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2. Trauma MCQs

Practice Set 97 of 640

This practice set contains high-yield board review questions covering key concepts in 2. Trauma. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.

Question 1921

Topic: 2. Trauma

A 38-year-old male presents after a 10-foot fall onto both feet, experiencing severe bilateral heel pain and inability to bear weight. Initial assessment reveals significant swelling, ecchymosis, and a negative 'wrinkle test' on the left hindfoot. Given the high-energy axial load mechanism, which of the following associated injuries is most critical to actively screen for during the initial evaluation?

. Talar body or neck fracture
. Tibial pilon fracture
. Lumbar spine fracture
. Contralateral calcaneal fracture
. Midfoot compartment syndrome

Correct Answer & Explanation

. Lumbar spine fracture

Explanation

Correct Answer: CThe mechanism of injury (high-energy axial load, fall from height) that causes calcaneal fractures is also associated with other significant injuries, particularly to the spine. The case explicitly states, 'specific inquiry was made regarding other potential injuries, especially those associated with high-energy axial loading. This included symptoms referable to the lumbar spine, which is crucial given the incidence of concomitant spinal fractures (up to 10-15% in calcaneal fractures).' Therefore, a lumbar spine fracture is the most critical associated injury to screen for due to its potential for neurological compromise and the high incidence rate. While other options like talar fractures, pilon fractures, and contralateral calcaneal fractures are important to consider in the differential for hindfoot trauma, the lumbar spine carries a higher risk of severe systemic implications and is specifically highlighted in the case as a crucial consideration for this mechanism.

Question 1922

Topic: 2. Trauma

The patient's clinical examination revealed tense, shiny skin over the lateral aspect of the left heel, and the 'wrinkle test' was negative. This finding has which of the following implications for the immediate surgical management of his displaced intra-articular calcaneal fracture?

. It indicates an impending compartment syndrome requiring emergent fasciotomy.
. It confirms adequate soft tissue envelope for immediate open reduction and internal fixation (ORIF).
. It mandates delayed surgery to allow for soft tissue recovery and resolution of swelling.
. It suggests a higher risk of sural nerve injury during the surgical approach.
. It is a benign finding with no significant impact on surgical timing.

Correct Answer & Explanation

. It mandates delayed surgery to allow for soft tissue recovery and resolution of swelling.

Explanation

Correct Answer: CThe case explicitly states, 'The 'wrinkle test' was negative on the left side, meaning the skin could not be pinched into fine wrinkles, signifying that the swelling had exceeded the elastic capacity of the dermis. Proceeding with an extensile lateral approach in the presence of a negative wrinkle test carries an unacceptably high risk of postoperative wound dehiscence.' This finding is a critical indicator of severe soft tissue compromise due to edema. Therefore, surgery must be delayed until the swelling has subsided and the wrinkle test becomes positive, typically 10 to 21 days post-injury, to minimize the risk of devastating wound complications. While compartment syndrome is a concern with high-energy injuries, a negative wrinkle test primarily relates to skin viability for surgical incision, not directly to compartment pressures. It does not confirm adequate soft tissue for immediate surgery; rather, it contraindicates it.

Question 1923

Topic: 2. Trauma
Based on the provided case description and the typical coronal CT appearance for a Sanders Type IIIBC calcaneal fracture, which of the following best describes the articular fragments of the posterior facet?
. Two articular fragments with a single fracture line through the lateral aspect.
. Three articular fragments with fracture lines centrally and laterally.
. Four articular fragments with comminution across the entire posterior facet.
. A non-displaced articular fracture.
. Two articular fragments with a single fracture line through the medial aspect.

Correct Answer & Explanation

. Three articular fragments with fracture lines centrally and laterally.

Explanation

The Sanders classification system, based on coronal CT cuts, divides the posterior facet into three potential fracture lines (A, B, and C). A Type III fracture indicates three-part articular fractures (two fracture lines) with a centrally depressed fragment. Specifically, IIIBC means there are fracture lines centrally (B) and laterally (C), resulting in three distinct articular fragments (medial, central, and lateral).

Question 1924

Topic: 2. Trauma

The sagittal CT cuts of the patient's calcaneal fracture confirmed a 'tongue-type variant.' This specific classification, based on the Essex-Lopresti system, implies which of the following about the fracture morphology?

. The secondary fracture line exits superiorly, just posterior to the posterior facet.
. The posterior facet is completely detached from the tuberosity fragment.
. The secondary fracture line exits posteriorly through the calcaneal tuberosity.
. The fracture is primarily extra-articular, with no subtalar joint involvement.
. The calcaneocuboid joint is the primary site of comminution.

Correct Answer & Explanation

. The secondary fracture line exits posteriorly through the calcaneal tuberosity.

Explanation

Correct Answer: CThe case clearly defines the Essex-Lopresti classification: 'Our patient exhibits a tongue-type variant. This distinction is critical for reduction maneuvers. In a tongue-type fracture, the entire posterior facet and tuberosity unit can often be manipulated via a Schanz pin placed percutaneously into the posterior tuberosity (the Essex-Lopresti maneuver). Plantarflexion of the pin elevates the posterior facet, while varus/valgus manipulation corrects the coronal alignment.' It further clarifies: 'The sagittal cuts confirmed a tongue-type variant where the secondary fracture line exited posteriorly through the tuberosity, rather than superiorly just behind the posterior facet (which would indicate a joint depression type).' Therefore, a tongue-type fracture is characterized by the secondary fracture line exiting posteriorly through the calcaneal tuberosity, meaning the posterior facet remains attached to the posterior tuberosity fragment.

Question 1925

Topic: 2. Trauma
Following surgical exposure via the extensile lateral approach for this Sanders Type IIIBC tongue-type calcaneal fracture, a logical, step-wise reduction sequence is crucial. What is the most appropriate initial step in the fracture reduction sequence?
. Provisional articular fixation of the posterior facet with subchondral K-wires.
. Reduction of the lateral wall blowout and buttressing with a plate.
. Elevation and reduction of the central and lateral posterior facet fragments.
. Reduction of the calcaneal tuberosity using a Schanz pin.
. Placement of definitive sustentacular screws through the plate.

Correct Answer & Explanation

. Reduction of the calcaneal tuberosity using a Schanz pin.

Explanation

The reduction of a highly comminuted Sanders IIIBC fracture must follow a logical, step-wise progression. The first step is tuberosity reduction: a 5.0 mm Schanz pin is inserted percutaneously into the calcaneal tuberosity fragment. Using this pin as a joystick, axial traction is applied to restore calcaneal length. The tuberosity is then translated medially and rotated out of varus to restore the mechanical axis of the hindfoot.

Question 1926

Topic: 2. Trauma

A 35-year-old male sustains a high-energy ankle injury. Plain radiographs demonstrate a highly displaced ankle fracture-dislocation that is irreducible in the emergency department. A subsequent CT scan reveals that the proximal fragment of a distal fibula fracture is trapped behind the posterior tubercle of the distal tibia. What is the most appropriate diagnosis?

. Dupuytren fracture
. Tillaux fracture
. Bosworth fracture-dislocation
. Maisonneuve fracture
. Wagstaffe fracture

Correct Answer & Explanation

. Bosworth fracture-dislocation

Explanation

A Bosworth fracture-dislocation involves the entrapment of the proximal fibular fragment behind the posterior tibial tubercle. It typically requires open reduction because closed reduction is mechanically blocked by the posterior aspect of the tibia.

Question 1927

Topic: 2. Trauma

A patient with an intra-articular calcaneus fracture is undergoing preoperative planning. Which imaging modality and specific slice view is standardly used to determine the Sanders classification?

. Sagittal CT scan through the anterior process
. Axial CT scan parallel to the plantar fascia
. Coronal CT scan through the widest portion of the posterior facet
. Coronal CT scan through the calcaneocuboid joint
. Harris axial radiograph

Correct Answer & Explanation

. Coronal CT scan through the widest portion of the posterior facet

Explanation

The Sanders classification for intra-articular calcaneal fractures relies on the number and location of articular fracture lines through the posterior facet. It is best evaluated on a coronal CT image taken at the widest portion of the posterior facet.

Question 1928

Topic: 2. Trauma

Six weeks following open reduction and internal fixation of a talar neck fracture, a subchondral radiolucent band is visualized in the talar dome on the AP mortise radiograph. What does this radiographic finding indicate?

. Avascular necrosis of the talar body
. Impending nonunion of the fracture
. Revascularization and intact blood supply
. Early post-traumatic osteomyelitis
. Charcot arthropathy

Correct Answer & Explanation

. Revascularization and intact blood supply

Explanation

The Hawkins sign is a subchondral radiolucent band seen in the talar dome 6 to 8 weeks after a talar neck fracture, representing active bone resorption. It indicates intact vascularity to the talar body, implying a very low risk of avascular necrosis.

Question 1929

Topic: 2. Trauma

During an extensile lateral approach for a calcaneus fracture, a full-thickness subperiosteal flap is elevated. If the inferior and proximal limb of the incision is carried too far posteriorly, which of the following structures is at greatest risk of iatrogenic injury?

. Deep peroneal nerve
. Superficial peroneal nerve
. Sural nerve
. Medial plantar nerve
. Saphenous nerve

Correct Answer & Explanation

. Sural nerve

Explanation

The sural nerve courses posterior to the lateral malleolus and along the lateral aspect of the hindfoot. It is the structure most at risk during the extensile lateral approach, particularly at the proximal vertical limb and the distal curve of the incision.

Question 1930

Topic: 2. Trauma

An apex-distal chevron olecranon osteotomy is utilized to expose the articular surface for the fixation of a highly comminuted intra-articular distal humerus fracture. What is the most common complication associated specifically with this osteotomy?

. Nonunion of the osteotomy site
. Ulnar nerve palsy
. Symptomatic hardware requiring later removal
. Triceps avulsion
. Heterotopic ossification of the olecranon bursa

Correct Answer & Explanation

. Symptomatic hardware requiring later removal

Explanation

The most common complication following a chevron olecranon osteotomy is symptomatic hardware from the tension band wiring or plating used for repair. Up to 80% of patients may require hardware removal, whereas nonunion rates are generally low.

Question 1931

Topic: 2. Trauma

During open reduction and internal fixation of a calcaneus fracture, screws are placed from lateral to medial into the sustentaculum tali. If these screws are excessively long and penetrate the inferior cortex of the sustentaculum, which tendon is at direct risk of tethering or injury?

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

Correct Answer & Explanation

. Flexor hallucis longus

Explanation

The flexor hallucis longus (FHL) tendon courses directly inferior to the sustentaculum tali. Plunging screws through the plantar cortex of the sustentaculum tali can impale or tether the FHL, leading to fixed flexion of the hallux.

Question 1932

Topic: 2. Trauma

A 45-year-old male falls from a height and sustains a displaced intra-articular calcaneus fracture. During an extensile lateral approach, the surgeon elevates a full-thickness subperiosteal flap. Which of the following vascular structures is the primary blood supply to this lateral soft tissue flap and must be meticulously protected?

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

Correct Answer & Explanation

. Lateral calcaneal artery

Explanation

The lateral calcaneal artery, a terminal branch of the peroneal artery, provides the primary vascular supply to the lateral flap in an extensile lateral approach. The full-thickness flap must be elevated subperiosteally with a 'no-touch' technique to prevent catastrophic flap necrosis.

Question 1933

Topic: 2. Trauma

A 22-year-old male sustains a high-energy ankle fracture-dislocation that is irreducible in the emergency department. A post-reduction attempt CT scan shows the proximal fibular fragment entrapped posterior to the posterolateral ridge of the distal tibia. What is the most likely diagnosis?

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

Correct Answer & Explanation

. Bosworth fracture-dislocation

Explanation

A Bosworth fracture-dislocation involves an irreducible ankle fracture where the proximal fibular shaft fragment becomes entrapped behind the posterior tubercle of the distal tibia. Closed reduction is typically impossible, necessitating urgent open reduction to prevent skin necrosis.

Question 1934

Topic: 2. Trauma

A 62-year-old female undergoes open reduction and internal fixation of a comminuted distal humerus fracture utilizing a chevron olecranon osteotomy. Which of the following complications is uniquely associated with this specific approach compared to triceps-sparing approaches?

. Ulnar neuropathy
. Heterotopic ossification
. Nonunion or symptomatic hardware at the osteotomy site
. Global elbow stiffness
. Triceps tendon rupture

Correct Answer & Explanation

. Nonunion or symptomatic hardware at the osteotomy site

Explanation

An olecranon osteotomy provides excellent visualization of the distal humeral articular surface but carries unique complications including osteotomy nonunion and symptomatic hardware. Triceps-sparing approaches avoid these specific risks but may offer more limited articular exposure.

Question 1935

Topic: 2. Trauma

A 32-year-old male is brought to the emergency department after a severe ankle twisting injury. Closed reduction is unsuccessful, and the ankle remains rigidly dislocated. Radiographs demonstrate that the proximal fibular fragment is entrapped behind the posterior tubercle of the distal tibia. What is the eponym for this specific fracture-dislocation?

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

Correct Answer & Explanation

. Bosworth fracture-dislocation

Explanation

A Bosworth fracture-dislocation occurs when the proximal fibular fragment becomes locked behind the posterior tubercle of the distal tibia. This mechanical block makes closed reduction typically impossible, necessitating urgent open reduction.

Question 1936

Topic: 2. Trauma

Which imaging modality and specific plane of view are required to properly classify intra-articular calcaneus fractures according to the Sanders classification system?

. Sagittal CT scan reconstructions
. Axial CT scan reconstructions parallel to the subtalar joint
. Coronal CT scan reconstructions perpendicular to the posterior facet
. Harris axial radiograph view
. Lateral radiograph of the hindfoot

Correct Answer & Explanation

. Coronal CT scan reconstructions perpendicular to the posterior facet

Explanation

The Sanders classification for intra-articular calcaneal fractures is based on the number and location of articular fracture lines through the posterior facet. It specifically requires a coronal plane CT scan formatted perpendicular to the posterior facet of the calcaneus.

Question 1937

Topic: 2. Trauma
A 6-year-old boy sustains a Bado Type III Monteggia fracture (lateral or anterolateral dislocation of the radial head with a proximal ulnar fracture). Which nerve is at the highest risk of injury in this specific Bado subtype?
. Ulnar nerve
. Anterior interosseous nerve
. Posterior interosseous nerve
. Median nerve
. Superficial radial nerve

Correct Answer & Explanation

. Posterior interosseous nerve

Explanation

A Bado Type III Monteggia fracture involves a lateral or anterolateral dislocation of the radial head. The displaced radial head directly compresses or stretches the posterior interosseous nerve (PIN), making it the most commonly injured nerve in this subtype.

Question 1938

Topic: 2. Trauma

A 45-year-old male sustains a high-energy pilon fracture. The extremity exhibits massive soft tissue swelling and multiple hemorrhagic fracture blisters. A spanning external fixator is placed. What is the most widely accepted clinical indicator that the soft tissues are ready for definitive open reduction and internal fixation?

. Exactly 24 hours post-injury regardless of clinical appearance
. When clear fluid blisters transition to hemorrhagic blisters
. Return of the 'wrinkle sign' upon dorsiflexion or pinch
. Immediately after the hemorrhagic blisters re-epithelialize, before swelling fully subsides
. Routine delay of precisely 6 weeks to ensure complete soft tissue healing

Correct Answer & Explanation

. Return of the 'wrinkle sign' upon dorsiflexion or pinch

Explanation

Definitive fixation of pilon fractures with severe soft tissue compromise must be delayed until swelling significantly subsides to minimize wound dehiscence and infection. The return of skin lines, or the 'wrinkle sign', is the standard clinical hallmark indicating it is safe to proceed.

Question 1939

Topic: 2. Trauma

During percutaneous fixation of a calcaneus fracture, a surgeon directs a screw from lateral to medial into the sustentaculum tali. If this screw is excessively long and breaches the medial cortex of the sustentaculum, which anatomical structure is at greatest risk of being injured or tethered?

. Tibialis posterior tendon
. Flexor hallucis longus tendon
. Flexor digitorum longus tendon
. Sural nerve
. Medial plantar nerve

Correct Answer & Explanation

. Flexor hallucis longus tendon

Explanation

The flexor hallucis longus (FHL) tendon courses in a groove directly underneath the sustentaculum tali. Overpenetration of a screw directed medially into the sustentaculum places the FHL tendon at direct risk.

Question 1940

Topic: 2. Trauma

A 35-year-old male undergoes open reduction and internal fixation of a displaced intra-articular calcaneus fracture utilizing an extensile lateral approach. To minimize the risk of full-thickness apex wound necrosis, the 'no-touch' subperiosteal flap must be elevated off the lateral wall to protect which of the following primary vascular structures?

. Sural artery
. Medial calcaneal artery
. Lateral calcaneal artery
. Peroneal artery perforators
. Dorsalis pedis artery

Correct Answer & Explanation

. Lateral calcaneal artery

Explanation

The lateral calcaneal artery, a terminal branch of the peroneal artery, provides the primary blood supply to the corner of the standard extensile lateral approach flap. The flap must be elevated subperiosteally to include and protect this critical vessel to prevent apical tip necrosis.

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