Menu

2. Trauma MCQs

Practice Set 144 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 2861

Topic: 2. Trauma

A 40-year-old male sustains a Bado Type II Monteggia fracture-dislocation. Based on this specific injury pattern, what additional associated injury is most likely to be present?

. Anterior interosseous nerve palsy
. Radial head or neck fracture
. Distal radioulnar joint (DRUJ) dislocation
. Median nerve entrapment
. Brachial artery transection

Correct Answer & Explanation

. Radial head or neck fracture

Explanation

Bado Type II (posterior) Monteggia fractures in adults are complex injuries highly associated with radial head and neck fractures. They are often considered variants of fracture-dislocations that share features with terrible triad injuries.

Question 2862

Topic: Upper Extremity Trauma

During open reduction and internal fixation of a radial head fracture in a terrible triad injury, screws are placed in the 'safe zone' to prevent impingement. Which of the following accurately describes this zone?

. A 90-degree arc directly medial
. A 110-degree arc centered laterally with the forearm in neutral
. A 120-degree arc centered anteriorly
. A 90-degree arc centered posteriorly
. A 180-degree arc corresponding to the entire anterior half

Correct Answer & Explanation

. A 110-degree arc centered laterally with the forearm in neutral

Explanation

The safe zone for radial head hardware placement is a 90 to 110-degree non-articulating arc on the lateral aspect of the radial head. This zone avoids impingement on the lesser sigmoid notch of the ulna during forearm pronation and supination.

Question 2863

Topic: 2. Trauma
A 25-year-old female presents with a closed Bado Type I Monteggia fracture and an isolated inability to extend her fingers and thumb at the metacarpophalangeal joints. What is the most appropriate management of her nerve injury?
. Immediate exploration and nerve graft
. Observation for 3 to 6 months
. Acute nerve transposition
. Tendon transfers at 2 weeks
. Routine EMG testing at 1 week post-injury

Correct Answer & Explanation

. Observation for 3 to 6 months

Explanation

Posterior interosseous nerve (PIN) palsy is the most common neurologic injury associated with Bado I and III Monteggia fractures. It is almost always a neuropraxia that recovers spontaneously, warranting observation for 3 to 6 months before considering exploration.

Question 2864

Topic: Upper Extremity Trauma

Which of the following best describes the typical mechanism of injury resulting in a terrible triad of the elbow?

. Axial load, valgus force, and posterolateral rotation
. Axial load, varus force, and posteromedial rotation
. Direct blow to the posterior olecranon with a flexed elbow
. Hyperflexion with an external rotation moment
. Axial traction with extreme forearm pronation

Correct Answer & Explanation

. Axial load, valgus force, and posterolateral rotation

Explanation

The terrible triad (elbow dislocation, radial head fracture, coronoid fracture) characteristically results from a fall onto an outstretched hand causing an axial load, a valgus force, and posterolateral rotation.

Question 2865

Topic: 2. Trauma

In a terrible triad injury, the coronoid fracture is often a small transverse tip fragment (Regan-Morrey Type I or II). What is the primary biomechanical rationale for surgically stabilizing this small fragment?

. To restore perfect articular congruity and prevent early arthritis
. To securely reattach the brachialis tendon
. To restore the anterior capsular insertion and prevent posterior subluxation
. To serve as a buttress for the medial collateral ligament
. To prevent proximal migration of the radius

Correct Answer & Explanation

. To restore the anterior capsular insertion and prevent posterior subluxation

Explanation

Small tip fractures of the coronoid involve the insertion of the anterior joint capsule. Repairing these fragments (often via suture lasso) restores the anterior capsular restraint, which is crucial for preventing recurrent posterior subluxation of the elbow.

Question 2866

Topic: 2. Trauma

A 6-year-old boy presents to the emergency department with a closed Bado Type I Monteggia fracture. What is the standard initial treatment of choice for this patient?

. Open reduction internal fixation of the ulna with a plate
. Closed reduction of the ulna and radial head, followed by casting
. Immediate radial head excision
. Percutaneous pinning of the radial head only
. Flexible intramedullary nailing of the radius

Correct Answer & Explanation

. Closed reduction of the ulna and radial head, followed by casting

Explanation

Unlike adult Monteggia fractures which require rigid internal fixation, pediatric Monteggia fractures can almost always be successfully managed non-operatively with closed reduction and long-arm casting.

Question 2867

Topic: 2. Trauma
A Bado Type III Monteggia fracture, characterized by lateral dislocation of the radial head, is most frequently associated with which type of ulnar fracture?
. Distal third transverse fracture
. Proximal metaphyseal greenstick fracture
. Comminuted olecranon articular fracture
. Coronoid process avulsion
. Midshaft spiral fracture

Correct Answer & Explanation

. Proximal metaphyseal greenstick fracture

Explanation

Bado Type III fractures predominantly occur in pediatric populations. They are typically associated with a greenstick fracture of the proximal ulnar metaphysis along with a lateral radial head dislocation.

Question 2868

Topic: Upper Extremity Trauma

Following a stable and anatomic surgical reconstruction of a terrible triad injury, what is the most widely recommended early rehabilitation protocol?

. Rigid immobilization in full extension for 6 weeks
. Early active range of motion with the forearm in pronation
. Early active range of motion with the forearm in supination
. Immobilization at 90 degrees flexion and full supination for 4 weeks
. Immediate aggressive passive stretching by a therapist

Correct Answer & Explanation

. Early active range of motion with the forearm in pronation

Explanation

Early active motion is crucial to prevent stiffness. Performing exercises with the forearm in pronation tightens the intact medial structures and protects the repaired lateral collateral ligament (LCL) from varus stress.

Question 2869

Topic: Upper Extremity Trauma

An adult patient undergoes open reduction and internal fixation of a Bado Type I Monteggia fracture. Intraoperatively, after plating the ulna, the radial head remains anteriorly dislocated. What is the most common cause of this failure of reduction?

. Annular ligament interposition
. A concurrent terrible triad injury
. Malreduction (often shortening or angulation) of the ulnar fracture
. Radial nerve entrapment within the joint
. Undiagnosed Essex-Lopresti lesion

Correct Answer & Explanation

. Malreduction (often shortening or angulation) of the ulnar fracture

Explanation

The radial head follows the alignment of the ulna. If the radial head fails to reduce in a Monteggia fracture, the most common reason is that the ulnar length, alignment, or rotation has not been anatomically restored.

Question 2870

Topic: Upper Extremity Trauma

During a radial head replacement in a terrible triad injury, which anatomical landmark is best used to determine the correct proximal-to-distal height of the radial head implant?

. The proximal edge of the lesser sigmoid notch of the ulna
. The inferior pole of the medial epicondyle
. The tip of the olecranon
. The level of the radial styloid
. The sublime tubercle

Correct Answer & Explanation

. The proximal edge of the lesser sigmoid notch of the ulna

Explanation

The articulating margin of the radial head implant should sit level with the proximal edge of the lesser sigmoid notch of the ulna. This ensures proper tracking and avoids overstuffing or under-sizing the joint.

Question 2871

Topic: 2. Trauma

A patient presents with an anteromedial facet fracture of the coronoid process. This specific fracture pattern is pathognomonic for which specific mechanism of elbow instability?

. Valgus posterolateral rotatory instability
. Varus posteromedial rotatory instability
. Anterior olecranon fracture-dislocation
. Isolated medial collateral ligament avulsion
. Longitudinal radioulnar dissociation

Correct Answer & Explanation

. Varus posteromedial rotatory instability

Explanation

Anteromedial facet fractures of the coronoid result from a varus force combined with posteromedial rotation. This injury pattern typically involves LCL rupture and leads to severe varus posteromedial rotatory instability.

Question 2872

Topic: 2. Trauma

A 45-year-old male undergoes complex surgical fixation for a terrible triad injury. Which of the following prophylactic measures is recommended to reduce his significant risk of developing heterotopic ossification (HO)?

. Low molecular weight heparin for 2 weeks post-operatively
. Prophylactic indomethacin or single-fraction localized radiation
. High-dose systemic corticosteroids for 5 days
. Continuous passive motion (CPM) machine usage for 24 hours/day
. High-dose Vitamin C (500mg daily) for 6 weeks

Correct Answer & Explanation

. Prophylactic indomethacin or single-fraction localized radiation

Explanation

Complex elbow trauma carries a high risk of heterotopic ossification. Prophylaxis with NSAIDs (such as indomethacin) or a single localized fraction of radiation is standard to mitigate this risk.

Question 2873

Topic: 2. Trauma

A 32-year-old male sustains a Bado Type I Monteggia fracture-dislocation. Following anatomic rigid plate fixation of the ulna, intraoperative fluoroscopy reveals that the radial head remains subluxated anteriorly. What is the most likely cause of this persistent subluxation?

. Interposition of the medial collateral ligament
. Inadequate restoration of the ulnar length or anatomic bow
. Entrapment of the posterior interosseous nerve (PIN)
. Unrecognized disruption of the interosseous membrane
. Failure to repair the annular ligament primarily

Correct Answer & Explanation

. Inadequate restoration of the ulnar length or anatomic bow

Explanation

In Monteggia fractures, the radial head should spontaneously reduce once the ulnar anatomy is perfectly restored. Persistent subluxation is most commonly caused by malreduction of the ulna, particularly a failure to restore its length or anatomic apex-posterior bow.

Question 2874

Topic: 2. Trauma
Which of the following describes the most appropriate management for a closed Bado Type III Monteggia fracture in a 6-year-old child who develops a complete posterior interosseous nerve (PIN) palsy upon presentation?
. Immediate open reduction of the radial head and nerve exploration
. Closed reduction, casting, and clinical observation of the nerve
. Urgent nerve decompression followed by delayed ulnar plating
. EMG testing within 24 hours to determine the necessity of surgical repair
. Open reduction of the ulna only with intraoperative nerve grafting

Correct Answer & Explanation

. Closed reduction, casting, and clinical observation of the nerve

Explanation

PIN palsies in pediatric Monteggia fractures are typically neuropraxias resulting from nerve stretch over the dislocated radial head. The standard of care is closed reduction and casting with clinical observation, as spontaneous recovery usually occurs within 3 to 6 months.

Question 2875

Topic: 2. Trauma

In the setting of a terrible triad injury, an O'Driscoll Type 2 (anteromedial facet) coronoid fracture is identified. What specific pattern of elbow instability is classically associated with this fracture subtype if left unaddressed?

. Posterolateral rotatory instability
. Varus posteromedial rotatory instability
. Valgus extension overload
. Straight posterior instability
. Anterior radioulnar dissociation

Correct Answer & Explanation

. Varus posteromedial rotatory instability

Explanation

Anteromedial facet fractures of the coronoid result in loss of the buttress against varus forces, classically causing varus posteromedial rotatory instability (VPMRI). They typically require fixation with an anteromedial buttress plate to restore stability.

Question 2876

Topic: Upper Extremity Trauma

A 40-year-old male requires plate fixation for a comminuted radial head fracture in a terrible triad injury. To prevent impingement on the proximal radioulnar joint during forearm rotation, the plate must be placed within the "safe zone." How is this safe zone defined anatomically?

. A 90-degree arc bordered by the radial styloid and the ulnar styloid
. A 110-degree lateral arc bordered by the radial styloid and Lister's tubercle
. A 90-degree medial arc bordered by the bicipital tuberosity and the supinator crest
. A 120-degree posterior arc directly opposite the bicipital tuberosity
. A 60-degree anterior arc bordered by the coronoid and the radial tuberosity

Correct Answer & Explanation

. A 110-degree lateral arc bordered by the radial styloid and Lister's tubercle

Explanation

The safe zone for radial head plating is approximately a 90 to 110-degree arc on the non-articulating lateral surface of the radial head. It corresponds distally to the area between the radial styloid and Lister's tubercle with the forearm in neutral rotation.

Question 2877

Topic: 2. Trauma

A 55-year-old male sustains a Bado Type II Monteggia fracture. Which of the following associated elbow injuries is most frequently seen with this specific adult Monteggia variant?

. Olecranon bursitis
. Capitellar osteochondral defect
. Radial head fracture and coronoid fracture
. Rupture of the triceps tendon
. Isolated ulnar nerve transection

Correct Answer & Explanation

. Radial head fracture and coronoid fracture

Explanation

Bado Type II Monteggia fractures (posterior dislocation of the radial head with an apex-posterior ulnar fracture) are the most common type in adults. They are frequently associated with a radial head fracture and coronoid fracture, essentially making them Monteggia-variant fracture-dislocations.

Question 2878

Topic: 2. Trauma

A 10-year-old boy presents with a missed Bado Type I Monteggia fracture 8 months after the initial injury. The patient has progressive valgus deformity and loss of elbow flexion. What is the most critical surgical step required to successfully maintain a reduced radial head in this chronic setting?

. Isolated annular ligament reconstruction using triceps fascia
. Radial nerve decompression and transposition
. Ulnar osteotomy to lengthen and correct the angulation
. Excision of the radial head
. Open capsulotomy and anterior transposition of the radial nerve

Correct Answer & Explanation

. Ulnar osteotomy to lengthen and correct the angulation

Explanation

In chronic missed Monteggia fractures in children, simply pulling the radial head back into place is insufficient due to relative ulnar shortening and overgrowth of the radius. An ulnar osteotomy (angulation and lengthening) is critical to decompress the radiocapitellar joint and maintain reduction.

Question 2879

Topic: 2. Trauma

Which of the following techniques is considered the "gold standard" for achieving fixation of a comminuted, transverse Type I (tip) coronoid fracture during a terrible triad reconstruction?

. Anteromedial buttress plating
. Headed compression screws placed anterior to posterior
. Suture lasso technique through the anterior capsule
. Excision of the fragment without capsular repair
. Bridge plating extending from the olecranon to the coronoid

Correct Answer & Explanation

. Suture lasso technique through the anterior capsule

Explanation

Small, transverse Type 1 coronoid tip fractures often cannot hold a screw. The "suture lasso" technique, capturing the anterior capsule and passing sutures through drill holes in the proximal ulna, provides robust fixation and restores the anterior stabilizing buttress.

Question 2880

Topic: Upper Extremity Trauma

In evaluating a pediatric patient with an isolated, traumatic bowing (plastic deformation) of the ulna and an intact radius, which of the following occult injuries MUST be explicitly ruled out with high-quality radiographs?

. Scapholunate dissociation
. Distal radioulnar joint dislocation (Galeazzi)
. Radial head dislocation (Monteggia variant)
. Supracondylar humerus fracture
. Medial epicondyle avulsion

Correct Answer & Explanation

. Radial head dislocation (Monteggia variant)

Explanation

Traumatic plastic deformation of the ulna in a child effectively shortens the bone and changes its bow. This is a classic Monteggia variant, and the clinician must meticulously assess the radiocapitellar alignment to rule out an occult radial head dislocation.

Test Yourself

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

On this Page