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 861
Topic: 8. Foot and Ankle
In a bimalleolar equivalent ankle fracture involving a lateral malleolus fracture and complete deltoid ligament rupture, the deep deltoid ligament serves as the primary restraint against which abnormal talar motion?
Correct Answer & Explanation
. Lateral translation and external rotation
Explanation
The deep deltoid ligament is the strongest component of the medial ankle complex and provides the primary restraint against lateral translation and external rotation of the talus.
Question 862
Topic: 8. Foot and Ankle
A 24-year-old football player presents with midfoot pain after a twisting injury.
If initial non-weight-bearing radiographs of the foot appear normal despite a high clinical suspicion for a Lisfranc injury, what is the MOST appropriate next diagnostic step?
Correct Answer & Explanation
. Weight-bearing AP and lateral radiographs of both feet
Explanation
Subtle Lisfranc instability often reduces at rest. Weight-bearing radiographs of both feet are required to unmask ligamentous instability, manifesting as diastasis of the 1st and 2nd metatarsal bases.
Question 863
Topic: 8. Foot and Ankle
Which of the following correctly describes the anatomical origin and insertion of the Lisfranc ligament?
Correct Answer & Explanation
. Lateral aspect of the medial cuneiform to the medial base of the second metatarsal
Explanation
The Lisfranc ligament is an interosseous ligament that originates on the lateral aspect of the medial cuneiform and inserts onto the medial base of the second metatarsal. It is the strongest of the tarsometatarsal ligaments and critical for midfoot stability.
Question 864
Topic: 8. Foot and Ankle
How many distinct fascial compartments are recognized in the foot, and which compartment contains the quadratus plantae muscle?
Correct Answer & Explanation
. 9 compartments; Central compartment
Explanation
There are 9 distinct fascial compartments in the foot: medial, lateral, superficial, calcaneal, four interosseous, and central. The calcaneal compartment contains the quadratus plantae muscle and the lateral plantar nerve.
Question 865
Topic: Midfoot & Hindfoot
In a 50-year-old patient with a purely ligamentous Lisfranc injury, what is the primary advantage of primary arthrodesis of the first, second, and third tarsometatarsal joints compared to open reduction and internal fixation (ORIF)?
Correct Answer & Explanation
. Decreased rate of hardware removal and secondary procedures
Explanation
Prospective randomized trials have shown that primary arthrodesis for purely ligamentous Lisfranc injuries results in comparable or superior functional outcomes while significantly decreasing the need for hardware removal and secondary salvage procedures compared to ORIF.
Question 866
Topic: 8. Foot and Ankle
During operative fixation of a Weber C ankle fracture, an intraoperative external rotation stress test reveals widening of the medial clear space. Following placement of a syndesmotic screw, which radiographic parameter best confirms anatomic reduction of the syndesmosis on a true anteroposterior (AP) radiograph?
Correct Answer & Explanation
. Tibiofibular clear space < 6 mm measured 1 cm above the joint line
Explanation
On a true AP radiograph, the tibiofibular clear space should be less than 6 mm (measured 1 cm proximal to the plafond). This is the most reliable radiographic parameter for evaluating syndesmotic reduction regardless of patient positioning.
Question 867
Topic: 8. Foot and Ankle
A 32-year-old male sustains a severe crush injury to his foot. Examination reveals tensely swollen compartments, pain with passive toe extension, and paresthesias. To definitively measure the pressure of the central compartment, where should the needle be optimally introduced?
Correct Answer & Explanation
. Medial aspect of the foot, advancing superior to the abductor hallucis muscle
Explanation
The central compartment of the foot is best accessed via a medial approach by advancing the needle superior to the abductor hallucis muscle, directed toward the plantar aspect of the central metatarsals. Approaching through the plantar skin is avoided due to the risk of painful scarring.
Question 868
Topic: 8. Foot and Ankle
A patient presents with a swollen midfoot following a high-energy motor vehicle collision. An AP radiograph of the foot reveals a small bony avulsion fragment in the space between the base of the first and second metatarsals. What is this radiographic finding called, and what does it indicate?
Correct Answer & Explanation
. Fleck sign; avulsion of the Lisfranc ligament from the second metatarsal base
Explanation
The "fleck sign" represents a bony avulsion of the Lisfranc ligament, typically from the medial base of the second metatarsal. It is highly pathognomonic for a severe Lisfranc injury and indicates significant midfoot instability.
Question 869
Topic: 8. Foot and Ankle
A 48-year-old female presents with persistent pain, swelling, and redness over her right medial malleolus following a minor ankle sprain 3 months ago. Radiographs show diffuse osteopenia in the tarsals and metatarsals, but no fracture. Bone scan reveals increased uptake in a diffuse pattern around the ankle and foot. What is the most likely diagnosis?
Correct Answer & Explanation
. Complex Regional Pain Syndrome (CRPS) Type I
Explanation
Correct Answer: BThis presentation with pain, swelling, redness, and diffuse osteopenia following a minor injury, along with diffuse increased uptake on bone scan, is classic for Complex Regional Pain Syndrome (CRPS) Type I (formerly Reflex Sympathetic Dystrophy). The disproportionate pain and vasomotor changes are key. Osteomyelitis would typically have more localized findings, and often systemic signs, and bone scan findings would be more focal. Stress fracture would be localized and pain directly related to activity. Charcot arthropathy is typically seen in patients with neuropathy (e.g., diabetes) and involves progressive joint destruction, often without significant preceding trauma. Gout would be acute, exquisitely painful, and related to hyperuricemia, with specific joint involvement.
Question 870
Topic: 8. Foot and Ankle
A 60-year-old male presents with severe, burning pain in the ball of his foot, especially between the 3rd and 4th toes, worse with tight shoes and walking. He describes a 'pebble in my shoe' sensation. Physical examination reveals a palpable mass in the interdigital space and reproduction of pain with compression of the metatarsal heads. What is the most likely diagnosis?
Correct Answer & Explanation
. Morton's neuroma
Explanation
Correct Answer: CThis is a classic presentation of Morton's neuroma, which is a perineural fibrosis and thickening of the common plantar digital nerve, most commonly between the third and fourth metatarsal heads. The burning pain, 'pebble' sensation, worsening with tight shoes, and a palpable mass or 'Mulder's click' are highly characteristic. Metatarsalgia is a general term for forefoot pain. Stress fractures typically cause localized bony tenderness. Freiberg's infarction is osteonecrosis of a metatarsal head, usually the second. Plantar plate tears typically cause instability or hammer toe deformity of the associated toe.
Question 871
Topic: 8. Foot and Ankle
A 25-year-old football player sustains a hyperplantarflexion injury to his foot. Radiographs demonstrate widening of the space between the medial and middle cuneiforms, and a small bony avulsion fragment in this space (Fleck sign). The torn ligament primarily connects which two structures?
Correct Answer & Explanation
. Lateral aspect of the medial cuneiform to the medial aspect of the second metatarsal base
Explanation
The Lisfranc ligament is an intra-articular interosseous ligament connecting the lateral surface of the medial cuneiform to the medial surface of the base of the second metatarsal. A "Fleck sign" represents an avulsion fracture of this crucial stabilizing ligament.
Question 872
Topic: 8. Foot and Ankle
A 29-year-old female horse rider presents to the emergency department after falling off her horse, sustaining an isolated closed injury to her left foot. Initial radiographs are obtained as shown below.
Correct Answer & Explanation
. C. CT scan of the foot.
Explanation
Correct Answer: CThe case explicitly states that after initial radiographs showing a displaced, comminuted navicular body fracture, the candidate would 'request further imaging, the modality of choice being CT scan.' A CT scan is crucial for detailed assessment of intra-articular involvement, comminution, and displacement, which are critical for surgical planning. While MRI can assess soft tissues, the immediate priority for a complex bony injury like this is detailed bone morphology. Immediate surgical exploration is premature without a full understanding of the fracture pattern, and other options are not the most appropriate next diagnostic step.
Question 873
Topic: 8. Foot and Ankle
The examiner asks about the occurrence of non-union and avascular necrosis in navicular fractures. What is the primary anatomical reason cited for the high risk of avascular necrosis and non-union in navicular body fractures?
Correct Answer & Explanation
. C. Its reliance on a radial arcade of vessels from the dorsalis pedis and medial plantar arteries, which can be easily disrupted.
Explanation
Correct Answer: CThe candidate explains: '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 unique and often tenuous blood supply makes the navicular susceptible to AVN and non-union following trauma or surgical disruption. Options A, B, D, and E are incorrect descriptions of the navicular's vascular anatomy or its biomechanical role.
Question 874
Topic: Midfoot & Hindfoot
A 30-year-old male sustains a displaced talar neck fracture with subluxation of the subtalar joint, while the ankle and talonavicular joints remain perfectly congruent. What is the Hawkins classification for this injury, and what is the approximate risk of avascular necrosis (AVN)?
Correct Answer & Explanation
. Type II; 20-50% risk
Explanation
A Hawkins Type II talar neck fracture involves displacement with subtalar subluxation or dislocation, while the tibiotalar and talonavicular joints remain reduced. The risk of AVN for Type II fractures is widely cited as 20% to 50%.
Question 875
Topic: Midfoot & Hindfoot
A 22-year-old athlete sustains a purely ligamentous Lisfranc injury with 3 mm of displacement between the medial and middle cuneiforms. Based on current literature comparing treatment modalities for purely ligamentous midfoot injuries, what is the best definitive surgical treatment?
Correct Answer & Explanation
. Primary arthrodesis of the first, second, and third tarsometatarsal joints
Explanation
Studies (e.g., Ly and Coetzee) have demonstrated that purely ligamentous Lisfranc injuries treated with primary arthrodesis yield better functional outcomes and lower reoperation rates compared to ORIF. Bony fracture-dislocations, however, are typically treated with ORIF.
Question 876
Topic: Forefoot
A 45-year-old male is undergoing open reduction and internal fixation of a highly comminuted intra-articular distal humerus fracture (AO/OTA 13C3). The surgeon decides to use a transolecranon approach for optimal articular visualization. To maximize joint stability and facilitate anatomic reduction of the osteotomy site postoperatively, which of the following describes the optimal orientation of the olecranon osteotomy?
Correct Answer & Explanation
. Apex-distal chevron osteotomy at the non-articular bare area
Explanation
An apex-distal chevron osteotomy directed at the "bare area" of the greater sigmoid notch is preferred. This configuration maximizes surface area for healing and provides inherent rotational and translational stability.
Question 877
Topic: 8. Foot and Ankle
A 5-year-old child with progressive infantile Blount disease is being evaluated for lateral hemiepiphysiodesis. Pre-operative planning includes a comprehensive radiographic assessment. Which of the following radiographic measurements is most crucial for assessing overall limb alignment and guiding the surgical correction?
Correct Answer & Explanation
. Mechanical Axis Deviation (MAD) on a standing full-length AP radiograph.
Explanation
While all listed options (except TFA, which is clinical) are relevant to Blount disease assessment, the Mechanical Axis Deviation (MAD) on a standing full-length AP radiograph is the most crucial for assessing overall limb alignment and guiding surgical correction. The MAD directly quantifies how far the mechanical axis deviates from the center of the knee joint, providing a comprehensive measure of the varus deformity across the entire limb. The Metaphyseal-Diaphyseal Angle (MDA) and Langenskiöld classification are important for diagnosing and staging Blount disease at the proximal tibia but do not provide a complete picture of overall limb alignment. The Distal Femoral Valgus Angle (mLDFA) assesses femoral alignment, which can be a confounding factor but is not the primary measure for tibial deformity. The Thigh-Foot Angle is a clinical measure of rotational alignment, not angular deformity.
Question 878
Topic: 8. Foot and Ankle
A 42-year-old male, a self-described 'weekend warrior,' presents to the emergency department after experiencing a sudden 'pop' in his right calf while playing recreational basketball. He reports immediate pain and difficulty pushing off his foot. Clinical examination reveals a palpable gap approximately 4 cm proximal to the calcaneal insertion and a positive Thompson test. Based on the provided case, which of the following statements best describes the most likely underlying pathological process contributing to this acute rupture?
Correct Answer & Explanation
. Underlying degenerative changes, exacerbated by relative hypovascularity in the mid-substance, predisposed the tendon to failure under eccentric load.
Explanation
Correct Answer: DThe case explicitly states that 'rupture typically occurs when an acute load exceeds the tendon's ultimate tensile strength, often in the presence of underlying degenerative changes. Such degenerative changes, including myxoid degeneration, collagen disorganization, and tenocyte apoptosis, are frequently observed histologically in ruptured tendons... and are more pronounced in the hypovascular watershed zone.' This directly supports option D, highlighting the combined role of degenerative changes and the hypovascular watershed zone in predisposing the tendon to rupture under eccentric load.Incorrect Options:A:While inflammation can occur post-injury, the primary underlying pathology predisposing to rupture is degenerative, not acute inflammatory. The case mentions 'degenerative changes' as preceding rupture.B:The mechanism of injury typically involves a 'sudden eccentric load applied to the actively contracting gastrocnemius-soleus complex,' often during ankle dorsiflexion simultaneous with knee extension, not a concentric contraction.C:The rupture typically occurs in the 'watershed zone' (2-6 cm proximal to insertion), which is described as a 'relatively hypovascular zone' and 'receives its blood supply predominantly from the paratenon, with fewer direct penetrating vessels compared to the proximal and distal ends.' This contradicts the idea of robust vascularity.E:While age and activity level are risk factors, the case clearly states that 'rupture typically occurs... often in the presence of underlying degenerative changes,' indicating intrinsic tendon pathology is involved, not just extrinsic factors.
Question 879
Topic: 8. Foot and Ankle
A 38-year-old male presents with an acute Achilles tendon rupture. During surgical planning, the surgeon notes that the rupture is located approximately 4 cm proximal to the calcaneal insertion, a region commonly referred to as the 'watershed zone.' Regarding the vascular supply to the Achilles tendon, particularly this critical zone, which statement is most accurate?
Correct Answer & Explanation
. The paratenon provides the predominant blood supply to the tendon's mid-portion, including the relatively hypovascular watershed zone.
Explanation
Correct Answer: CThe case explicitly states under 'Vascularity' that 'Critically, a relatively hypovascular zone, the 'watershed zone,' exists approximately 2-6 cm proximal to the calcaneal insertion. This region receives its blood supply predominantly from the paratenon, with fewer direct penetrating vessels compared to the proximal and distal ends.' This directly supports option C.Incorrect Options:A:The calcaneal arterial arcade primarily supplies the osseotendinous junction (distal end), not the mid-substance watershed zone.B:The musculotendinous junction supplies the proximal third of the tendon, not the entire mid-substance, and the watershed zone is specifically noted for its relative hypovascularity.D:The case states, 'Unlike tendons with a true synovial sheath, the Achilles tendon's paratenon provides its primary external blood supply.' This refutes the presence of a true synovial sheath.E:The presence of a 'watershed zone' directly contradicts the idea of uniform vascularity along the tendon's length.
Question 880
Topic: 8. Foot and Ankle
A 55-year-old sedentary female with a history of well-controlled diabetes presents with a suspected Achilles tendon rupture. Clinical examination reveals a positive Thompson test and a palpable gap of approximately 0.8 cm. She is reluctant to undergo surgery due to concerns about wound healing. Based on the provided case, which of the following is the most appropriate initial management strategy?
Correct Answer & Explanation
. Non-operative management with an accelerated rehabilitation protocol, considering her comorbidities and small gap.
Explanation
Correct Answer: CThe case provides clear indications for non-operative management: 'Elderly or sedentary individuals,' 'Significant medical comorbidities' (like diabetes), and 'Small tendon gap (<1 cm) and good apposition.' The patient fits all these criteria. The case also highlights that 'Non-operative treatment is increasingly utilized, especially with advancements in functional rehabilitation protocols that incorporate early protected motion and weight-bearing.'Incorrect Options:A:While diabetes is a comorbidity, it is listed as an indication fornon-operativemanagement due to increased surgical risks (e.g., wound healing complications), especially when well-controlled and with a small gap.B:While percutaneous repair aims to reduce wound complications, non-operative management is explicitly favored for patients with significant medical comorbidities and small gaps, making it a more appropriate initial choice.D:Delayed surgical repair is typically indicated for chronic ruptures (>2-4 weeks), not as an initial strategy for an acute presentation, especially when non-operative management is suitable.E:The case states, 'Clinically, the diagnosis is usually straightforward... Imaging, particularly MRI, can confirm the diagnosis... though it is not always necessary for acute cases.' Given the clear clinical findings (positive Thompson, palpable gap), MRI is not an absolute prerequisite for initiating treatment, especially when non-operative management is indicated.
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