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2. Trauma MCQs

Practice Set 544 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 10861

Topic: 2. Trauma

A 32-year-old male presents with bilateral femur fractures and pulmonary contusions following a motor vehicle collision. Which of the following parameters is the MOST reliable indicator of adequate resuscitation, allowing the surgical team to safely proceed from a damage control approach to early total care (definitive intramedullary nailing)?

. Normalization of heart rate and blood pressure
. Urine output greater than 0.5 mL/kg/hr for 2 hours
. Serum lactate clearance to less than 2.0 mmol/L
. Core body temperature of 35.0°C

Correct Answer & Explanation

. Normalization of heart rate and blood pressure

Explanation

Serum lactate and base deficit are the most reliable markers of tissue perfusion and adequate resuscitation in polytrauma. Normalization of lactate (< 2.0 mmol/L) indicates resolution of occult hypoperfusion, making early definitive fracture care safer.

Question 10862

Topic: 2. Trauma

A hemodynamically unstable 40-year-old female presents with a severe lateral compression (LC) pelvic ring injury. After binder application and fluid resuscitation, she remains hypotensive and is taken for pelvic angiography. Which vessel is most commonly the source of life-threatening arterial hemorrhage in this specific fracture pattern?

. Superior gluteal artery
. Obturator artery
. Internal pudendal artery
. Corona mortis

Correct Answer & Explanation

. Superior gluteal artery

Explanation

The superior gluteal artery is the most common source of arterial bleeding in pelvic fractures, particularly those involving posterior pelvic ring disruptions. Anterior injuries (like APC) are more prone to obturator or internal pudendal artery injuries.

Question 10863

Topic: 2. Trauma
A 45-year-old construction worker sustains a Gustilo-Anderson Grade IIIA open tibia fracture. According to established orthopedic trauma guidelines, what is the single most important intervention for decreasing the patient's risk of deep bone infection?
. Surgical debridement within exactly 6 hours
. Early administration of systemic intravenous antibiotics
. Use of high-pressure pulsatile lavage
. Immediate primary wound closure

Correct Answer & Explanation

. Early administration of systemic intravenous antibiotics

Explanation

The time to administration of intravenous antibiotics is the most critical factor in reducing infection rates in open fractures. The historical '6-hour rule' for surgical debridement has been shown to be less strongly correlated with infection risk than immediate antibiotic delivery.

Question 10864

Topic: 2. Trauma

A 25-year-old male sustains a closed comminuted tibial shaft fracture. His blood pressure is 110/70 mmHg. He complains of severe pain out of proportion to the injury. Which of the following intracompartmental pressure measurements strictly mandates emergency fasciotomy?

. An absolute compartment pressure of 25 mmHg
. An absolute compartment pressure of 30 mmHg
. A Delta P (Diastolic BP minus Compartment Pressure) of less than 30 mmHg
. A Delta P (Diastolic BP minus Compartment Pressure) of greater than 40 mmHg

Correct Answer & Explanation

. An absolute compartment pressure of 25 mmHg

Explanation

A Delta P (diastolic blood pressure minus compartment pressure) of less than 30 mmHg is the accepted threshold for diagnosing acute compartment syndrome and mandates emergency fasciotomy. Absolute pressure readings are less reliable due to variations in systemic blood pressure.

Question 10865

Topic: 2. Trauma

A 22-year-old male sustains a low-velocity civilian gunshot wound to the distal thigh. Radiographs demonstrate a non-displaced distal femur fracture. Which of the following findings is an absolute indication for formal surgical debridement of the bullet track?

. A transcavitary trajectory through the thigh musculature
. Intra-articular extension of the bullet path into the knee joint
. A retained bullet fragment in the vastus lateralis
. The presence of a non-displaced fracture

Correct Answer & Explanation

. A transcavitary trajectory through the thigh musculature

Explanation

Intra-articular gunshot wounds require formal arthrotomy or arthroscopic debridement to prevent lead arthropathy and septic arthritis. Uncomplicated low-velocity transcavitary wounds without vascular injury or severe contamination can generally be managed with local wound care and antibiotics.

Question 10866

Topic: 2. Trauma

In a polytraumatized patient with significant bilateral pulmonary contusions, early reamed intramedullary nailing of a femoral shaft fracture (Early Total Care) is most closely associated with an increased risk of developing which complication?

. Fat embolism syndrome and Acute Respiratory Distress Syndrome (ARDS)
. Atrophic nonunion of the fracture
. Deep surgical site infection
. Avascular necrosis of the femoral head

Correct Answer & Explanation

. Fat embolism syndrome and Acute Respiratory Distress Syndrome (ARDS)

Explanation

Reaming of the femoral canal increases intramedullary pressure, releasing fat emboli into the venous circulation. In a patient with pre-existing lung injury (e.g., pulmonary contusions), this "second hit" significantly increases the risk of ARDS and systemic inflammatory response.

Question 10867

Topic: 2. Trauma
A 32-year-old male sustains a Gustilo-Anderson Grade IIIB open tibia fracture with an anterior 10x10 cm soft tissue defect. To minimize the risk of deep infection and osteomyelitis, definitive soft tissue coverage (e.g., free flap) should ideally be performed within what timeframe?
. Within 24 hours of injury
. Within 3 to 7 days of injury
. After 14 days, once the wound bed granulates
. Immediately during the index debridement, regardless of contamination

Correct Answer & Explanation

. Within 3 to 7 days of injury

Explanation

Godina's classic principles, supported by modern studies, demonstrate that soft tissue coverage within 3 to 7 days (the "fix and flap" window) minimizes infection rates and flap failure. Delaying coverage beyond this period increases colonization and deep infection risks.

Question 10868

Topic: 2. Trauma
A 28-year-old male sustained a Hawkins Type III talar neck fracture. At 8 weeks post-fixation, an AP radiograph of the ankle demonstrates a subchondral radiolucent band in the dome of the talus (Hawkins sign). What does this specific radiographic finding indicate?
. Avascular necrosis (AVN) of the talar body
. Impending nonunion of the talar neck
. Intact vascularity to the talar body
. Severe post-traumatic osteoarthritis

Correct Answer & Explanation

. Intact vascularity to the talar body

Explanation

The Hawkins sign is a subchondral radiolucent band representing subchondral osteopenia secondary to disuse. Its presence indicates that the vascular supply to the talar body is intact, effectively ruling out avascular necrosis.

Question 10869

Topic: 2. Trauma

A patient with a complex bicondylar tibial plateau fracture requires an open reduction and internal fixation of a displaced posteromedial fragment. During a standard posteromedial approach, which neurovascular structures are at greatest risk of iatrogenic injury during superficial dissection?

. Common peroneal nerve and anterior tibial artery
. Saphenous nerve and great saphenous vein
. Sural nerve and small saphenous vein
. Deep peroneal nerve and posterior tibial artery

Correct Answer & Explanation

. Common peroneal nerve and anterior tibial artery

Explanation

The posteromedial approach to the tibial plateau uses the interval between the pes anserinus and the medial head of the gastrocnemius. The saphenous nerve and great saphenous vein lie in the superficial fascia of this region and must be carefully protected.

Question 10870

Topic: 2. Trauma

A 45-year-old presents with a high-energy supracondylar distal femur fracture. Which imaging modality or specific sequence is most critical to effectively rule out an associated coronal plane articular (Hoffa) fracture?

. Standard AP radiograph of the knee
. Internal oblique radiograph of the knee
. CT scan with sagittal and coronal reconstructions
. Non-contrast MRI of the knee

Correct Answer & Explanation

. Standard AP radiograph of the knee

Explanation

Hoffa fractures are coronal plane fractures of the femoral condyles that are frequently missed on standard AP radiographs. A CT scan with 2D reconstructions is the gold standard for identifying and characterizing these intra-articular injuries.

Question 10871

Topic: 2. Trauma

When applying a temporary spanning external fixator for a proximal tibia fracture in a polytrauma patient, half-pins placed in the anterior tibial diaphysis should be placed slightly medial to the anterior tibial crest to avoid injury to which anatomical compartment/structure?

. The superficial posterior compartment and sural nerve
. The anterior compartment and deep peroneal nerve
. The lateral compartment and superficial peroneal nerve
. The medial gastrocnemius and saphenous nerve

Correct Answer & Explanation

. The superficial posterior compartment and sural nerve

Explanation

The safe corridor for pin placement in the tibial diaphysis is the anteromedial face. Placing pins lateral to the tibial crest risks injury to the anterior compartment musculature (tibialis anterior) and the deep peroneal nerve.

Question 10872

Topic: 2. Trauma

An 82-year-old female presents with a displaced femoral neck fracture. She has a history of stable coronary artery disease. According to extensive registry data and current guidelines, what is the optimal timing for surgical intervention to minimize 1-year mortality?

. Immediately within 6 hours of presentation
. Within 48 hours of admission
. After 72 hours of aggressive cardiac optimization
. Within 1 week

Correct Answer & Explanation

. Immediately within 6 hours of presentation

Explanation

Delaying surgery for geriatric hip fractures beyond 48 hours is associated with significantly increased morbidity and 1-year mortality. Medical optimization should occur concurrently, but surgery should not be unnecessarily delayed for routine cardiac testing if the patient is stable.

Question 10873

Topic: 2. Trauma

A 45-year-old male is 9 months post-intramedullary nailing for a tibial shaft fracture. He complains of persistent pain with weight-bearing. Radiographs show a persistent fracture line with abundant, dense 'elephant shoe' callus formation. What is the most appropriate next step in management?

. Open bone grafting with iliac crest autograft
. Exchange nailing with a larger diameter implant to increase stability
. Application of an external bone stimulator
. Systemic administration of bisphosphonates

Correct Answer & Explanation

. Open bone grafting with iliac crest autograft

Explanation

An 'elephant shoe' callus represents a hypertrophic nonunion, which implies excellent local biology but inadequate mechanical stability. Exchange nailing provides increased mechanical stability, which is the definitive treatment to achieve union in this scenario.

Question 10874

Topic: 2. Trauma

A 25-year-old male with an isolated closed femur fracture becomes acutely confused and tachypneic 36 hours after admission. Physical examination reveals a petechial rash over his axilla and conjunctiva. Arterial blood gas shows severe hypoxemia. What is the most likely diagnosis?

. Acute massive pulmonary embolism
. Sepsis secondary to occult infection
. Fat embolism syndrome (FES)
. Malignant hyperthermia

Correct Answer & Explanation

. Acute massive pulmonary embolism

Explanation

Fat embolism syndrome (FES) classically presents 24 to 72 hours after long bone fractures with a triad of hypoxemia, neurological abnormalities, and a petechial rash. Early fracture fixation is the most effective prophylaxis.

Question 10875

Topic: 2. Trauma

A 28-year-old polytrauma patient develops petechial rashes over the axilla, conjunctiva, and chest 48 hours after sustaining bilateral femur fractures. He is tachypneic and confused. According to Gurd's criteria, which of the following is considered a major criterion for the diagnosis of Fat Embolism Syndrome (FES)?

. Fever greater than 38.5°C
. Petechial rash
. Tachycardia greater than 110 bpm
. Thrombocytopenia
. Unexplained anemia

Correct Answer & Explanation

. Fever greater than 38.5°C

Explanation

Gurd's major criteria for Fat Embolism Syndrome include petechial rash, respiratory insufficiency, and cerebral involvement. Fever, tachycardia, thrombocytopenia, and anemia are considered minor criteria.

Question 10876

Topic: 2. Trauma

In the context of Damage Control Orthopedics (DCO), which of the following physiological parameters is the most reliable indicator of adequate resuscitation, allowing for safe transition to early total care (ETC) for a femur fracture?

. Serum lactate < 2.0 mmol/L
. Heart rate < 100 bpm
. Urine output > 0.5 mL/kg/hr
. Systolic blood pressure > 90 mmHg
. Hemoglobin > 9 g/dL

Correct Answer & Explanation

. Serum lactate < 2.0 mmol/L

Explanation

Clearance of serum lactate to less than 2.0 mmol/L (or normal base excess) is an objective marker of restored tissue perfusion. It is widely considered the best indicator of adequate resuscitation before undertaking definitive intramedullary nailing.

Question 10877

Topic: 2. Trauma

Which of the following interventions has been proven to be the most critical factor in reducing the risk of deep infection in the management of open long bone fractures?

. Surgical debridement within 6 hours of injury
. High-pressure pulsatile lavage
. Early administration of systemic antibiotics
. Immediate definitive soft tissue coverage
. Use of local antibiotic-impregnated beads

Correct Answer & Explanation

. Surgical debridement within 6 hours of injury

Explanation

The early administration of appropriate systemic antibiotics is the single most critical and evidence-based factor for reducing infection in open fractures. The traditional '6-hour rule' for operative debridement has been challenged by recent literature.

Question 10878

Topic: 2. Trauma

A 45-year-old male sustains an acetabular fracture. Radiographs including AP and Judet views reveal disruption of the iliopectineal line extending to the anterior iliac crest, with an intact ilioischial line. Based on the Letournel classification, what is the diagnosis?

. Posterior column fracture
. Anterior column fracture
. Transverse fracture
. Both-column fracture
. Anterior wall fracture

Correct Answer & Explanation

. Posterior column fracture

Explanation

Disruption of the iliopectineal line characterizes an anterior column injury. Extension to the iliac crest further confirms a high anterior column fracture, distinguishing it from an isolated anterior wall fracture.

Question 10879

Topic: 2. Trauma

A 22-year-old intubated trauma patient is hypotensive with a diastolic blood pressure of 55 mmHg. His right leg is tense and swollen following a severe crush injury. Intracompartmental pressure monitoring reveals a pressure of 30 mmHg. What is the most appropriate next step?

. Immediate four-compartment fasciotomy
. Observation and repeat measurement in 2 hours
. Elevation of the leg above the level of the heart
. Administration of intravenous mannitol

Correct Answer & Explanation

. Immediate four-compartment fasciotomy

Explanation

Compartment syndrome is diagnosed when the Delta P (diastolic BP minus compartment pressure) is less than 30 mmHg. In this hypotensive patient, a Delta P of 25 mmHg (55 - 30) mandates emergent fasciotomy.

Question 10880

Topic: 2. Trauma

A patient presents with a vertical shear pelvic ring disruption after a fall from a height. Which of the following arterial structures is at the highest risk of injury with this specific fracture pattern?

. Internal pudendal artery
. Obturator artery
. Superior gluteal artery
. External iliac artery
. Inferior epigastric artery

Correct Answer & Explanation

. Internal pudendal artery

Explanation

Vertical shear pelvic fractures involve significant posterior ring disruption, placing the superior gluteal artery at highest risk as it exits the greater sciatic notch. Anterior-posterior compression injuries typically affect the internal pudendal and obturator arteries.

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