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2. Trauma MCQs

Practice Set 406 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 8101

Topic: 2. Trauma

A 22-year-old elite college basketball player sustains an inversion injury to his foot. Radiographs demonstrate an acute, non-displaced fracture of the fifth metatarsal at the metaphyseal-diaphyseal junction extending into the fourth-fifth intermetatarsal articulation.

To minimize the risk of nonunion and expedite his return to play, what is the best treatment option?

. Short leg walking boot for 6 weeks
. Non-weight-bearing cast for 6-8 weeks
. Intramedullary screw fixation
. Tension band wiring
. Primary bone grafting and plating

Correct Answer & Explanation

. Short leg walking boot for 6 weeks

Explanation

The clinical scenario and imaging describe a Jones fracture (Zone 2 fracture of the 5th metatarsal base). Because of the watershed blood supply in this region, these fractures are highly prone to delayed union and nonunion. In elite athletes, early intramedullary screw fixation is recommended to significantly reduce the time to union, lower the nonunion rate, and allow for a faster return to competitive sports compared to conservative cast immobilization.

Question 8102

Topic: 2. Trauma

A 40-year-old roofer falls 15 feet, sustaining a closed, displaced, intra-articular calcaneus fracture (Sanders Type III). Open reduction and internal fixation via an extensile lateral approach is planned. During the approach, which of the following structures is at greatest risk of iatrogenic injury if the full-thickness flap is not appropriately mobilized and protected?

. Sural nerve
. Superficial peroneal nerve
. Deep peroneal nerve
. Posterior tibial nerve
. Medial plantar nerve

Correct Answer & Explanation

. Sural nerve

Explanation

The extensile lateral approach is the standard workhorse approach for open reduction and internal fixation of displaced intra-articular calcaneus fractures. The subperiosteal flap must be elevated as a single full-thickness unit (including the periosteum, peroneal tendons, and sural nerve) to preserve its blood supply. The sural nerve crosses the lateral aspect of the hindfoot and is at highest risk of iatrogenic injury or neuroma formation at both the proximal (vertical) and distal (horizontal) limbs of the L-shaped incision.

Question 8103

Topic: 2. Trauma

A 21-year-old collegiate basketball player experiences acute lateral foot pain during practice. Radiographs reveal a transverse fracture of the fifth metatarsal at the metaphyseal-diaphyseal junction (Zone 2). To minimize the risk of nonunion and allow the fastest safe return to play, what is the most appropriate management?

. Non-weight-bearing in a short leg cast for 8 weeks
. Weight-bearing as tolerated in a stiff-soled shoe
. Intramedullary screw fixation
. Open reduction and crossed K-wire fixation
. Excision of the proximal fragment and peroneus brevis advancement

Correct Answer & Explanation

. Non-weight-bearing in a short leg cast for 8 weeks

Explanation

A fracture at the metaphyseal-diaphyseal junction of the fifth metatarsal (Zone 2) is a true Jones fracture. This area represents a vascular watershed zone, predisposing these fractures to delayed union and nonunion. In high-level or elite athletes, intramedullary screw fixation is considered the gold standard to significantly decrease the risk of nonunion, allow for an accelerated rehabilitation protocol, and provide a faster, more predictable return to play compared to nonoperative cast immobilization.

Question 8104

Topic: 2. Trauma

A 21-year-old collegiate basketball player presents with acute lateral foot pain after a sudden pivoting maneuver during practice. Radiographs and an MRI confirm an acute, non-displaced transverse fracture of the fifth metatarsal at the metaphyseal-diaphyseal junction (Zone 2). What is the recommended treatment to minimize his risk of nonunion and expedite his return to competitive play?

. Non-weight bearing in a short leg cast for 6 weeks.
. Weight-bearing as tolerated in a stiff-soled boot.
. Intramedullary screw fixation.
. Open reduction and internal fixation with a dynamic compression plate.
. Bone marrow aspirate concentrate (BMAC) injection and functional bracing.

Correct Answer & Explanation

. Non-weight bearing in a short leg cast for 6 weeks.

Explanation

Fractures of the fifth metatarsal metaphyseal-diaphyseal junction (Zone 2, Jones fractures) occur in a vascular watershed area and have a high propensity for delayed union or nonunion if treated non-operatively, reaching up to 15-30% in some series. In elite or highly competitive athletes, the standard of care to minimize the risk of nonunion, reduce the time to clinical union, and expedite the return to play is prompt operative fixation, most commonly utilizing a solid, solid-core intramedullary screw. Non-operative management with non-weight bearing casting carries an unacceptably high risk of prolonged absence from sports for elite athletes.

Question 8105

Topic: 2. Trauma

A 60-year-old male sustains a comminuted Mason Type III radial head fracture after falling onto an outstretched hand. Radiographs show significant displacement and articular depression. He has severe pain with forearm rotation and limited extension. Which of the following is the MOST appropriate initial management strategy?

. Closed reduction and immobilization for 4 weeks
. Excision of the radial head fragment
. Open reduction and internal fixation (ORIF) with low-profile plates/screws
. Radial head arthroplasty
. Initial aspiration and corticosteroid injection

Correct Answer & Explanation

. Closed reduction and immobilization for 4 weeks

Explanation

A Mason Type III radial head fracture is severely comminuted and displaced, often involving the entire radial head. While ORIF can be considered for reconstructible fractures (typically Type II), Type III fractures are often non-reconstructible, leading to poor outcomes with fixation due to persistent pain and stiffness. Excision of the radial head in a comminuted fracture is generally discouraged, especially in older patients, due to the risk of proximal radial migration, valgus instability, and subsequent elbow arthritis. Radial head arthroplasty is the preferred treatment for non-reconstructible Mason Type III fractures, especially in patients over 40-50 years of age, as it restores elbow stability, preserves forearm rotation, and prevents proximal migration of the radius. This intervention is critical for maintaining stability, particularly in the context of associated ligamentous injuries (Essex-Lopresti lesion, terrible triad) which must be ruled out.

Question 8106

Topic: Upper Extremity Trauma

A 30-year-old rugby player sustains an injury to his shoulder after falling directly onto the tip of his shoulder. Radiographs demonstrate a complete dislocation of the acromioclavicular (AC) joint with significant superior displacement of the clavicle, disrupting both the AC and coracoclavicular (CC) ligaments. The deltoid and trapezius muscles are detached from the distal clavicle. Which Rockwood classification type does this describe, and what is the MOST appropriate management?

. Type III; Closed reduction and sling immobilization
. Type IV; Open reduction and internal fixation
. Type V; Surgical stabilization (e.g., CC ligament reconstruction)
. Type VI; Coracoclavicular screw fixation
. Type III; Distal clavicle excision

Correct Answer & Explanation

. Type III; Closed reduction and sling immobilization

Explanation

The description of a complete dislocation of the AC joint with significant superior displacement of the clavicle, disruption of both AC and CC ligaments, AND detachment of the deltoid and trapezius muscles from the distal clavicle corresponds to a Rockwood Type V AC joint injury. This is a severe injury with gross instability. While Rockwood Type III injuries are often managed non-operatively, Types IV, V, and VI are generally treated surgically due to significant displacement and associated soft tissue disruption, leading to poor functional outcomes with non-operative management. Type IV involves posterior displacement of the clavicle through the trapezius. Type VI involves inferior displacement. For Type V, surgical stabilization, often involving CC ligament reconstruction or repair, is the recommended treatment to restore stability and function. Distal clavicle excision is typically for chronic AC joint arthritis, not acute instability.

Question 8107

Topic: 2. Trauma

A 16-year-old male sustains a supracondylar humerus fracture and is placed in a cast. Six hours later, he complains of excruciating pain in his forearm, disproportionate to the injury. His fingers are stiff, and passive extension of the fingers is exquisitely painful. Radial pulse is palpable, but capillary refill is sluggish. Which of the following is the MOST appropriate immediate management?

. Bivalve the cast and elevate the arm
. Administer stronger analgesics and monitor closely
. Perform an immediate forearm fasciotomy
. Obtain a compartment pressure measurement
. Remove the cast and apply a loose splint

Correct Answer & Explanation

. Bivalve the cast and elevate the arm

Explanation

The patient's symptoms (excruciating pain disproportionate to injury, pain with passive finger extension, stiff fingers, sluggish capillary refill, despite a palpable pulse) are highly suspicious for acute forearm compartment syndrome, a surgical emergency that can lead to irreversible muscle and nerve damage (Volkmann's ischemic contracture). While bivalving the cast and elevation are initial steps in some cases, with such clear clinical signs, immediate forearm fasciotomy is the definitive and most appropriate management to decompress the compartments and prevent permanent damage. Delaying for compartment pressure measurements, removing the cast without fasciotomy, or administering more analgesics are dangerous and can lead to devastating consequences. A palpable pulse does not rule out compartment syndrome, as compartment pressures often exceed diastolic pressure before arterial flow is completely obliterated.

Question 8108

Topic: 2. Trauma

A 5-year-old child falls from playground equipment, sustaining an isolated fracture of the mid-shaft of the ulna. There is no associated radial fracture or dislocation. What is the MOST likely associated injury that must be ruled out?

. Radial head dislocation (Monteggia equivalent)
. Distal radioulnar joint (DRUJ) dislocation (Galeazzi equivalent)
. Scaphoid fracture
. Elbow dislocation
. Proximal humerus fracture

Correct Answer & Explanation

. Radial head dislocation (Monteggia equivalent)

Explanation

An isolated fracture of the ulna shaft in a child is highly suspicious for a Monteggia equivalent injury, which involves an ulnar fracture with an associated radial head dislocation. The mechanism of injury often involves a fall, and the ulna fracture occurs, but the force continues to propagate, leading to disruption of the annular ligament and radial head displacement. It is crucial to carefully examine the elbow radiographs to ensure the radial head is reduced and aligned with the capitellum in all views. Failure to diagnose a radial head dislocation can lead to chronic pain and deformity. Galeazzi equivalent involves a radial shaft fracture and DRUJ dislocation. Scaphoid and humerus fractures are less likely directly associated.

Question 8109

Topic: 2. Trauma

A 22-year-old male sustains an open Monteggia fracture-dislocation (Type B2) after a motor vehicle accident. Radiographs confirm an anteriorly angulated ulnar shaft fracture and an anterior radial head dislocation. There is gross contamination of the wound. What is the MOST appropriate initial step in management?

. Immediate closed reduction and casting
. Thorough irrigation and debridement, followed by ORIF of the ulna and radial head reduction/stabilization
. Application of an external fixator for both radius and ulna
. Antibiotic prophylaxis only
. Radial head excision

Correct Answer & Explanation

. Immediate closed reduction and casting

Explanation

An open Monteggia fracture-dislocation is a severe injury requiring urgent surgical management. Given the open nature and gross contamination, the initial and MOST critical step is thorough irrigation and debridement (I&D) of the wound to prevent infection. Following debridement, stable fixation of the ulnar shaft fracture (ORIF) is performed, which often reduces and stabilizes the radial head spontaneously. If the radial head remains unstable after ulnar fixation, it needs to be stabilized (e.g., with temporary pinning or repair of the annular ligament). Antibiotic prophylaxis is essential but is secondary to I&D. Closed reduction and casting are contraindicated for open fractures. External fixation might be considered in severe cases, but ORIF is generally preferred for Monteggia. Radial head excision is generally avoided in young patients to preserve forearm rotation and length.

Question 8110

Topic: 2. Trauma

A 50-year-old factory worker complains of chronic, aching pain in his posterior elbow, exacerbated by direct pressure and repetitive elbow flexion/extension. Examination reveals a large, fluctuant, non-tender mass over the olecranon tip. He has no signs of infection. What is the MOST likely diagnosis and recommended management?

. Gouty tophus; Allopurinol
. Septic olecranon bursitis; Incision and drainage
. Olecranon stress fracture; Immobilization
. Olecranon bursitis; Activity modification, NSAIDs, elbow pads
. Lipoma; Observation

Correct Answer & Explanation

. Gouty tophus; Allopurinol

Explanation

The patient's presentation of a chronic, aching posterior elbow pain exacerbated by pressure and movement, with a large, fluctuant, non-tender mass over the olecranon tip and no signs of infection, is classic for non-septic (aseptic) olecranon bursitis. This is often caused by repetitive trauma or prolonged pressure. The initial management is conservative: activity modification, avoidance of direct pressure (e.g., with elbow pads), NSAIDs, and sometimes aspiration with corticosteroid injection (though aspiration alone can be therapeutic and diagnostic). Gouty tophus would be painful and could be aspirated for crystals. Septic bursitis would have signs of acute inflammation (redness, warmth, significant tenderness, fever) and usually requires I&D. Olecranon stress fracture presents with bone pain. Lipoma is less likely in this specific location and presentation.

Question 8111

Topic: 2. Trauma

A 40-year-old male with a history of intravenous drug use presents with a painful, erythematous, and swollen proximal forearm. He has diffuse tenderness and severe pain with passive stretch of the wrist and finger flexors. He appears systemically unwell. What is the MOST appropriate immediate management?

. Oral antibiotics and rest
. Elevate the arm and apply ice
. Immediate surgical fasciotomy of the forearm compartments
. Aspiration of the forearm for culture
. Start intravenous antibiotics and monitor

Correct Answer & Explanation

. Oral antibiotics and rest

Explanation

The patient's presentation (painful, swollen forearm, diffuse tenderness, severe pain with passive stretch of flexors, systemic unwellness, IV drug use history) is highly indicative of acute forearm compartment syndrome, possibly exacerbated by infection. This is a surgical emergency. Immediate surgical fasciotomy of the forearm compartments is critical to decompress the muscles and nerves, preventing irreversible ischemic damage (Volkmann's contracture). While intravenous antibiotics are necessary, they are secondary to surgical decompression. Aspiration may provide a diagnosis but delays definitive treatment. Oral antibiotics, elevation, and ice are wholly inadequate for acute compartment syndrome.

Question 8112

Topic: 2. Trauma

A 10-year-old child presents with a painful, swollen, and warm elbow. He has a fever and refuses to move his arm. There is tenderness over the olecranon fossa. Laboratory tests reveal elevated white blood cell count and C-reactive protein. Aspiration of the elbow joint yields cloudy fluid. What is the MOST likely diagnosis?

. Septic arthritis
. Juvenile idiopathic arthritis
. Fracture of the distal humerus
. Olecranon bursitis
. Osteochondritis dissecans

Correct Answer & Explanation

. Septic arthritis

Explanation

The child's presentation of a painful, swollen, warm elbow, refusal to move the arm (pseudoparalysis), fever, elevated inflammatory markers, and cloudy aspirate is highly indicative of septic arthritis. Septic arthritis is a pediatric emergency requiring urgent diagnosis and treatment (joint aspiration and surgical irrigation/debridement with antibiotics) to prevent joint destruction. Juvenile idiopathic arthritis is a chronic inflammatory condition, usually without acute fever or systemic illness. A fracture would have a history of trauma. Olecranon bursitis would be superficial to the joint. Osteochondritis dissecans is chronic, localized pain, not acute infection.

Question 8113

Topic: 2. Trauma

A 65-year-old female presents with a 4-part proximal humerus fracture. According to Hertel's criteria, which of the following radiographic findings is the STRONGEST individual predictor of humeral head ischemia?

. Metaphyseal head extension < 8 mm
. Medial hinge disruption > 2 mm
. Angular displacement > 45 degrees
. Greater tuberosity displacement > 1 cm
. Presence of a split humeral head

Correct Answer & Explanation

. Metaphyseal head extension < 8 mm

Explanation

Hertel et al. described radiographic criteria for predicting humeral head ischemia following proximal humerus fractures. The strongest positive predictive value for ischemia is the combination of an anatomic neck fracture pattern, a medial hinge disruption > 2 mm, and a metaphyseal head extension (calcar segment attached to the articular surface) of < 8 mm. Among the individual factors, a metaphyseal extension of < 8 mm is the single best predictor of ischemia.

Question 8114

Topic: 2. Trauma

A 22-year-old mountain biker falls over his handlebars and sustains a midshaft clavicle fracture. Which of the following findings is considered an absolute indication for acute open reduction and internal fixation?

. 10 mm of displacement
. 15 mm of shortening
. Open fracture
. Presence of a butterfly fragment
. Concomitant non-displaced scapular body fracture

Correct Answer & Explanation

. 10 mm of displacement

Explanation

Absolute indications for operative fixation of a clavicle fracture include open fractures, fractures with associated neurovascular compromise, and severe skin tenting that threatens the integrity of the overlying skin. Relative indications include shortening > 2 cm (20 mm), 100% displacement, symptomatic nonunions, and multiple injuries (e.g., floating shoulder with a displaced scapular neck fracture).

Question 8115

Topic: 2. Trauma

A 55-year-old woman falls and sustains a displaced 4-part proximal humerus fracture.

According to Hertel's criteria, which of the following radiographic findings is the most reliable predictor of subsequent avascular necrosis (AVN) of the humeral head?

. Angular displacement > 45 degrees
. Medial hinge disruption > 2 mm
. Greater tuberosity displacement > 1 cm
. Metaphyseal head extension > 8 mm
. Shortening of the surgical neck > 5 mm

Correct Answer & Explanation

. Angular displacement > 45 degrees

Explanation

Hertel et al. described reliable predictors for ischemia and subsequent AVN in proximal humerus fractures. The most critical predictors of ischemia are a medial calcar hinge disruption greater than 2 mm, a metaphyseal head extension (calcar length attached to the articular segment) of less than 8 mm, and an anatomic neck fracture pattern. Metaphyseal head extension greater than 8 mm (Option 3) is actually protective against AVN, as it indicates better preservation of the blood supply.

Question 8116

Topic: 2. Trauma

A 40-year-old man falls from a ladder and sustains a 'terrible triad' injury of the elbow. Intraoperatively, the surgeon fixes the coronoid fracture, replaces the highly comminuted radial head with an arthroplasty, and robustly repairs the lateral collateral ligament (LCL) complex to the lateral epicondyle. Upon testing stability, the elbow remains congruous in flexion but persistently subluxates posteriorly when extended beyond 30 degrees. What is the most appropriate next step in management?

. Apply a hinged external fixator
. Repair the medial collateral ligament (MCL)
. Perform an olecranon osteotomy to assess the joint
. Immobilize the elbow in 90 degrees of flexion for 6 weeks
. Revise the radial head to a larger size to overstuff the joint

Correct Answer & Explanation

. Apply a hinged external fixator

Explanation

The standard surgical protocol for a terrible triad injury of the elbow involves sequential restoration of stabilizers: coronoid fixation (or anterior capsule repair), radial head fixation or replacement, and LCL repair. If the elbow remains unstable in extension after these lateral and anterior structures are restored, the medial collateral ligament (MCL) should be repaired. Hinged external fixation is typically reserved for residual instability after all primary ligamentous repairs, including the MCL, have been completed.

Question 8117

Topic: 2. Trauma

A 32-year-old male wrestler sustains a closed, spiral fracture of the distal third of the humeral shaft. On presentation in the emergency department, he is unable to extend his wrist or fingers and has numbness in the first dorsal web space.

According to the American Academy of Orthopaedic Surgeons (AAOS) guidelines, what is the most appropriate initial management for this nerve injury?

. Immediate surgical exploration of the radial nerve
. Application of a coaptation splint or functional brace and observation of the nerve palsy
. Open reduction internal fixation of the humerus without nerve exploration
. Immediate nerve transfer (e.g., median nerve branches to radial nerve)
. External fixation of the humerus to prevent further nerve stretching

Correct Answer & Explanation

. Immediate surgical exploration of the radial nerve

Explanation

A primary radial nerve palsy associated with a closed humeral shaft fracture (even a Holstein-Lewis distal third spiral fracture) is not an absolute indication for immediate surgical exploration. The vast majority of these lesions are neurapraxias or axonotmeses that will recover spontaneously. The standard of care is functional bracing or splinting with observation. Exploration is indicated if the fracture is open, if the palsy develops secondarily after a closed reduction, or if there is no clinical or EMG sign of recovery at 3 to 4 months.

Question 8118

Topic: 2. Trauma

A 68-year-old woman sustains a 3-part proximal humerus fracture after a fall.

When evaluating the initial trauma radiographs, which of the following findings is the strongest independent predictor for the subsequent development of avascular necrosis (AVN) of the humeral head?

. Displacement of the greater tuberosity > 5 mm
. Angulation of the humeral head > 20 degrees
. Superior translation of the humeral head > 3 mm
. Posteromedial hinge disruption with a calcar length of less than 8 mm
. Valgus impaction of the humeral head into the metaphysis

Correct Answer & Explanation

. Displacement of the greater tuberosity > 5 mm

Explanation

According to Hertel's criteria, the most reliable radiographic predictors for ischemia and subsequent AVN of the humeral head after a proximal humerus fracture are a posteromedial hinge disruption, a metaphyseal head extension (calcar length) of less than 8 mm, and an anatomic neck fracture pattern. The disruption of the medial hinge and short calcar signify profound disruption of the ascending branch of the anterior humeral circumflex artery and intraosseous collateral blood supply.

Question 8119

Topic: 2. Trauma

A 24-year-old male presents with radial-sided wrist pain after a fall. Initial radiographs are negative, but an MRI demonstrates a nondisplaced fracture of the proximal pole of the scaphoid. The patient is at high risk for avascular necrosis due to the unique vascular anatomy of the scaphoid. The predominant blood supply to the proximal pole enters through which of the following regions?

. Volar tubercle
. Dorsal ridge
. Distal pole articular surface
. Scapholunate interosseous ligament
. Volar radiocarpal ligaments

Correct Answer & Explanation

. Volar tubercle

Explanation

The major blood supply to the scaphoid (approximately 70-80%) arises from the radial artery and enters via the dorsal ridge. This dorsal supply perfuses the proximal pole in a retrograde fashion. Consequently, fractures at the proximal pole have a very high risk of avascular necrosis and nonunion due to interruption of this tenuous retrograde blood flow. A minor blood supply (20-30%) enters via the volar tubercle, supplying only the distal pole.

Question 8120

Topic: 2. Trauma

A 24-year-old male presents with severe radial-sided wrist pain after falling on an outstretched hand. Radiographs reveal a displaced fracture of the proximal pole of the scaphoid. The high risk of avascular necrosis in this specific fracture pattern is primarily due to the retrograde blood supply originating from branches of which of the following arteries?

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

Correct Answer & Explanation

. Ulnar artery

Explanation

The scaphoid receives approximately 70-80% of its blood supply from the dorsal carpal branch of the radial artery, which enters the scaphoid at the dorsal ridge (distal pole) and supplies the proximal pole in a retrograde fashion. Proximal pole fractures have a notoriously high risk of nonunion and avascular necrosis because the fracture disrupts this tenuous retrograde intraosseous blood flow.

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