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2. Trauma MCQs

Practice Set 89 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 1761

Topic: 2. Trauma

When treating a comminuted distal humerus fracture, what do modern biomechanical studies indicate regarding the placement of medial and lateral plates in an orthogonal (90-degree) configuration versus a parallel (180-degree) configuration?

. Orthogonal plating has vastly superior torsional stiffness
. Parallel plating offers superior resistance to sagittal bending
. Orthogonal plating leads to higher rates of ulnar nerve palsy
. Neither configuration has proven biomechanical superiority when fixed properly
. Parallel plating prevents varus collapse significantly better

Correct Answer & Explanation

. Neither configuration has proven biomechanical superiority when fixed properly

Explanation

Modern biomechanical and clinical studies have shown that parallel and orthogonal plating constructs offer comparable stability for distal humerus fractures, provided the principles of stable fracture fixation (e.g., interdigitation of distal screws) are met.

Question 1762

Topic: 2. Trauma

A patient with a severe crush injury to the forearm develops an acute compartment syndrome. During volar fasciotomy, which muscle group represents the critical deep compartment that must be released to prevent ischemic contracture?

. Flexor carpi ulnaris
. Flexor digitorum superficialis
. Flexor digitorum profundus and flexor pollicis longus
. Pronator teres and flexor carpi radialis
. Brachioradialis

Correct Answer & Explanation

. Flexor digitorum profundus and flexor pollicis longus

Explanation

The flexor digitorum profundus (FDP) and flexor pollicis longus (FPL) reside in the deep volar compartment of the forearm. This compartment is highly vulnerable to ischemia and must be thoroughly released to prevent Volkmann's ischemic contracture.

Question 1763

Topic: 2. Trauma

In the radiographic evaluation of a suspected Monteggia fracture in an adult, which line must invariably align with the capitellum on all views to confirm a reduced radiocapitellar joint?

. Radiocapitellar line
. Anterior humeral line
. Proximal radioulnar line
. Coronoid line
. Olecranon-capitellar axis

Correct Answer & Explanation

. Radiocapitellar line

Explanation

A line drawn through the center of the radial shaft and head (radiocapitellar line) must bisect the center of the capitellum on all radiographic views, regardless of the degree of elbow flexion, to confirm an anatomic joint reduction.

Question 1764

Topic: 2. Trauma

A 28-year-old male requires a free vascularized fibular graft for a 6 cm bone defect following an infected nonunion of the radial diaphysis. To which forearm artery is the peroneal artery most commonly anastomosed during this procedure?

. Ulnar artery
. Radial artery
. Common interosseous artery
. Anterior interosseous artery
. Posterior interosseous artery

Correct Answer & Explanation

. Radial artery

Explanation

When performing a free vascularized fibular graft for a large radial defect, the peroneal artery pedicle is typically anastomosed to the radial artery due to its excellent anatomical proximity and suitable vessel caliber.

Question 1765

Topic: 2. Trauma

A 35-year-old manual laborer sustains a closed, extra-articular distal-third diaphyseal fracture of the humerus (Holstein-Lewis). On initial presentation, he exhibits a complete radial nerve palsy. What is the most appropriate initial management?

. Immediate open exploration of the radial nerve and ORIF
. Closed reduction and application of a functional fracture brace
. External fixation of the humerus
. Immediate magnetic resonance imaging to evaluate the nerve
. Electromyography (EMG) studies prior to any intervention

Correct Answer & Explanation

. Closed reduction and application of a functional fracture brace

Explanation

A closed Holstein-Lewis fracture with a primary (pre-manipulation) radial nerve palsy is typically managed with closed reduction and functional bracing. Immediate exploration is reserved for open fractures, irreducible fractures, or secondary palsies.

Question 1766

Topic: 2. Trauma

A 35-year-old male sustains a Bado Type II Monteggia fracture-dislocation. Following closed reduction of the radial head, open reduction and internal fixation of the ulnar fracture is planned. For optimal biomechanical stability, where should the plate be applied on the ulna?

. Anterior surface
. Medial surface
. Posterior (tension) surface
. Lateral surface
. Volar surface

Correct Answer & Explanation

. Posterior (tension) surface

Explanation

A Bado Type II Monteggia involves posterior dislocation of the radial head and a posteriorly angulated ulnar fracture. Placing the plate on the posterior surface of the ulna utilizes the tension band principle to counter the deforming forces.

Question 1767

Topic: 2. Trauma

A 78-year-old female with osteoporosis presents with an AO/OTA 13C3 (comminuted, intra-articular) distal humerus fracture. Compared to open reduction and internal fixation (ORIF), primary Total Elbow Arthroplasty (TEA) for this specific patient profile provides which of the following advantages?

. Lower lifetime risk of implant loosening
. Absence of lifting restrictions postoperatively
. Decreased rates of postoperative ulnar neuropathy
. More predictable functional outcome and lower early reoperation rate
. Better preservation of extensor mechanism strength

Correct Answer & Explanation

. More predictable functional outcome and lower early reoperation rate

Explanation

In elderly patients with severe osteopenia and comminuted distal humerus fractures, TEA offers a more predictable short-to-midterm functional outcome and lower early reoperation rates compared to ORIF, albeit with a lifelong 5-lb lifting restriction.

Question 1768

Topic: 2. Trauma

A 22-year-old trauma patient undergoes ORIF for diaphyseal fractures of the radius and ulna. Postoperatively, he develops a dense proximal radioulnar synostosis. Which of the following intraoperative factors is the most recognized risk factor for developing this complication?

. Use of locking plates instead of dynamic compression plates
. Failure to use a bone graft
. Fixation of the ulna prior to the radius
. Operating through a single incisional approach for both bones
. Immobilization in supination for 2 weeks postoperatively

Correct Answer & Explanation

. Operating through a single incisional approach for both bones

Explanation

Operating on both the radius and ulna through a single surgical incision significantly increases the risk of cross-union (synostosis). Fractures at the same level and significant soft tissue trauma are also major risk factors.

Question 1769

Topic: 2. Trauma

A 45-year-old male sustains an isolated, closed fracture of the ulnar shaft (nightstick fracture) after blocking a blunt object. Radiographs show a transverse fracture in the middle third. Nonoperative management with functional bracing is appropriate if displacement and angulation are below which of the following thresholds?

. < 50% displacement and < 10 degrees of angulation
. < 100% displacement and < 20 degrees of angulation
. < 25% displacement and < 5 degrees of angulation
. < 50% displacement and < 20 degrees of angulation
. < 10% displacement and < 5 degrees of angulation

Correct Answer & Explanation

. < 50% displacement and < 10 degrees of angulation

Explanation

Isolated ulnar shaft fractures can be successfully treated nonoperatively with a functional brace if there is less than 50% displacement and less than 10 degrees of angulation in any plane.

Question 1770

Topic: 2. Trauma

During ORIF of a bicolumnar distal humerus fracture, a surgeon elects to place parallel locking plates based on the principles described by O'Driscoll. Which of the following is a key biomechanical requirement of parallel plating in the distal humerus?

. Screws in the distal fragments should interdigitate and maximize bone purchase from medial to lateral
. The plates must be placed at exactly a 90-degree orthogonal angle to one another
. The medial plate must be placed on the posterior aspect of the medial epicondyle
. Distal screws must be non-locking to allow for dynamic articular compression
. The construct relies entirely on the olecranon osteotomy for coronal plane stability

Correct Answer & Explanation

. Screws in the distal fragments should interdigitate and maximize bone purchase from medial to lateral

Explanation

A key principle of parallel plating for distal humerus fractures is that the distal screws should interdigitate, acting as an architectural arch that maximizes fixation in the dense subchondral bone of the distal articular block.

Question 1771

Topic: 2. Trauma

When performing open reduction and internal fixation of a diaphyseal fracture of the radius using a 3.5-mm dynamic compression plate (DCP), what is the minimum recommended number of cortical purchases required on each side of the fracture to ensure adequate construct stiffness and avoid fixation failure?

. 4 cortices
. 6 cortices
. 8 cortices
. 10 cortices
. 12 cortices

Correct Answer & Explanation

. 6 cortices

Explanation

For diaphyseal fractures of the forearm, biomechanical studies and clinical guidelines recommend a minimum of 6 cortices (typically three bicortical screws) of fixation on each side of the fracture when using a 3.5-mm plate.

Question 1772

Topic: 2. Trauma
A 6-year-old boy presents to the emergency department after a playground fall. Radiographs demonstrate a metaphyseal fracture of the proximal ulna with an associated lateral dislocation of the radial head. According to the Bado classification, what type of Monteggia lesion is this?
. Bado Type I
. Bado Type II
. Bado Type III
. Bado Type IV
. Bado Type V

Correct Answer & Explanation

. Bado Type III

Explanation

A Bado Type III Monteggia fracture is characterized by a fracture of the ulnar metaphysis with a lateral dislocation of the radial head. This pattern is seen almost exclusively in the pediatric population.

Question 1773

Topic: 2. Trauma

A 50-year-old male requires revision ORIF for a distal humerus nonunion. The surgeon chooses to use a Triceps-Reflecting Anconeus Pedicle (TRAP) approach. What is the primary biomechanical advantage of the TRAP approach compared to an olecranon osteotomy?

. It maintains the continuity of the triceps insertion, allowing for earlier active extension without risking osteotomy nonunion
. It completely denervates the anconeus, reducing postoperative muscle spasms
. It provides superior visualization of the anterior articular surface of the capitellum
. It allows for an internervous approach that completely spares the ulnar nerve from any dissection
. It preserves the lateral collateral ligament origin entirely attached to the triceps flap

Correct Answer & Explanation

. It maintains the continuity of the triceps insertion, allowing for earlier active extension without risking osteotomy nonunion

Explanation

The TRAP approach mobilizes the triceps and anconeus as a continuous flap, avoiding an olecranon osteotomy. This eliminates the risk of osteotomy nonunion and hardware prominence while allowing preservation of the extensor mechanism's broad fascial continuity.

Question 1774

Topic: 2. Trauma

A 25-year-old male suffers a Galeazzi fracture. The distal fragment of the radius is displaced volarly and proximally. Which of the following muscles acts as the primary deforming force pulling the distal radius fragment volarly and ulnarly, necessitating rigid internal fixation?

. Pronator Quadratus
. Brachioradialis
. Flexor Carpi Radialis
. Pronator Teres
. Flexor Pollicis Longus

Correct Answer & Explanation

. Pronator Quadratus

Explanation

In a Galeazzi fracture, the pronator quadratus exerts a strong volar and ulnar pull on the distal radial fragment. The brachioradialis contributes to proximal migration (shortening).

Question 1775

Topic: 2. Trauma

An 80-year-old sedentary female sustains a highly comminuted intra-articular distal humerus fracture (AO/OTA 13-C3). Which treatment modality provides the most reliable early return of functional range of motion and the lowest short-term reoperation rate in this demographic?

. Cast immobilization with early functional bracing
. Open reduction and internal fixation with orthogonal plating
. Open reduction and internal fixation with parallel plating
. Total elbow arthroplasty
. Hemiarthroplasty

Correct Answer & Explanation

. Total elbow arthroplasty

Explanation

In elderly, low-demand patients with osteoporotic comminuted distal humerus fractures, total elbow arthroplasty (TEA) provides reliable early ROM and lower short-term reoperation rates compared to ORIF. ORIF in this population is associated with a high rate of hardware failure, nonunion, and stiffness.

Question 1776

Topic: 2. Trauma

A 25-year-old male sustains an isolated ulnar shaft fracture after sustaining a direct blow. Which of the following is an accepted indication for acute open reduction and internal fixation (ORIF) of an isolated ulnar shaft 'nightstick' fracture?

. Displacement of 20%
. Angulation of 5 degrees
. Fracture located in the distal third
. Displacement greater than 50%
. Intact interosseous membrane

Correct Answer & Explanation

. Displacement greater than 50%

Explanation

Non-operative management of isolated ulnar shaft fractures is successful if displacement is <50% and angulation is <10 degrees. Fractures with >50% displacement or >10 degrees of angulation, especially in the proximal third, have a high nonunion rate and require ORIF.

Question 1777

Topic: 2. Trauma

A 34-year-old male undergoes surgical fixation of a both-bone forearm fracture. The surgeon utilizes a single dorsal incision (Boyd approach) to address both fractures. What is the most significant complication associated with this specific surgical approach?

. Nonunion of the radius
. Radioulnar synostosis
. Persistent posterior interosseous nerve palsy
. Median nerve transection
. Early hardware failure

Correct Answer & Explanation

. Radioulnar synostosis

Explanation

Using a single incision for both-bone forearm fractures significantly increases the risk of radioulnar synostosis by allowing the fracture hematomas to communicate. Current standards dictate using separate incisions (e.g., volar Henry for radius, direct ulnar approach for ulna) to minimize this risk.

Question 1778

Topic: Upper Extremity Trauma

A 50-year-old male presents with an intra-articular distal humerus fracture. The surgeon elects to perform an olecranon osteotomy for maximal articular exposure. Which type of olecranon osteotomy provides the highest inherent biomechanical stability upon repair?

. Transverse osteotomy at the bare area
. Oblique osteotomy from dorsal-proximal to volar-distal
. Chevron osteotomy with the apex pointing distally
. Chevron osteotomy with the apex pointing proximally
. Step-cut osteotomy

Correct Answer & Explanation

. Chevron osteotomy with the apex pointing distally

Explanation

A chevron osteotomy with the apex pointing distally is preferred for olecranon osteotomies because it provides excellent inherent rotational and translational stability upon reduction. This osteotomy is typically performed at the bare area of the greater sigmoid notch.

Question 1779

Topic: 2. Trauma

What is the optimal plate fixation construct for a diaphyseal both-bone forearm fracture in a young, healthy adult to achieve primary bone healing?

. Bridge plating with a locking plate
. Compression plating utilizing a 3.5 mm LC-DCP
. Intramedullary nailing
. Single plate spanning both bones
. External fixation

Correct Answer & Explanation

. Compression plating utilizing a 3.5 mm LC-DCP

Explanation

Diaphyseal forearm fractures are treated as articular-equivalent fractures requiring anatomic reduction and absolute stability. Compression plating with 3.5 mm plates provides absolute stability, leading to primary bone healing without extensive callus formation.

Question 1780

Topic: Upper Extremity Trauma



When performing a paratricipital (Alonso-Llames) approach for a distal humerus extra-articular fracture, which of the following best describes the management of the triceps mechanism?

. The triceps is split completely down the midline
. The triceps insertion is osteotomized with the olecranon
. The triceps is elevated off the posterior humerus and retracted medially and laterally
. The triceps is detached from its olecranon insertion and reflected proximally
. The triceps is split laterally and retracted medially

Correct Answer & Explanation

. The triceps is elevated off the posterior humerus and retracted medially and laterally

Explanation

The paratricipital approach leaves the triceps insertion intact while creating windows on the medial and lateral borders of the triceps. The triceps muscle belly is elevated off the posterior humerus, allowing visualization of the extra-articular distal humerus.

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