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2. Trauma MCQs

Practice Set 572 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 11421

Topic: 2. Trauma

A 35-year-old male sustains a highly displaced subtrochanteric femur fracture. Which muscle is primarily responsible for the flexion and external rotation deformity characteristic of the proximal fracture fragment?

. Gluteus medius
. Gluteus maximus
. Iliopsoas
. Adductor magnus
. Tensor fasciae latae

Correct Answer & Explanation

. Gluteus medius

Explanation

The iliopsoas inserts on the lesser trochanter and strongly flexes and externally rotates the proximal fragment in a subtrochanteric femur fracture.

Question 11422

Topic: 2. Trauma

A 40-year-old skier sustains a spiral distal tibia fracture with a concurrent posterior malleolus (Volkmann's) fracture fragment. Which ligament's avulsion creates this specific posterior malleolar fragment?

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

Correct Answer & Explanation

. Anterior inferior tibiofibular ligament (AITFL)

Explanation

The posterior malleolar fragment, often referred to as Volkmann's fragment, is created by the strong pull of the intact posterior inferior tibiofibular ligament (PITFL) during a rotational ankle injury.

Question 11423

Topic: 2. Trauma

A patient with a Holstein-Lewis humeral shaft fracture presents with a new complete radial nerve palsy immediately following a closed reduction in the emergency department. The nerve was documented as intact prior to manipulation. What is the most appropriate next step in management?

. Observation and electromyography (EMG) at 3 weeks
. Immediate surgical exploration and internal fixation
. Re-manipulation under conscious sedation to free the nerve
. Urgent MRI of the humerus to visualize the nerve
. Application of a functional fracture brace and physical therapy

Correct Answer & Explanation

. Observation and electromyography (EMG) at 3 weeks

Explanation

An iatrogenic radial nerve palsy that occurs after closed reduction of a humeral shaft fracture is an absolute indication for immediate surgical exploration, as the nerve may be entrapped in the fracture site.

Question 11424

Topic: 2. Trauma

A 32-year-old is diagnosed with a Hoffa fracture of the distal femur. Which of the following best describes this specific injury pattern?

. A coronal shear fracture of the femoral condyle
. A sagittal split fracture of the distal femoral metaphysis
. A transverse supracondylar femur fracture
. An articular depression of the lateral tibial plateau
. An avulsion of the medial epicondyle

Correct Answer & Explanation

. A coronal shear fracture of the femoral condyle

Explanation

A Hoffa fracture is a coronal plane shear fracture of the distal femoral condyle (most commonly the lateral condyle), typically requiring anterior-to-posterior or posterior-to-anterior screw fixation.

Question 11425

Topic: 2. Trauma

A 25-year-old male sustains a midshaft clavicle fracture in a cycling accident. Which of the following is considered an absolute indication for open reduction and internal fixation?

. Fracture displacement greater than 2 cm
. Comminution with a transverse Z-fragment
. Shortening of 1.5 cm
. Open fracture
. A brachial plexus neuropraxia that is progressively recovering

Correct Answer & Explanation

. Fracture displacement greater than 2 cm

Explanation

Absolute indications for operative fixation of clavicle fractures include open fractures, skin tenting leading to imminent skin breakdown, and progressive neurologic deficit.

Question 11426

Topic: 2. Trauma

A 25-year-old male with a comminuted tibial shaft fracture is evaluated for acute compartment syndrome. His blood pressure is 120/80 mmHg. What absolute or differential intra-compartmental pressure parameter is the most universally accepted threshold for performing an emergency four-compartment fasciotomy?

. Absolute compartment pressure > 20 mmHg
. Absolute compartment pressure > 15 mmHg
. Delta pressure (Diastolic BP minus compartment pressure) < 30 mmHg
. Delta pressure (Systolic BP minus compartment pressure) < 40 mmHg
. Delta pressure (Mean Arterial Pressure minus compartment pressure) < 50 mmHg

Correct Answer & Explanation

. Absolute compartment pressure > 20 mmHg

Explanation

A delta pressure (diastolic blood pressure minus compartment pressure) of less than 30 mmHg is the most reliable and widely accepted indication for fasciotomy to treat acute compartment syndrome.

Question 11427

Topic: 2. Trauma

When performing an intramedullary nailing of a proximal third tibial shaft fracture via an infrapatellar approach, the proximal fragment classically displaces into which deformity, and how can it be technically mitigated?

. Varus and recurvatum; mitigated by a medial starting point
. Valgus and recurvatum; mitigated by avoiding knee flexion
. Valgus and procurvatum (apex anterior); mitigated by a superior-lateral starting point or posterior blocking screws
. Varus and procurvatum; mitigated by a medial starting point and anterior blocking screws
. Recurvatum only; mitigated by extending the knee fully during insertion

Correct Answer & Explanation

. Varus and recurvatum; mitigated by a medial starting point

Explanation

Proximal third tibia fractures notoriously displace into valgus and procurvatum during intramedullary nailing. Using a more superior, slightly lateral entry point or posterior Poller (blocking) screws helps prevent this malalignment.

Question 11428

Topic: 2. Trauma
A 30-year-old motorcyclist sustains an open midshaft tibia fracture. The wound is 12 cm long with extensive soft tissue crushing and periosteal stripping. However, after thorough debridement, adequate soft tissue coverage of the bone is possible without requiring a local or free flap. How is this injury classified according to Gustilo-Anderson?
. Type I
. Type II
. Type IIIA
. Type IIIB
. Type IIIC

Correct Answer & Explanation

. Type IIIA

Explanation

Gustilo-Anderson Type IIIA denotes a high-energy trauma with extensive soft tissue laceration and periosteal stripping, but where adequate soft tissue coverage of the fractured bone remains possible without a flap.

Question 11429

Topic: 2. Trauma

A 40-year-old male sustains a coronal plane fracture of the lateral femoral condyle (Hoffa fracture) after a high-velocity motor vehicle collision. Which of the following fixation strategies provides the most biomechanically stable construct for this fracture pattern?

. Two anterior-to-posterior 6.5 mm partially threaded cannulated screws
. Two posterior-to-anterior 6.5 mm partially threaded cannulated screws
. An isolated laterally applied anatomic locking plate
. A medial buttress plate with interfragmentary screws
. A retrograde intramedullary nail with distal locking screws

Correct Answer & Explanation

. Two anterior-to-posterior 6.5 mm partially threaded cannulated screws

Explanation

Posterior-to-anterior oriented lag screws provide the most biomechanically stable fixation for a Hoffa fracture. They are inserted perpendicular to the fracture plane, optimizing compression and resisting shear forces better than anterior-to-posterior screws.

Question 11430

Topic: 2. Trauma

A 25-year-old male is evaluated 6 weeks after undergoing open reduction and internal fixation of a talar neck fracture. Radiographs demonstrate a band of subchondral radiolucency in the talar dome. What does this radiographic finding signify?

. Impending avascular necrosis (AVN) of the talar body
. Nonunion of the talar neck
. Intact vascularity to the talar body
. Post-traumatic osteoarthritis of the tibiotalar joint
. Osteomyelitis of the talus

Correct Answer & Explanation

. Impending avascular necrosis (AVN) of the talar body

Explanation

This finding is the Hawkins sign, characterized by subchondral lucency in the talar dome indicating active bone resorption. It signifies that vascular supply to the talar body is intact, making avascular necrosis highly unlikely.

Question 11431

Topic: 2. Trauma

A 30-year-old male presents with a subtrochanteric femur fracture. The proximal fracture fragment is characteristically deformed in flexion, external rotation, and abduction. Which combination of muscles is primarily responsible for this classic deformity?

. Iliopsoas, gluteus maximus, and adductor longus
. Rectus femoris, gluteus minimus, and adductor magnus
. Iliopsoas, short external rotators, and gluteus medius/minimus
. Sartorius, piriformis, and vastus lateralis
. Biceps femoris, obturator internus, and gluteus medius

Correct Answer & Explanation

. Iliopsoas, gluteus maximus, and adductor longus

Explanation

The proximal fragment in a subtrochanteric fracture is flexed by the iliopsoas, abducted by the gluteus medius and minimus, and externally rotated by the short external rotators. Understanding these deforming forces is critical for proper intraoperative reduction.

Question 11432

Topic: 2. Trauma
A 24-year-old female sustains an open midshaft tibia fracture with a 10 cm soft tissue defect over the anterior leg, exposing bone stripped of periosteum. Peripheral pulses are normal. According to the Gustilo-Anderson classification, what is the most appropriate soft tissue coverage option?
. Split-thickness skin graft
. Local fasciocutaneous rotation flap
. Pedicled gastrocnemius flap
. Pedicled soleus flap
. Free tissue transfer (e.g., latissimus dorsi or anterolateral thigh flap)

Correct Answer & Explanation

. Pedicled soleus flap

Explanation

This is a Gustilo-Anderson IIIB open fracture. For soft tissue defects in the middle third of the tibia, a pedicled soleus muscle flap is typically the preferred local coverage option.

Question 11433

Topic: 2. Trauma

A 45-year-old male with a tibial shaft fracture complains of severe, escalating leg pain. His blood pressure is 120/70 mmHg (MAP 86). Intracompartmental pressure monitoring reveals an anterior compartment pressure of 45 mmHg. What is the calculated delta P, and what is the next step in management?

. Delta P is 25 mmHg; perform a four-compartment fasciotomy
. Delta P is 25 mmHg; continue serial examinations
. Delta P is 41 mmHg; perform a four-compartment fasciotomy
. Delta P is 41 mmHg; continue serial examinations
. Delta P is 75 mmHg; elevate the leg and observe

Correct Answer & Explanation

. Delta P is 25 mmHg; perform a four-compartment fasciotomy

Explanation

Delta P is defined as the diastolic blood pressure minus the intracompartmental pressure (70 - 45 = 25 mmHg). A delta P of less than 30 mmHg is an absolute indication for emergency four-compartment fasciotomy.

Question 11434

Topic: 2. Trauma
A 28-year-old male sustains a high-energy Pauwels type III (vertical shear) femoral neck fracture. To minimize the risk of nonunion and fixation failure, which of the following constructs provides the most biomechanically stable fixation for this specific fracture pattern in a young patient?
. Three parallel cannulated screws placed in an inverted triangle
. A dynamic hip screw (sliding hip screw) with a derotational screw
. Two large-diameter fully threaded screws
. A long cephalomedullary nail
. Primary total hip arthroplasty

Correct Answer & Explanation

. A dynamic hip screw (sliding hip screw) with a derotational screw

Explanation

Pauwels type III fractures experience high shear forces. A fixed-angle device such as a sliding hip screw combined with a derotational screw provides superior biomechanical stability compared to multiple cannulated screws.

Question 11435

Topic: Pelvic & Acetabular Trauma
A 50-year-old male presents with a pelvic ring injury and a large, fluctuant soft-tissue swelling over the greater trochanter. Aspiration yields serosanguinous fluid containing fat globules. What is the pathophysiologic mechanism of this specific lesion?
. Bacterial inoculation of a superficial hematoma
. Arterial pseudoaneurysm formation from the superior gluteal artery
. Closed degloving injury separating subcutaneous tissue from the underlying deep fascia
. Herniation of muscle tissue through a traumatic fascial defect
. Rupture of the trochanteric bursa due to direct impact

Correct Answer & Explanation

. Closed degloving injury separating subcutaneous tissue from the underlying deep fascia

Explanation

A Morel-Lavallรฉe lesion is a closed degloving injury where the subcutaneous tissue is separated from the underlying deep fascia. This disrupts perforating vessels, leading to the accumulation of blood, lymph, and necrotic fat.

Question 11436

Topic: 2. Trauma

During preoperative planning for an acetabular fracture, an obturator oblique radiograph demonstrates a disruption of the iliopectineal line with an intact ilioischial line. Which classical fracture pattern does this isolated finding suggest?

. Anterior column fracture
. Posterior column fracture
. Transverse fracture
. Both-column fracture
. T-type fracture

Correct Answer & Explanation

. Anterior column fracture

Explanation

The obturator oblique view highlights the anterior column and the posterior lip of the acetabulum. Disruption of the iliopectineal line with an intact ilioischial line (seen on the iliac oblique view) is diagnostic of an isolated anterior column fracture.

Question 11437

Topic: 2. Trauma

A 35-year-old patient presents with a transverse acetabular fracture. Which radiographic finding reliably distinguishes a transverse acetabular fracture from a T-type acetabular fracture?

. Disruption of both the iliopectineal and ilioischial lines
. Fracture involvement of the obturator ring
. Presence of a "spur sign" on the obturator oblique view
. Involvement of the posterior wall
. Medial displacement of the quadrilateral plate

Correct Answer & Explanation

. Disruption of both the iliopectineal and ilioischial lines

Explanation

Both transverse and T-type fractures disrupt the anterior and posterior columns. However, a T-type fracture includes a vertical split that extends distally to disrupt the obturator ring (ischiopubic rami), which is absent in a pure transverse fracture.

Question 11438

Topic: 2. Trauma

A patient with a high-energy trauma is diagnosed with scapulothoracic dissociation. Which of the following associated injuries is considered an absolute indicator of a poor long-term functional outcome, frequently leading to amputation?

. Subclavian artery disruption
. Fracture of the clavicle
. Complete avulsion of the brachial plexus
. Sternoclavicular joint dislocation
. Scapular body fracture

Correct Answer & Explanation

. Subclavian artery disruption

Explanation

Complete brachial plexus avulsion is the most significant prognostic factor in scapulothoracic dissociation. It results in a flail, insensate limb, making early forequarter amputation a common outcome.

Question 11439

Topic: 2. Trauma

A 68-year-old female on prolonged bisphosphonate therapy presents with thigh pain. Radiographs reveal a transverse fracture of the femoral shaft with lateral cortical thickening and a medial spike. What is the recommended surgical management for this atypical femur fracture?

. Open reduction and internal fixation with a lateral locking plate
. Fixation with an unreamed cephalomedullary nail
. Fixation with a reamed, full-length cephalomedullary nail
. Application of a circular external fixator
. Conservative management with a long leg cast

Correct Answer & Explanation

. Open reduction and internal fixation with a lateral locking plate

Explanation

Atypical femur fractures associated with bisphosphonates are best treated with full-length cephalomedullary nailing to protect the entire femur. Reaming is recommended to stimulate the sluggish biologic healing characteristic of these fractures.

Question 11440

Topic: 2. Trauma

A 32-year-old female sustains a U-shaped sacral fracture (spinopelvic dissociation) after a fall from height. Given this specific fracture pattern, which complication is most highly associated with this injury?

. High-volume arterial retroperitoneal hemorrhage
. Lumbosacral plexus avulsion with isolated L5 weakness
. Bowel and bladder dysfunction
. Rupture of the female urethra
. Nonunion requiring late spinopelvic fixation

Correct Answer & Explanation

. High-volume arterial retroperitoneal hemorrhage

Explanation

U-shaped sacral fractures involve bilateral vertical transforaminal fractures connected by a transverse fracture, effectively dissociating the spine from the pelvis. This pattern severely compromises the sacral nerve roots, leading to high rates of bowel, bladder, and sexual dysfunction.

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