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2. Trauma MCQs

Practice Set 546 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 10901

Topic: 2. Trauma

A 35-year-old male sustains a high-energy Schatzker VI tibial plateau fracture. On examination, he has tense swelling, and his compartment pressures in the anterior compartment measure 40 mmHg with a diastolic blood pressure of 65 mmHg. After performing emergent four-compartment fasciotomies, what is the most appropriate initial management of the fracture?

. Primary open reduction and internal fixation with dual plating
. Long leg cast
. Spanning external fixation across the knee
. Intramedullary nailing
. Ilizarov frame application

Correct Answer & Explanation

. Primary open reduction and internal fixation with dual plating

Explanation

In a high-energy Schatzker VI tibial plateau fracture with compartment syndrome, the standard of care is a staged, damage-control approach. Following fasciotomies, the fracture should be stabilized with a spanning external fixator across the knee to allow soft tissue swelling to resolve before definitive internal fixation, thereby minimizing severe soft tissue complications and infection.

Question 10902

Topic: 2. Trauma

During open reduction and internal fixation of a distal femur fracture, a coronal plane fracture of the lateral femoral condyle (Hoffa fragment) is identified. To appropriately compress and fix this articular fragment, what is the ideal direction of the lag screws?

. Posterior to anterior
. Anterior to posterior
. Medial to lateral
. Lateral to medial
. Proximal to distal

Correct Answer & Explanation

. Posterior to anterior

Explanation

A Hoffa fracture is a coronal shear fracture of the femoral condyle. Biomechanically, fixation is optimally achieved using anterior-to-posterior (AP) directed lag screws. This configuration provides perpendicular compression across the coronal fracture plane and allows the screw heads to be countersunk outside the primary articular weight-bearing surface.

Question 10903

Topic: 2. Trauma

A 22-year-old male is involved in a high-speed motor vehicle collision. He presents with a closed midshaft femur fracture, bilateral pulmonary contusions, and a closed head injury (GCS 14). His initial BP is 90/60 mmHg, HR 120 bpm, lactate 4.5 mmol/L, and base deficit -8. After resuscitation with crystalloids and 2 units of packed RBCs, his lactate drops to 3.8 and base deficit to -6. What is the most appropriate management of his femur fracture?

. Immediate reamed intramedullary nailing
. External fixation of the femur
. Skeletal traction and delayed surgery
. Immediate unreamed intramedullary nailing
. Open reduction and internal fixation with a plate

Correct Answer & Explanation

. Immediate reamed intramedullary nailing

Explanation

This polytrauma patient is in a 'borderline' or 'unstable' physiologic state based on persistent elevated lactate, base deficit, and an associated severe chest injury (pulmonary contusions). Under Damage Control Orthopedics (DCO) principles, definitive intramedullary nailing can precipitate ARDS. Rapid provisional stabilization with an external fixator is indicated until his physiology normalizes.

Question 10904

Topic: 2. Trauma

A 65-year-old female sustains a displaced 3-part proximal humerus fracture. According to Hertel's criteria, which of the following fracture characteristics is the most critical predictor of subsequent avascular necrosis (AVN) of the humeral head?

. Shortening of the greater tuberosity
. Disruption of the medial hinge with < 8 mm of calcar attached
. Angulation of the surgical neck > 30 degrees
. Involvement of the lesser tuberosity
. Displacement of the long head of the biceps

Correct Answer & Explanation

. Shortening of the greater tuberosity

Explanation

Hertel's criteria for predicting ischemia of the humeral head following proximal humerus fractures highlight that a posteromedial metaphyseal head extension (calcar length) of less than 8 mm and disruption of the medial hinge are the strongest predictors of ischemia. These factors indicate compromised blood supply from the ascending branch of the anterior humeral circumflex artery and posterior ascending intraosseous vessels.

Question 10905

Topic: 2. Trauma
A 28-year-old motorcyclist sustains a Gustilo-Anderson Type IIIB open fracture of the middle third of the tibia. After thorough surgical debridement, a free tissue transfer will be required for coverage. According to established microsurgical trauma literature, what is the optimal timeframe for definitive soft tissue coverage to minimize infection rates and flap failure?
. Within 24 hours
. Between 7 and 10 days
. Within 72 hours
. Between 2 and 3 weeks
. After bony union is achieved

Correct Answer & Explanation

. Within 72 hours

Explanation

Classic literature (Godina) and modern limb salvage protocols demonstrate that early soft tissue coverage of severe open tibia fractures (Type IIIB) within 72 hours significantly decreases the rate of flap failure, deep infection, and nonunion compared to delayed coverage (beyond 7-10 days).

Question 10906

Topic: 2. Trauma
A 7-year-old boy falls on an outstretched hand and sustains a Bado Type I Monteggia fracture-dislocation. Which of the following describes the correct anatomic configuration of a Bado Type I injury?
. Posterior angulation of the ulna with posterior radial head dislocation
. Lateral angulation of the ulna with lateral radial head dislocation
. Proximal third ulna fracture with radial shaft fracture
. Anterior angulation of the ulna with anterior radial head dislocation
. Distal third radius fracture with distal radioulnar joint dislocation

Correct Answer & Explanation

. Anterior angulation of the ulna with anterior radial head dislocation

Explanation

The Bado classification system for Monteggia fractures (ulna fracture with radial head dislocation) dictates: Type I (most common): Anterior angulation of the ulna fracture with anterior radial head dislocation. Type II: Posterior angulation/dislocation. Type III: Lateral angulation/dislocation. Type IV: Proximal radius and ulna fractures with anterior radial head dislocation.

Question 10907

Topic: 2. Trauma

A 24-year-old male presents with a closed, highly comminuted tibial shaft fracture. He complains of severe pain out of proportion to his injury. His clinical exam is equivocal due to his high anxiety. His blood pressure is 110/70 mmHg. Intracompartmental pressure testing is performed. Which of the following criteria provides the most accepted and specific threshold for performing a four-compartment fasciotomy?

. Absolute intracompartmental pressure > 20 mmHg
. Delta P (Systolic BP - Compartment Pressure) < 40 mmHg
. Delta P (Diastolic BP - Compartment Pressure) < 30 mmHg
. Absolute intracompartmental pressure > 15 mmHg
. Delta P (Mean Arterial Pressure - Compartment Pressure) < 30 mmHg

Correct Answer & Explanation

. Absolute intracompartmental pressure > 20 mmHg

Explanation

The most widely accepted threshold for diagnosing compartment syndrome using pressure measurements is a Delta P (Diastolic blood pressure minus intracompartmental pressure) of less than 30 mmHg. Relying on absolute pressure can lead to overtreatment, especially in hypotensive patients, whereas Delta P appropriately accounts for the local tissue perfusion pressure.

Question 10908

Topic: 2. Trauma

A 45-year-old active smoker presents with persistent pain 9 months after intramedullary nailing of a closed tibial shaft fracture. Radiographs demonstrate a distinct fracture line with significant hypertrophic callus formation ('elephant foot' appearance) but lack bridging across the fracture site. What is the underlying cause of this specific type of nonunion?

. Inadequate blood supply to the fracture site
. Infection at the fracture site
. Severe malnutrition
. Inadequate mechanical stability
. Use of NSAIDs

Correct Answer & Explanation

. Inadequate blood supply to the fracture site

Explanation

A hypertrophic ('elephant foot') nonunion is characterized by abundant callus formation that fails to bridge the fracture gap. It indicates that the biological environment and blood supply are excellent, but the mechanical stability is inadequate to allow the cartilaginous phase of the callus to ossify and bridge. Treatment involves improving stability, typically by exchange nailing or compression plating.

Question 10909

Topic: Pelvic & Acetabular Trauma
A 38-year-old male sustains a severe APC-III pelvic fracture and arrives in hemorrhagic shock. Despite immediate pelvic binder application and massive transfusion protocol, he remains hypotensive and tachycardic. In the majority of pelvic ring injuries, what is the most common anatomic source of massive internal hemorrhage?
. Superior gluteal artery
. Internal pudendal artery
. External iliac artery
. Corona mortis
. Presacral venous plexus and cancellous bone

Correct Answer & Explanation

. Presacral venous plexus and cancellous bone

Explanation

While arterial bleeding (especially from the superior gluteal artery or internal pudendal) can be life-threatening and may require angioembolization, bleeding from the presacral venous plexus and the fractured cancellous bone surfaces accounts for approximately 80-90% of all pelvic bleeding. A pelvic binder works by closing the pelvic volume, facilitating a tamponade effect primarily on these low-pressure venous and osseous bleeding sources.

Question 10910

Topic: 2. Trauma

In the surgical management of a lateral Hoffa fracture (OTA/AO 33B3), which of the following statements regarding the biomechanics of fixation is most accurate?

. Posterior-to-anterior (PA) directed lag screws provide superior biomechanical pull-out strength and stability compared to AP directed screws.
. Anterior-to-posterior (AP) directed lag screws offer superior biomechanical stability compared to posterior-to-anterior (PA) screws.
. A medially applied buttress plate provides optimal stability.
. The lateral collateral ligament (LCL) typically remains attached to the posterior articular fragment, contributing to displacement.
. Nonoperative management is preferred for non-displaced fractures due to the high risk of avascular necrosis.

Correct Answer & Explanation

. Posterior-to-anterior (PA) directed lag screws provide superior biomechanical pull-out strength and stability compared to AP directed screws.

Explanation

Biomechanical studies have demonstrated that posterior-to-anterior (PA) directed lag screws are biomechanically superior to anterior-to-posterior (AP) directed screws for coronal plane (Hoffa) fractures of the distal femur. The LCL typically attaches to the anterior fragment (lateral epicondyle), not the posterior fragment.

Question 10911

Topic: 2. Trauma
A 45-year-old female presents after an MVC with a pelvic ring injury. Radiographs demonstrate a lateral compression injury. Which of the following specifically defines an LC-II injury according to the Young-Burgess classification?
. Rami fracture and ipsilateral anterior sacral compression fracture.
. Rami fracture and contralateral open book injury.
. Rami fracture and ipsilateral crescent fracture of the ilium.
. Rami fracture, anterior sacral compression fracture, and contralateral sacroiliac joint disruption.
. Symphysis pubis widening greater than 2.5 cm with anterior sacroiliac ligament disruption.

Correct Answer & Explanation

. Rami fracture and ipsilateral crescent fracture of the ilium.

Explanation

In the Young-Burgess classification, an LC-I injury involves a sacral compression fracture on the side of impact. An LC-II injury involves an iliac wing fracture (specifically a crescent fracture) on the side of impact due to internal rotation forces continuing through the ilium. An LC-III is a "windswept pelvis" with an LC injury on the impact side and an APC injury on the contralateral side.

Question 10912

Topic: 2. Trauma

A 32-year-old man sustains an acetabular fracture. CT scan reveals a fracture line separating the anterior half of the innominate bone from the intact posterior ilium, associated with a transverse fracture line through the posterior column. Which Letournel classification best fits this pattern?

. T-type
. Both column
. Transverse and posterior wall
. Anterior column and posterior hemitransverse (ACPHT)
. Posterior column and posterior wall

Correct Answer & Explanation

. T-type

Explanation

An anterior column and posterior hemitransverse (ACPHT) fracture is characterized by a primary anterior column fracture with a secondary transverse component extending through the posterior column. Unlike a both column fracture, a portion of the articular surface (usually the posterior roof) remains attached to the intact axial skeleton.

Question 10913

Topic: 2. Trauma

In the evaluation of a complex tibial pilon fracture, the anterolateral fragment is frequently avulsed. What ligamentous structure attaches to this specific fragment?

. Anterior inferior tibiofibular ligament (AITFL)
. Posterior inferior tibiofibular ligament (PITFL)
. Interosseous membrane
. Deltoid ligament
. Anterior talofibular ligament (ATFL)

Correct Answer & Explanation

. Anterior inferior tibiofibular ligament (AITFL)

Explanation

The anterolateral fragment of the distal tibia is commonly referred to as the Chaput fragment. It serves as the attachment for the anterior inferior tibiofibular ligament (AITFL). The posterolateral fragment is the Volkmann fragment, which is the attachment site for the PITFL.

Question 10914

Topic: 2. Trauma

A 42-year-old construction worker falls from a height and sustains a closed, displaced intra-articular calcaneus fracture. The Sanders classification is utilized for operative planning. Which specific anatomic structure is the primary landmark used to determine the Sanders classification?

. Anterior process
. Sustentaculum tali
. Poster facet
. Calcaneocuboid joint
. Tuberosity

Correct Answer & Explanation

. Anterior process

Explanation

The Sanders classification is based on coronal CT images detailing the posterior facet of the calcaneus. It categorizes fractures based on the number and location of primary fracture lines extending through the posterior facet. The sustentaculum fragment, although critical for reduction, is not the basis of the classification.

Question 10915

Topic: 2. Trauma

In evaluating a displaced proximal humerus fracture, which of the following radiographic criteria (Hertel criteria) is the most reliable predictor of ensuing avascular necrosis (AVN) of the humeral head?

. Greater tuberosity displacement > 5mm
. Shaft displacement > 50%
. Involvement of the bicipital groove
. Length of the dorsomedial metaphyseal extension (calcar) < 8mm
. Integrity of the medial hinge > 2mm

Correct Answer & Explanation

. Greater tuberosity displacement > 5mm

Explanation

Hertel criteria for predicting ischemia/AVN of the humeral head include: a metaphyseal head extension (calcar length) of less than 8 mm, disruption of the medial hinge (> 2mm), and a basicervical fracture pattern. A short calcar segment (< 8mm) combined with medial hinge disruption is highly predictive of AVN.

Question 10916

Topic: 2. Trauma

A 30-year-old male presents with a closed spiral fracture of the distal third of the humeral shaft resulting from a throwing injury. On examination, he is unable to extend his wrist or fingers. Which of the following is the most appropriate initial management?

. Immediate surgical exploration and nerve repair
. Open reduction and internal fixation with immediate nerve exploration
. External fixation
. EMG/NCS studies immediately
. Application of a coaptation splint or functional brace and observation

Correct Answer & Explanation

. Immediate surgical exploration and nerve repair

Explanation

A Holstein-Lewis fracture is a spiral fracture of the distal third of the humerus. Although associated with radial nerve palsy (up to 22%), the standard of care is initial nonoperative management with a coaptation splint or functional bracing, as the vast majority (over 85%) of closed primary radial nerve palsies will undergo spontaneous recovery.

Question 10917

Topic: 2. Trauma
A 6-year-old child presents with a hyperpronation injury to the forearm. Radiographs reveal a fracture of the proximal ulna with an associated radial head dislocation. The radial head is dislocated laterally. According to the Bado classification, what type of Monteggia lesion is this?
. Type I
. Type II
. Type IV
. Type V
. Type III

Correct Answer & Explanation

. Type III

Explanation

The Bado classification for Monteggia fractures: Type I: Anterior dislocation. Type II: Posterior dislocation. Type III: Lateral or anterolateral dislocation with an ulnar metaphyseal fracture. Type IV: Anterior dislocation with fractures of both the radius and ulna. Type III is most commonly seen in children following a hyperpronation force.

Question 10918

Topic: Pelvic & Acetabular Trauma
A 35-year-old male is struck by a motor vehicle and sustains a closed pelvic ring injury. Examination reveals a large, fluctuant area over the greater trochanter with overlying skin hypermobility and bruising. An MRI confirms a hemolymphatic fluid collection between the subcutaneous fat and the underlying fascia. What is the most appropriate initial management of this soft tissue injury to prevent deep infection prior to definitive internal fixation?
. Immediate large-bore needle aspiration followed by compressive wrapping
. Administration of prophylactic intravenous antibiotics without intervention
. Sclerotherapy using doxycycline
. Early open surgical debridement and delayed closure or negative pressure wound therapy
. Immediate percutaneous drainage catheter placement left in situ indefinitely

Correct Answer & Explanation

. Early open surgical debridement and delayed closure or negative pressure wound therapy

Explanation

The clinical presentation is classic for a Morel-Lavallรฉe lesion (a closed degloving injury). Because a surgical approach for fracture fixation often must pass through or near the lesion, the standard of care to minimize infection is early open debridement of necrotic tissue and evacuation of the hematoma, frequently utilizing negative pressure wound therapy prior to or concurrently with definitive fixation.

Question 10919

Topic: 2. Trauma
In the evaluation of a patient with a severe tibial shaft fracture, acute compartment syndrome is suspected. Intracompartmental pressure measurements are obtained. Which of the following parameters is considered the most reliable indicator for performing a fasciotomy?
. Absolute compartment pressure greater than 30 mmHg
. Absolute compartment pressure greater than 45 mmHg
. Delta P (Diastolic Blood Pressure minus Compartment Pressure) less than 30 mmHg
. Delta P (Mean Arterial Pressure minus Compartment Pressure) less than 40 mmHg
. Delta P (Systolic Blood Pressure minus Compartment Pressure) less than 30 mmHg

Correct Answer & Explanation

. Delta P (Diastolic Blood Pressure minus Compartment Pressure) less than 30 mmHg

Explanation

Delta P (ฮ”P) is considered the most reliable objective measurement for the diagnosis of acute compartment syndrome. It is calculated as Diastolic Blood Pressure minus Intracompartmental Pressure. A ฮ”P of less than 30 mmHg indicates inadequate tissue perfusion and is a strong indication for fasciotomy. Absolute pressures can be misleading in hypotensive trauma patients.

Question 10920

Topic: 2. Trauma

A 25-year-old male sustains a gunshot wound to the thigh with a fractured femoral shaft. The weapon was a high-velocity military rifle. Which of the following principles best guides the management of the soft tissues in this injury?

. Primary closure of the entry and exit wounds after superficial irrigation
. Local wound care and administration of oral antibiotics without surgical debridement
. Immediate open reduction and internal fixation with plate and screws, leaving the wounds open
. Formal surgical exploration, extensive debridement of all devitalized muscle, and delayed primary closure
. Debridement followed by immediate skin grafting of the exit wound

Correct Answer & Explanation

. Primary closure of the entry and exit wounds after superficial irrigation

Explanation

High-velocity gunshot wounds (> 2,000 feet per second) cause significant cavitation and extensive soft tissue destruction far beyond the permanent tract. They must be treated as high-energy open fractures requiring formal surgical exploration in the OR, extensive debridement of necrotic tissue, and delayed closure.

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