Menu

2. Trauma MCQs

Practice Set 540 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 10781

Topic: 2. Trauma

A 35-year-old male sustains a posterior wall acetabular fracture. Which of the following is the most reliable predictor of hip joint instability necessitating operative fixation?

. Fracture involves >10% of the posterior wall
. Presence of a marginal impaction fragment
. Positive dynamic fluoroscopic stress examination under anesthesia
. Ischial spine avulsion
. Concomitant sciatic nerve palsy

Correct Answer & Explanation

. Fracture involves >10% of the posterior wall

Explanation

Dynamic fluoroscopic stress examination under anesthesia is the gold standard for determining hip instability in posterior wall fractures. While fractures involving >20% are generally fixed, stress testing remains the most reliable dynamic indicator.

Question 10782

Topic: 2. Trauma

A 45-year-old male sustains a severe intra-articular distal femur fracture. CT scan reveals a coronal shear fracture of the lateral femoral condyle (Hoffa fragment). What is the optimal surgical approach and fixation strategy for this specific fragment?

. Standard medial approach with locking plate
. Lateral approach with anterior-to-posterior interfragmentary lag screws
. Direct posterior approach with posterior plate
. Retrograde intramedullary nailing
. Circular external fixation

Correct Answer & Explanation

. Standard medial approach with locking plate

Explanation

A lateral Hoffa fracture is a coronal plane shear injury best addressed through a lateral or anterolateral approach. Stable fixation is typically achieved using anterior-to-posterior lag screws, often supplemented by a lateral neutralization plate.

Question 10783

Topic: 2. Trauma

A 38-year-old male sustains a high-energy Schatzker VI tibial plateau fracture. He presents with a tense, swollen leg, and resting compartment pressures are measured at 45 mmHg with a diastolic blood pressure of 65 mmHg. What is the immediate management?

. Elevation and re-evaluation in 2 hours
. Immediate spanning external fixation
. Immediate four-compartment fasciotomy and spanning external fixation
. Immediate open reduction and internal fixation with dual plating
. Administration of mannitol and dexamethasone

Correct Answer & Explanation

. Elevation and re-evaluation in 2 hours

Explanation

The patient has acute compartment syndrome as indicated by a Delta P of 20 mmHg (Delta P < 30 mmHg is diagnostic). Immediate treatment requires a four-compartment fasciotomy combined with a spanning external fixator for skeletal stabilization.

Question 10784

Topic: 2. Trauma
Which of the following is the most critical predictive factor for the development of deep infection in an open type III tibial shaft fracture?
. Time to initial surgical debridement
. Type of skeletal fixation used
. Time to administration of systemic antibiotics
. Use of local antibiotic delivery systems
. Age of the patient

Correct Answer & Explanation

. Time to administration of systemic antibiotics

Explanation

The single most important factor in reducing the risk of infection in open fractures is the early administration of appropriate systemic antibiotics. While timely debridement is essential, antibiotic timing is the most critical independent variable.

Question 10785

Topic: 2. Trauma

A 40-year-old male falls from a height and sustains a displaced, closed intra-articular calcaneus fracture. To minimize wound healing complications associated with the extensile lateral approach, what is the optimal timing for definitive surgery?

. Within 24 hours of injury
. 3 to 5 days post-injury regardless of swelling
. When the wrinkle sign is present, typically 10 to 14 days
. Immediately after reduction of the fracture in the emergency department
. After 4 weeks to ensure complete soft tissue healing

Correct Answer & Explanation

. Within 24 hours of injury

Explanation

The extensile lateral approach to the calcaneus has a notoriously high risk of wound complications. Surgery should be delayed until soft tissue swelling has significantly subsided, indicated by the return of skin wrinkles (the wrinkle sign).

Question 10786

Topic: 2. Trauma

A 28-year-old male presents to the emergency department 4 hours after a crush injury to his right forearm. He complains of excruciating pain in his forearm, disproportionate to the injury, which is markedly exacerbated by passive extension of his fingers. His forearm is tense and swollen, but radial and ulnar pulses are palpable, and capillary refill is brisk. Sensory examination is normal. What is the most appropriate immediate next step in management?

. Administer high-dose NSAIDs and observe for 24 hours.
. Obtain an emergent MRI to confirm the diagnosis of compartment syndrome.
. Elevate the limb, apply ice, and re-evaluate in 2 hours.
. Perform an urgent forearm fasciotomy.
. Reassure the patient, provide oral pain medication, and discharge with strict instructions for follow-up.

Correct Answer & Explanation

. Administer high-dose NSAIDs and observe for 24 hours.

Explanation

This patient's presentation with severe pain disproportionate to the injury, a tense forearm, and pain with passive stretching of muscles (a classic hallmark sign) are highly suggestive of acute forearm compartment syndrome. Although pulses may still be palpable and sensation initially intact, these are late signs of compartment syndrome. Compartment syndrome is a clinical diagnosis and a surgical emergency. Delay in treatment can lead to irreversible muscle necrosis, nerve damage, and limb dysfunction. Urgent fasciotomy is the definitive treatment to decompress the compartments. NSAIDs, elevation, ice, and imaging studies (like MRI) cause critical delays and are inappropriate in this acute setting. Discharging the patient would be a severe medical error.

Question 10787

Topic: 2. Trauma

A 35-year-old male sustains a midshaft clavicle fracture. Which of the following radiographic or clinical findings is the most significant predictor of nonunion with nonoperative management?

. <1 cm of shortening
. Male gender
. 100% fracture displacement
. Location in the medial third
. Presence of a skin abrasion

Correct Answer & Explanation

. <1 cm of shortening

Explanation

The most significant risk factors for nonunion in midshaft clavicle fractures include 100% displacement, shortening greater than 2 cm, and comminution. Advanced age and female gender are also associated risk factors.

Question 10788

Topic: 2. Trauma



An 80-year-old female with severe rheumatoid arthritis sustains a comminuted intra-articular distal humerus fracture (AO/OTA 13-C3). Radiographs show profound osteopenia. What is the most appropriate surgical management?

. Closed reduction and percutaneous pinning
. Open reduction and internal fixation with dual orthogonal plates
. Total elbow arthroplasty
. Hemiarthroplasty of the distal humerus
. Bridging external fixation

Correct Answer & Explanation

. Closed reduction and percutaneous pinning

Explanation

Total elbow arthroplasty (TEA) is the treatment of choice for elderly patients with complex, comminuted distal humerus fractures and poor bone quality, particularly in the setting of pre-existing rheumatoid arthritis. It allows for early mobilization and predictable pain relief compared to ORIF in osteoporotic bone.

Question 10789

Topic: 2. Trauma

A 25-year-old male sustains a closed, spiral fracture of the distal third of the humeral shaft (Holstein-Lewis fracture). Upon initial presentation in the emergency department, he has weak wrist extension and numbness in the first dorsal web space. What is the most appropriate next step in management?

. Immediate surgical exploration of the radial nerve
. Application of a coaptation splint and observation
. Electromyography (EMG) of the upper extremity
. Open reduction and internal fixation with nerve grafting
. Urgent MRI of the arm

Correct Answer & Explanation

. Immediate surgical exploration of the radial nerve

Explanation

A primary radial nerve palsy in the setting of a closed humeral shaft fracture should initially be managed expectantly with a coaptation splint and observation. Surgical exploration is indicated for open fractures, associated vascular injuries, or if the palsy develops after a closed reduction attempt.

Question 10790

Topic: 2. Trauma

A 22-year-old male presents with radial-sided wrist pain after a fall. Imaging reveals a displaced fracture of the proximal pole of the scaphoid. Why is this specific fracture pattern at a high risk for avascular necrosis (AVN)?

. The proximal pole lacks a cartilaginous covering
. The blood supply enters distally and flows in a retrograde fashion
. The proximal pole is primarily supplied by the anterior interosseous artery
. The radiocarpal ligaments tear and disrupt the volar blood supply
. Synovial fluid in the radiocarpal joint dissolves the fracture hematoma

Correct Answer & Explanation

. The proximal pole lacks a cartilaginous covering

Explanation

The scaphoid receives its primary blood supply from the dorsal carpal branch of the radial artery, which enters at the distal pole and flows retrograde to the proximal pole. Fractures at the proximal pole disrupt this delicate blood supply, leading to a high rate of avascular necrosis.

Question 10791

Topic: 2. Trauma

A 22-year-old cyclist sustains a closed midshaft clavicle fracture with 2.5 cm of shortening.

The patient asks about the expected outcome if he chooses non-operative management. Which of the following is the most likely functional deficit associated with non-operative treatment of significantly shortened midshaft clavicle fractures?

. Loss of terminal internal rotation
. High rate of brachial plexopathy
. Decreased shoulder endurance and strength
. Frozen shoulder syndrome
. Chronic acromioclavicular joint instability

Correct Answer & Explanation

. Loss of terminal internal rotation

Explanation

Midshaft clavicle fractures with shortening greater than 2 cm treated non-operatively are associated with decreased shoulder strength, rapid fatigability, and a higher risk of symptomatic nonunion.

Question 10792

Topic: 2. Trauma

A 30-year-old male sustains a closed spiral fracture of the distal third of the humeral shaft (Holstein-Lewis fracture). On presentation, he exhibits a complete radial nerve palsy. What is the most appropriate initial management?

. Functional bracing and observation of the nerve deficit
. Immediate open reduction, internal fixation, and nerve exploration
. External fixation and nerve grafting
. Closed reduction and spica casting
. Amputation and prosthetic fitting

Correct Answer & Explanation

. Functional bracing and observation of the nerve deficit

Explanation

Primary radial nerve palsies with closed humeral shaft fractures typically recover spontaneously (neurapraxia). Initial management is non-operative with functional bracing and clinical observation for 3-4 months.

Question 10793

Topic: Upper Extremity Trauma

A 21-year-old collegiate baseball pitcher reports medial elbow pain during the late cocking and early acceleration phases of throwing. MRI confirms a full-thickness tear of the anterior bundle of the ulnar collateral ligament (UCL). To correctly reconstruct this ligament, where must the ulnar tunnel be primarily centered?

. Olecranon tip
. Sublime tubercle
. Coronoid base
. Lateral epicondyle
. Radial tuberosity

Correct Answer & Explanation

. Olecranon tip

Explanation

The anterior bundle of the UCL is the primary restraint to valgus stress at the elbow, and it inserts distally on the sublime tubercle of the proximal ulna.

Question 10794

Topic: Upper Extremity Trauma
A 25-year-old rugby player sustains a Type V acromioclavicular (AC) joint separation, characterized by >100% superior displacement of the clavicle into the trapezius fascia. What is the most widely accepted surgical approach for this severe injury?
. Isolated repair of the acromioclavicular capsule
. Distal clavicle excision alone
. Surgical reconstruction of the coracoclavicular (CC) ligaments
. Closed reduction and percutaneous pinning of the AC joint
. Observation and physical therapy

Correct Answer & Explanation

. Surgical reconstruction of the coracoclavicular (CC) ligaments

Explanation

Type IV, V, and VI AC separations are indications for operative management due to severe displacement and soft tissue disruption. This requires robust reconstruction of the coracoclavicular (CC) ligaments.

Question 10795

Topic: 2. Trauma

A 24-year-old male is trapped under heavy machinery, resulting in a severe crush injury to his forearm. On examination, he has extreme pain with passive extension of his fingers. In acute compartment syndrome of the volar forearm, which muscle is most susceptible to irreversible ischemia and subsequent Volkmann's contracture?

. Flexor carpi radialis
. Pronator teres
. Palmaris longus
. Flexor digitorum profundus
. Flexor digitorum superficialis

Correct Answer & Explanation

. Flexor carpi radialis

Explanation

The deep compartment of the volar forearm is the most severely affected in ischemic contracture. The flexor digitorum profundus (FDP) and flexor pollicis longus (FPL) are the most profoundly involved muscles.

Question 10796

Topic: 2. Trauma

A 35-year-old male sustains a distal third spiral humeral shaft fracture (Holstein-Lewis). Upon arrival at the emergency department, he is unable to extend his wrist or fingers. Closed reduction and splinting are performed, but post-reduction examination shows no change in his neurologic status. What is the most appropriate next step in management?

. Immediate surgical exploration and internal fixation
. Observation and EMG at 6 weeks if no improvement
. Urgent MRI of the humerus
. Corticosteroid injection into the radial tunnel
. Radial nerve grafting

Correct Answer & Explanation

. Immediate surgical exploration and internal fixation

Explanation

Primary radial nerve palsy associated with a closed humeral shaft fracture is typically managed with observation, as 70-90% will spontaneously recover. Surgical exploration is indicated for open fractures, secondary nerve palsies (loss of function after reduction), or failure to improve clinically or on EMG by 3 to 4 months.

Question 10797

Topic: 2. Trauma

A 22-year-old male presents with a nonunion of a proximal pole scaphoid fracture 8 months after the initial injury. MRI reveals avascular necrosis (AVN) of the proximal pole. What is the most appropriate surgical management?

. Arthroscopic debridement and pinning
. Non-vascularized iliac crest bone graft
. Vascularized medial femoral condyle bone graft
. Proximal row carpectomy
. Four-corner fusion

Correct Answer & Explanation

. Arthroscopic debridement and pinning

Explanation

For a scaphoid nonunion with avascular necrosis of the proximal pole, a vascularized bone graft (such as the medial femoral condyle) is indicated to restore blood supply and promote healing. Non-vascularized grafts have a high failure rate in the presence of AVN.

Question 10798

Topic: 2. Trauma

Which of the following is an absolute indication for open reduction and internal fixation of an acute midshaft clavicle fracture?

. Shortening greater than 2 cm
. Displacement greater than 100%
. Open fracture
. Presence of a Z-type fragment
. Patient preference for earlier return to sport

Correct Answer & Explanation

. Shortening greater than 2 cm

Explanation

Open fracture, skin tenting leading to necrosis, and neurovascular compromise are absolute indications for ORIF of a midshaft clavicle fracture. Shortening and displacement are relative indications based on an increased risk of nonunion or symptomatic malunion.

Question 10799

Topic: 2. Trauma

A 6-year-old child sustains a Bado Type I Monteggia fracture-dislocation. Closed reduction of the ulna fracture is achieved, but the radial head remains anteriorly dislocated. What is the most likely blocking structure preventing radial head reduction?

. Biceps tendon
. Annular ligament
. Brachialis muscle
. Joint capsule
. Ulnar nerve

Correct Answer & Explanation

. Biceps tendon

Explanation

In Monteggia fracture-dislocations, the annular ligament can become interposed or wrapped around the radial head, acting as a physical block to closed reduction of the radiocapitellar joint.

Question 10800

Topic: 2. Trauma

Tension band wiring is an accepted treatment for simple transverse olecranon fractures. This fixation principle converts which type of force at the articular surface into compressive forces during active elbow flexion?

. Shear forces
. Torsional forces
. Distraction (tensile) forces
. Bending forces
. Axial loading forces

Correct Answer & Explanation

. Shear forces

Explanation

The tension band principle relies on placing fixation (wires) on the tension side (dorsal cortex) of the bone. During active triceps contraction and elbow flexion, the tensile forces are converted into dynamic compressive forces at the articular surface.

Test Yourself

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

On this Page