Menu

2. Trauma MCQs

Practice Set 571 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 11401

Topic: 2. Trauma

A 42-year-old male presents with a coronal plane fracture of the distal femoral condyle (Hoffa fracture) after a high-speed motor vehicle collision. This fracture pattern most commonly involves which of the following osseous structures?

. Medial femoral condyle
. Lateral femoral condyle
. Trochlear groove
. Intercondylar notch
. Adductor tubercle

Correct Answer & Explanation

. Medial femoral condyle

Explanation

A Hoffa fracture is a coronal shear fracture of the distal femur. It most commonly involves the lateral femoral condyle. This is due to the physiologic valgus alignment of the femur and the typical mechanism of injury, which involves a direct axial load transmitted through the lateral compartment with the knee in flexion.

Question 11402

Topic: 2. Trauma
A 45-year-old female sustains a Schatzker IV (medial) tibial plateau fracture. Which of the following associated injuries has the highest incidence with this specific, high-energy fracture pattern?
. Anterior cruciate ligament tear
. Medial meniscus tear
. Lateral meniscus tear
. Common peroneal nerve palsy
. Popliteal artery injury

Correct Answer & Explanation

. Popliteal artery injury

Explanation

A Schatzker IV fracture involves the medial tibial plateau and generally occurs due to high-energy varus forces (unlike Schatzker I-III, which are lateral and often lower energy). It is frequently associated with knee subluxation or dislocation, leading to a high risk of vascular injury to the tethered popliteal artery. A thorough vascular examination, including ABIs, is mandatory.

Question 11403

Topic: 2. Trauma

A 32-year-old male undergoes intramedullary nailing for a closed tibial shaft fracture. Post-operatively, he develops severe pain out of proportion to the injury. His blood pressure is 110/80 mmHg. A compartment pressure monitor is inserted. What threshold mandates emergent fasciotomy?

. Absolute compartment pressure > 20 mmHg
. Delta pressure (Diastolic BP - Compartment Pressure) < 30 mmHg
. Delta pressure (Systolic BP - Compartment Pressure) < 40 mmHg
. Absolute compartment pressure > 25 mmHg
. Delta pressure (Mean Arterial Pressure - Compartment Pressure) < 50 mmHg

Correct Answer & Explanation

. Absolute compartment pressure > 20 mmHg

Explanation

The Delta pressure, calculated as the Diastolic Blood Pressure minus the Intracompartmental Pressure, is the most reliable objective indicator for acute compartment syndrome. A delta pressure of less than 30 mmHg represents inadequate tissue perfusion and is an absolute indication for emergent four-compartment fasciotomy of the leg.

Question 11404

Topic: 2. Trauma

A 50-year-old man falls from a ladder, sustaining a highly comminuted distal tibia pilon fracture. An ankle-spanning external fixator is placed on the day of injury. What clinical sign best indicates that the soft tissues are ready for definitive open reduction and internal fixation?

. Resolution of hemorrhagic fracture blisters
. Re-epithelialization of all superficial abrasions
. Appearance of the wrinkle sign
. Erythrocyte sedimentation rate (ESR) < 20 mm/hr
. Normalization of capillary refill to less than 2 seconds

Correct Answer & Explanation

. Resolution of hemorrhagic fracture blisters

Explanation

The 'wrinkle sign' indicates that the acute post-traumatic edema has subsided sufficiently to allow the skin to wrinkle when pinched or with joint motion. This is the critical clinical milestone confirming that the soft tissue envelope can safely tolerate surgical incisions for definitive fixation, typically occurring 10 to 21 days post-injury.

Question 11405

Topic: 2. Trauma
Eight weeks after open reduction and internal fixation of a Hawkins type III talar neck fracture, an AP radiograph of the ankle demonstrates subchondral radiolucency in the dome of the talus. What does this specific radiographic finding indicate?
. Avascular necrosis of the talar body
. Septic arthritis of the ankle joint
. Intact vascularity to the talar body
. Nonunion of the talar neck
. Osteochondral defect of the talar dome

Correct Answer & Explanation

. Intact vascularity to the talar body

Explanation

The subchondral radiolucency seen in the talar dome on an AP or mortise radiograph 6 to 8 weeks post-injury is known as the Hawkins sign. It represents subchondral atrophy (osteopenia) due to disuse and active hyperemia. Its presence indicates that the vascular supply to the talar body is intact, making avascular necrosis highly unlikely.

Question 11406

Topic: Lower Extremity Trauma

In the evaluation of intra-articular calcaneus fractures, the Sanders classification is highly prognostic for clinical outcomes. Which specific imaging view is primarily used to determine the Sanders classification?

. Lateral radiograph of the foot
. Harris axial radiograph
. Sagittal CT reconstruction
. Coronal CT image through the widest part of the posterior facet
. Axial CT image at the level of the sustentaculum tali

Correct Answer & Explanation

. Lateral radiograph of the foot

Explanation

The Sanders classification relies on coronal CT images. Specifically, it uses the coronal slice that displays the widest portion of the posterior facet of the calcaneus (sustentaculum tali to the lateral wall) to identify the number and location of primary fracture lines through the articular surface.

Question 11407

Topic: 2. Trauma
A 40-year-old farmer sustains a severe Grade III open fracture of the tibial shaft after his leg is caught in a tractor power take-off. The wound is heavily contaminated with soil. In addition to a first-generation cephalosporin and an aminoglycoside, what prophylactic antibiotic should be added to specifically cover Clostridium species?
. Vancomycin
. Ciprofloxacin
. High-dose penicillin
. Clindamycin
. Metronidazole

Correct Answer & Explanation

. High-dose penicillin

Explanation

High-energy open fractures heavily contaminated with soil, feces, or standing water (often farm-related injuries) carry a significant risk for Clostridium perfringens infection (gas gangrene). Standard protocol dictates adding high-dose penicillin to the cephalosporin and aminoglycoside regimen to provide specific coverage for these anaerobic bacteria.

Question 11408

Topic: 2. Trauma
A 40-year-old man sustains a posterior hip dislocation with an associated femoral head fracture. CT imaging reveals the fracture involves the fovea capitis and extends superiorly into the weight-bearing zone, but there is no femoral neck or acetabular rim fracture. According to the Pipkin classification, what type of injury is this?
. Pipkin I
. Pipkin II
. Pipkin III
. Pipkin IV
. Pipkin V

Correct Answer & Explanation

. Pipkin II

Explanation

The Pipkin classification describes femoral head fractures associated with posterior hip dislocations. Type I is a fracture below the fovea (non-weight bearing). Type II is a fracture above the fovea (weight-bearing zone). Type III has an associated femoral neck fracture. Type IV has an associated acetabular rim fracture.

Question 11409

Topic: 2. Trauma
A 45-year-old male presents with a severely displaced, closed Ruedi-Allgower Type III tibial pilon fracture with massive soft tissue swelling, fracture blisters, and a positive wrinkle sign absent. What is the most appropriate initial management?
. Immediate ORIF with dual plating
. Immediate reamed intramedullary nailing
. Spanning external fixation with delayed definitive ORIF
. Closed reduction and long leg cast
. Primary ankle arthrodesis

Correct Answer & Explanation

. Spanning external fixation with delayed definitive ORIF

Explanation

High-energy pilon fractures with severe soft tissue compromise (Tscherne Grade II/III) are standardly managed with a staged protocol. This involves initial temporary spanning external fixation (with or without fibula fixation) to restore length and alignment, followed by delayed definitive ORIF once the soft tissue envelope has healed (typically 10-21 days, indicated by the return of skin wrinkles).

Question 11410

Topic: Lower Extremity Trauma
What is the primary determinant used to classify intra-articular calcaneus fractures according to the Sanders classification?
. The degree of Bohler's angle depression on the lateral radiograph
. The number and location of articular fragments on the coronal CT scan at the widest aspect of the posterior facet
. The degree of comminution of the anterior process on the axial CT scan
. The angle of Gissane on the plain lateral radiograph
. The involvement and displacement of the calcaneocuboid joint

Correct Answer & Explanation

. The number and location of articular fragments on the coronal CT scan at the widest aspect of the posterior facet

Explanation

The Sanders classification is based strictly on coronal CT scan images. It dictates the number of articular fragments of the posterior facet at its widest point. Type I is non-displaced; Type II is two-part; Type III is three-part; Type IV is four or more parts (highly comminuted).

Question 11411

Topic: 2. Trauma

A 25-year-old motorcyclist is thrown from his bike, resulting in a flail upper extremity, massive shoulder swelling, and absent distal pulses. Radiographs show significant lateral displacement of the scapula and a distracted clavicle fracture. What is the most reliable prognostic indicator for eventual functional recovery of the limb?

. The severity of the axillary artery disruption
. The degree of lateral scapular displacement on the AP chest radiograph
. The presence of a complete brachial plexus avulsion
. The promptness of surgical vascular repair
. The presence of associated massive soft tissue necrosis

Correct Answer & Explanation

. The severity of the axillary artery disruption

Explanation

The clinical scenario describes scapulothoracic dissociation. While vascular injury requires emergent intervention for limb salvage, the functional outcome of the limb is overwhelmingly dictated by the severity of the neurological injury. Complete brachial plexus avulsions are common and carry a devastating prognosis, often resulting in a flail, insensate arm or delayed amputation.

Question 11412

Topic: 2. Trauma

Based on recent anatomic and perfusion studies, which artery is considered to provide the primary blood supply to the humeral head, and is thus most critical to preserve in a displaced proximal humerus fracture?

. Posterior circumflex humeral artery
. Anterior circumflex humeral artery (arcuate branch)
. Profunda brachii artery
. Thoracoacromial artery
. Suprascapular artery

Correct Answer & Explanation

. Posterior circumflex humeral artery

Explanation

Historically, the anterolateral branch (arcuate artery) of the anterior circumflex humeral artery was taught as the primary supply. However, contemporary quantitative perfusion studies (e.g., Brooks et al., Hettrich et al.) have definitively shown that the posterior circumflex humeral artery provides the dominant blood supply (approx. 64%) to the humeral head.

Question 11413

Topic: 2. Trauma

A 30-year-old patient sustains a coronal plane fracture of the lateral femoral condyle extending into the knee joint. What is the eponym for this fracture, and what is the biomechanically optimal direction for screw fixation?

. Barton's fracture; Anterior-to-posterior
. Hoffa fracture; Anterior-to-posterior
. Hoffa fracture; Posterior-to-anterior
. Segond fracture; Lateral-to-medial
. Tillaux fracture; Anterior-to-posterior

Correct Answer & Explanation

. Barton's fracture; Anterior-to-posterior

Explanation

A coronal shear fracture of the femoral condyle is a Hoffa fracture. Biomechanical studies indicate that anterior-to-posterior (AP) screw placement provides superior fixation strength and resistance to shear forces compared to posterior-to-anterior (PA) screw placement.

Question 11414

Topic: 2. Trauma

During the initial preparation for intramedullary nailing of a subtrochanteric femur fracture, the surgeon notes classic characteristic deformity of the proximal fragment. What deforming muscle forces act on the proximal segment, and what is the resulting position?

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

Correct Answer & Explanation

. Extension, adduction, and external rotation

Explanation

In a subtrochanteric femur fracture, the proximal fragment is typically deformed into flexion (by the iliopsoas), abduction (by the gluteus medius and minimus), and external rotation (by the short external rotators).

Question 11415

Topic: 2. Trauma

A 24-year-old male sustains a low-velocity civilian gunshot wound to the thigh, resulting in a comminuted midshaft femur fracture. The entry and exit wounds are less than 1 cm each, and the patient is neurovascularly intact without massive contamination. What is the most appropriate acute management?

. Immediate open surgical debridement of the bullet track and temporary external fixation
. Bedside local wound care, short-course antibiotics, and immediate intramedullary nailing
. Excision of the entire bullet track, primary closure, and plating
. Formal angiography followed by non-operative functional bracing
. Broad-spectrum IV antibiotics for 7 days followed by delayed nailing

Correct Answer & Explanation

. Immediate open surgical debridement of the bullet track and temporary external fixation

Explanation

Low-velocity gunshot wounds resulting in femur fractures without neurovascular compromise or gross contamination are treated similarly to closed fractures. They do not require formal operative debridement of the bullet track. Standard treatment includes local wound care, a short course of antibiotics (typically a first-generation cephalosporin), and early intramedullary nailing.

Question 11416

Topic: 2. Trauma

Which of the following radiographic fracture patterns in a 6-month-old infant carries the highest specificity for non-accidental trauma (child abuse)?

. Midshaft clavicle fracture
. Linear skull fracture
. Spiral fracture of the tibial diaphysis (Toddler's fracture)
. Classic metaphyseal lesion (corner or bucket-handle fracture)
. Distal radius buckle (torus) fracture

Correct Answer & Explanation

. Midshaft clavicle fracture

Explanation

The classic metaphyseal lesion (CML), radiographically visible as a 'corner fracture' or 'bucket-handle fracture,' is highly specific for non-accidental trauma in infants. It is caused by violent pulling, twisting, or shaking forces that disrupt the primary spongiosa of the metaphysis.

Question 11417

Topic: 2. Trauma
When utilizing intra-compartmental pressure monitoring to diagnose acute compartment syndrome of the lower leg, which parameter is the most reliable threshold indicating the need for emergent fasciotomy?
. Absolute compartment pressure > 20 mmHg
. Absolute compartment pressure > 25 mmHg
. Diastolic blood pressure minus compartment pressure < 30 mmHg
. Mean arterial pressure minus compartment pressure > 40 mmHg
. Systolic blood pressure minus compartment pressure < 20 mmHg

Correct Answer & Explanation

. Diastolic blood pressure minus compartment pressure < 30 mmHg

Explanation

Delta pressure (ΔP) is the most reliable indicator for compartment syndrome, accounting for individual variations in perfusion pressure. A delta pressure (Diastolic BP - compartment pressure) of less than 30 mmHg strongly indicates inadequate tissue perfusion and is a recognized indication for emergent fasciotomy.

Question 11418

Topic: 2. Trauma
A 35-year-old farm worker sustains a severe open tibial shaft fracture (Gustilo-Anderson Type IIIA) heavily contaminated with barnyard soil. In addition to a first-generation cephalosporin and an aminoglycoside, what specific antibiotic should be added to the empiric regimen?
. Vancomycin
. Clindamycin
. High-dose Penicillin
. Ciprofloxacin
. Metronidazole

Correct Answer & Explanation

. High-dose Penicillin

Explanation

Farmyard injuries or wounds heavily contaminated with soil carry a specific high risk of Clostridium perfringens infection (gas gangrene). High-dose Penicillin is the classic standard addition to the antibiotic regimen in these specific agricultural environments to provide anaerobic coverage against Clostridium species.

Question 11419

Topic: 2. Trauma
A 25-year-old male sustains a vertically oriented femoral neck fracture (Pauwels type III). What is the most critical biomechanical factor to minimize the risk of nonunion and avascular necrosis in this patient?
. Anatomical reduction and stable fixation to resist severe shear forces
. Capsulotomy performed within 6 hours of injury
. Use of a sliding hip screw instead of multiple cannulated screws
. Prophylactic valgus-producing subtrochanteric osteotomy
. Immediate full weight-bearing to promote impaction

Correct Answer & Explanation

. Anatomical reduction and stable fixation to resist severe shear forces

Explanation

Pauwels type III fractures are highly unstable due to vertical shear forces. Anatomical reduction and stable internal fixation are the most critical factors in minimizing nonunion and avascular necrosis.

Question 11420

Topic: 2. Trauma

A 45-year-old male sustains a high-energy Schatzker VI tibial plateau fracture. He initially undergoes temporary spanning external fixation. What is the most reliable clinical indicator to safely proceed with definitive open reduction and internal fixation?

. Complete resolution of fracture blisters
. Appearance of skin wrinkles (wrinkle sign) indicating soft tissue swelling has subsided
. Normalization of serum C-reactive protein levels
. Reduction of intracompartmental pressures to less than 30 mmHg
. Exactly 14 days post-injury regardless of soft tissue appearance

Correct Answer & Explanation

. Complete resolution of fracture blisters

Explanation

The 'wrinkle sign' indicates that severe soft tissue swelling has subsided, significantly reducing the risk of wound dehiscence and deep infection following definitive fixation.

Test Yourself

Switch to an interactive, timed exam simulation to truly master this topic.

On this Page