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2. Trauma MCQs

Practice Set 543 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 10841

Topic: 2. Trauma

A 35-year-old male arrives via trauma bay after a close-range shotgun blast to the lower extremity. The extremity is severely mangled. When using the Mangled Extremity Severity Score (MESS) to assist in deciding between amputation and limb salvage, which of the following factors specifically adds points to the patient's score?

. Patient age greater than 30 years
. Presence of an open pelvic fracture
. Associated traumatic brain injury
. A venous injury alone, without arterial compromise
. Time to surgery less than 6 hours

Correct Answer & Explanation

. Patient age greater than 30 years

Explanation

The MESS system evaluates four criteria: 1) Skeletal and soft-tissue injury (energy level), 2) Limb ischemia, 3) Shock (systemic hypotension), and 4) Patient Age. For Age, points are assigned as follows: <30 years = 0 points; 30-50 years = 1 point; >50 years = 2 points. A score of 7 or greater historically correlates with a high likelihood of amputation.

Question 10842

Topic: 2. Trauma

A 40-year-old male sustains a low-velocity civilian handgun injury to the right thigh. Radiographs demonstrate a comminuted midshaft femur fracture. His neurovascular exam is intact, and the wounds are small without gross contamination. What is the standard of care for definitive management?

. Formal surgical excision of the entire bullet tract, followed by external fixation
. Local wound care, tetanus prophylaxis, and antegrade intramedullary nailing
. Primary amputation due to massive energy transfer and cavitation
. Intravenous antibiotics for 6 weeks, skeletal traction, and delayed plating
. Surgical debridement, placement of antibiotic beads, and delayed intramedullary nailing at 2 weeks

Correct Answer & Explanation

. Formal surgical excision of the entire bullet tract, followed by external fixation

Explanation

Civilian low-velocity gunshot wounds resulting in femur fractures without neurovascular injury or gross contamination can typically be treated similar to closed fractures. Formal excision of the bullet tract is unnecessary and increases surgical morbidity. Management consists of local wound care, tetanus prophylaxis, a short course of IV antibiotics, and early intramedullary nailing.

Question 10843

Topic: 2. Trauma

A 25-year-old cyclist sustains a midshaft clavicle fracture. Which of the following displacement characteristics is most strongly associated with an increased risk of symptomatic nonunion if treated non-operatively?

. Superior displacement of the lateral fragment
. More than 2 cm of fracture shortening
. Inferior angulation of 10 degrees
. Presence of a single butterfly fragment
. Coracoclavicular ligament injury

Correct Answer & Explanation

. Superior displacement of the lateral fragment

Explanation

While non-operative management of midshaft clavicle fractures was historically the standard, recent evidence shows higher rates of nonunion and symptomatic malunion in specifically displaced patterns. The most widely accepted risk factor for nonunion/poor functional outcome is fracture shortening greater than 2 cm. Displacement >100% (complete off-ending) and severe comminution are also relative indications for ORIF.

Question 10844

Topic: 2. Trauma
A 45-year-old pedestrian is struck by a car and dragged, sustaining a closed pelvic fracture and a large, fluctuant swelling over the lateral greater trochanter. Aspiration yields serosanguineous fluid. This lesion is caused by a shear force that results in the separation of which two anatomic layers?
. Epidermis and dermis
. Dermis and subcutaneous fat
. Subcutaneous tissue (hypodermis) and underlying deep fascia
. Deep fascia and skeletal muscle
. Skeletal muscle and periosteum

Correct Answer & Explanation

. Subcutaneous tissue (hypodermis) and underlying deep fascia

Explanation

This is the classic presentation of a Morel-Lavallée lesion, which is a closed degloving injury. High-energy shear forces abruptly separate the subcutaneous tissue (hypodermis) from the relatively immobile underlying deep fascia. This creates a potential space that fills with blood, lymph, and liquefied fat, often requiring percutaneous drainage and sclerosis or open debridement if an underlying fracture requires surgical fixation.

Question 10845

Topic: Pelvic & Acetabular Trauma

A 60-year-old male sustains an isolated transverse acetabular fracture involving the posterior wall. According to the Judet-Letournel classification, an isolated anterior column fracture would classically demonstrate a disruption of which primary radiographic line on the anteroposterior (AP) pelvis view?

. Ilioischial line
. Iliopectineal line
. Radiographic teardrop
. Anterior border of the obturator foramen
. Posterior wall line

Correct Answer & Explanation

. Ilioischial line

Explanation

In the Judet-Letournel classification, the fundamental radiographic landmark for the anterior column is the iliopectineal line. The fundamental landmark for the posterior column is the ilioischial line. Disruption of the iliopectineal line with an intact ilioischial line suggests an isolated anterior column (or anterior wall) fracture.

Question 10846

Topic: 2. Trauma
A 42-year-old farmer sustains a severe open tibia fracture after being caught in a tractor bailer. The wound is 12 cm long with gross soil and organic contamination. In addition to a first-generation cephalosporin and an aminoglycoside, which of the following antibiotics is classically recommended in his initial empiric regimen?
. Vancomycin
. Penicillin
. Clindamycin
. Metronidazole
. Ciprofloxacin

Correct Answer & Explanation

. Penicillin

Explanation

In severe open fractures with heavy soil or farm contamination (Gustilo-Anderson Type III), anaerobic coverage with Penicillin is historically recommended to prevent Clostridium perfringens infection (gas gangrene). While modern guidelines sometimes utilize alternative anaerobic agents, Penicillin remains the classic board-tested standard.

Question 10847

Topic: 2. Trauma

According to the principles of Damage Control Orthopedics (DCO), which of the following laboratory values most strongly indicates the need for temporary external fixation rather than Early Total Care (ETC) for a patient with bilateral femur fractures?

. Serum lactate of 2.0 mmol/L
. Base deficit of -8 mEq/L
. Platelet count of 150,000/mcL
. Hemoglobin of 9.5 g/dL
. Urine output of 1.0 mL/kg/hr

Correct Answer & Explanation

. Serum lactate of 2.0 mmol/L

Explanation

A base deficit worse than -6 mEq/L or a serum lactate greater than 4.0 mmol/L are classical markers of physiologic exhaustion and ongoing shock. Proceeding with early total care in these borderline or unstable patients significantly increases the risk of ARDS and multiorgan failure.

Question 10848

Topic: Pelvic & Acetabular Trauma

A 30-year-old male is involved in a high-speed MVC. A Judet obturator oblique radiograph of the pelvis is obtained.

Which of the following acetabular structures are best profiled on this specific radiographic view?

. Anterior column and posterior wall
. Posterior column and anterior wall
. Ilioischial line and anterior column
. Pelvic brim and posterior column
. Ischial spine and anterior wall

Correct Answer & Explanation

. Anterior column and posterior wall

Explanation

The obturator oblique view best profiles the anterior column and the posterior wall of the acetabulum. Conversely, the iliac oblique view highlights the posterior column and the anterior wall.

Question 10849

Topic: 2. Trauma

A 22-year-old male sustains a closed tibial shaft fracture. Twelve hours post-admission, he develops severe pain out of proportion to the injury. Which of the following pressure criteria is generally accepted as an absolute indication for emergent four-compartment 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 < 30 mmHg

Correct Answer & Explanation

. Absolute compartment pressure > 20 mmHg

Explanation

A Delta P (Diastolic Blood Pressure minus Compartment Pressure) of less than 30 mmHg is the most reliable threshold for diagnosing acute compartment syndrome and warrants emergent fasciotomy. Using absolute pressures is less reliable due to fluctuations in systemic blood pressure.

Question 10850

Topic: Pelvic & Acetabular Trauma
A 45-year-old male sustains a closed pelvic ring injury. Clinical examination reveals a massive, fluctuant swelling over the greater trochanter with intact, but ecchymotic overlying skin. What is the primary pathophysiologic mechanism of this specific soft tissue injury?
. Rupture of the gluteus medius insertion
. Arterial hemorrhage from the superior gluteal artery
. Shearing of subcutaneous tissue from the underlying fascia
. Focal fat necrosis secondary to direct contusion
. Lymphatic obstruction from pelvic ring disruption

Correct Answer & Explanation

. Shearing of subcutaneous tissue from the underlying fascia

Explanation

A Morel-Lavallée lesion is a closed degloving injury caused by traumatic shearing of the subcutaneous tissue away from the underlying deep fascia. This creates a potential space that fills with hematoma and liquefied fat, significantly increasing the risk of deep infection if surgical incisions are placed directly through it.

Question 10851

Topic: 2. Trauma

A 24-year-old male is awaiting fixation of bilateral femur fractures. On hospital day 2, he develops acute confusion, tachypnea, and a petechial rash over his axillae. Arterial blood gas shows a PaO2 of 55 mmHg. What is the most appropriate initial management of this condition?

. Emergent bilateral femur intramedullary nailing
. Intravenous administration of high-dose corticosteroids
. Heparin infusion for systemic anticoagulation
. Supportive care with aggressive oxygenation and mechanical ventilation if needed
. Administration of broad-spectrum intravenous antibiotics

Correct Answer & Explanation

. Emergent bilateral femur intramedullary nailing

Explanation

The patient is exhibiting classic signs of Fat Embolism Syndrome (FES), diagnosed clinically using Gurd's criteria. The mainstay of treatment is purely supportive, prioritizing oxygenation and mechanical ventilation if necessary; corticosteroids and heparin have not proven consistently beneficial in acute management.

Question 10852

Topic: 2. Trauma

A 32-year-old polytrauma patient is in the intensive care unit after damage control orthopedic surgery. Which of the following is the most reliable indicator of adequate global tissue perfusion and the endpoint of resuscitation?

. Heart rate less than 100 beats per minute
. Urine output greater than 0.5 mL/kg/hr
. Normalization of serum lactate and base deficit
. Systolic blood pressure greater than 110 mmHg
. Central venous pressure between 8 and 12 mmHg

Correct Answer & Explanation

. Heart rate less than 100 beats per minute

Explanation

Serum lactate and base deficit are the most reliable indicators of global tissue perfusion and successful resuscitation in polytrauma patients. Normalization of these markers correlates with improved survival and guides the timing for definitive fracture fixation.

Question 10853

Topic: 2. Trauma
A 45-year-old farmer sustains a Gustilo-Anderson Type IIIB open tibia fracture severely contaminated with manure. According to current guidelines, what is the most appropriate initial intravenous antibiotic regimen?
. Cefazolin alone
. Cefazolin and an aminoglycoside
. Ceftriaxone and vancomycin
. Cefazolin, an aminoglycoside, and high-dose penicillin
. Fluoroquinolone monotherapy

Correct Answer & Explanation

. Cefazolin, an aminoglycoside, and high-dose penicillin

Explanation

For Type III open fractures with severe soil or farm contamination, the addition of high-dose penicillin is recommended to cover Clostridium species, alongside gram-positive and gram-negative coverage. This minimizes the risk of gas gangrene in high-risk environments.

Question 10854

Topic: 2. Trauma

A 22-year-old male sustains a closed tibial shaft fracture. Two hours post-admission, his blood pressure is 110/60 mmHg, and compartment pressure monitoring reveals an anterior compartment pressure of 40 mmHg. What is the calculated Delta P, and what is the indicated treatment?

. Delta P is 20 mmHg; perform immediate four-compartment fasciotomy.
. Delta P is 40 mmHg; closely observe the patient.
. Delta P is 20 mmHg; perform an isolated anterior compartment fasciotomy.
. Delta P is 60 mmHg; elevate the leg and observe.
. Delta P is 70 mmHg; perform a two-incision fasciotomy.

Correct Answer & Explanation

. Delta P is 20 mmHg; perform immediate four-compartment fasciotomy.

Explanation

Delta P is calculated as diastolic blood pressure minus compartment pressure (60 - 40 = 20 mmHg). A Delta P of less than 30 mmHg is an absolute indication for emergency four-compartment fasciotomy of the lower leg to prevent irreversible muscle necrosis.

Question 10855

Topic: 2. Trauma
A 55-year-old male presents with an APC-III pelvic ring injury and refractory hypotension. During pre-peritoneal pelvic packing, active arterial bleeding is encountered over the superior pubic ramus. Which vascular structure is most likely injured?
. Internal iliac to external iliac artery anastomosis
. Obturator to external iliac or inferior epigastric artery anastomosis
. Superior gluteal to inferior gluteal artery anastomosis
. Internal pudendal to obturator artery anastomosis
. External pudendal to femoral artery anastomosis

Correct Answer & Explanation

. Obturator to external iliac or inferior epigastric artery anastomosis

Explanation

The 'corona mortis' is a critical vascular anastomosis between the obturator vessels and the external iliac or inferior epigastric vessels. It crosses the superior pubic ramus and is highly susceptible to injury in anterior pelvic ring fractures.

Question 10856

Topic: 2. Trauma

A 24-year-old male sustains a low-velocity gunshot wound to the thigh, resulting in a comminuted femoral shaft fracture. The entrance and exit wounds are clean and measure approximately 1 cm each. The patient is neurovascularly intact. What is the most appropriate management?

. Immediate extensive wound debridement and external fixation
. Local wound care, short-course IV antibiotics, and antegrade intramedullary nailing
. Wide excision of the bullet tract and open plating
. Angiography followed by spica casting
. Immediate above-knee amputation

Correct Answer & Explanation

. Immediate extensive wound debridement and external fixation

Explanation

Low-velocity gunshot wounds with associated long bone fractures and no significant contamination or vascular injury are treated similarly to closed fractures. Local wound care, short-course IV antibiotics, and standard intramedullary nailing yield excellent outcomes without the need for extensive debridement.

Question 10857

Topic: 2. Trauma

A polytrauma patient with bilateral pulmonary contusions and a closed midshaft femur fracture undergoes reamed intramedullary nailing on hospital day 2. Postoperatively, he develops severe hypoxemia, a petechial rash on the axilla, and altered mental status. What is the most likely diagnosis?

. Fat embolism syndrome
. Pulmonary embolism
. Acute respiratory distress syndrome (ARDS) due to pneumonia
. Transfusion-related acute lung injury (TRALI)
. Septic shock

Correct Answer & Explanation

. Fat embolism syndrome

Explanation

The classic triad of hypoxemia, neurologic abnormalities, and a petechial rash following intramedullary reaming and fixation of a long bone fracture is highly indicative of fat embolism syndrome. Intramedullary pressurization drives marrow fat into the venous circulation.

Question 10858

Topic: 2. Trauma

A 42-year-old roofer falls and sustains a closed, displaced, intra-articular joint depression type calcaneus fracture. The skin is severely swollen with fracture blisters. What is the optimal timing for definitive open reduction and internal fixation (ORIF) via an extensile lateral approach?

. Immediately within 24 hours of injury
. Within 48 hours to prevent cartilage necrosis
. After 7 to 14 days when the positive wrinkle sign appears
. After 4 weeks to allow early bone healing
. Surgical intervention is strictly contraindicated

Correct Answer & Explanation

. Immediately within 24 hours of injury

Explanation

ORIF of calcaneus fractures should be delayed until soft tissue swelling subsides to minimize catastrophic wound complications. This is indicated by the return of skin wrinkles (the 'wrinkle sign'), which typically occurs 7 to 14 days post-injury.

Question 10859

Topic: 2. Trauma

An 82-year-old female with severe pre-existing osteoarthritis of the knee and profound osteopenia sustains a highly comminuted, displaced intra-articular distal femur fracture (AO/OTA 33-C3). Which surgical option provides the earliest mobilization and most predictable return to function?

. Retrograde intramedullary nailing
. Distal femoral replacement (megaprosthesis)
. Open reduction and internal fixation with dual plating
. Spanning external fixation
. Prolonged skeletal traction

Correct Answer & Explanation

. Retrograde intramedullary nailing

Explanation

In elderly patients with poor bone quality, pre-existing osteoarthritis, and severe intra-articular comminution, distal femoral replacement acts as an arthroplasty. It provides immediate stability, allows early weight-bearing, and avoids the high failure rates associated with internal fixation in this demographic.

Question 10860

Topic: 2. Trauma

A 40-year-old male sustains a medial tibial plateau fracture with knee subluxation (Schatzker IV) after a high-energy varus-directed force. Which associated injury must be ruled out emergently?

. Anterior tibial artery disruption
. Superficial peroneal nerve palsy
. Popliteal artery injury
. Medial collateral ligament avulsion
. Patellar tendon rupture

Correct Answer & Explanation

. Anterior tibial artery disruption

Explanation

Schatzker IV (medial plateau) fractures often involve high-energy trauma with knee subluxation or dislocation. Because the popliteal artery is anatomically tethered at the soleus arch, these injuries carry a high risk of vascular injury requiring emergent evaluation.

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