Menu

2. Trauma MCQs

Practice Set 484 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 9661

Topic: 2. Trauma
What is the main reason for late presentation of a Monteggia fracture in a young child?
. Lack of parent compliance.
. Slow onset of symptoms.
. Misdiagnosis or overlooked injury due to subtle radiographic findings.
. Spontaneous reduction and redislocation.
. Delayed bone healing in children.

Correct Answer & Explanation

. Misdiagnosis or overlooked injury due to subtle radiographic findings.

Explanation

The main reason for late presentation of Monteggia fractures in young children is often misdiagnosis or overlooked injury, especially Type III. The ulnar fracture might be a subtle greenstick or plastic deformation, and the radial head dislocation can be difficult to appreciate on initial, potentially suboptimal, radiographs. This can lead to the child being treated for a 'sprain' or a simple ulnar fracture, with the radial head dislocation going unnoticed until chronic symptoms (pain, limited rotation, deformity) develop weeks or months later. Symptoms are usually acute, not slow onset. Bone healing is typically fast in children.

Question 9662

Topic: 2. Trauma

In the case of a Monteggia Type I fracture with an associated coronoid process fracture, what additional concern arises?

. Increased risk of radial nerve palsy.
. Enhanced elbow stability due to the coronoid fracture.
. Risk of recurrent posterior instability of the elbow joint (terrible triad equivalent).
. Inability to achieve ulnar healing.
. Decreased risk of heterotopic ossification.

Correct Answer & Explanation

. Risk of recurrent posterior instability of the elbow joint (terrible triad equivalent).

Explanation

A Monteggia Type I fracture with an associated coronoid process fracture is a more complex injury. The coronoid process is a primary stabilizer of the elbow against posterior displacement. Its fracture, especially significant displacement, compromises elbow stability, increasing the risk of recurrent posterior instability (analogous to a 'terrible triad' injury but with an ulnar fracture instead of radial head fracture). This often necessitates specific fixation of the coronoid fracture in addition to the ulnar shaft and radial head reduction. It does not directly affect radial nerve palsy risk (PIN is common with Type I, not radial nerve proper) or ulnar healing itself, nor does it decrease HO risk.

Question 9663

Topic: 2. Trauma

Which characteristic differentiates a Monteggia equivalent from a Monteggia variant?

. Monteggia equivalents refer to injuries with different locations of the ulnar fracture, while variants have additional associated fractures.
. Monteggia equivalents include radial head fractures or concomitant distal radial fractures, while variants are based on the direction of radial head dislocation.
. Monteggia equivalents are only seen in children, while variants are in adults.
. Variants always require open reduction, while equivalents can be closed reduced.
. Equivalents involve nerve injury, variants do not.

Correct Answer & Explanation

. Monteggia equivalents refer to injuries with different locations of the ulnar fracture, while variants have additional associated fractures.

Explanation

The term 'Monteggia equivalent' refers to a group of injuries that are biomechanically similar to a classic Monteggia fracture (ulnar injury + radial head dislocation) but include additional or slightly different injury patterns, such as a radial head fracture, a radial neck fracture, a concomitant distal radial fracture, or an ulnar physeal injury instead of a diaphyseal fracture. 'Monteggia variants' typically refers to the Bado and Peril types (I-IV) based on the direction of radial head dislocation relative to the ulnar fracture angulation. Therefore, equivalents have additional or altered bony injuries while variants are specific classifications of the classic Monteggia pattern.

Question 9664

Topic: 2. Trauma

What is a typical pitfall in the post-operative management of adult Monteggia fractures that can lead to poor outcomes?

. Excessively early range of motion, disrupting fixation.
. Over-aggressive pain management leading to patient drowsiness.
. Inadequate and prolonged immobilization, leading to significant elbow stiffness.
. Failure to administer prophylactic antibiotics post-surgery.
. Neglecting to assess the integrity of the contralateral elbow.

Correct Answer & Explanation

. Inadequate and prolonged immobilization, leading to significant elbow stiffness.

Explanation

A significant pitfall in the post-operative management of adult Monteggia fractures is inadequate or prolonged immobilization. While stable fixation is achieved surgically, too long a period of cast immobilization (beyond what is necessary for early soft tissue healing and initial fracture stability) can lead to severe and debilitating elbow stiffness, particularly loss of pronation and supination, and flexion/extension. Early, controlled range of motion is crucial to prevent this. Excessively early motion can disrupt fixation, but conservative, prolonged immobilization is a more common cause of poor functional outcome in adults.

Question 9665

Topic: 2. Trauma

A 45-year-old male sustains a direct fall onto his elbow, resulting in a displaced olecranon fracture. Which of the following structures is least likely to be directly involved in the primary function of the olecranon as an anatomical structure and lever arm for extension?

. Triceps brachii tendon
. Anconeus muscle
. Capsule of the ulnohumeral joint
. Radial collateral ligament
. Ulnar nerve

Correct Answer & Explanation

. Triceps brachii tendon

Explanation

The olecranon serves as the primary insertion point for the triceps brachii tendon (A), forming a critical lever arm for elbow extension. The anconeus muscle (B) originates from the lateral epicondyle and inserts onto the lateral aspect of the olecranon and proximal ulna, assisting in extension and stabilizing the ulnohumeral joint. The joint capsule (C) encompasses the ulnohumeral joint, and its integrity is often compromised in intra-articular fractures. The ulnar nerve (E) runs in the cubital tunnel posterior to the medial epicondyle, making it vulnerable to injury with olecranon fractures or surgical approaches. The radial collateral ligament (D) is located laterally and stabilizes the humeroradial and proximal ulnar joints against varus stress, having a less direct role in theprimary functionof the olecranon's lever arm for extension compared to the other options. While indirect involvement or associated injury is possible, its direct contribution to the olecranon's lever arm function is less central.

Question 9666

Topic: 2. Trauma

A patient falls directly onto the point of their elbow. Which of the following olecranon fracture patterns is most commonly associated with this mechanism?

. Transverse non-displaced fracture
. Oblique fracture with proximal extension
. Highly comminuted fracture with articular involvement
. Avulsion fracture of the triceps insertion
. Anterior coronoid process fracture

Correct Answer & Explanation

. Highly comminuted fracture with articular involvement

Explanation

A direct fall onto the point of the elbow typically results in high-energy trauma, driving the olecranon directly against the trochlea. This commonly leads to highly comminuted fractures with significant articular involvement (C) due to the crushing force. Avulsion fractures (D) are more often due to indirect mechanisms (sudden triceps contraction). Transverse non-displaced fractures (A) or simple oblique fractures (B) can occur with direct trauma but are less characteristic of high-energy impact onto the olecranon apex. Anterior coronoid fractures (E) are often associated with posterior dislocations and varus posteromedial rotatory instability, not typically a direct impact mechanism to the olecranon apex itself.

Question 9667

Topic: 2. Trauma

A 32-year-old male presents after a motorcycle accident with a suspected olecranon fracture. On examination, he has a visible deformity, swelling, and ecchymosis over the posterior elbow. He is unable to actively extend his elbow against gravity. What is the most critical initial finding to assess regarding ulnohumeral joint stability?

. Range of passive elbow flexion
. Palpation for a palpable gap at the fracture site
. Assessment of ulnar nerve function
. Varus/valgus stress testing of the elbow
. Thorough distal neurovascular examination

Correct Answer & Explanation

. Palpation for a palpable gap at the fracture site

Explanation

While all options are important, the question specifically asks for the 'most critical initial finding to assess regarding ulnohumeral joint stability' in the context of asuspected olecranon fracture. A palpable gap at the fracture site (B) directly indicates significant displacement of the olecranon, which often correlates with profound disruption of the triceps mechanism and compromise of the ulnohumeral joint's posterior stability. The inability to actively extend the elbow against gravity is already mentioned, which points to disruption. Varus/valgus stress testing (D) assesses collateral ligament integrity, which is important, but a displaced olecranon fragment itself significantly compromises the posterior stability. Assessment of ulnar nerve function (C) and distal neurovascular status (E) are crucial for managing complications but do not directly assess ulnohumeralmechanical stabilityrelated to the fracture pattern itself. Passive elbow flexion (A) provides information about potential stiffness but not acute stability.

Question 9668

Topic: 2. Trauma

A 40-year-old healthy male sustains a simple transverse, displaced olecranon fracture with intact articular surface. Which surgical technique is generally considered the gold standard for fixation in this scenario?

. Plate and screw fixation
. Intramedullary screw fixation
. Excision of the proximal fragment
. Tension band wiring
. Total elbow arthroplasty

Correct Answer & Explanation

. Tension band wiring

Explanation

For simple transverse, displaced olecranon fractures (especially Mayo Type IIA) with intact articular surface and good bone stock, tension band wiring (D) is considered the gold standard. It effectively converts tensile forces from the triceps pull into compressive forces at the fracture site, promoting healing and allowing for early mobilization. Plate and screw fixation (A) is preferred for comminuted fractures, unstable fractures, or osteoporotic bone. Intramedullary screw fixation (B) has limited, specific indications. Excision of the proximal fragment (C) is reserved for very small, distal fragments in low-demand patients or severely comminuted segments that cannot be reconstructed. Total elbow arthroplasty (E) is a salvage procedure for highly complex, unreconstructable fractures, especially in the elderly.

Question 9669

Topic: 2. Trauma

When considering plate fixation for an olecranon fracture, which of the following scenarios would most strongly indicate a locking plate over a conventional compression plate?

. Simple transverse fracture in a young, healthy patient
. Displaced oblique fracture with excellent bone quality
. Highly comminuted fracture in an osteoporotic elderly patient
. Avulsion fracture of the triceps insertion
. Distal ulna shaft fracture extension

Correct Answer & Explanation

. Highly comminuted fracture in an osteoporotic elderly patient

Explanation

Locking plates provide angular stability independent of plate-bone compression, making them particularly advantageous in osteoporotic bone or highly comminuted fractures (C) where conventional screw purchase may be inadequate. In these cases, locking screws 'lock' into the plate, creating a fixed-angle construct that resists collapse and provides stable fixation even with poor bone quality. Simple transverse (A) or oblique fractures (B) in good bone quality often respond well to tension band wiring or conventional compression plating. Avulsion fractures (D) are typically managed with tension band wiring or direct suture. Distal ulna shaft extension (E) would indicate a longer plate but not necessarily a locking plate without other factors.

Question 9670

Topic: 2. Trauma

Following surgical fixation of an olecranon fracture, what is the most common long-term complication reported?

. Nonunion
. Ulnar nerve neuropathy
. Infection
. Stiffness/loss of range of motion
. Hardware failure

Correct Answer & Explanation

. Stiffness/loss of range of motion

Explanation

Stiffness and loss of range of motion, particularly extension, is the most common long-term complication following olecranon fracture fixation, occurring in a significant percentage of patients. While nonunion (A), ulnar nerve neuropathy (B), infection (C), and hardware failure (E) can occur, elbow stiffness is a near-universal concern that requires diligent rehabilitation and patient compliance to minimize its impact.

Question 9671

Topic: 2. Trauma

A patient with an olecranon fracture reports persistent pain and mechanical symptoms in the forearm despite adequate fixation of the olecranon. Physical examination reveals tenderness over the radial head and pain with forearm rotation. What associated injury should be most strongly suspected?

. Distal humerus fracture
. Monteggia fracture-dislocation
. Essex-Lopresti injury
. Medial collateral ligament tear
. Triceps tendon rupture

Correct Answer & Explanation

. Essex-Lopresti injury

Explanation

Persistent forearm pain, tenderness over the radial head, and pain with forearm rotation after an olecranon fracture raises strong suspicion for an Essex-Lopresti injury (C). This injury involves a radial head fracture, rupture of the interosseous membrane, and disruption of the distal radioulnar joint (DRUJ), often associated with a coronoid or olecranon fracture as part of a high-energy elbow trauma. A Monteggia fracture-dislocation (B) involves an ulna shaft fracture with radial head dislocation, which is a distinct pattern. Distal humerus fracture (A) would typically present with different pain patterns. Medial collateral ligament (D) tear typically presents with valgus instability. Triceps tendon rupture (E) would impact extension, not forearm rotation or radial head pain.

Question 9672

Topic: 2. Trauma

Following successful tension band wiring of a simple transverse olecranon fracture, what is the most appropriate initial post-operative rehabilitation protocol?

. Immediate full active range of motion
. Immobilization for 6 weeks, then gradual passive range of motion
. Early controlled active and passive range of motion, within pain limits
. Continuous passive motion (CPM) machine use for 24 hours/day
. Immediate strengthening exercises

Correct Answer & Explanation

. Early controlled active and passive range of motion, within pain limits

Explanation

Early controlled active and passive range of motion (C) within pain limits is crucial to prevent stiffness and promote articular cartilage health after olecranon fracture fixation. The stability provided by tension band wiring allows for this early motion. Immediate full active range of motion (A) may risk displacement. Prolonged immobilization (B) leads to severe stiffness and is generally avoided. CPM (D) can be used, but not typically 24/7 and usually as an adjunct to active/passive motion, not the sole therapy. Immediate strengthening (E) is too aggressive and could disrupt the repair.

Question 9673

Topic: 2. Trauma

A patient complains of persistent pain and irritation over the posterior aspect of the elbow six months after olecranon fracture fixation with tension band wiring. Radiographs show healed fracture and intact hardware. What is the most likely cause of symptoms?

. Nonunion
. Infection
. Hardware prominence/irritation
. Ulnar nerve entrapment
. Post-traumatic arthritis

Correct Answer & Explanation

. Hardware prominence/irritation

Explanation

Hardware prominence and irritation (C) is an extremely common complication following olecranon tension band wiring, occurring in up to 80% of cases due to the superficial location of the olecranon and its hardware. It often necessitates hardware removal once the fracture has healed, as is indicated by 'healed fracture and intact hardware'. Nonunion (A) would typically present with persistent pain, instability, and poor healing on radiographs. Infection (B) would show signs of inflammation. Ulnar nerve entrapment (D) causes specific neurological symptoms. Post-traumatic arthritis (E) is a longer-term complication, typically manifesting years later, and while hardware can contribute, direct irritation is a more immediate and common cause for symptoms at 6 months post-op with a healed fracture.

Question 9674

Topic: 2. Trauma

In which of the following scenarios might excision of the olecranon fragment be a viable treatment option?

. Highly comminuted fracture with large fragments in a young, active patient.
. Nondisplaced transverse fracture.
. Fracture of the distal 20% of the olecranon, stable, in an elderly, low-demand patient.
. Displaced fracture involving >50% of the articular surface.
. Open fracture with significant bone loss.

Correct Answer & Explanation

. Fracture of the distal 20% of the olecranon, stable, in an elderly, low-demand patient.

Explanation

Excision of the olecranon fragment is typically reserved for small, distal fragments (representing <50% of the articular surface, often <2cm), particularly in elderly, low-demand patients (C) where reconstruction is difficult or unnecessary. This approach aims to restore triceps function without requiring complex hardware. For larger fragments or in active patients (A, D), fixation is preferred to restore the triceps lever arm and joint stability. Nondisplaced fractures (B) are managed non-operatively or with simpler fixation. Open fractures with significant bone loss (E) may require more complex reconstructive techniques or external fixation, not simple excision.

Question 9675

Topic: 2. Trauma

The principle behind tension band wiring for olecranon fractures is to convert which type of force into a compressive force at the fracture site?

. Shear
. Bending
. Torsional
. Tensile
. Axial

Correct Answer & Explanation

. Tensile

Explanation

Tension band wiring works by converting the tensile forces (D) exerted by the triceps muscle contraction (which normally would distract the fracture) into compressive forces at the fracture site. This allows for active range of motion without distraction, promoting bone healing and stability.

Question 9676

Topic: 2. Trauma
A patient presents with a Mayo Type IIIB olecranon fracture. What is a defining characteristic of this type that dictates management?
. Nondisplaced with comminution.
. Displaced, noncomminuted, and stable.
. Displaced, comminuted, and stable.
. Displaced, noncomminuted, and unstable.
. Displaced, comminuted, and unstable.

Correct Answer & Explanation

. Displaced, comminuted, and unstable.

Explanation

Mayo Type IIIB signifies a displaced, comminuted, and unstable olecranon fracture. The 'B' denotes comminution, and the 'III' denotes instability. Instability implies compromise of the ulnohumeral articulation (often due to associated ligamentous or coronoid injury), which often requires more robust fixation than tension band wiring, such as plate fixation, to restore joint congruence and stability.

Question 9677

Topic: 2. Trauma

For a highly comminuted olecranon fracture in an active 30-year-old patient, which treatment option is generally preferred over tension band wiring?

. Excision of all fragments
. Long arm cast immobilization
. Plate and screw fixation
. Intramedullary screw fixation
. Total elbow arthroplasty

Correct Answer & Explanation

. Plate and screw fixation

Explanation

For highly comminuted olecranon fractures, especially in young, active individuals where anatomical reconstruction and stable fixation are paramount, plate and screw fixation (C) is preferred. It provides greater stability, allows for anatomical reconstruction of the articular surface, and better maintains fragment alignment, which is critical for long-term function. Tension band wiring is less effective for comminuted fractures as it relies on good bone stock for effective compression. Excision (A) is for small fragments in low-demand patients. Cast immobilization (B) is non-operative and unsuitable for displaced comminuted fractures. Intramedullary screw fixation (D) has limited indications and may not address comminution effectively. Total elbow arthroplasty (E) is a salvage procedure.

Question 9678

Topic: 2. Trauma

Which of the following factors is least likely to contribute to an increased risk of nonunion following operative fixation of an olecranon fracture?

. Smoking
. High-energy comminuted fracture
. Inadequate fixation technique
. Early, aggressive rehabilitation
. Malnutrition

Correct Answer & Explanation

. Early, aggressive rehabilitation

Explanation

Early,controlledrehabilitation (D) is generally beneficial for fracture healing by promoting joint motion, reducing stiffness, and stimulating bone biology, not typically a cause of nonunion unless it leads to hardware failure or significant displacement due to uncontrolled motion. However, 'aggressive' in this context could be ambiguous, but compared to the other options, it's the least likelydirectcause. Factors like smoking (A), high-energy comminution (B), inadequate fixation (C), and malnutrition (E) are well-known, direct risk factors for nonunion.

Question 9679

Topic: Upper Extremity Trauma

The articular surface of the olecranon forms part of which joint?

. Humeroradial joint
. Proximal radioulnar joint
. Distal radioulnar joint
. Ulnohumeral joint
. Acromioclavicular joint

Correct Answer & Explanation

. Ulnohumeral joint

Explanation

The articular surface of the olecranon forms the proximal portion of the trochlear notch, which articulates with the trochlea of the humerus to form the ulnohumeral joint (D). This is the primary articulation responsible for elbow flexion and extension.

Question 9680

Topic: 2. Trauma

A 42-year-old presents with a Gustilo-Anderson Type II open olecranon fracture. Initial management steps prior to definitive fixation should include:

. Immediate total elbow arthroplasty
. Broad-spectrum intravenous antibiotics, tetanus prophylaxis, urgent debridement and irrigation
. Closed reduction and cast immobilization
. Delayed primary closure without debridement
. Application of continuous passive motion machine

Correct Answer & Explanation

. Broad-spectrum intravenous antibiotics, tetanus prophylaxis, urgent debridement and irrigation

Explanation

Management of open fractures (B) requires urgent surgical debridement and copious irrigation, broad-spectrum intravenous antibiotics, and tetanus prophylaxis to prevent infection, often within 6-8 hours. Total elbow arthroplasty (A) is a definitive procedure and not initial management. Closed reduction and casting (C) is inappropriate for an open fracture. Delayed primary closure without debridement (D) is incorrect; debridement is paramount. CPM (E) is for post-operative rehabilitation, not acute open fracture management.

Test Yourself

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

On this Page