Menu

2. Trauma MCQs

Practice Set 311 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 6201

Topic: 2. Trauma

A 40-year-old man presents with a closed, highly comminuted midshaft tibia fracture. His blood pressure is 110/70 mmHg. He requires large amounts of analgesics for leg pain and has pain on passive stretch of his toes. His anterior compartment pressure is measured at 45 mmHg. Which of the following statements regarding his diagnosis and management is most accurate?

. Fasciotomy is indicated because the absolute compartment pressure is greater than 30 mmHg.
. Fasciotomy is indicated because the delta p (diastolic blood pressure minus compartment pressure) is less than 30 mmHg.
. Fasciotomy is not indicated because his absolute pressure is less than 50 mmHg.
. Fasciotomy is not indicated because his delta p is greater than 30 mmHg.
. Fasciotomy should be delayed until absent pulses and motor deficits are objectively noted.

Correct Answer & Explanation

. Fasciotomy is indicated because the delta p (diastolic blood pressure minus compartment pressure) is less than 30 mmHg.

Explanation

The diagnosis of acute compartment syndrome is largely clinical, but pressure measurements are essential when the clinical picture is ambiguous or in uncooperative patients. The 'delta p' concept is the most reliable threshold: a difference of less than 30 mmHg between the diastolic blood pressure and the compartment pressure is an indication for emergent fasciotomy. In this case, 70 mmHg (diastolic BP) - 45 mmHg (compartment pressure) = 25 mmHg, which dictates surgical intervention.

Question 6202

Topic: 2. Trauma

A 38-year-old woman falls from a ladder and sustains a complex intra-articular distal femur fracture. CT scanning identifies a Hoffa fracture fragment.

Which of the following statements accurately characterizes this specific injury component?

. It is an extra-articular fracture located on the medial epicondyle.
. It is most commonly visualized on an anteroposterior (AP) radiograph of the knee.
. It represents a sagittal plane cleavage injury of the patellofemoral joint.
. It is a coronal plane fracture that requires independent interfragmentary lag screw fixation.
. It rarely displaces and is optimally managed with hinged knee bracing.

Correct Answer & Explanation

. It is a coronal plane fracture that requires independent interfragmentary lag screw fixation.

Explanation

A Hoffa fracture is a coronal plane fracture of the distal femoral condyle (most commonly the lateral condyle). Because it is an intra-articular shear fracture, it requires anatomical reduction and independent interfragmentary compression (typically with anterior-to-posterior or posterior-to-anterior lag screws) prior to the application of a neutralization or buttress plate for the main distal femur fracture.

Question 6203

Topic: Pelvic & Acetabular Trauma

A 42-year-old man is brought to the emergency department after a high-speed motorcycle collision. His blood pressure is 80/50 mm Hg and heart rate is 120 bpm. Primary survey reveals an unstable pelvis. The trauma team decides to apply a pelvic binder. To be maximally effective in reducing pelvic volume, the binder should be centered over which of the following anatomic landmarks?

. Iliac crests
. Anterior superior iliac spines
. Greater trochanters
. Symphysis pubis
. Ischial tuberosities

Correct Answer & Explanation

. Greater trochanters

Explanation

Pelvic binders are most effective in reducing pelvic volume and controlling hemorrhage in anterior-posterior compression pelvic ring injuries when they are centered over the greater trochanters. Placement over the iliac crests or anterior superior iliac spines can paradoxically open the pelvis further or be less effective in creating the necessary compression.

Question 6204

Topic: 2. Trauma

A 24-year-old man sustains a closed midshaft tibia fracture following a soccer injury and undergoes antegrade intramedullary nailing. Postoperatively, he develops severe leg pain out of proportion to his injury. Passive extension of his great toe elicits excruciating pain. Which of the following compartments is most likely affected?

. Anterior compartment
. Lateral compartment
. Superficial posterior compartment
. Deep posterior compartment
. Peroneal compartment

Correct Answer & Explanation

. Deep posterior compartment

Explanation

Pain with passive extension of the toes, particularly the great toe via the flexor hallucis longus, is a hallmark clinical sign of deep posterior compartment syndrome. The deep posterior compartment of the leg contains the flexor digitorum longus, flexor hallucis longus, tibialis posterior, and the tibial nerve. While the anterior compartment is the most commonly affected overall, the deep posterior compartment is frequently missed, making a careful physical examination critical.

Question 6205

Topic: 2. Trauma
A 35-year-old construction worker sustains a severe open tibia fracture with extensive soft tissue stripping and a 12 cm laceration (Gustilo-Anderson Type IIIB). According to current evidence-based guidelines, which of the following is the most critical factor in preventing deep infection?
. Initiation of intravenous antibiotics within 1 hour of injury
. Surgical debridement strictly within 6 hours of injury
. Immediate definitive soft tissue coverage
. Use of high-pressure pulsatile lavage during debridement
. Addition of an aminoglycoside to a first-generation cephalosporin for all open fractures

Correct Answer & Explanation

. Initiation of intravenous antibiotics within 1 hour of injury

Explanation

The prompt administration of systemic intravenous antibiotics (ideally within 1 hour of injury) has consistently been shown to be the single most important factor in reducing the rate of infection in open fractures. While the historic "6-hour rule" for surgical debridement was taught for decades, recent literature demonstrates that early administration of antibiotics outweighs the strict adherence to the 6-hour surgical window, although urgent debridement is still recommended.

Question 6206

Topic: 2. Trauma

A 40-year-old man falls from a height of 15 feet and sustains a highly comminuted, intra-articular distal tibia (pilon) fracture. On presentation, there is severe swelling and hemorrhagic fracture blisters. What is the most appropriate initial management?

. Immediate open reduction and internal fixation through an anterolateral approach
. Immediate open reduction and internal fixation through an anteromedial approach
. Application of a spanning ankle external fixator and delayed open reduction and internal fixation
. Primary arthrodesis of the tibiotalar joint
. Placement in a short leg cast until swelling subsides, followed by open reduction and internal fixation

Correct Answer & Explanation

. Application of a spanning ankle external fixator and delayed open reduction and internal fixation

Explanation

High-energy pilon fractures often present with severe soft tissue compromise. Immediate open reduction and internal fixation (ORIF) in this setting is associated with unacceptably high rates of wound breakdown, necrosis, and deep infection. The standard of care is a staged protocol: initial application of a spanning external fixator (with or without limited internal fixation of the fibula) to restore length and alignment, followed by delayed definitive ORIF 10-21 days later once the soft tissue swelling has subsided and the "wrinkle sign" appears.

Question 6207

Topic: 2. Trauma

A 28-year-old motorcyclist is struck by a car and thrown 30 feet. He presents with a completely flail, pulseless left upper extremity. Radiographs demonstrate marked lateral displacement of the scapula relative to the thoracic spine and a displaced clavicle fracture. Which of the following associated injuries is responsible for the highest early mortality rate in this condition?

. Subclavian or axillary artery disruption
. Complete brachial plexus avulsion
. Traumatic brain injury
. Ipsilateral rib fractures and flail chest
. Splenic rupture

Correct Answer & Explanation

. Subclavian or axillary artery disruption

Explanation

Scapulothoracic dissociation is effectively a closed, traumatic forequarter amputation. It is characterized by severe trauma to the shoulder girdle with lateral displacement of the scapula. This injury carries a high incidence of devastating vascular and neurologic injuries. The most immediate life-threatening component, and the one with the highest early mortality, is catastrophic hemorrhage secondary to subclavian or axillary artery disruption.

Question 6208

Topic: 2. Trauma
A 30-year-old man sustains a completely displaced, vertically oriented (Pauwels type III) femoral neck fracture in a motor vehicle accident. He undergoes closed reduction and internal fixation. Which of the following biomechanical constructs provides the most stable fixation for this specific high-shear fracture pattern?
. Three parallel cannulated screws in an inverted triangle configuration
. Two parallel cannulated screws
. A sliding hip screw with an anti-rotation screw
. A single large diameter partially threaded cancellous screw
. A proximal femoral locking plate

Correct Answer & Explanation

. A sliding hip screw with an anti-rotation screw

Explanation

Vertical shear (Pauwels type III) femoral neck fractures in young adults are notoriously difficult to treat and have a high rate of nonunion and hardware failure due to massive shear forces across the fracture site. Biomechanical studies have demonstrated that a sliding hip screw (often supplemented with a derotational screw) provides superior biomechanical stability and increased resistance to shear forces compared to multiple parallel cancellous screws for this vertically oriented pattern.

Question 6209

Topic: 2. Trauma

A 25-year-old snowboarder sustains a displaced talar neck fracture with subluxation of the subtalar joint (Hawkins Type II). He undergoes prompt open reduction and internal fixation. Six weeks later, an AP radiograph of the ankle demonstrates a subchondral radiolucent band in the dome of the talus. What does this radiographic finding indicate?

. Impending avascular necrosis of the talar body
. Nonunion of the talar neck
. Subchondral collapse and early post-traumatic arthritis
. Revascularization and an intact blood supply to the talar body
. Undiagnosed subchondral impaction fracture

Correct Answer & Explanation

. Revascularization and an intact blood supply to the talar body

Explanation

The finding described is the Hawkins sign, which is a subchondral radiolucent band seen on the AP or mortise radiograph of the ankle, typically 6-8 weeks following a talus fracture. It represents subchondral osteopenia secondary to disuse and hyperemia. The presence of the Hawkins sign is a positive prognostic indicator; it demonstrates that the talar body has an intact blood supply and is undergoing revascularization, making avascular necrosis highly unlikely.

Question 6210

Topic: 2. Trauma

A 22-year-old man sustains a low-velocity gunshot wound to the right thigh resulting in a comminuted midshaft femur fracture. The entrance and exit wounds are 1 cm in diameter with no active bleeding or expanding hematoma. His neurovascular examination is entirely intact. What is the most appropriate orthopedic management?

. Immediate operative debridement, followed by skeletal traction for 6 weeks
. Intravenous antibiotics for 48 hours and skeletal traction
. Local wound care, tetanus prophylaxis, and antegrade intramedullary nailing
. Excisional debridement of the missile tract and external fixation
. Immediate angiography followed by intramedullary nailing

Correct Answer & Explanation

. Local wound care, tetanus prophylaxis, and antegrade intramedullary nailing

Explanation

Low-velocity gunshot wounds resulting in femur fractures, without signs of neurovascular compromise or massive tissue destruction/contamination, can be safely managed in a manner similar to closed fractures. Standard management includes local wound care, tetanus prophylaxis, a short course of intravenous antibiotics, and definitive stabilization with an intramedullary nail. Extensive surgical debridement of the missile tract is unnecessary for low-velocity, non-cavitating injuries.

Question 6211

Topic: 2. Trauma

A 35-year-old man presents with a severe crush injury to his lower leg with a completely ischemic foot. The trauma team is deciding between limb salvage and primary amputation. Which of the following statements regarding the Mangled Extremity Severity Score (MESS) is most accurate according to the Lower Extremity Assessment Project (LEAP) study?

. A MESS score greater than 7 definitively indicates that primary amputation will yield better functional outcomes than salvage.
. The MESS is highly sensitive and specific for predicting the necessity of amputation.
. The LEAP study found that MESS scores were not highly predictive of the eventual need for amputation or functional outcome.
. A high MESS score strongly correlates with the development of chronic regional pain syndrome.
. The MESS score heavily relies on the timing of definitive soft tissue coverage to predict salvageability.

Correct Answer & Explanation

. The LEAP study found that MESS scores were not highly predictive of the eventual need for amputation or functional outcome.

Explanation

The Lower Extremity Assessment Project (LEAP) study was a landmark multicenter prospective study that investigated severe lower extremity trauma. It concluded that commonly used injury severity scores, including the MESS, were not predictive of functional outcomes or the eventual need for amputation. While a high MESS score historically dictated primary amputation, modern trauma literature emphasizes that these scores should not be used as the sole determinant for clinical decision-making regarding amputation versus limb salvage.

Question 6212

Topic: Pelvic & Acetabular Trauma
A 42-year-old man arrives in the emergency department hypotensive and tachycardic following a high-speed motor vehicle collision. A pelvic radiograph reveals an anteroposterior compression (APC) type III pelvic ring injury. A pelvic binder is applied, and a FAST scan is negative for intra-abdominal fluid. Despite fluid resuscitation, he remains hypotensive. What is the most common anatomic source of hemorrhage in this clinical scenario?
. Superior gluteal artery
. Presacral venous plexus and cancellous bone
. Internal pudendal artery
. Obturator artery
. External iliac vein

Correct Answer & Explanation

. Presacral venous plexus and cancellous bone

Explanation

The most common source of bleeding in pelvic ring injuries is the presacral venous plexus and bleeding from the cancellous bone edges, accounting for up to 80% of cases. Arterial bleeding (e.g., from the superior gluteal or internal pudendal arteries) occurs in only 10% to 20% of cases but is more likely to be the culprit in a patient who remains hemodynamically unstable despite mechanical stabilization with a binder. However, standard board teaching dictates that overall, the venous plexus and cancellous bone are the most frequent sources of hemorrhage in pelvic fractures.

Question 6213

Topic: 2. Trauma
A 28-year-old man sustains a displaced, highly vertical femoral neck fracture (Pauwels III) following a fall from a roof. Which of the following internal fixation constructs provides the greatest biomechanical stability to resist the high shear forces inherent in this specific fracture pattern?
. Three parallel cancellous screws in an inverted triangle configuration
. A sliding hip screw (fixed-angle device) with a derotational cancellous screw
. Multiple fully threaded non-cannulated cortical screws
. Bipolar hemiarthroplasty
. Dynamic condylar screw

Correct Answer & Explanation

. A sliding hip screw (fixed-angle device) with a derotational cancellous screw

Explanation

Pauwels III fractures are characterized by a highly vertical fracture line (angle > 50 degrees), which subjects the fracture site to significant shear forces rather than compressive forces. Biomechanical studies have consistently demonstrated that a fixed-angle construct, such as a sliding hip screw (with an additional anti-rotation screw), provides superior mechanical stability and higher load-to-failure compared to three parallel cancellous screws for vertical shear fracture patterns in young adults.

Question 6214

Topic: 2. Trauma

A 35-year-old motorcyclist sustains a complex intra-articular fracture of the distal femur. Computed tomography (CT) reveals a coronal plane fracture of the lateral femoral condyle (Hoffa fracture).

What is the optimal method of internal fixation for this specific articular fragment?

. Lateral locked plating spanning the articular surface
. Anterior-to-posterior (AP) or posterior-to-anterior (PA) interfragmentary lag screws
. Medial-to-lateral fully threaded positioning screws
. Tension band wiring utilizing K-wires
. Spanning external fixation only

Correct Answer & Explanation

. Anterior-to-posterior (AP) or posterior-to-anterior (PA) interfragmentary lag screws

Explanation

A Hoffa fracture is a coronal plane fracture of the femoral condyle, most commonly involving the lateral condyle. Because the fracture line runs in the coronal plane, medial-to-lateral fixation (like standard plating or transverse screws) will not effectively compress the fragment. It requires anterior-to-posterior (AP) or posterior-to-anterior (PA) lag screws placed perpendicular to the fracture plane to achieve anatomic reduction and interfragmentary compression.

Question 6215

Topic: 2. Trauma

A 40-year-old man falls from a height of 15 feet and presents with a severely swollen leg. Radiographs demonstrate a bicondylar tibial plateau fracture with diaphyseal-metaphyseal dissociation (Schatzker VI).

On physical examination, he has severe pain with passive stretch of his toes and decreased sensation in the first web space. His calf is extremely tense. What is the most appropriate next step in management?

. Immediate open reduction and internal fixation through dual incisions
. Placement of a spanning external fixator and delayed internal fixation
. Immediate four-compartment fasciotomy
. Urgent noninvasive vascular studies (ABI)
. Measurement of intra-compartmental pressures

Correct Answer & Explanation

. Immediate four-compartment fasciotomy

Explanation

The patient exhibits classic signs of acute compartment syndrome (pain out of proportion, pain with passive stretch, tense compartments, and early sensory deficits in the deep peroneal nerve distribution—first web space). When the clinical diagnosis of compartment syndrome is unequivocal, immediate four-compartment fasciotomy is indicated. Compartment pressure measurements are unnecessary and delay limb-saving treatment in clinically obvious cases.

Question 6216

Topic: 2. Trauma

A 30-year-old man undergoes open reduction and internal fixation for a displaced talar neck fracture (Hawkins type II).

Eight weeks postoperatively, an anteroposterior mortise radiograph of the ankle reveals a subchondral radiolucent band localized to the dome of the talus (Hawkins sign). What does this radiographic finding indicate?

. Avascular necrosis of the talar body
. Imminent articular collapse of the talar dome
. Nonunion of the talar neck fracture
. Intact vascularity to the talar body
. Deep infection of the subtalar joint

Correct Answer & Explanation

. Intact vascularity to the talar body

Explanation

The Hawkins sign is a subchondral radiolucent band seen in the talar dome on AP or mortise radiographs, typically appearing 6 to 8 weeks after a talar neck fracture. It represents subchondral atrophy/resorption of bone secondary to disuse hyperemia. Its presence is a highly reliable indicator that the vascular supply to the talar body is intact, thereby effectively ruling out the development of avascular necrosis (AVN).

Question 6217

Topic: 2. Trauma

A 25-year-old man with a closed tibial shaft fracture develops acute compartment syndrome. If left untreated, irreversible muscle necrosis will typically begin to occur after how many hours of continuous ischemia?

. Less than 2 hours
. 4 to 6 hours
. 10 to 12 hours
. 14 to 16 hours
. 24 hours

Correct Answer & Explanation

. 4 to 6 hours

Explanation

Muscle tissue is highly sensitive to ischemia. Studies show that irreversible muscle necrosis typically begins after 4 to 6 hours of continuous complete ischemia (with significant necrosis evident by 8 hours). Peripheral nerves may show reversible changes (neurapraxia) within 30 minutes to 2 hours, but irreversible nerve damage generally parallels muscle necrosis timelines. Urgent fasciotomy is required well before this window closes.

Question 6218

Topic: 2. Trauma
A 45-year-old pedestrian is struck by a vehicle and sustains a Gustilo-Anderson Type IIIB open fracture of the distal third of the tibia. Following serial debridements, a clean 6 cm x 4 cm soft tissue defect remains with exposed bone completely devoid of periosteum. What is the most appropriate method for providing definitive soft tissue coverage for this specific location?
. Split-thickness skin grafting over the exposed bone
. Gastrocnemius rotational muscle flap
. Soleus rotational muscle flap
. Free tissue transfer (e.g., anterolateral thigh or latissimus dorsi flap)
. Reverse sural artery fasciocutaneous flap

Correct Answer & Explanation

. Free tissue transfer (e.g., anterolateral thigh or latissimus dorsi flap)

Explanation

Soft tissue coverage for the tibia is classically based on the level of the defect. Proximal third defects are covered with a gastrocnemius rotational flap; middle third defects use a soleus flap. Distal third defects with exposed bone devoid of periosteum (Gustilo IIIB) lack local muscle bulk for rotational flaps and routinely require free tissue transfer (free flap) for adequate and reliable coverage.

Question 6219

Topic: 2. Trauma

A 6-year-old boy presents to the emergency department after falling from monkey bars, sustaining a severely displaced, extension-type supracondylar humerus fracture. On initial examination, the radial pulse is absent, but the hand is warm and pink with a capillary refill time of less than 2 seconds. The fracture is taken to the operating room for closed reduction and percutaneous pinning. Postoperatively, the hand remains warm and pink with brisk capillary refill, but the radial pulse remains unpalpable. What is the most appropriate next step in management?

. Immediate exploration of the brachial artery
. Formal angiography of the upper extremity
. Observation with close clinical monitoring
. Fasciotomy of the forearm compartments
. Administration of intra-arterial vasodilators

Correct Answer & Explanation

. Observation with close clinical monitoring

Explanation

The management of a "pulseless, pink hand" following reduction and pinning of a pediatric supracondylar humerus fracture is observation. The collateral circulation around the elbow is robust enough to maintain distal perfusion even if the brachial artery is in spasm or compressed. Immediate exploration is indicated only if the hand is pulseless and white/ischemic (poor perfusion) after a technically adequate fracture reduction.

Question 6220

Topic: 2. Trauma

A 28-year-old polytrauma patient presents after a high-speed motor vehicle collision with bilateral femur fractures, a pelvic ring injury, and a grade IV splenic laceration. Following initial damage control surgery and splenectomy, the patient is in the ICU. Which of the following parameters is the most reliable indicator of adequate global tissue perfusion and resuscitation prior to proceeding with definitive orthopedic fixation?

. Normalization of heart rate and blood pressure
. Urine output greater than 0.5 mL/kg/hr
. Serum lactate level < 2.0 mmol/L and base deficit > -2
. Central venous pressure between 8-12 mm Hg
. Mixed venous oxygen saturation > 60%

Correct Answer & Explanation

. Serum lactate level < 2.0 mmol/L and base deficit > -2

Explanation

Serum lactate and base deficit are the most reliable markers of global tissue perfusion and resolution of shock. Normalization of lactate (< 2.0 mmol/L) and base deficit (>-2) indicates adequate resuscitation and is utilized by orthopedic trauma surgeons to determine the safe timing for definitive fixation in polytrauma patients, transitioning them from damage control to definitive care.

Test Yourself

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

On this Page