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2. Trauma MCQs

Practice Set 396 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 7901

Topic: 2. Trauma

A 29-year-old male presents with a comminuted midshaft femur fracture after a high-speed motorcycle crash. To avoid missing an ipsilateral femoral neck fracture, which is an easily overlooked complication in this scenario, what is the most sensitive diagnostic imaging modality recommended prior to operative intervention?

. Anteroposterior (AP) pelvis radiograph
. Cross-table lateral radiograph of the hip
. Dedicated fine-cut computed tomography (CT) scan of the proximal femur
. Intraoperative fluoroscopic stress views of the hip
. Magnetic resonance imaging (MRI) of the hip

Correct Answer & Explanation

. Anteroposterior (AP) pelvis radiograph

Explanation

Ipsilateral femoral neck fractures occur in up to 9% of femoral shaft fractures and are frequently non-displaced and missed on initial plain radiographs. A dedicated fine-cut CT scan of the proximal femur is the most sensitive and routinely recommended modality in high-energy femoral shaft fractures to rule out an occult neck injury.

Question 7902

Topic: 2. Trauma

A 32-year-old male presents with a high-energy knee injury. Radiographs reveal a posteromedial tibial plateau fracture. Which surgical approach and fixation strategy is most appropriate?

. Anterolateral approach with a precontoured locking plate
. Posteromedial approach with an anti-glide or buttress plate
. Medial approach with cancellous lag screws alone
. Anterior midline approach with dual plating
. Spanning external fixation without definitive internal fixation

Correct Answer & Explanation

. Anterolateral approach with a precontoured locking plate

Explanation

Posteromedial tibial plateau fractures typically require a posteromedial approach with an anti-glide or buttress plate to counteract shear forces. Anterolateral plating alone will not capture the posteromedial fragment adequately.

Question 7903

Topic: 2. Trauma

A 28-year-old male sustains a vertically oriented femoral neck fracture (Pauwels Type III). What is the primary biomechanical advantage of adding a fully threaded positional screw or a medial buttress plate to sliding hip screw fixation?

. Prevents femoral head avascular necrosis
. Increases fracture compression during weight bearing
. Resists vertical shear forces and varus collapse
. Allows for earlier unrestricted range of motion
. Decreases surgical time and intraoperative blood loss

Correct Answer & Explanation

. Prevents femoral head avascular necrosis

Explanation

Pauwels Type III fractures are highly unstable due to vertical shear forces. Adding a fully threaded positional screw or medial buttress plate mitigates shear stress and prevents varus collapse.

Question 7904

Topic: 2. Trauma

A 35-year-old male undergoes nonoperative treatment for a talar neck fracture. At 8 weeks, a subchondral radiolucent band is seen in the talar dome on an AP mortise radiograph. What does this finding indicate?

. Nonunion of the talar neck
. Impending avascular necrosis
. Intact vascular supply to the talar body
. Osteomyelitis of the talus
. Post-traumatic arthritis

Correct Answer & Explanation

. Nonunion of the talar neck

Explanation

Hawkins sign is a subchondral radiolucent band seen in the talar dome, indicating subchondral osteopenia. This demonstrates active bone resorption, which requires an intact vascular supply, thereby ruling out avascular necrosis.

Question 7905

Topic: 2. Trauma

A 45-year-old male sustained a distal femur fracture in a motor vehicle collision. The CT scan reveals a coronal plane fracture of the lateral femoral condyle. What is the eponymous name for this fracture?

. Segond fracture
. Stieda fracture
. Hoffa fracture
. Tillaux fracture
. Bosworth fracture

Correct Answer & Explanation

. Segond fracture

Explanation

A Hoffa fracture is a coronal plane fracture of the femoral condyle, most commonly involving the lateral condyle. It typically requires anterior-to-posterior interfragmentary screw fixation for stability.

Question 7906

Topic: 2. Trauma

A 24-year-old male with a closed tibial shaft fracture develops disproportionate leg pain. Intracompartmental pressures are measured. Which delta pressure measurement indicates a need for emergent fasciotomy?

. Diastolic blood pressure minus compartment pressure < 30 mmHg
. Systolic blood pressure minus compartment pressure < 40 mmHg
. Mean arterial pressure minus compartment pressure > 30 mmHg
. Diastolic blood pressure minus compartment pressure > 45 mmHg
. Compartment pressure absolute value > 20 mmHg

Correct Answer & Explanation

. Diastolic blood pressure minus compartment pressure < 30 mmHg

Explanation

Acute compartment syndrome is diagnosed when the delta pressure (diastolic blood pressure minus intracompartmental pressure) is less than 30 mmHg. When this threshold is met, emergent four-compartment fasciotomy is required.

Question 7907

Topic: 2. Trauma

Following standard tension band wiring of a transverse olecranon fracture, what is the most common complication necessitating reoperation?

. Ulnar nerve palsy
. Prominent symptomatic hardware
. Nonunion
. Heterotopic ossification
. Triceps tendon avulsion

Correct Answer & Explanation

. Ulnar nerve palsy

Explanation

The most common complication after tension band wiring of an olecranon fracture is prominent and symptomatic hardware (such as K-wires backing out), which frequently necessitates secondary hardware removal.

Question 7908

Topic: 2. Trauma

In the management of midshaft clavicle fractures, which of the following is considered an absolute indication for immediate open reduction and internal fixation?

. 100% displacement of the fracture ends
. 1.5 cm of shortening
. Open fracture
. Z-deformity with superior displacement
. Associated non-displaced scapula body fracture

Correct Answer & Explanation

. 100% displacement of the fracture ends

Explanation

Absolute indications for operative management of clavicle fractures include open fractures, neurovascular compromise, and severe skin tenting that threatens skin integrity. Displacement and shortening are relative indications.

Question 7909

Topic: 2. Trauma

A 65-year-old female sustains a 3-part proximal humerus fracture. According to Hertel's criteria, which structural feature is the most important predictor of humeral head ischemia?

. Length of the metaphyseal head extension < 8 mm
. Integrity of the medial hinge < 2 mm
. Displaced greater tuberosity > 5 mm
. Angulation > 45 degrees
. Complete disruption of the medial calcar hinge

Correct Answer & Explanation

. Length of the metaphyseal head extension < 8 mm

Explanation

Hertel's criteria for predicting humeral head ischemia include a metaphyseal head extension < 8mm, medial hinge disruption > 2mm, and basicervical fracture patterns. Complete disruption of the medial hinge is a major predictor of avascular necrosis.

Question 7910

Topic: 2. Trauma

A 42-year-old female sustains a displaced transverse patella fracture and is treated with anterior tension band wiring. What biomechanical principle does this fixation construct rely upon?

. Conversion of tension forces into compression forces at the articular surface during knee flexion
. Rigid absolute stability through interfragmentary lag screws
. Distraction osteogenesis of the anterior cortex
. Neutralization of shear forces through splinting
. Dynamic compression exclusively during knee extension

Correct Answer & Explanation

. Conversion of tension forces into compression forces at the articular surface during knee flexion

Explanation

The anterior tension band construct converts anterior tension forces created by the extensor mechanism during knee flexion into compressive forces at the articular surface, promoting stability and healing.

Question 7911

Topic: 2. Trauma

A 78-year-old male with a highly comminuted, reverse obliquity intertrochanteric femur fracture is treated with a cephalomedullary nail. Why is a sliding hip screw (DHS) contraindicated in this fracture pattern?

. It causes excessive medialization and varus collapse due to lack of a lateral wall restraint
. It increases the risk of femoral head avascular necrosis
. It is technically too demanding for this specific pattern
. It requires a larger incision and guarantees greater blood loss
. It completely restricts early post-operative weight-bearing

Correct Answer & Explanation

. It causes excessive medialization and varus collapse due to lack of a lateral wall restraint

Explanation

In reverse obliquity and lateral wall-deficient intertrochanteric fractures, the femoral shaft tends to displace medially. A sliding hip screw relies on an intact lateral wall; without it, excessive sliding leads to medialization and construct failure.

Question 7912

Topic: 2. Trauma

A 34-year-old construction worker falls from a ladder and sustains a severely comminuted, open (Gustilo type IIIA) tibial pilon fracture. Initial management includes formal debridement and application of a delta-frame spanning external fixator. What is the most reliable clinical indicator that the patient is ready for definitive open reduction and internal fixation (ORIF)?

. Re-epithelialization of fracture blisters
. Appearance of skin wrinkles around the ankle
. C-reactive protein levels returning to baseline
. Erythrocyte sedimentation rate below 20 mm/hr
. Four weeks elapsed since the initial injury

Correct Answer & Explanation

. Re-epithelialization of fracture blisters

Explanation

The 'wrinkle sign' indicates that soft tissue swelling has subsided adequately, significantly reducing the risk of wound dehiscence and deep infection following extensile surgical approaches for pilon fractures.

Question 7913

Topic: 2. Trauma

A 32-year-old male sustains a proximal-third extra-articular tibial shaft fracture. He undergoes intramedullary nailing via an infrapatellar approach. Postoperatively, what is the most common malalignment deformity expected with this specific fracture pattern and surgical approach?

. Apex posterior (procurvatum) and varus
. Apex anterior (recurvatum) and valgus
. Neutral alignment with >1 cm shortening
. Apex posterior (procurvatum) and valgus
. Apex anterior (recurvatum) and varus

Correct Answer & Explanation

. Apex posterior (procurvatum) and varus

Explanation

Proximal-third tibial shaft fractures treated with standard infrapatellar intramedullary nailing are highly prone to apex anterior (recurvatum) and valgus malalignment. This is due to the unopposed pull of the patellar tendon on the proximal fragment and the anatomy of the tibial metaphysis.

Question 7914

Topic: 2. Trauma

A 28-year-old unrestrained driver is involved in a high-speed motor vehicle collision and sustains a highly vertical (Pauwels Type III) femoral neck fracture. Which of the following internal fixation constructs provides the greatest biomechanical stability to resist the predominant shear forces?

. Three parallel 7.3mm cancellous screws in an inverted triangle
. A sliding hip screw (SHS) with a derotation screw
. A cephalomedullary nail with dual lag screws
. A dynamic condylar screw (DCS)
. Two parallel fully threaded cortical screws

Correct Answer & Explanation

. Three parallel 7.3mm cancellous screws in an inverted triangle

Explanation

Pauwels Type III fractures are highly vertical and subjected to intense shear and varus deforming forces. A sliding hip screw supplemented with a derotation screw provides the most biomechanically stable construct to resist these specific forces in young adults.

Question 7915

Topic: 2. Trauma

A 45-year-old male presents with a coronal plane fracture of the lateral femoral condyle (Hoffa fracture) following a motorcycle accident. Which of the following anatomic structures acts as the primary deforming force on the fractured fragment?

. Lateral collateral ligament
. Iliotibial band
. Lateral head of the gastrocnemius
. Popliteus tendon
. Biceps femoris

Correct Answer & Explanation

. Lateral collateral ligament

Explanation

A Hoffa fracture is a coronal plane fracture of the femoral condyle, most often the lateral condyle. The primary deforming force on this fragment is the lateral head of the gastrocnemius, which pulls the fragment posteriorly and inferiorly.

Question 7916

Topic: 2. Trauma

An 8-week postoperative radiograph of a 35-year-old male who underwent ORIF for a talar neck fracture demonstrates a subchondral radiolucent band extending across the talar dome. What does this radiographic finding indicate?

. Impending hardware failure
. Avascular necrosis of the talar body
. Intact vascularity to the talar body
. Deep bone infection (osteomyelitis)
. Post-traumatic chondrolysis

Correct Answer & Explanation

. Impending hardware failure

Explanation

The presence of a subchondral radiolucency in the talar dome at 6 to 8 weeks post-injury is known as the Hawkins sign. It represents subchondral atrophy from disuse in the setting of intact vascularity, effectively ruling out avascular necrosis.

Question 7917

Topic: 2. Trauma

A 29-year-old male sustains a closed, spiral fracture of the distal third of the humeral shaft (Holstein-Lewis fracture) and exhibits an immediate inability to extend his wrist and fingers. Closed reduction is performed, and acceptable alignment is achieved; however, the nerve palsy persists. What is the most appropriate next step in management?

. Immediate surgical exploration and internal fixation
. Electromyography (EMG) testing immediately to assess nerve continuity
. Ultrasound evaluation of the radial nerve
. Observation and supportive splinting for 3 months
. Early tendon transfers to restore wrist and digit extension

Correct Answer & Explanation

. Immediate surgical exploration and internal fixation

Explanation

Radial nerve palsies associated with closed humeral shaft fractures are overwhelmingly neurapraxias. The standard of care is clinical observation for 3 months; if no spontaneous recovery is noted by then, an EMG and potential nerve exploration are indicated.

Question 7918

Topic: 2. Trauma

A 40-year-old female sustains a comminuted subtrochanteric femur fracture. During closed reduction attempts, the proximal fragment exhibits a characteristic deformity. What are the primary deforming forces acting on this proximal fragment?

. Extension, adduction, and internal rotation
. Flexion, abduction, and external rotation
. Flexion, adduction, and internal rotation
. Extension, abduction, and external rotation
. Flexion, adduction, and external rotation

Correct Answer & Explanation

. Extension, adduction, and internal rotation

Explanation

In a subtrochanteric femur fracture, the proximal fragment is typically flexed by the iliopsoas, abducted by the gluteus medius and minimus, and externally rotated by the short external rotators.

Question 7919

Topic: 2. Trauma

A 48-year-old male sustains a high-energy pilon fracture. Initial management consists of a spanning external fixator. He develops significant soft tissue swelling and clear fracture blisters. When is it most appropriate to proceed with definitive open reduction and internal fixation?

. Immediately, to prevent soft tissue contracture
. Within 3-5 days when the blisters naturally rupture
. When the blisters have re-epithelialized and the skin wrinkles on dorsiflexion
. Strictly at 21 days post-injury, regardless of clinical swelling
. When systemic inflammatory markers (ESR/CRP) normalize

Correct Answer & Explanation

. Immediately, to prevent soft tissue contracture

Explanation

Definitive ORIF of high-energy pilon fractures must be delayed until the soft tissue envelope has adequately recovered. This is indicated by the resolution of swelling (a positive skin 'wrinkle sign') and the complete re-epithelialization of fracture blisters.

Question 7920

Topic: 2. Trauma

A 25-year-old male sustains a completely displaced midshaft clavicle fracture with a Z-deformity and 2.5 cm of shortening. The surgeon recommends operative fixation over nonoperative management. Based on the most robust current evidence, what is the primary clinical advantage of surgery in this specific scenario?

. Decreased risk of developing thoracic outlet syndrome
. Decreased rate of fracture nonunion
. Zero incidence of symptomatic hardware
. Improved cosmesis and prevention of skin necrosis
. Faster union time by 6 weeks compared to sling immobilization

Correct Answer & Explanation

. Decreased risk of developing thoracic outlet syndrome

Explanation

In highly displaced midshaft clavicle fractures (especially those with >2 cm shortening and complete displacement), operative fixation significantly decreases the rate of nonunion and symptomatic malunion compared to nonoperative management.

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