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2. Trauma MCQs

Practice Set 317 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 6321

Topic: 2. Trauma
A 25-year-old man sustains a displaced, vertically oriented (Pauwels type III) femoral neck fracture. He undergoes open reduction and internal fixation. What biomechanical advantage does a sliding hip screw with a derotation screw provide over three parallel cancellous screws for this specific fracture pattern?
. Increased resistance to vertical shear forces
. Decreased risk of osteonecrosis of the femoral head
. Preservation of the lateral epiphyseal artery
. Decreased surgical time and blood loss
. Improved resistance to femoral neck shortening

Correct Answer & Explanation

. Increased resistance to vertical shear forces

Explanation

Pauwels type III femoral neck fractures are highly vertically oriented, leading to significant vertical shear forces and a high risk of varus collapse and nonunion. A sliding hip screw with a derotation screw provides superior biomechanical resistance to these vertical shear forces compared to three parallel cancellous screws, making it the preferred construct for young patients with this fracture pattern.

Question 6322

Topic: 2. Trauma

What is the most critical factor in reducing the risk of infection in a patient who sustains a severe, open tibia fracture in a high-speed motor vehicle collision?

. Time to surgical debridement being less than 6 hours
. Type of soft tissue coverage employed (flap versus graft)
. Early administration of systemic antibiotics
. Use of high-pressure pulsatile lavage
. Application of local antibiotic cement beads during the initial surgery

Correct Answer & Explanation

. Early administration of systemic antibiotics

Explanation

While surgical debridement is essential, literature and current guidelines emphasize that the single most important factor in reducing the rate of infection in open fractures is the early administration of systemic antibiotics, ideally within 1 hour of injury.

Question 6323

Topic: 2. Trauma

A 22-year-old man sustains a low-velocity gunshot wound to the right distal thigh. Radiographs demonstrate a comminuted fracture of the distal femoral diaphysis with the bullet lodged in the adjacent soft tissues. Distal pulses are palpable, and the ABI is 1.0. Which of the following is the most appropriate initial soft tissue management?

. Formal operative debridement of the entire bullet track and removal of the bullet
. Local wound care, tetanus prophylaxis, and a short course of systemic antibiotics
. Surgical exploration of the femoral artery
. Application of a vacuum-assisted closure (VAC) dressing
. Emergent hyperbaric oxygen therapy

Correct Answer & Explanation

. Local wound care, tetanus prophylaxis, and a short course of systemic antibiotics

Explanation

Low-velocity gunshot wounds causing fractures, without clinical evidence of vascular compromise or massive soft tissue contamination/destruction, are typically treated similarly to closed fractures regarding the soft tissues. Local wound care, tetanus prophylaxis, and short-course systemic antibiotics are indicated, followed by definitive fracture fixation. Routine exploration and debridement of the bullet track or bullet removal are not necessary.

Question 6324

Topic: Pelvic & Acetabular Trauma

A 42-year-old man sustains an anteroposterior compression type II (APC II) pelvic ring injury. He is hemodynamically stable. Imaging shows a 3.5 cm symphyseal diastasis and bilateral anterior sacroiliac joint widening. The posterior sacroiliac ligaments are intact. What is the optimal surgical treatment to restore pelvic ring stability?

. Anterior external fixation alone
. Open reduction and internal fixation of the pubic symphysis alone
. Percutaneous iliosacral screw fixation alone
. ORIF of the pubic symphysis combined with bilateral percutaneous iliosacral screws
. Nonoperative management with a pelvic binder for 6 weeks

Correct Answer & Explanation

. Open reduction and internal fixation of the pubic symphysis alone

Explanation

An APC II injury involves disruption of the symphysis pubis (or anterior ring) and the anterior sacroiliac, sacrotuberous, and sacrospinous ligaments, while the robust posterior sacroiliac ligaments remain intact. Because the posterior tension band is intact, restoring the anterior ring with open reduction and internal fixation of the pubic symphysis alone is sufficient to stabilize the entire pelvic ring.

Question 6325

Topic: 2. Trauma

A 45-year-old man sustains a closed, highly comminuted tibial pilon fracture with severe soft tissue swelling and multiple clear and blood-filled fracture blisters over the ankle. What is the preferred initial management strategy?

. Immediate open reduction and internal fixation of the tibia and fibula with dual plating
. Immediate reamed intramedullary nailing of the tibia
. Application of a spanning external fixator with delayed definitive internal fixation
. Closed reduction, casting, and immediate full weight-bearing
. Primary tibiotalar arthrodesis via an anterior approach

Correct Answer & Explanation

. Application of a spanning external fixator with delayed definitive internal fixation

Explanation

High-energy tibial pilon fractures with severe soft tissue compromise (e.g., massive swelling, fracture blisters) are associated with unacceptably high rates of wound complications and deep infection if treated with immediate open reduction and internal fixation. The standard of care is a staged approach: immediate application of a joint-spanning external fixator to restore length and alignment while allowing the soft tissues to heal, followed by definitive internal fixation 10 to 21 days later.

Question 6326

Topic: 2. Trauma

A 25-year-old man sustains a low-velocity gunshot wound to the right thigh, resulting in a comminuted midshaft femur fracture. The bullet is retained in the soft tissues adjacent to the fracture. Distal pulses are palpable and symmetrical to the contralateral limb, and there are no expanding hematomas. What is the most appropriate initial management of the wound and fracture?

. Superficial wound debridement, administration of intravenous antibiotics, and reamed intramedullary nailing
. Extensive formal debridement of the entire bullet track and intramedullary nailing
. Spanning external fixation followed by staged intramedullary nailing in 2 weeks
. Formal extraction of the retained bullet followed by plate osteosynthesis
. Nonoperative management with skeletal traction for 6 weeks

Correct Answer & Explanation

. Superficial wound debridement, administration of intravenous antibiotics, and reamed intramedullary nailing

Explanation

Low-velocity gunshot wounds to the femur without hard signs of vascular injury or severe gross contamination can be safely treated with superficial wound debridement, systemic antibiotics, and antegrade reamed intramedullary nailing. Extensive exploration of the bullet track or formal extraction of the bullet is unnecessary unless the bullet is within the joint space, causing neurovascular compression, or associated with a high-velocity weapon with massive soft tissue destruction.

Question 6327

Topic: 2. Trauma

A 32-year-old man is brought to the trauma bay after a fall from a height of 15 feet. Radiographs reveal a displaced basicervical femoral neck fracture. Which of the following internal fixation constructs is considered biomechanically superior for this specific fracture pattern?

. Three parallel partially threaded cancellous screws
. A sliding hip screw (SHS) supplemented with a derotational screw
. Three fully threaded cortical screws
. A single-screw cephalomedullary nail
. Bipolar hemiarthroplasty

Correct Answer & Explanation

. A sliding hip screw (SHS) supplemented with a derotational screw

Explanation

Basicervical femoral neck fractures are mechanically distinct from subcapital fractures. They behave more like intertrochanteric fractures and are inherently unstable due to the lack of interlocking bony fragments. Multiple cancellous screws and single-screw cephalomedullary nails have a high rate of biomechanical failure in this pattern. A sliding hip screw (SHS), often supplemented with a derotational screw, provides fixed-angle stability and is the preferred construct.

Question 6328

Topic: 2. Trauma
A 30-year-old farmer with no known allergies sustains a severe open tibia fracture (Gustilo-Anderson Type IIIA) heavily contaminated with manure and soil. In addition to a first-generation cephalosporin and an aminoglycoside, which of the following antibiotics is most critical to include in his initial prophylactic regimen?
. Vancomycin
. Ciprofloxacin
. Penicillin
. Clindamycin
. Doxycycline

Correct Answer & Explanation

. Penicillin

Explanation

Farm injuries, particularly those contaminated with soil or manure, carry a significant risk for anaerobic infections, most notably Clostridium perfringens, which can lead to gas gangrene (myonecrosis). The addition of high-dose intravenous penicillin is strongly recommended for anaerobic coverage in these heavily contaminated farm injuries, on top of the standard gram-positive (cefazolin) and gram-negative (gentamicin) coverage.

Question 6329

Topic: 2. Trauma
A 28-year-old construction worker sustains a Hawkins type III talar neck fracture following a fall. At his 8-week postoperative follow-up, an AP radiograph of the ankle demonstrates 'Hawkins sign'. What does this radiographic finding represent?
. Sclerosis of the entire talar dome, indicating impending avascular necrosis
. Subchondral radiolucency of the talar dome, indicating intact vascularity
. Joint space narrowing of the tibiotalar articulation, indicating early post-traumatic arthritis
. A step-off at the subtalar joint, indicating inadequate reduction
. Collapse of the talar body, indicating established osteonecrosis

Correct Answer & Explanation

. Subchondral radiolucency of the talar dome, indicating intact vascularity

Explanation

Hawkins sign is characterized by a subchondral radiolucent band seen on an AP radiograph of the ankle, typically appearing 6 to 8 weeks after a talar neck fracture. This radiolucency is secondary to subchondral bone atrophy (disuse osteopenia). For bone resorption to occur, the blood supply to the talar dome must be intact. Therefore, the presence of Hawkins sign is a highly reliable indicator that avascular necrosis (AVN) will not occur.

Question 6330

Topic: 2. Trauma

A 40-year-old woman with a highly comminuted Schatzker VI tibial plateau fracture undergoes application of a spanning external fixator. Twelve hours postoperatively, she reports excruciating, unremitting leg pain that is out of proportion to her injury. Passive stretch of her toes elicits severe pain. Intracompartmental pressure testing reveals an anterior compartment pressure of 45 mm Hg. Her current blood pressure is 100/60 mm Hg. What is the most appropriate next step in management?

. Urgent four-compartment fasciotomy of the leg
. Observation with repeat compartment pressure testing in 2 hours
. Elevation of the affected limb significantly above the level of the heart
. Loosening of the external fixator pin-site dressings and administration of pain medication
. Administration of a high-dose intravenous corticosteroid bolus

Correct Answer & Explanation

. Urgent four-compartment fasciotomy of the leg

Explanation

The patient is presenting with classic signs of acute compartment syndrome. The diagnosis is confirmed by measuring the Delta P (Diastolic Blood Pressure - Compartment Pressure). In this case, 60 mm Hg - 45 mm Hg = 15 mm Hg. A Delta P of less than 30 mm Hg indicates critically impaired tissue perfusion and is an absolute indication for urgent four-compartment fasciotomy. Elevation above the heart is contraindicated as it further decreases arterial perfusion to the compartment.

Question 6331

Topic: 2. Trauma

A 76-year-old female with advanced osteoporosis and severe preexisting osteoarthritis of the elbow sustains a comminuted, intra-articular distal humerus fracture (AO/OTA 13-C3) after a mechanical fall. Which of the following is the most appropriate definitive surgical intervention?

. Open reduction and internal fixation with dual orthogonal locking plates
. Total elbow arthroplasty
. Hemiarthroplasty of the distal humerus
. Closed reduction and long-arm cast immobilization
. Application of a hinged external fixator

Correct Answer & Explanation

. Total elbow arthroplasty

Explanation

In an elderly patient with poor bone quality (osteoporosis), severe comminution of the articular surface, and preexisting symptomatic osteoarthritis or rheumatoid arthritis, total elbow arthroplasty (TEA) is the treatment of choice for a distal humerus fracture. TEA allows for immediate stability, early range of motion, and predictable pain relief, circumventing the high risk of fixation failure and stiffness associated with ORIF in this demographic.

Question 6332

Topic: 2. Trauma

A 29-year-old active male falls directly onto his left shoulder, sustaining a completely displaced, shortened midshaft clavicle fracture. Which of the following radiographic or demographic characteristics is recognized as the most significant predictor for nonunion if this injury is treated nonoperatively?

. Male gender
. Associated closed head injury
. Fracture displacement greater than 100% of the bone width
. Age less than 30 years
. Medial third fracture location

Correct Answer & Explanation

. Fracture displacement greater than 100% of the bone width

Explanation

The most significant risk factors for nonunion in midshaft clavicle fractures treated nonoperatively include complete fracture displacement (greater than 100% of the width of the clavicle), shortening greater than 2 cm, severe comminution, and advancing patient age. A completely displaced clavicle fracture has a significantly higher rate of nonunion compared to a nondisplaced or minimally displaced fracture, making it a strong relative indication for operative fixation in active patients.

Question 6333

Topic: 2. Trauma

In the context of damage control orthopaedics for a polytrauma patient, when is it most appropriate to convert an external fixator of a femoral shaft fracture to a reamed intramedullary nail?

. Within 24 hours of the initial injury
. When the patient's base deficit normalizes and hemodynamics are stable
. Strictly after 3 weeks to prevent infection
. Immediately after the initial fluid resuscitation, regardless of pulmonary status
. Only after definitive closure of an open abdomen

Correct Answer & Explanation

. When the patient's base deficit normalizes and hemodynamics are stable

Explanation

In damage control orthopaedics, conversion from external fixation to intramedullary nailing of a femur fracture is typically done when the patient's systemic physiology has improved and stabilized. Reliable indicators of adequate resuscitation include normalization of lactate and base deficit, as well as stable hemodynamics, coagulation profiles, and pulmonary function. Proceeding too early in a physiologically unresuscitated patient risks triggering a lethal secondary hit.

Question 6334

Topic: 2. Trauma

A 35-year-old man sustains an isolated closed tibial shaft fracture treated with a reamed intramedullary nail. Postoperatively, he develops severe pain out of proportion to the injury, which is markedly exacerbated by passive stretch of the hallux. His leg is tense and swollen. What is the most appropriate next step in management?

. Elevation of the leg above heart level and ice application
. Measurement of compartment pressures to confirm the diagnosis
. Immediate fasciotomy of all four compartments of the leg
. Fasciotomy of the anterior and lateral compartments only
. Administration of intravenous patient-controlled analgesia and reassessment in 2 hours

Correct Answer & Explanation

. Immediate fasciotomy of all four compartments of the leg

Explanation

The clinical presentation of severe pain out of proportion, a tense extremity, and pain with passive muscle stretch in an awake and alert patient with a recently nailed tibia fracture is the classic diagnostic triad for acute compartment syndrome. When the clinical diagnosis is clear, immediate four-compartment fasciotomies are required. Measuring pressures is unnecessary and delays definitive treatment when the diagnosis is clinically unequivocal.

Question 6335

Topic: 2. Trauma

A 45-year-old man presents to the emergency department with a midshaft clavicle fracture after falling off his bicycle. Which of the following is considered an absolute indication for operative fixation of this injury?

. 1.5 cm of shortening
. Completely displaced fracture with no cortical contact
. Open fracture
. The patient is a high-level overhead athlete
. The presence of a butterfly fragment

Correct Answer & Explanation

. Open fracture

Explanation

Absolute indications for operative treatment of a clavicle fracture include open fracture, displaced fracture with compromised or threatened skin (skin tenting with impending necrosis), vascular injury requiring repair, and progressive neurologic deficit. Shortening >2 cm, complete displacement, and high athletic demands are considered relative indications for surgery.

Question 6336

Topic: 2. Trauma

A 25-year-old male sustains a low-velocity gunshot wound to the thigh, resulting in a minimally displaced midshaft femur fracture. The bullet completely traversed the thigh. Examination reveals normal distal pulses and no signs of compartment syndrome. What is the most appropriate management?

. Immediate formal irrigation and debridement of the bullet track and external fixation
. Local wound care, tetanus prophylaxis, appropriate antibiotics, and intramedullary nailing
. Intravenous antibiotics for 2 weeks and hip spica casting
. Formal irrigation and debridement of the entire track, followed by open plating
. Traction pin placement and delayed nailing after 7 to 10 days

Correct Answer & Explanation

. Local wound care, tetanus prophylaxis, appropriate antibiotics, and intramedullary nailing

Explanation

Low-velocity gunshot wounds resulting in femur fractures without vascular injury, massive tissue destruction, severe contamination, or compartment syndrome can be treated similarly to closed fractures. Local wound care, tetanus prophylaxis, a short course of antibiotics (usually a first-generation cephalosporin), and reamed intramedullary nailing represents the standard of care. Formal I&D of the bullet track is not routinely indicated for low-velocity injuries.

Question 6337

Topic: 2. Trauma

Which of the following injury patterns represents the classic 'terrible triad' of the elbow?

. Radial head fracture, olecranon fracture, ulnar collateral ligament tear
. Coronoid fracture, radial head fracture, lateral collateral ligament tear
. Radial head fracture, capitellum fracture, medial collateral ligament tear
. Coronoid fracture, olecranon fracture, medial collateral ligament tear
. Monteggia fracture-dislocation with a comminuted radial head fracture

Correct Answer & Explanation

. Coronoid fracture, radial head fracture, lateral collateral ligament tear

Explanation

The terrible triad of the elbow consists of an elbow dislocation, a radial head or neck fracture, and a coronoid fracture. It is invariably associated with a tear of the lateral collateral ligament (LCL) complex, which is avulsed from its origin on the lateral epicondyle during the dislocation. The mechanism typically involves a fall on an outstretched hand with the elbow in extension, applying valgus, axial, and posterolateral rotatory forces.

Question 6338

Topic: 2. Trauma

In the initial management of a severe Type II open tibia fracture, what is the single most important factor in decreasing the risk of deep infection?

. Early administration of appropriate systemic intravenous antibiotics
. Time to surgical debridement strictly within 6 hours of injury
. Application of a negative pressure wound therapy (NPWT) device
. The choice of skeletal fixation (external fixator vs intramedullary nail)
. Continuous irrigation with antibiotic solution during surgery

Correct Answer & Explanation

. Early administration of appropriate systemic intravenous antibiotics

Explanation

The single most critical factor in preventing infection in open fractures is the early and adequate administration of systemic intravenous antibiotics. While thorough surgical debridement is absolutely essential, the classic '6-hour rule' for timing of debridement has been challenged by modern literature, which places primary emphasis on antibiotic timing (ideally within 1 hour of presentation) and the thoroughness of the debridement, rather than an arbitrary 6-hour surgical window.

Question 6339

Topic: 2. Trauma

A 65-year-old female sustains a completely displaced, off-ended subtrochanteric femur fracture. She is scheduled for cephalomedullary nailing. To prevent the most common malreduction during this procedure, what intraoperative consideration is most critical?

. Positioning the patient in the lateral decubitus position without a fracture table
. Using a piriformis entry portal instead of a greater trochanter entry portal
. Achieving anatomical reduction using percutaneous clamps or an open approach prior to reaming
. Applying maximal traction on the fracture table until the fracture ends distract
. Reaming the canal aggressively without prior reduction, relying on the nail to align the fracture

Correct Answer & Explanation

. Achieving anatomical reduction using percutaneous clamps or an open approach prior to reaming

Explanation

Subtrochanteric fractures are subject to strong deforming forces: the proximal fragment is flexed (iliopsoas), abducted (gluteus medius/minimus), and externally rotated (short external rotators), while the distal fragment is pulled proximally and into varus. Nailing in a varus malreduction leads to high rates of hardware failure and nonunion. Therefore, these fractures must be anatomically reduced (often utilizing percutaneous clamps, blocking screws, or an open reduction) prior to reaming and nail passage.

Question 6340

Topic: Pelvic & Acetabular Trauma

A 40-year-old man presents with a pelvic ring injury after a high-speed motorcycle crash. An AP pelvis radiograph demonstrates widening of the pubic symphysis of 3.5 cm and widening of the left sacroiliac joint. He remains hemodynamically unstable (BP 70/40) despite receiving 2 liters of crystalloid and 2 units of PRBCs. What is the most appropriate next step in orthopedic management?

. Application of a pelvic binder centered over the iliac crests
. Application of a pelvic binder centered over the greater trochanters
. Immediate CT scan of the abdomen and pelvis to identify the bleeder
. Transfer to the operating room for an immediate exploratory laparotomy
. Placement of a supra-acetabular external fixator in the emergency department

Correct Answer & Explanation

. Application of a pelvic binder centered over the greater trochanters

Explanation

In a hemodynamically unstable patient with an anteroposterior compression (APC) pelvic ring injury, immediate mechanical stabilization must be achieved to reduce pelvic volume and promote venous tamponade. This is best accomplished emergently with a pelvic binder or sheet placed correctly and centered over the greater trochanters. Placement over the iliac crests is incorrect and can act as a fulcrum, paradoxically exacerbating the pubic symphysis diastasis.

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