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 901
Topic: 8. Foot and Ankle
A 45-year-old patient presents with a chronic Achilles tendon rupture and a 5 cm gap measured on MRI. Which of the following tendon transfers is most commonly performed to augment the reconstruction of this defect?
Correct Answer & Explanation
. Flexor hallucis longus
Explanation
The flexor hallucis longus (FHL) is the preferred tendon transfer for chronic Achilles ruptures with a large gap (>3 cm). It is favored due to its close anatomical proximity, in-phase firing, favorable line of pull, and high muscle belly that brings robust vascularity to the poorly perfused repair site.
Question 902
Topic: 8. Foot and Ankle
A 32-year-old recreational basketball player feels a 'pop' in his heel. In the emergency department, a Thompson test is positive. What does a positive Thompson test specifically indicate on physical examination?
Correct Answer & Explanation
. Absence of plantar flexion of the ankle upon squeezing the calf muscle
Explanation
A positive Thompson test occurs when squeezing the calf muscle fails to produce passive plantar flexion of the foot. This finding indicates a complete disruption of the Achilles tendon continuity.
Question 903
Topic: 8. Foot and Ankle
Based on the Kuwada classification of Achilles tendon ruptures, a defect measuring 4.5 cm in a chronic setting should optimally be treated with which of the following techniques?
Correct Answer & Explanation
. Primary repair augmented with a V-Y advancement flap
Explanation
Kuwada Type 3 involves an Achilles tendon defect of 3 to 6 cm. It is typically treated with a V-Y tendinous flap advancement, frequently with or without FHL augmentation, to bridge the gap without overtensioning the repair.
Question 904
Topic: 8. Foot and Ankle
A 50-year-old male with an acute Achilles tendon rupture opts for nonoperative management and is placed in a functional rehabilitation protocol. Compared to operative repair, he has a statistically higher risk of which of the following?
Correct Answer & Explanation
. Tendon re-rupture
Explanation
Historically, and confirmed in several meta-analyses, nonoperative management of Achilles tendon ruptures carries a slightly higher risk of re-rupture compared to operative management. However, operative repair carries higher risks of complications such as infection and nerve injury.
Question 905
Topic: 8. Foot and Ankle
A 65-year-old male sustains a spontaneous Achilles tendon rupture while walking up a flight of stairs. Which of the following classes of medications in his recent history is most strongly associated with this spontaneous injury?
Correct Answer & Explanation
. Fluoroquinolones
Explanation
Fluoroquinolone antibiotics (e.g., ciprofloxacin) are a well-documented risk factor for tendinopathy and spontaneous tendon rupture. The risk is highest for the Achilles tendon, especially in older patients or those concomitantly using corticosteroids.
Question 906
Topic: 8. Foot and Ankle
A 38-year-old male undergoes a percutaneous repair of an acute Achilles tendon rupture. Postoperatively, he reports paresthesias and numbness along the lateral border of his foot. This complication is most likely due to entrapment of which nerve during suture passage?
Correct Answer & Explanation
. Sural nerve
Explanation
The sural nerve runs intimately close to the lateral aspect of the Achilles tendon. It is the most commonly injured structure during percutaneous or minimally invasive Achilles tendon repairs due to blind or semi-blind suture passage through the paratenon.
Question 907
Topic: 8. Foot and Ankle
The Achilles tendon is most susceptible to rupture at its 'watershed' area. Approximately where is this hypovascular zone located relative to its calcaneal insertion?
Correct Answer & Explanation
. 2 to 6 cm proximal
Explanation
The Achilles tendon has a 'watershed' region of poor vascularity located approximately 2 to 6 cm proximal to its insertion on the calcaneus. This zone relies on perfusion from the paratenon and is the most frequent site of degenerative tendinopathy and acute rupture.
Question 908
Topic: 8. Foot and Ankle
Following an open repair of an acute Achilles tendon rupture in an elite athlete, which of the following objective criteria is most commonly used by physical therapists and surgeons to determine readiness for full return to sport?
Correct Answer & Explanation
. Limb symmetry index >90% on single-leg heel raise testing
Explanation
Return to sport after Achilles tendon repair requires significant recovery of plantar flexion strength, power, and endurance. A standard evidence-based criterion is achieving a limb symmetry index (LSI) of >90% on functional tests, most notably the single-leg heel raise endurance test.
Question 909
Topic: 8. Foot and Ankle
A 38-year-old male sustains a high-energy ankle injury. Initial radiographs show a trimalleolar fracture with a large posterior malleolus fragment. A pre-operative CT scan, as depicted conceptually below, confirms a displaced posterior malleolus fragment involving 35% of the articular surface and a posterolateral pilon component. The patient is otherwise healthy, and the soft tissue envelope is viable. During the posterolateral approach, after skin incision and subcutaneous dissection, which neurovascular structure is most vulnerable and requires meticulous identification and protection?
Correct Answer & Explanation
. Sural Nerve
Explanation
Correct Answer: CThe sural nerve is a purely sensory nerve that runs superficially along the posterolateral aspect of the lower leg, typically coursing with the small saphenous vein. It is highly vulnerable during the skin incision and initial dissection of the posterolateral approach, especially at the level of the ankle joint. Meticulous identification and retraction (usually anteriorly with the peroneal tendons) are crucial for its preservation.Option A (Posterior Tibial Nerve):This nerve is located more medially and deep, within the tarsal tunnel (posterior to the medial malleolus). It is generally not at direct risk with a strictly posterolateral approach.Option B (Peroneal Artery):This artery is located deep in the posterior compartment, more medially, and is not typically at risk with the posterolateral approach.Option D (Flexor Hallucis Longus Tendon):The FHL tendon is located deep and medial to the Achilles tendon. While it forms part of the medial boundary of the internervous plane and may be exposed during deeper dissection for pilon fractures, it is a tendon, not a neurovascular structure, and is not the most vulnerable structure during initial superficial dissection.Option E (Tibialis Posterior Tendon):This tendon is located more medially and deeper within the posterior compartment, generally not directly exposed or at risk with the posterolateral approach.
Question 910
Topic: 8. Foot and Ankle
A 28-year-old athlete sustains an ankle injury during a soccer match. Radiographs show a lateral malleolus fracture and a posterior malleolus fracture. A CT scan, as conceptually shown below, confirms a displaced posterior malleolus fragment involving 20% of the distal tibial articular surface, with an associated fibular fracture. Intraoperatively, after reducing and fixing the lateral malleolus, a Cotton test reveals persistent syndesmotic instability. Which of the following statements best explains the biomechanical significance of the posterior malleolus in this scenario?
Correct Answer & Explanation
. Displaced posterior malleolus fractures imply disruption of the Posterior Inferior Tibiofibular Ligament (PITFL), a critical syndesmotic stabilizer.
Explanation
Correct Answer: CThe posterior malleolus serves as the primary attachment site for the Posterior Inferior Tibiofibular Ligament (PITFL), which is a critical component of the syndesmosis. A displaced posterior malleolus fracture, even if relatively small (e.g., 20% as in this case), implies disruption or avulsion of the PITFL from the tibia. This directly compromises syndesmotic stability, leading to persistent instability even after fibular fixation, as demonstrated by the positive Cotton test. Direct reduction and fixation of the posterior malleolus are often necessary to restore PITFL integrity and syndesmotic stability.Option A (Ankle plantarflexion strength):Ankle plantarflexion strength is primarily provided by the gastrocnemius and soleus muscles via the Achilles tendon, not directly by the posterior malleolus.Option B (Deltoid ligament attachment):The deltoid ligament attaches to the medial malleolus and is crucial for medial ankle stability, not the posterior malleolus.Option D (Subtalar joint congruity):The subtalar joint is formed by the talus and calcaneus. While overall ankle alignment can indirectly affect subtalar mechanics, the posterior malleolus primarily affects tibiotalar and syndesmotic stability, not subtalar joint congruity directly.Option E (Achilles tendon rupture risk):There is no direct correlation between the size of the posterior malleolus fragment and the risk of Achilles tendon rupture. Achilles tendon rupture is a separate injury mechanism.
Question 911
Topic: 8. Foot and Ankle
During a posterolateral approach for a displaced posterior malleolus fracture, the surgeon identifies the internervous plane. Which of the following structures defines the anterolateral boundary of this surgical interval?
Correct Answer & Explanation
. Peroneal tendons (longus and brevis)
Explanation
Correct Answer: CThe key internervous and internervascular plane for the posterolateral approach is between the Achilles tendon and FHL muscle belly (medially/posteriorly) and the peroneal tendons (longus and brevis) and their muscle belly (anterolaterally). The peroneal tendons are mobilized and retracted anteriorly to expose the posterior aspect of the distal tibia and fibula.Option A (Achilles tendon):The Achilles tendon forms the posterior/medial boundary of the approach and is retracted medially.Option B (Flexor Hallucis Longus (FHL) muscle belly):The FHL muscle belly is located deep and medial to the Achilles tendon and forms part of the medial/posterior boundary of the interval, retracted medially.Option D (Posterior Tibial Artery):The posterior tibial artery is located more medially within the tarsal tunnel and is not part of the direct internervous plane for the posterolateral approach.Option E (Tibialis Posterior tendon):The Tibialis Posterior tendon is located more medially and deeper within the posterior compartment, generally not directly exposed or at risk with the posterolateral approach.
Question 912
Topic: 8. Foot and Ankle
Initial plain radiographs of the left calcaneus demonstrated a Bohler's angle of 5 degrees (normal 20-40 degrees) and Gissane's angle of 140 degrees (normal 100-120 degrees). These specific radiographic findings are most indicative of which of the following?
Correct Answer & Explanation
. Significant collapse of the posterior facet and disruption of the crucial angle.
Explanation
Correct Answer: CThe case states that a Bohler's angle of 5 degrees (significantly decreased from the normal 20-40 degrees) is 'indicative of substantial collapse of the posterior facet and loss of calcaneal height.' Concurrently, an increased Gissane's angle to 140 degrees (normal 100-120 degrees) reflects 'the disruption of the lateral process of the talus and the primary fracture line.' Both angles are critical indicators of displaced intra-articular calcaneal fractures. A decreased Bohler's angle signifies loss of calcaneal height and posterior facet depression, while an increased Gissane's angle indicates disruption of the lateral process of the talus, which acts as a wedge in the injury mechanism. These findings are pathognomonic for significant intra-articular involvement and collapse, not normal morphology, extra-articular fractures, or isolated sustentacular injuries.
Question 913
Topic: 8. Foot and Ankle
During the surgical intervention for this Sanders IIIBC calcaneal fracture, an extensile lateral approach is utilized. To minimize the risk of postoperative marginal flap necrosis, the surgeon employs a 'no-touch' technique and uses three 1.6 mm K-wires driven into the lateral talus, talar neck, and cuboid to retract the full-thickness flap. This specific K-wire retraction technique primarily serves which of the following purposes?
Correct Answer & Explanation
. To eliminate continuous point pressure on the flap edges, thereby reducing microvascular compromise.
Explanation
To retract the flap without causing crush injury to the microvasculature, self-retaining retractors are strictly avoided. Instead, K-wires are driven into the bone and the flap is gently retracted superiorly and held in place by bending the wires. This technique eliminates continuous point pressure on the flap edges, significantly reducing the risk of postoperative marginal necrosis.
Question 914
Topic: 8. Foot and Ankle
In the definitive internal fixation of this Sanders IIIBC calcaneal fracture, a low-profile, anatomically contoured calcaneal perimeter plate is utilized. The case emphasizes the critical importance of strategic screw placement. Which of the following screw placements is described as most critical for securing the lateral construct to the constant medial fragment?
Correct Answer & Explanation
. Screws directed from lateral to medial into the dense bone of the sustentaculum tali.
Explanation
Correct Answer: C. The case highlights the importance of sustentacular screws: 'The most critical screws are placed through the plate, just inferior to the posterior facet, directed from lateral to medial into the dense bone of the sustentaculum tali.' These screws (typically 3.5 mm cortical or locking screws) secure the lateral construct to the constant medial fragment. Absolute care must be taken to ensure these screws are of appropriate length; over-penetration medially can tether the flexor hallucis longus (FHL) tendon or injure the posterior tibial neurovascular bundle. These screws are crucial because the sustentaculum tali is part of the 'constant' fragment, which remains attached to the talus, providing a stable anchor for the reconstructed lateral calcaneus.
Question 915
Topic: 8. Foot and Ankle
A patient presents to the emergency department with severe hindfoot pain, swelling, and inability to bear weight after a high-energy fall. While a calcaneal fracture is a strong consideration, the differential diagnosis for axial load injuries to the hindfoot is broad. Which of the following clinical findings would most strongly suggest a subtalar dislocation as the primary diagnosis, rather than an isolated calcaneal fracture?
Correct Answer & Explanation
. Gross deformity of the hindfoot with skin tenting and a locked joint.
Explanation
Correct Answer: CThe differential diagnosis table in the case provides key differentiating features. For subtalar dislocation, the 'Key Clinical Findings' are 'Gross deformity of the hindfoot (medial or lateral shift), skin tenting, locked joint.' In contrast, intra-articular calcaneal fractures typically present with a 'widened heel, decreased height, Mondor's sign, varus tuberosity.' While Mondor's sign and localized tenderness over the calcaneus are characteristic of calcaneal fractures, and a decreased Bohler's angle is a radiographic hallmark, a gross deformity with skin tenting and a locked joint is a more specific and immediate indicator of a subtalar dislocation, which involves disruption of the talocalcaneal and talonavicular joints.
Question 916
Topic: 8. Foot and Ankle
A 60-year-old diabetic smoker presents with a tongue-type calcaneus fracture. Clinical examination reveals severe posterior heel swelling with distinct blanching of the skin overlying the posterior tuberosity fragment. What is the most appropriate next step in management?
Correct Answer & Explanation
. Urgent reduction and percutaneous fixation
Explanation
Displaced tongue-type calcaneus fractures can cause severe posterior skin tension and subsequent necrosis if left untreated. Urgent reduction and percutaneous fixation are indicated to relieve tension and preserve the tenuous soft tissue envelope.
Question 917
Topic: 8. Foot and Ankle
During the evaluation of an ankle syndesmotic injury, it is important to understand the biomechanical contributions of the syndesmotic ligaments. Which of the following structures provides the greatest resistance to diastasis of the distal tibiofibular joint?
The posterior inferior tibiofibular ligament (PITFL) is the strongest and most important stabilizer of the distal tibiofibular syndesmosis. It contributes to approximately 40% of the overall syndesmotic strength.
Question 918
Topic: Ankle Trauma & Sports
According to the Lauge-Hansen classification, what is the exact sequence of structures injured in a Pronation-External Rotation (PER) stage IV ankle fracture?
In the Pronation-External Rotation mechanism, the sequence of injury is: 1) Medial structures (Deltoid or medial malleolus), 2) Anterior syndesmosis (AITFL), 3) High fibular fracture above the syndesmosis, and 4) Posterior syndesmosis (PITFL or posterior malleolus).
Question 919
Topic: 8. Foot and Ankle
A 32-year-old female sustains a twisting injury to her foot. Radiographs demonstrate an avulsion fracture of the anterior process of the calcaneus. Tension from which of the following ligaments is the most common cause of this fracture?
Correct Answer & Explanation
. Bifurcate ligament
Explanation
Fractures of the anterior process of the calcaneus are most commonly avulsion fractures. They are typically caused by tension from the bifurcate ligament during forced plantarflexion and inversion of the foot.
Question 920
Topic: 8. Foot and Ankle
A 55-year-old diabetic patient sustains a tongue-type calcaneus fracture. Clinical examination reveals profound swelling and distinct blanching of the skin directly over the posterior heel. What is the most appropriate initial management?
Correct Answer & Explanation
. Urgent percutaneous reduction and screw fixation of the tuberosity fragment
Explanation
Tongue-type calcaneus fractures cause superior displacement of the tuberosity fragment, placing extreme tension on the posterior heel skin. This is a surgical emergency requiring urgent percutaneous or minimal-incision reduction and fixation to prevent catastrophic skin necrosis.
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