Menu

Question 4401

Topic: 2. Trauma

When performing a decompressive fasciotomy for acute compartment syndrome of the foot, the surgeon intentionally opens the medial compartment. Which of the following muscles is located exclusively within this specific compartment?

. Adductor hallucis
. Flexor digitorum brevis
. Abductor hallucis
. Quadratus plantae
. Flexor hallucis longus

Correct Answer & Explanation

. Adductor hallucis


Explanation

The medial compartment of the foot contains the abductor hallucis and the flexor hallucis brevis muscles. The superficial (central) compartment contains the flexor digitorum brevis. The adductor compartment contains the adductor hallucis. The calcaneal compartment contains the quadratus plantae.

Question 4402

Topic: 2. Trauma

A 22-year-old collegiate basketball player sustains a fracture of the fifth metatarsal at the metaphyseal-diaphyseal junction extending into the intermetatarsal facet. What is the most appropriate management to ensure optimal outcome and return to play?

. Hard-soled shoe weight-bearing as tolerated
. Short leg cast non-weight-bearing for 6 weeks
. Intramedullary screw fixation
. Plating of the fifth metatarsal
. Resection of the proximal pole

Correct Answer & Explanation

. Hard-soled shoe weight-bearing as tolerated


Explanation

This describes a Zone 2 (Jones) fracture. In high-level or competitive athletes, acute intramedullary screw fixation is recommended. It significantly reduces the risk of nonunion and allows for an earlier return to sport compared to non-operative management, which carries a high rate of delayed union or nonunion due to the watershed blood supply in this zone.

Question 4403

Topic: 2. Trauma

A 20-year-old track athlete is diagnosed with a mid-body tarsal navicular stress fracture. Non-operative management is chosen. Why is this specific anatomical location at high risk for delayed union or nonunion?

. It is subjected to constant tensile forces from the tibialis posterior
. The central third is relatively avascular
. It is the primary insertion of the spring ligament
. It relies entirely on retrograde blood supply from the medial cuneiform
. It is composed primarily of cortical bone

Correct Answer & Explanation

. It is subjected to constant tensile forces from the tibialis posterior


Explanation

The tarsal navicular receives its blood supply from branches of the dorsalis pedis and medial plantar arteries forming a network on its dorsal and plantar surfaces. Microangiographic studies show that the central third of the navicular body is a watershed area and is relatively avascular. This renders stress fractures in this central region highly prone to delayed union or nonunion.

Question 4404

Topic: 2. Trauma

A 35-year-old male sustains a severe crush injury to the foot from heavy machinery. Clinical examination demonstrates tense swelling and excruciating pain with passive toe extension, raising strong clinical suspicion for compartment syndrome. How many distinct fascial compartments are generally recognized in the foot?

. 4
. 5
. 7
. 9
. 11

Correct Answer & Explanation

. 4


Explanation

There are 9 recognized fascial compartments in the foot: the medial, lateral, superficial, and calcaneal compartments, four interosseous compartments, and the adductor compartment. Fasciotomies are typically performed via a dual dorsal incision approach or a single extensive medial incision, depending on the injury pattern and surgeon preference.

Question 4405

Topic: 2. Trauma

A 25-year-old skier sustains an inversion injury to the ankle. Examination reveals tenderness over the posterior margin of the distal fibula. Radiographs show a small cortical avulsion fracture from the lateral ridge of the distal fibula (Fleck sign). What is the most likely diagnosis?

. Anterior talofibular ligament avulsion
. Calcaneofibular ligament avulsion
. Superior peroneal retinaculum avulsion
. Inferior peroneal retinaculum avulsion
. Base of the fifth metatarsal avulsion

Correct Answer & Explanation

. Anterior talofibular ligament avulsion


Explanation

The 'fleck sign' at the posterior margin of the lateral malleolus on an AP or mortise radiograph represents a bony avulsion of the superior peroneal retinaculum (SPR). This radiographic finding is pathognomonic for a peroneal tendon subluxation or dislocation.

Question 4406

Topic: 2. Trauma

In the operative management of a trimalleolar ankle fracture, what constitutes a widely accepted modern indication for direct internal fixation of the posterior malleolus?

. Any posterior malleolus fracture regardless of fragment size
. Posterior malleolus fractures involving >10% of the articular surface with any syndesmotic injury
. Any posterior malleolus fracture that prevents reduction of the fibula
. Posterior malleolar fractures that remain displaced after reduction of the lateral and medial structures, or involvement of >25% of the articular surface
. Only posterior malleolus fractures associated with a medial malleolus nonunion

Correct Answer & Explanation

. Any posterior malleolus fracture regardless of fragment size


Explanation

Traditionally, posterior malleolar fragments were fixed only if they involved >25-33% of the articular surface. Modern indications have expanded, recognizing the importance of the posterior malleolus in syndesmotic stability (via the PITFL). Current indications include fragments involving >25% of the articular surface, persistent posterior subluxation of the talus, persistent displacement or step-off of the fragment after fibular reduction, or concomitant syndesmotic instability where fixing the fragment securely restores the PITFL.

Question 4407

Topic: 2. Trauma
According to the Lauge-Hansen classification of ankle fractures, a Supination-External Rotation (SER) type IV fracture classically involves disruption of the deltoid ligament or a transverse fracture of the medial malleolus. What represents the very first stage (Stage I) of injury in the SER sequence?
. Rupture of the deltoid ligament
. Fracture of the medial malleolus
. Rupture of the anterior inferior tibiofibular ligament (AITFL)
. Spiral fracture of the lateral malleolus
. Rupture of the posterior inferior tibiofibular ligament (PITFL)

Correct Answer & Explanation

. Rupture of the anterior inferior tibiofibular ligament (AITFL)


Explanation

The Lauge-Hansen Supination-External Rotation (SER) sequence is the most common ankle fracture pattern and progresses in four distinct stages: Stage I: Rupture of the anterior inferior tibiofibular ligament (AITFL); Stage II: Spiral or oblique fracture of the distal fibula; Stage III: Rupture of the posterior inferior tibiofibular ligament (PITFL) or avulsion fracture of the posterior malleolus; Stage IV: Rupture of the deltoid ligament or transverse avulsion fracture of the medial malleolus.

Question 4408

Topic: 2. Trauma

A 38-year-old female presents with a closed spiral fracture of the distal third of the tibial shaft following a skiing fall. Initial anteroposterior and lateral radiographs of the tibia demonstrate the diaphyseal fracture but are otherwise unremarkable. What is the most appropriate next step in radiographic evaluation to rule out a commonly associated, yet frequently missed, injury?

. Anteroposterior and lateral radiographs of the knee
. Computed tomography (CT) scan of the ankle
. Magnetic resonance imaging (MRI) of the tibial shaft
. Technetium-99m bone scan
. Weight-bearing ankle radiographs

Correct Answer & Explanation

. Anteroposterior and lateral radiographs of the knee


Explanation

Spiral distal third tibia fractures have a high association (up to 50-90%) with occult posterior malleolar fractures. A CT scan of the ankle is highly recommended in this fracture pattern to identify and characterize intra-articular extension.

Question 4409

Topic: 2. Trauma

A 27-year-old male sustains a Hawkins II talar neck fracture and undergoes urgent open reduction and internal fixation. At the 8-week postoperative visit, an anteroposterior radiograph of the ankle demonstrates a subchondral radiolucent band across the talar dome. What does this radiographic finding indicate?

. Impending avascular necrosis of the talar body
. Nonunion of the talar neck
. Intact vascularity to the talar body
. Subchondral impaction fracture
. Septic arthritis of the tibiotalar joint

Correct Answer & Explanation

. Impending avascular necrosis of the talar body


Explanation

A subchondral radiolucent band on the talar dome is known as the Hawkins sign. It represents subchondral atrophy secondary to hyperemia and disuse, indicating that the vascular supply to the talar body remains intact.

Question 4410

Topic: 2. Trauma

A 32-year-old male sustains a severe ankle fracture-dislocation. Closed reduction in the emergency department is unsuccessful despite adequate sedation and muscle relaxation. Post-reduction radiographs reveal that the distal fibula remains entrapped posterior to the posterior tubercle of the distal tibia. Which of the following best describes this specific injury pattern?

. Tillaux fracture
. Wagstaffe-Le Fort fracture
. Bosworth fracture-dislocation
. Maisonneuve fracture
. Chaput fracture

Correct Answer & Explanation

. Tillaux fracture


Explanation

A Bosworth fracture-dislocation is characterized by the proximal fragment of the fractured fibula becoming locked behind the posterior tubercle of the tibia. This irreducible pattern invariably requires open reduction.

Question 4411

Topic: 2. Trauma

A 21-year-old collegiate track athlete presents with insidious onset dorsal midfoot pain. A CT scan confirms a stress fracture of the tarsal navicular. Which specific region of the navicular is at the highest risk for delayed union or nonunion due to its inherently poor vascularity?

. Dorsal lip
. Plantar tuberosity
. Medial pole
. Central third
. Lateral third

Correct Answer & Explanation

. Dorsal lip


Explanation

The central third of the tarsal navicular constitutes a vascular watershed area between the branches of the dorsalis pedis and medial plantar arteries. This tenuous blood supply makes stress fractures in this zone prone to nonunion.

Question 4412

Topic: 2. Trauma

A 68-year-old diabetic female with a history of peripheral neuropathy sustains a closed avulsion fracture of the calcaneal tuberosity following a fall. The posterior skin over the heel is severely blanched and tented by the fracture fragment. What is the most appropriate initial management?

. Application of a short leg cast in maximal equinus
. Application of a short leg cast in neutral dorsiflexion
. Urgent surgical reduction and internal fixation
. Percutaneous lengthening of the Achilles tendon in the emergency department
. Strict elevation and delayed fixation at 2 weeks to allow swelling to subside

Correct Answer & Explanation

. Application of a short leg cast in maximal equinus


Explanation

Displaced calcaneal tuberosity avulsion fractures that cause skin tenting and blanching are orthopedic emergencies. Urgent surgical reduction and fixation are required to relieve pressure and prevent devastating posterior heel skin necrosis.

Question 4413

Topic: Lower Extremity Trauma

A 28-year-old soccer player experiences sudden lateral ankle pain accompanied by a popping sensation during a rapid cutting maneuver. Physical examination reveals subluxation of the peroneal tendons anterior to the lateral malleolus with resisted eversion. Insufficiency of which of the following structures is most likely responsible?

. Inferior peroneal retinaculum
. Superior peroneal retinaculum
. Calcaneofibular ligament
. Anterior talofibular ligament
. Posterior talofibular ligament

Correct Answer & Explanation

. Inferior peroneal retinaculum


Explanation

The superior peroneal retinaculum (SPR) is the primary restraint preventing anterior subluxation of the peroneal tendons over the lateral malleolus. Injury to the SPR or its fibular attachment ('fleck sign') is the hallmark of peroneal tendon dislocation.

Question 4414

Topic: 2. Trauma

A 30-year-old construction worker sustains a severe crush injury to the foot from a falling steel beam. Acute compartment syndrome of the foot is suspected. Anatomically, how many distinct fascial compartments are generally recognized within the foot?

. 3
. 5
. 7
. 9
. 11

Correct Answer & Explanation

. 3


Explanation

There are 9 commonly recognized fascial compartments in the foot: medial, lateral, superficial central, deep central, calcaneal, and four interosseous compartments. All must be carefully released if full foot compartment syndrome is confirmed.

Question 4415

Topic: 2. Trauma

A 20-year-old elite basketball player sustains a fracture of the fifth metatarsal at the metaphyseal-diaphyseal junction, with the fracture line extending into the fourth-fifth intermetatarsal facet. To minimize the risk of nonunion and expedite return to play, what is the most appropriate definitive management?

. Non-weight-bearing short leg cast for 6 weeks
. Weight-bearing walking boot for 4 weeks
. Intramedullary screw fixation
. Plantar locking plate fixation
. Excision of the proximal fragment with peroneus brevis advancement

Correct Answer & Explanation

. Non-weight-bearing short leg cast for 6 weeks


Explanation

This describes a true Jones fracture (Zone 2). In elite athletes, operative treatment with an intramedullary screw is recommended to decrease the time to union, lower the nonunion rate, and accelerate return to sport.

Question 4416

Topic: 2. Trauma

During an extensile lateral approach for a displaced intra-articular calcaneus fracture, the surgeon must be careful to protect the primary vascular supply to the lateral soft tissue flap. Which artery provides this primary supply?

. Lateral calcaneal artery
. Sural artery
. Peroneal artery
. Anterior tibial artery
. Dorsalis pedis artery

Correct Answer & Explanation

. Lateral calcaneal artery


Explanation

The lateral calcaneal artery provides the primary blood supply to the lateral extensile flap used in calcaneus fracture fixation. Careful full-thickness subperiosteal dissection is required to protect this vessel and minimize the risk of wound edge necrosis.

Question 4417

Topic: 2. Trauma

A 32-year-old female presents with an isolated lateral malleolus fracture. A gravity stress radiograph demonstrates a medial clear space of 6 mm. This finding is indicative of a complete disruption of which of the following structures?

. Anterior inferior tibiofibular ligament
. Calcaneofibular ligament
. Deep deltoid ligament
. Interosseous membrane
. Spring ligament

Correct Answer & Explanation

. Anterior inferior tibiofibular ligament


Explanation

A medial clear space of greater than 4 to 5 mm on a gravity stress or weight-bearing radiograph indicates a complete disruption of the deep deltoid ligament. This converts an isolated lateral malleolus fracture into an unstable bimalleolar-equivalent injury requiring operative fixation.

Question 4418

Topic: 2. Trauma

A 21-year-old collegiate basketball player sustains a fracture at the metaphyseal-diaphyseal junction of the fifth metatarsal base. What is the most appropriate management to minimize the risk of nonunion and allow early return to sport?

. Non-weight bearing in a short leg cast for 6 weeks
. Weight bearing as tolerated in a stiff-soled shoe
. Open reduction and internal fixation with a mini-fragment plate
. Percutaneous intramedullary screw fixation
. Bone marrow aspirate injection and cast immobilization

Correct Answer & Explanation

. Non-weight bearing in a short leg cast for 6 weeks


Explanation

Intramedullary screw fixation is the gold standard for acute Jones fractures in elite athletes. This approach provides rigid stabilization of the watershed vascular zone, minimizing nonunion risk and allowing for an accelerated return to competitive sports.

Question 4419

Topic: 2. Trauma

A 22-year-old man falls 30 feet from a roof, landing on his buttocks. He complains of severe sacral pain, perineal numbness, and inability to void. Radiographs and CT demonstrate a transverse sacral fracture at the S2 level connecting bilateral longitudinal sacral fractures. Which of the following terms best describes this fracture pattern, and what is the primary neurovascular concern?

. U-type sacral fracture (spinopelvic dissociation); cauda equina syndrome
. Vertical shear fracture; superior gluteal artery injury
. Denis Zone I fracture; L5 nerve root injury
. Sacral ala fracture; internal iliac artery rupture
. Straddle fracture; pudendal nerve injury

Correct Answer & Explanation

. U-type sacral fracture (spinopelvic dissociation); cauda equina syndrome


Explanation

A transverse fracture through the upper sacrum (typically S1 or S2) connecting bilateral longitudinal transforaminal fractures represents a 'U-type' or 'H-type' sacral fracture. This results in spinopelvic dissociation, separating the upper spine/central sacrum from the pelvis. Because the fracture passes transversely through the sacral canal, there is a very high incidence of neurologic injury, specifically cauda equina syndrome, leading to bowel, bladder, and sexual dysfunction, as well as perineal numbness.

Question 4420

Topic: Pelvic & Acetabular Trauma
A 35-year-old male is involved in a motorcycle accident. Radiographs reveal an anteroposterior compression (APC) type II pelvic ring injury. Which of the following posterior pelvic ligamentous structures is characteristically disrupted in this specific injury pattern?
. Anterior sacroiliac, sacrotuberous, and sacrospinous ligaments
. Posterior sacroiliac, sacrotuberous, and sacrospinous ligaments
. Anterior sacroiliac, posterior sacroiliac, and sacrotuberous ligaments
. Posterior sacroiliac and iliolumbar ligaments
. Sacrotuberous and iliolumbar ligaments

Correct Answer & Explanation

. Anterior sacroiliac, sacrotuberous, and sacrospinous ligaments


Explanation

APC II injuries involve symphyseal diastasis and disruption of the anterior sacroiliac (SI) ligaments, as well as the sacrotuberous and sacrospinous ligaments. The critical distinction is that the strong posterior SI ligaments remain intact, providing vertical stability but allowing rotational instability (the 'open book' pelvic injury). APC III involves disruption of both anterior and posterior SI ligaments, resulting in both rotational and vertical instability.