to accomplish this initial step?
Correct Answer & Explanation
. Supination of the forefoot by elevating the first ray
Explanation
The cavus deformity in clubfoot is primarily driven by pronation of the forefoot relative to the hindfoot. The first and most critical step in the Ponseti method is to correct the cavus by elevating the first ray (dorsiflexing the first metatarsal), which effectively supinates the forefoot to align it with the midfoot and hindfoot. Subsequent casts correct the adductus and varus by abducting the supinated foot around the stabilized head of the talus.
Question 2915
Topic: 8. Foot and Ankle
A 55-year-old male with long-standing, poorly controlled type 2 diabetes presents with a warm, swollen, and erythematous left foot.
He denies any recent trauma, fevers, or systemic signs of infection. Plain radiographs show early fragmentation and subluxation of the tarsometatarsal joints. His inflammatory markers are mildly elevated. What is the most appropriate initial management?
Correct Answer & Explanation
. Total contact casting (TCC) and strict non-weight bearing
Explanation
This patient is presenting with acute Eichenholtz stage I Charcot neuroarthropathy. The foot is acutely inflamed, and initial radiographs show fragmentation. The mainstay of treatment in the acute fragmentation phase is immobilization and strict offloading, ideally utilizing a total contact cast (TCC), to arrest progression of the deformity until the acute inflammatory phase subsides and the bones coalesce.
Question 2916
Topic: 8. Foot and Ankle
A 60-year-old male with poorly controlled diabetes presents with a swollen, warm, and minimally painful foot. Radiographs are obtained to evaluate for Charcot neuroarthropathy. According to the Eichenholtz classification, which of the following clinical and radiographic findings is characteristic of Stage II (Coalescence)?
Correct Answer & Explanation
. Periarticular fragmentation, joint subluxation, and copious debris
Explanation
The Eichenholtz classification of Charcot neuroarthropathy includes: Stage 0 (Pre-radiographic): erythema, swelling, warmth, normal X-rays. Stage I (Development/Fragmentation): joint destruction, subluxation, fragmentation, and debris. Stage II (Coalescence): decreased warmth/swelling, absorption of fine debris, early sclerosis, and fracture healing. Stage III (Remodeling): consolidated fractures, rounded bone ends, osteophyte formation, and fixed residual deformity.
Question 2917
Topic: 8. Foot and Ankle
A 35-year-old recreational athlete undergoes percutaneous repair of an acute Achilles tendon rupture. During passage of the proximal transverse sutures, a nerve is inadvertently entrapped. Which nerve is at greatest risk during this procedure, and what is its normal anatomic relationship to the Achilles tendon insertion?
Correct Answer & Explanation
. Sural nerve; crosses the lateral border of the tendon approximately 10 cm proximal to the insertion
Explanation
The sural nerve is at the greatest risk of iatrogenic injury during percutaneous or minimally invasive Achilles tendon repair, particularly during the placement of proximal, lateral sutures. Anatomically, the sural nerve travels distally in the posterior calf and classically crosses the lateral border of the Achilles tendon from medial to lateral at an average of 9.8 cm (approximately 10 cm) proximal to the calcaneal insertion.
Question 2918
Topic: 8. Foot and Ankle
A 42-year-old recreational athlete sustains an acute, complete rupture of the Achilles tendon. He opts for non-operative management and is enrolled in a functional rehabilitation protocol featuring early weight-bearing in a functional brace. Compared to traditional management involving prolonged non-weight-bearing cast immobilization, functional rehabilitation is associated with:
Correct Answer & Explanation
. Similar rerupture rates but improved early functional outcomes and faster return to work
Explanation
Recent high-level evidence demonstrates that for acute Achilles tendon ruptures, non-operative management utilizing an early functional rehabilitation protocol (early weight-bearing and controlled range of motion in a brace) provides similar rerupture rates to surgical repair and traditional casting, while improving early functional outcomes, reducing DVT risk, and expediting return to work compared to prolonged immobilization.
Question 2919
Topic: 8. Foot and Ankle
A 25-year-old athlete sustains a midfoot injury after a forceful plantarflexion mechanism.
Radiographs demonstrate widening of the space between the base of the first and second metatarsals. MRI confirms a complete rupture of the Lisfranc ligament. Anatomically, the Lisfranc ligament is an interosseous ligament that connects the:
Correct Answer & Explanation
. Medial cuneiform to the base of the second metatarsal
Explanation
The Lisfranc ligament is a strong interosseous ligament that originates from the lateral aspect of the medial cuneiform and inserts onto the medial aspect of the base of the second metatarsal. It is a critical stabilizer of the tarsometatarsal joint complex.
Question 2920
Topic: 8. Foot and Ankle
A 16-year-old female with a diagnosis of Charcot-Marie-Tooth disease presents with a progressive, symptomatic cavovarus foot deformity. During clinical evaluation, her first ray is noted to be rigidly plantarflexed. This specific component of her deformity is primarily driven by the unopposed action of which muscle?
Correct Answer & Explanation
. Peroneus longus
Explanation
In Charcot-Marie-Tooth (CMT) disease, the classic cavovarus foot deformity is driven by specific muscle imbalances. The tibialis anterior and peroneus brevis weaken early. The relatively preserved strength of the peroneus longus, which is unopposed by the weak tibialis anterior, powerfully plantarflexes the first ray, causing the forefoot-driven cavus deformity.
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