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Question 4321

Topic: 8. Foot and Ankle

A patient presents with heel pain, exacerbated by the first steps in the morning and prolonged standing. Clinical diagnosis is plantar fasciitis. To which bony structure does the plantar fascia primarily attach?

. Navicular tuberosity
. Cuboid
. Head of the 5th metatarsal
. Medial tubercle of the calcaneus
. Sustentaculum tali

Correct Answer & Explanation

. Navicular tuberosity


Explanation

The plantar fascia (also known as plantar aponeurosis) is a thick fibrous band that originates from the medial tubercle of the calcaneus. It then fans out distally to attach to the bases of the proximal phalanges and the flexor tendon sheaths of the toes. Plantar fasciitis involves inflammation or degeneration at its origin on the medial tubercle of the calcaneus. The sustentaculum tali is part of the calcaneus but serves as an attachment for the spring ligament and flexor hallucis longus tendon, not the plantar fascia directly. Other options are incorrect attachments.

Question 4322

Topic: 8. Foot and Ankle

A patient presents with pain and weakness during eversion of the foot following a ankle injury. Which anatomical structure functions as a pulley or retinaculum for the peroneal tendons as they pass around the lateral malleolus?

. Inferior extensor retinaculum
. Superior peroneal retinaculum
. Cruciate ligament of the ankle
. Flexor retinaculum
. Deltoid ligament

Correct Answer & Explanation

. Inferior extensor retinaculum


Explanation

The superior peroneal retinaculum (SPR) is a strong fibrous band that originates from the lateral malleolus and inserts onto the lateral calcaneus. Its primary function is to hold the fibularis longus (peroneus longus) and fibularis brevis (peroneus brevis) tendons in place behind the lateral malleolus, preventing subluxation or dislocation. Injuries to the SPR can lead to recurrent peroneal tendon instability. The inferior extensor retinaculum is on the dorsum of the foot, the flexor retinaculum forms the tarsal tunnel medially, and the deltoid ligament is on the medial side of the ankle.

Question 4323

Topic: 8. Foot and Ankle

A patient sustains a calcaneal fracture involving the sustentaculum tali. This specific part of the calcaneus provides support for which crucial anatomical structure?

. Cuboid bone
. Head of talus
. Body of talus
. Navicular bone
. Fifth metatarsal base

Correct Answer & Explanation

. Cuboid bone


Explanation

The sustentaculum tali is a shelf-like projection from the medial side of the calcaneus. It is anatomically significant because it provides crucial support for the medial facet of the body of the talus. It also serves as an attachment point for the spring ligament (plantar calcaneonavicular ligament) and the flexor hallucis longus tendon wraps beneath it. Fractures involving the sustentaculum tali can lead to disruption of talocalcaneal articulation and potential long-term hindfoot pain and deformity. The head of the talus articulates with the navicular, not directly supported by sustentaculum tali.

Question 4324

Topic: 8. Foot and Ankle

A 10-year-old child presents with a painful prominence on the medial aspect of the foot, just proximal to the navicular. Radiographs reveal an accessory navicular bone. Which tendon commonly attaches to this accessory bone, leading to symptoms?

. Flexor hallucis longus
. Peroneus longus
. Tibialis anterior
. Tibialis posterior
. Extensor hallucis longus

Correct Answer & Explanation

. Flexor hallucis longus


Explanation

An accessory navicular (os naviculare accessorium or os tibiale externum) is an accessory ossicle found on the medial aspect of the foot, at the tuberosity of the navicular bone. The tibialis posterior tendon, which inserts primarily into the navicular tuberosity, commonly attaches to this accessory bone. When the accessory bone is symptomatic, it is often due to traction or inflammation at this attachment site, or trauma. This condition is also sometimes referred to as 'prehallux.' The other tendons listed have different primary insertion sites.

Question 4325

Topic: 8. Foot and Ankle

A patient complains of burning pain, numbness, and tingling in the third webspace of the foot, often described as 'walking on a marble.' This condition, Morton's neuroma, most commonly involves entrapment and fibrosis of which specific nerve structure?

. Medial plantar nerve
. Lateral plantar nerve
. Deep peroneal nerve
. Common plantar digital nerve (from medial plantar nerve)
. Common plantar digital nerve (from lateral plantar nerve)

Correct Answer & Explanation

. Medial plantar nerve


Explanation

Morton's neuroma is a common forefoot pathology characterized by entrapment neuropathy and perineural fibrosis of a common plantar digital nerve. While it can occur in other webspaces, it is most prevalent in the third intermetatarsal space (between the 3rd and 4th metatarsals). The common plantar digital nerve in this space receives contributions fromboththe medial plantar nerve (for the third toe's medial side) and the lateral plantar nerve (for the fourth toe's lateral side), making it susceptible to shear forces and compression. Therefore, it's a common plantar digital nerve (from lateral plantar nerve) for the lateral side of the 3rd webspace and a common plantar digital nerve (from medial plantar nerve) for the medial side of the 3rd webspace, but the option specifiescommon plantar digital nerveoriginating from the lateral plantar nerve contributing to the 3rd webspace (4th digital nerve), which is a key component.

Question 4326

Topic: 8. Foot and Ankle

A patient presents with persistent lateral ankle pain following an inversion injury. Examination reveals tenderness in the 'sinus tarsi.' Which two bones form the boundaries of the sinus tarsi?

. Tibia and fibula
. Talus and navicular
. Calcaneus and cuboid
. Talus and calcaneus
. Cuboid and 5th metatarsal

Correct Answer & Explanation

. Tibia and fibula


Explanation

The sinus tarsi is a conical canal located on the lateral aspect of the hindfoot, between the talus and the calcaneus. It is bounded by the neck of the talus superiorly and the anterior process of the calcaneus inferiorly. It contains several ligaments (cervical and interosseous talocalcaneal ligaments), fat, and nerve endings. Injuries to the structures within the sinus tarsi can cause 'sinus tarsi syndrome,' characterized by lateral ankle pain and instability. Therefore, the talus and calcaneus form its boundaries.

Question 4327

Topic: 8. Foot and Ankle

A patient undergoes surgical exploration for chronic hallux valgus with a painful callus beneath the first metatarsal head. Which two sesamoid bones are typically found within the flexor hallucis brevis tendon, located beneath the first metatarsal head?

. Medial and lateral cuneiforms
. Tibial and fibular sesamoids
. Proximal and distal sesamoids
. Dorsal and plantar sesamoids
. Navicular and cuboid

Correct Answer & Explanation

. Medial and lateral cuneiforms


Explanation

The first metatarsophalangeal (MTP) joint complex includes two sesamoid bones (tibial/medial and fibular/lateral) embedded within the medial and lateral heads of the flexor hallucis brevis (FHB) tendon. These sesamoids articulate with the plantar aspect of the first metatarsal head, forming a critical part of the weight-bearing mechanism and enhancing the mechanical advantage of the FHB. They are commonly involved in pathologies such as sesamoiditis, fractures, or dislocation, particularly in hallux valgus deformity. The cuneiforms, navicular, and cuboid are distinct tarsal bones.

Question 4328

Topic: 8. Foot and Ankle

A patient undergoes surgical repair for a chronic Achilles tendon rupture. To ensure adequate healing and prevent re-rupture, the surgeon must be aware of the primary blood supply to the Achilles tendon. Which artery provides the most significant vascularization to the midportion of the Achilles tendon, making this area prone to hypovascularity and rupture?

. Anterior tibial artery
. Fibular artery (peroneal artery)
. Posterior tibial artery
. Dorsalis pedis artery
. Medial plantar artery

Correct Answer & Explanation

. Anterior tibial artery


Explanation

The Achilles tendon receives its blood supply from branches of the posterior tibial artery, fibular (peroneal) artery, and sural arteries. However, themidportionof the Achilles tendon, approximately 2-6 cm proximal to its calcaneal insertion, is notoriously hypovascular. The primary blood supply to the main body of the tendon is often described as coming from the posterior tibial artery via musculotendinous junctions and from the fibular artery, with a critical zone of hypovascularity in the mid-substance. Given the options, the posterior tibial artery is the most significant contributor to the overall supply, with specific small branches, but themidportionremains a watershed zone. The fibular artery also plays a significant role, but the posterior tibial artery is often cited as the predominant supply in many texts. For high-yield, Posterior Tibial Artery is a very common answer here for the main supply.

Question 4329

Topic: Midfoot & Hindfoot

A 48-year-old female presents with stage IIb posterior tibial tendon dysfunction and a flexible flatfoot deformity. Reconstruction requires stabilization of the spring ligament complex. Which of the following bands of the spring ligament complex is the strongest, providing the most critical support to the talar head?

. Superomedial calcaneonavicular ligament
. Inferior calcaneonavicular ligament
. Medioplantar oblique calcaneonavicular ligament
. Plantar calcaneocuboid ligament
. Dorsal talonavicular ligament

Correct Answer & Explanation

. Superomedial calcaneonavicular ligament


Explanation

The spring ligament (calcaneonavicular ligament) complex has three major bands: the superomedial, inferior, and medioplantar oblique. The superomedial calcaneonavicular ligament is the thickest, strongest, and most critical component for static support of the talar head and maintenance of the medial longitudinal arch.

Question 4330

Topic: 8. Foot and Ankle

A 24-year-old collegiate football player sustains a midfoot sprain. Weight-bearing radiographs reveal a 4 mm diastasis between the first and second metatarsal bases. The primary stabilizing ligament of this complex (the Lisfranc ligament) connects which two osseous structures?

. Medial cuneiform and first metatarsal base
. Medial cuneiform and second metatarsal base
. Middle cuneiform and second metatarsal base
. Lateral cuneiform and third metatarsal base
. Navicular and second metatarsal base

Correct Answer & Explanation

. Medial cuneiform and first metatarsal base


Explanation

The Lisfranc ligament is an oblique, stout 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 the strongest and primary stabilizer of the tarsometatarsal articulation, especially given the lack of an intermetatarsal ligament between the first and second metatarsal bases.

Question 4331

Topic: 8. Foot and Ankle

A 28-year-old gymnast requires surgical fixation for a displaced intra-articular calcaneus fracture. A lateral extensile approach is utilized. The surgeon places a cortical screw from lateral to medial into the sustentaculum tali for primary fracture fragment purchase. To avoid injury to the primary structure running immediately inferior to the sustentaculum tali, care must be taken not to plunge past the medial cortex. Which tendon runs directly beneath the sustentaculum tali?

. Tibialis posterior
. Flexor digitorum longus
. Flexor hallucis longus
. Peroneus longus
. Tibialis anterior

Correct Answer & Explanation

. Tibialis posterior


Explanation

The sustentaculum tali is a medial osseous projection of the calcaneus that supports the middle articular facet for the talus. The tendon of the flexor hallucis longus (FHL) courses directly inferior to the sustentaculum tali within its own fibro-osseous groove. When placing lateral-to-medial screws into the constant sustentacular fragment during calcaneus fracture fixation, screws that protrude past the medial cortex can irritate or tether the FHL tendon.

Question 4332

Topic: 8. Foot and Ankle

A surgeon is performing a midfoot reconstruction and exploring the medial plantar aspect of the foot. The 'Master Knot of Henry' is identified just plantar and lateral to the navicular tuberosity. Which of the following accurately describes the relationship of the tendons at this anatomical landmark?

. The flexor hallucis longus crosses superficial (plantar) to the flexor digitorum longus
. The flexor digitorum longus crosses superficial (plantar) to the flexor hallucis longus
. The tibialis posterior crosses superficial (plantar) to the flexor hallucis longus
. The peroneus longus crosses dorsal to the flexor digitorum longus
. The flexor hallucis longus crosses deep (dorsal) to the tibialis anterior

Correct Answer & Explanation

. The flexor hallucis longus crosses superficial (plantar) to the flexor digitorum longus


Explanation

The Master Knot of Henry is an important anatomical landmark located in the medial plantar midfoot, just plantarlateral to the navicular tuberosity. At this precise location, the tendon of the flexor digitorum longus (FDL) crosses superficial (plantar) to the tendon of the flexor hallucis longus (FHL). It is a critical site for harvesting the FDL during tendon transfers, such as for posterior tibial tendon dysfunction.

Question 4333

Topic: 8. Foot and Ankle

The distal tibiofibular syndesmosis is crucial for maintaining the stability of the ankle mortise. The anterior inferior tibiofibular ligament (AITFL) is a primary component of this complex. Which of the following correctly identifies its anatomical origin and insertion?

. Originates from the posterior tibial tubercle (Volkmann) and inserts on the posterior fibula
. Originates from the anterior tibial tubercle (Chaput) and inserts on the anterior fibular tubercle (Wagstaffe)
. Originates from the medial malleolus and inserts on the navicular tuberosity
. Originates from the lateral malleolus and inserts on the lateral talar process
. Originates from Gerdy's tubercle and inserts on the fibular head

Correct Answer & Explanation

. Originates from the posterior tibial tubercle (Volkmann) and inserts on the posterior fibula


Explanation

The ankle syndesmotic ligament complex includes the anterior inferior tibiofibular ligament (AITFL), the posterior inferior tibiofibular ligament (PITFL), the transverse tibiofibular ligament, and the interosseous membrane. The AITFL originates on the anterolateral tubercle of the tibia, eponymously known as Chaput's tubercle, and inserts onto the anterior tubercle of the fibula, known as Wagstaffe's (or Le Fort-Wagstaffe) tubercle. The PITFL attaches to the posterior tibial tubercle (Volkmann's tubercle).

Question 4334

Topic: 8. Foot and Ankle

A 28-year-old man sustains a displaced talar neck fracture. To prevent avascular necrosis, the surgeon must preserve the dominant blood supply to the talar body. The artery of the tarsal canal arises predominantly from which of the following vessels?

. Anterior tibial artery
. Perforating peroneal artery
. Dorsalis pedis artery
. Posterior tibial artery
. Medial plantar artery

Correct Answer & Explanation

. Anterior tibial artery


Explanation

The artery of the tarsal canal is the dominant blood supply to the talar body. It typically arises from the posterior tibial artery about 1 cm proximal to the bifurcation into the medial and lateral plantar arteries. It enters the tarsal canal and forms an anastomotic vascular sling with the artery of the sinus tarsi, which usually arises from the perforating peroneal or dorsalis pedis artery.

Question 4335

Topic: 8. Foot and Ankle

A 45-year-old distance runner is undergoing a tarsal tunnel release for refractory posterior tibial nerve entrapment. From anterior to posterior (or medial to lateral within the tunnel), what is the correct anatomical order of structures passing behind the medial malleolus?

. Tibialis posterior, Flexor hallucis longus, Posterior tibial artery, Posterior tibial nerve, Flexor digitorum longus
. Flexor digitorum longus, Tibialis posterior, Posterior tibial nerve, Posterior tibial artery, Flexor hallucis longus
. Tibialis posterior, Flexor digitorum longus, Posterior tibial artery, Posterior tibial nerve, Flexor hallucis longus
. Posterior tibial artery, Posterior tibial nerve, Tibialis posterior, Flexor digitorum longus, Flexor hallucis longus
. Flexor hallucis longus, Posterior tibial nerve, Posterior tibial artery, Flexor digitorum longus, Tibialis posterior

Correct Answer & Explanation

. Tibialis posterior, Flexor hallucis longus, Posterior tibial artery, Posterior tibial nerve, Flexor digitorum longus


Explanation

The structures passing through the tarsal tunnel behind the medial malleolus are, from anterior to posterior: Tibialis posterior tendon, Flexor digitorum longus tendon, Posterior tibial Artery, Posterior tibial Nerve, and Flexor hallucis longus tendon. This anatomy is commonly remembered by the mnemonic 'Tom, Dick, And Very Nervous Harry'. The flexor retinaculum forms the roof of the tunnel, and release of this retinaculum decompresses the posterior tibial nerve.

Question 4336

Topic: 8. Foot and Ankle

During open reduction and internal fixation of a severe midfoot crush injury, the surgeon must anatomically restore the Lisfranc complex. The primary Lisfranc ligament is essential for the stability of this joint. What are the correct anatomical attachments of the Lisfranc ligament?

. Dorsal aspect of the medial cuneiform to the dorsal base of the second metatarsal
. Plantar aspect of the intermediate cuneiform to the plantar base of the second metatarsal
. Lateral aspect of the medial cuneiform to the medial aspect of the base of the second metatarsal
. Medial aspect of the cuboid to the lateral aspect of the base of the third metatarsal
. Anterior aspect of the navicular to the dorsal base of the first metatarsal

Correct Answer & Explanation

. Dorsal aspect of the medial cuneiform to the dorsal base of the second metatarsal


Explanation

The Lisfranc ligament is the largest and thickest of the ligaments connecting the midfoot to the forefoot. It is an interosseous ligament that runs obliquely from the lateral surface 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, making the Lisfranc ligament critical for stability.

Question 4337

Topic: 8. Foot and Ankle

A 42-year-old roofer falls from a height and sustains a displaced intra-articular calcaneus fracture. The surgeon elects to proceed with an extensile lateral approach. Which of the following structures is most at risk of injury at the proximal extent of the vertical limb of the incision, and what is its anatomic relationship to the Achilles tendon?

. Sural nerve, located 1.5 cm medial to the lateral border of the Achilles tendon
. Sural nerve, located 1.5 cm lateral to the lateral border of the Achilles tendon
. Superficial peroneal nerve, located 2.5 cm lateral to the lateral border of the Achilles tendon
. Tibial nerve, located deep to the medial border of the Achilles tendon
. Deep peroneal nerve, located strictly on the dorsum of the foot

Correct Answer & Explanation

. Sural nerve, located 1.5 cm medial to the lateral border of the Achilles tendon


Explanation

During an extensile lateral approach to the calcaneus, the vertical limb of the incision is typically placed midway between the posterior aspect of the fibula and the lateral border of the Achilles tendon. The sural nerve is at risk in this region. Anatomical studies demonstrate that the sural nerve runs approximately 1.5 to 2.0 cm lateral to the lateral border of the Achilles tendon at the level of the lateral malleolus.

Question 4338

Topic: 8. Foot and Ankle

An extended lateral approach is performed for open reduction and internal fixation of a highly comminuted, intra-articular calcaneus fracture. To minimize the risk of wound edge necrosis, the surgeon raises a full-thickness subperiosteal flap. Which of the following structures are deliberately elevated within this full-thickness flap?

. Sural nerve and superficial peroneal nerve
. Peroneal tendons and sural nerve
. Tibial nerve and posterior tibial artery
. Extensor digitorum brevis and superficial peroneal nerve
. Achilles tendon and lesser saphenous vein

Correct Answer & Explanation

. Sural nerve and superficial peroneal nerve


Explanation

In the extended lateral approach to the calcaneus, creating a full-thickness subperiosteal flap is paramount to preserving the blood supply to the skin (supplied mainly by the lateral calcaneal artery). This 'no-touch' flap technique involves subperiosteal dissection that lifts the peroneal tendons (longus and brevis) and the sural nerve within the flap. Retraction is performed using K-wires placed into the talus and fibula, keeping the soft tissue undisturbed and minimizing wound healing complications.

Question 4339

Topic: 8. Foot and Ankle

A 45-year-old marathon runner presents with medial ankle pain and paresthesias radiating to the plantar aspect of the foot. Nonoperative management has failed, and a tarsal tunnel release is planned. As the surgeon incises the flexor retinaculum, multiple structures are encountered. Moving from anteromedial to posterolateral, which structure is located most posterolaterally within the tarsal tunnel?

. Tibialis posterior tendon
. Flexor digitorum longus tendon
. Posterior tibial artery
. Tibial nerve
. Flexor hallucis longus tendon

Correct Answer & Explanation

. Tibialis posterior tendon


Explanation

The structures passing through the tarsal tunnel posterior to the medial malleolus, arranged from anteromedial to posterolateral (or anterior to posterior), are the Tibialis posterior tendon, Flexor digitorum longus tendon, Posterior tibial artery/vein, Tibial nerve, and Flexor hallucis longus (FHL) tendon. The FHL is the most posterior/lateral structure, classically remembered by the mnemonic 'Tom, Dick, AND Very Nervous Harry'.

Question 4340

Topic: 8. Foot and Ankle

A 45-year-old male is undergoing minimally invasive percutaneous repair of an acute Achilles tendon rupture. The surgeon must exercise extreme caution when passing locking sutures laterally to avoid capturing the sural nerve. At what approximate distance proximal to the calcaneal insertion does the sural nerve typically cross the lateral border of the Achilles tendon, moving from the midline to a more lateral position?

. 2 cm
. 5 cm
. 10 cm
. 15 cm
. 20 cm

Correct Answer & Explanation

. 2 cm


Explanation

The sural nerve is at significant risk during both open and percutaneous Achilles tendon repairs, particularly during lateral suture passage. Cadaveric and anatomical studies consistently demonstrate that the sural nerve typically crosses the lateral border of the Achilles tendon approximately 10 cm (range 9-11 cm) proximal to its insertion on the calcaneal tuberosity. Distal to this level, the nerve lies lateral to the tendon, and proximal to this level, it courses closer to the midline over the lateral aspect of the gastrocnemius complex.