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2. Trauma MCQs

Practice Set 20 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 381

Topic: 2. Trauma

A 28-year-old man sustained a closed midshaft tibia fracture treated with an intramedullary nail. Six hours postoperatively, he complains of severe leg pain out of proportion to the injury, not relieved by opioids. Passive stretch of his toes causes excruciating pain. What is the most sensitive early clinical sign of this condition?

. Loss of palpable pedal pulses
. Pain with passive stretch of the involved muscles
. Paresthesia in the first web space
. Paralysis of the extensor hallucis longus
. Pallor of the foot

Correct Answer & Explanation

. Pain with passive stretch of the involved muscles

Explanation

Pain out of proportion to the injury and pain exacerbated by passive stretch of the ischemic muscles are the earliest and most sensitive clinical signs of acute compartment syndrome. Pulselessness and paralysis are very late, often irreversible signs.

Question 382

Topic: 2. Trauma

A 65-year-old woman falls on her outstretched hand and sustains a dorsally displaced distal radius fracture. Which eponym correctly describes this specific fracture pattern?

. Smith fracture
. Colles fracture
. Barton fracture
. Chauffeur fracture
. Galeazzi fracture

Correct Answer & Explanation

. Colles fracture

Explanation

A Colles fracture is an extra-articular fracture of the distal radius with dorsal comminution and dorsal displacement. A Smith fracture is its reverse counterpart, characterized by volar angulation and displacement.

Question 383

Topic: 2. Trauma
A 30-year-old man sustains a Gustilo-Anderson Type IIIB open tibia fracture following a motorcycle accident. The wound is 12 cm long with extensive soft tissue stripping and exposed bone. Which of the following intravenous antibiotic regimens is most appropriate initially?
. First-generation cephalosporin alone
. First-generation cephalosporin and an aminoglycoside
. Penicillin alone
. Vancomycin alone
. Fluoroquinolone alone

Correct Answer & Explanation

. First-generation cephalosporin and an aminoglycoside

Explanation

Correct Answer: B. For Gustilo-Anderson Type III open fractures, broad-spectrum antibiotic coverage is required to mitigate infection risk. Standard initial therapy includes a first-generation cephalosporin for Gram-positive coverage combined with an aminoglycoside for Gram-negative coverage.

Question 384

Topic: 2. Trauma
A 25-year-old man sustains an anteroposterior compression (APC) type III pelvic ring injury in a crush accident. He remains hemodynamically unstable despite initial fluid resuscitation and the application of a pelvic binder. What is the most appropriate next step to control the hemorrhage?
. Exploratory laparotomy with direct packing
. External fixation of the pelvis
. Pelvic angiography and embolization
. Immediate open reduction and internal fixation of the symphysis pubis
. Application of a pneumatic antishock garment

Correct Answer & Explanation

. Pelvic angiography and embolization

Explanation

Correct Answer: C. In a hemodynamically unstable patient with a pelvic ring injury where mechanical volume reduction (pelvic binder) has failed, pelvic angiography with embolization is indicated. This helps identify and occlude arterial bleeding, which is frequently from branches of the internal iliac artery.

Question 385

Topic: 2. Trauma

During an intramedullary nailing of a femur fracture, an otherwise healthy 20-year-old man develops sudden tachycardia, muscle rigidity, and a rapid rise in end-tidal CO2. His core temperature spikes to 39.5 degrees Celsius. What is the immediate drug of choice for this condition?

. Epinephrine
. Naloxone
. Dantrolene
. Flumazenil
. Atropine

Correct Answer & Explanation

. Dantrolene

Explanation

The patient is experiencing malignant hyperthermia, an acute hypermetabolic crisis triggered by volatile anesthetics or succinylcholine. Dantrolene, a ryanodine receptor antagonist, must be administered immediately to halt the uncontrolled release of calcium from the sarcoplasmic reticulum.

Question 386

Topic: 2. Trauma
A 32-year-old male presents with a hemodynamically unstable APC III pelvic ring injury following a motorcycle crash. A pelvic binder is applied, but he remains hypotensive despite initial fluid resuscitation. What is the most appropriate next step in management?
. CT angiography
. Retrograde urethrogram
. Preperitoneal pelvic packing and/or angioembolization
. Anterior external fixation
. Exploratory laparotomy

Correct Answer & Explanation

. Preperitoneal pelvic packing and/or angioembolization

Explanation

Correct Answer: C. Hemodynamically unstable pelvic fractures requiring massive transfusion should undergo emergent pelvic packing or angioembolization. External fixation alone is insufficient for controlling ongoing major retroperitoneal venous or arterial hemorrhage.

Question 387

Topic: 2. Trauma

A 30-year-old male sustains a closed tibial shaft fracture. Twelve hours post-injury, he complains of severe leg pain out of proportion to the injury. Which of the following clinical findings is the most sensitive early indicator of acute compartment syndrome?

. Loss of distal pulses
. Capillary refill greater than 3 seconds
. Motor paralysis of the extensor hallucis longus
. Pain with passive stretch of the toes
. Pallor of the foot

Correct Answer & Explanation

. Pain with passive stretch of the toes

Explanation

Pain with passive muscle stretch is the most sensitive and earliest clinical sign of acute compartment syndrome. Pulselessness, paralysis, and pallor are late signs indicating irreversible ischemia.

Question 388

Topic: Lower Extremity Trauma

A 12-year-old boy of Ashkenazi Jewish descent presents with hepatosplenomegaly, anemia, and bone pain. Radiographs of his distal femora demonstrate an 'Erlenmeyer flask' deformity. Bone marrow aspirate reveals large macrophages with a 'wrinkled tissue paper' appearance. What is the deficient enzyme?

. Sphingomyelinase
. Hexosaminidase A
. Alpha-L-iduronidase
. Glucocerebrosidase
. Arylsulfatase A

Correct Answer & Explanation

. Glucocerebrosidase

Explanation

Gaucher disease is a lysosomal storage disorder caused by a deficiency of glucocerebrosidase. The accumulation of glucocerebroside in macrophages leads to bone marrow expansion, causing osteopenia, bone crises, and the classic Erlenmeyer flask deformity of the distal femur.

Question 389

Topic: 2. Trauma

A 25-year-old man with bilateral closed femoral shaft fractures treated with intramedullary nailing develops progressive hypoxemia, a petechial rash over his axillae and conjunctivae, and confusion 36 hours postoperatively. His arterial blood gas reveals a pO2 of 55 mmHg. What is the most likely diagnosis?

. Fat embolism syndrome
. Acute pulmonary embolism
. Transfusion-related acute lung injury
. Myocardial infarction
. Disseminated intravascular coagulation

Correct Answer & Explanation

. Fat embolism syndrome

Explanation

This patient exhibits the classic triad of fat embolism syndrome: hypoxemia, neurologic compromise, and a petechial rash. It is a known complication of long bone fractures, particularly of the femur, usually occurring 24 to 72 hours after injury.

Question 390

Topic: 2. Trauma

A 62-year-old heavy smoker with known non-small cell lung carcinoma presents with increasing thigh pain. Radiographs reveal a 3.5 cm lytic lesion in the subtrochanteric region of the right femur with cortical destruction. His Mirels' score is 10. What is the most appropriate management?

. Systemic chemotherapy only
. External beam radiation therapy alone
. Prophylactic intramedullary nailing followed by radiation
. Wide local excision and endoprosthetic reconstruction
. Intravenous bisphosphonates and protected weight bearing

Correct Answer & Explanation

. Prophylactic intramedullary nailing followed by radiation

Explanation

A Mirels' score of 9 or greater indicates a high risk for impending pathologic fracture. Prophylactic surgical fixation, typically with an intramedullary nail, followed by adjuvant radiotherapy is the standard of care to prevent fracture and relieve pain.

Question 391

Topic: 2. Trauma

A 28-year-old man sustains a closed midshaft tibia fracture. Six hours later, he develops excruciating leg pain exacerbated by passive stretch of his toes. His diastolic blood pressure is 80 mmHg. A compartment pressure reading confirms acute compartment syndrome. What is the critical threshold for the delta pressure?

. Less than 10 mmHg
. Less than 20 mmHg
. Less than 30 mmHg
. Less than 40 mmHg
. Less than 50 mmHg

Correct Answer & Explanation

. Less than 30 mmHg

Explanation

Acute compartment syndrome is diagnosed when the delta pressure (diastolic blood pressure minus intracompartmental pressure) falls to less than 30 mmHg. Immediate four-compartment fasciotomy is indicated to prevent irreversible ischemia.

Question 392

Topic: 2. Trauma
A 30-year-old man sustains an open diaphyseal fracture of the tibia in a motorcycle accident. The wound is 12 cm long with extensive soft-tissue crushing and periosteal stripping, requiring a rotational flap for coverage. According to the Gustilo-Anderson classification, what is the recommended empiric antibiotic regimen?
. First-generation cephalosporin alone
. First-generation cephalosporin and an aminoglycoside
. Oral amoxicillin/clavulanate
. Vancomycin monotherapy
. Fluoroquinolone alone

Correct Answer & Explanation

. First-generation cephalosporin and an aminoglycoside

Explanation

This is a Gustilo-Anderson Type IIIb open fracture. Current guidelines recommend a first-generation cephalosporin (like cefazolin) combined with an aminoglycoside (like gentamicin) to cover both Gram-positive and Gram-negative organisms in severe open fractures.

Question 393

Topic: 2. Trauma

A 25-year-old man fell on his extended wrist 6 months ago. He did not seek medical care at the time but now presents with chronic radial-sided wrist pain. X-rays reveal a scaphoid nonunion with avascular necrosis of the proximal pole. The retrograde blood supply to the scaphoid is primarily derived from branches of which artery?

. Ulnar artery
. Radial artery
. Anterior interosseous artery
. Posterior interosseous artery
. Deep palmar arch

Correct Answer & Explanation

. Radial artery

Explanation

The major blood supply to the scaphoid enters distally via the dorsal carpal branch of the radial artery and flows retrograde to the proximal pole. This retrograde anatomy makes proximal pole fractures highly susceptible to avascular necrosis and nonunion.

Question 394

Topic: 2. Trauma

A 24-year-old man sustains bilateral closed femoral shaft fractures in a motor vehicle collision. Thirty-six hours later, he becomes confused, develops a petechial rash over his axillae and conjunctivae, and requires supplemental oxygen for hypoxemia. What is the most likely diagnosis?

. Acute pulmonary embolism
. Fat embolism syndrome
. Acute respiratory distress syndrome (ARDS)
. Aspiration pneumonia
. Sepsis

Correct Answer & Explanation

. Fat embolism syndrome

Explanation

Fat embolism syndrome typically presents 24 to 72 hours after long-bone fractures. It is classically characterized by Bergman's triad: hypoxemia, neurological abnormalities, and a petechial rash.

Question 395

Topic: 2. Trauma

An 18-year-old male with homozygous sickle cell disease sustains a closed femoral shaft fracture. On post-injury day 2, he develops chest pain, fever, tachypnea, and new pulmonary infiltrates on his chest X-ray. What is the best initial management?

. Immediate intramedullary nailing of the femur
. Broad-spectrum antibiotics, oxygen, and aggressive hydration
. Therapeutic intravenous heparin
. High-dose systemic corticosteroids
. Immediate bone marrow transplant

Correct Answer & Explanation

. Broad-spectrum antibiotics, oxygen, and aggressive hydration

Explanation

This presentation is highly suspicious for acute chest syndrome. Initial management focuses on supportive care, including oxygenation, aggressive hydration, analgesia, and broad-spectrum antibiotics, often followed by blood transfusion.

Question 396

Topic: 2. Trauma

A 28-year-old male involved in a high-speed collision sustains bilateral femur fractures. On post-injury day 3, he is intubated for hypoxemia. His PaO2/FiO2 ratio is 150 mmHg, and a chest radiograph shows bilateral diffuse opacities. According to the Berlin definition, what is his condition?

. Moderate ARDS
. Mild ARDS
. Severe ARDS
. Pulmonary contusion
. Cardiogenic shock

Correct Answer & Explanation

. Moderate ARDS

Explanation

Under the Berlin definition, Acute Respiratory Distress Syndrome (ARDS) is categorized by the PaO2/FiO2 ratio. A ratio between 100 and 200 mmHg with bilateral opacities defines moderate ARDS.

Question 397

Topic: 2. Trauma
A 45-year-old man undergoes intramedullary nailing for a closed tibia fracture. When is he at the highest risk of developing the full clinical presentation of fat embolism syndrome?
. Immediately upon injury
. During the first 12 hours post-injury
. 24 to 72 hours post-injury
. 5 to 7 days post-injury
. 2 weeks post-injury

Correct Answer & Explanation

. 24 to 72 hours post-injury

Explanation

Fat embolism syndrome most commonly manifests 24 to 72 hours following a major long bone fracture. Earlier presentations are rare, and respiratory failure beyond one week is more suspicious for venous thromboembolism.

Question 398

Topic: 2. Trauma

A 22-year-old man sustains a closed comminuted femur fracture in a motor vehicle collision. On postoperative day 2, he becomes acutely confused, tachypneic, and develops a petechial rash over his axillae and chest. Arterial blood gas shows a pO2 of 55 mmHg. Which of the following best describes the dual pathophysiology of this syndrome?

. Autoimmune reaction to marrow elements and subsequent complement activation
. Mechanical occlusion of pulmonary capillaries by fat macroglobules followed by biochemical injury from toxic free fatty acids
. Widespread platelet aggregation leading to microvascular thrombosis and disseminated intravascular coagulation
. Release of vasoactive peptides causing profound pulmonary vasodilation and shunting
. Direct bacterial seeding of the lungs from the initial trauma site

Correct Answer & Explanation

. Mechanical occlusion of pulmonary capillaries by fat macroglobules followed by biochemical injury from toxic free fatty acids

Explanation

Fat Embolism Syndrome (FES) has a biphasic pathophysiology. It begins with mechanical occlusion of the pulmonary microvasculature by fat droplets, followed by a biochemical phase where lipase degrades the fat into highly toxic free fatty acids that damage the pneumocytes.

Question 399

Topic: 2. Trauma

A 65-year-old heavy smoker presents with an unprovoked pathologic fracture of the proximal humerus. Radiographs show a destructive lytic lesion. He has no known history of malignancy. What is the most appropriate next step in his workup before considering operative fixation?

. Immediate prophylactic intramedullary nailing
. CT of the chest, abdomen, and pelvis along with a whole-body bone scan
. Initiation of intravenous bisphosphonates
. MRI of the bilateral upper extremities
. Empiric radiation therapy to the shoulder

Correct Answer & Explanation

. CT of the chest, abdomen, and pelvis along with a whole-body bone scan

Explanation

In a patient presenting with an unknown primary malignancy and a pathologic fracture, complete staging must be performed before any surgical intervention. CT of the chest, abdomen, pelvis, and a bone scan will identify the primary source and extent of skeletal disease.

Question 400

Topic: 2. Trauma

An 82-year-old man sustains a displaced femoral neck fracture. His medical history includes placement of a bare-metal coronary stent 2 months ago, for which he takes aspirin and clopidogrel. To balance his cardiac and surgical risks, what is the most widely accepted perioperative management of his antiplatelet therapy?

. Stop both aspirin and clopidogrel and proceed immediately with surgery
. Delay surgical fixation for 1 year to complete dual antiplatelet therapy
. Continue both aspirin and clopidogrel and proceed with surgery
. Stop clopidogrel, continue aspirin, and proceed with surgery as soon as feasible
. Administer a massive platelet transfusion to reverse both drugs and operate immediately

Correct Answer & Explanation

. Stop clopidogrel, continue aspirin, and proceed with surgery as soon as feasible

Explanation

In urgent orthopedic trauma such as hip fractures, delaying surgery drastically increases mortality. The standard compromise is to continue aspirin for cardiac protection while holding clopidogrel (or proceeding if the risk of stent thrombosis outweighs bleeding risks), without excessive delays.

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