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2. Trauma MCQs

Practice Set 480 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 9581

Topic: 2. Trauma

What is the most likely cause of a persistent flexion contracture after a well-fixed distal humerus fracture in a young adult?

. Nonunion of the fracture
. Hardware failure
. Inadequate rehabilitation and/or heterotopic ossification
. Acute infection
. Ulnar nerve entrapment

Correct Answer & Explanation

. Inadequate rehabilitation and/or heterotopic ossification

Explanation

The most likely cause of a persistent flexion contracture (loss of full extension) after a well-fixed distal humerus fracture in a young adult is often related to inadequate or delayed rehabilitation, leading to capsular contracture, and/or the development of heterotopic ossification. Both conditions can mechanically limit elbow extension. Nonunion or hardware failure would typically present with pain, instability, or loss of reduction, not primarily a contracture. Acute infection causes pain, swelling, and systemic signs. Ulnar nerve entrapment causes paresthesia/weakness, not a direct mechanical block to extension.

Question 9582

Topic: 2. Trauma

When assessing the need for surgical intervention for a distal humerus fracture, what is a key differentiating factor between non-operative and operative candidates?

. Patient's height
. Fracture displacement and articular involvement
. Presence of a distal radius fracture
. Hand dominance
. Blood type

Correct Answer & Explanation

. Fracture displacement and articular involvement

Explanation

Fracture displacement and articular involvement are key differentiating factors when deciding between non-operative and operative management for a distal humerus fracture. Non-operative management is typically reserved for non-displaced or minimally displaced extra-articular fractures. Displaced, unstable, or intra-articular fractures almost invariably require surgical fixation to restore anatomy and function. The other options (height, distal radius fracture, hand dominance, blood type) are generally not primary determinants for this decision.

Question 9583

Topic: 2. Trauma

What is the primary concern when considering non-operative management for a minimally displaced intercondylar distal humerus fracture in a physically active 30-year-old?

. Risk of systemic infection
. Development of post-traumatic arthritis due to malunion or instability
. Deep vein thrombosis (DVT)
. Hair loss
. Loss of appetite

Correct Answer & Explanation

. Development of post-traumatic arthritis due to malunion or instability

Explanation

Even minimally displaced intercondylar fractures, if managed non-operatively, carry a significant risk of developing post-traumatic arthritis due to subtle malunion, articular incongruity, or subsequent instability. In a young, active patient, preserving joint congruity and function is paramount, making ORIF generally preferred even for seemingly 'minimally displaced' intra-articular fractures to ensure precise anatomical reduction. Systemic infection or DVT are general risks but not specific to non-operative treatment of this fracture type. Hair loss and loss of appetite are irrelevant.

Question 9584

Topic: 2. Trauma

When assessing a distal humerus fracture with suspected arterial injury, what is the most appropriate diagnostic study?

. Plain radiographs
. CT scan with 3D reconstruction
. Doppler ultrasound and/or CT angiography
. MRI of the elbow
. Nerve conduction study

Correct Answer & Explanation

. Doppler ultrasound and/or CT angiography

Explanation

If arterial injury is suspected (e.g., signs of ischemia, absent or diminished pulses, expanding hematoma), a Doppler ultrasound is a quick, non-invasive screening tool. If positive or suspicion remains high, a CT angiography (CTA) is the gold standard to precisely localize the injury and plan intervention. Plain radiographs and CT scans are for bone. MRI is for soft tissue, but not typically for acute vascular emergencies. Nerve conduction studies are for nerve function, not acute vascular assessment.

Question 9585

Topic: 2. Trauma

Which type of implant is typically used for securing the olecranon osteotomy fragment after fixation of a distal humerus fracture?

. A single cortical screw
. Multiple K-wires alone
. Tension band wiring with K-wires and cerclage wire
. An absorbable pin
. A long intramedullary nail

Correct Answer & Explanation

. Tension band wiring with K-wires and cerclage wire

Explanation

A tension band wiring construct, typically involving two K-wires inserted across the osteotomy and a cerclage wire passed through a transverse drill hole and around the K-wires, is the most common and biomechanically sound method for securing a Chevron or oblique olecranon osteotomy. This converts the triceps' distracting forces into compression at the osteotomy site. A single cortical screw is insufficient. K-wires alone do not provide adequate stability. Absorbable pins are not strong enough. An intramedullary nail is not used for this. Small plates can also be used but tension band is standard.

Question 9586

Topic: 2. Trauma

In the case of a severely comminuted intra-articular distal humerus fracture in a young, active patient where stable ORIF is deemed impossible, what salvage procedure might be considered as a last resort to preserve some function?

. Total Elbow Arthroplasty (TEA)
. Elbow arthrodesis (fusion)
. Excision arthroplasty (fascial interposition)
. Long-term external fixation with a hinged elbow fixator
. Amputation

Correct Answer & Explanation

. Elbow arthrodesis (fusion)

Explanation

In a young, active patient, if ORIF of a severely comminuted intra-articular distal humerus fracture is truly impossible and the joint cannot be salvaged, elbow arthrodesis (fusion) might be considered as a salvage procedure. While it results in a stiff, pain-free elbow, it provides a stable limb for weight-bearing and functional use, which is often preferable to the outcomes of excision arthroplasty in an active individual. TEA is generally avoided in young, active patients due to implant longevity and high-demand limitations. Excision arthroplasty (flail joint) leads to poor stability and strength. Long-term external fixation is usually temporary. Amputation is a last, extreme resort.

Question 9587

Topic: 2. Trauma

A 40-year-old male presents with persistent wrist pain and decreased range of motion 1 year after non-operative management of a distal radius fracture. Radiographs show a dorsal tilt of 25 degrees, radial shortening of 5mm, and a 3mm intra-articular step-off. According to common malunion criteria, which of these findings is least acceptable for good functional outcomes in a younger, active patient?

. Dorsal tilt of 25 degrees
. Radial shortening of 5mm
. 3mm intra-articular step-off
. Loss of radial inclination
. Ulnar positive variance

Correct Answer & Explanation

. 3mm intra-articular step-off

Explanation

While all listed findings represent aspects of malunion, an intra-articular step-off of 3mm is widely considered the most critical predictor of poor long-term outcomes, particularly post-traumatic arthritis, especially in an active younger patient. Even 1-2mm of intra-articular incongruity is often deemed unacceptable. Dorsal tilt >10-15 degrees and radial shortening >2-3mm are also significant, and ulnar positive variance is directly related to radial shortening. However, articular step-off directly compromises joint congruity and leads to accelerated degenerative changes, making it the least acceptable from a functional prognosis standpoint.

Question 9588

Topic: 2. Trauma

When using K-wire fixation for a dorsally displaced distal radius fracture, what is the most biomechanically advantageous configuration to prevent recurrent dorsal displacement?

. Dorsal-to-volar placement through the fracture site
. Cross K-wires from radial styloid to ulnar cortex
. Buttress wires placed across the volar cortex
. Trans-styloid K-wires only
. Percutaneous pinning into the carpus (Kapandji technique)

Correct Answer & Explanation

. Percutaneous pinning into the carpus (Kapandji technique)

Explanation

For dorsally displaced fractures, the Kapandji technique (intrafocal pinning) involves inserting K-wires into the fragments from the radial styloid, driving them across the fracture site and impacting them into the opposite intact cortex (usually volar). This creates a 'joystick' or 'buttress' effect, maintaining reduction and providing volar cortical support against dorsal collapse. Cross K-wires provide overall stability but don't specifically buttress the volar cortex as effectively against dorsal collapse. Dorsal-to-volar wires are not typically used to prevent dorsal displacement. Buttress wires across the volar cortex would require open exposure and are typically plates.

Question 9589

Topic: 2. Trauma

Which of the following distal radius fracture patterns is generally considered the most suitable indication for primary external fixation, particularly as a definitive treatment rather than just temporary stabilization?

. Stable, extra-articular Colles' fracture
. Unstable, highly comminuted intra-articular fracture with metaphyseal bone loss
. Non-displaced volar Barton's fracture
. Pediatric Salter-Harris II fracture
. Isolated ulnar styloid fracture

Correct Answer & Explanation

. Unstable, highly comminuted intra-articular fracture with metaphyseal bone loss

Explanation

External fixation excels in managing highly comminuted, unstable intra-articular distal radius fractures, especially those with significant metaphyseal bone loss, open fractures, or severe soft tissue compromise. It provides ligamentotaxis (distraction across the wrist joint) to indirectly reduce fragments and maintain length and alignment, while allowing for soft tissue care. Stable, non-displaced fractures are managed conservatively. Volar Barton's fractures are often treated with volar plating. Pediatric fractures have different considerations. Isolated ulnar styloid fractures are rarely treated with external fixation.

Question 9590

Topic: 2. Trauma

A 45-year-old male sustains a volar Barton's fracture. What is the generally accepted definitive management strategy for this fracture pattern?

. Closed reduction and long-arm cast immobilization
. Closed reduction and K-wire fixation
. Dorsal plate fixation
. Volar plate fixation
. External fixation with adjuvant K-wires

Correct Answer & Explanation

. Volar plate fixation

Explanation

A volar Barton's fracture is an intra-articular fracture-dislocation where a rim of the distal radius (volar lip) displaces proximally and volarly with the carpus. This fracture is inherently unstable due to the articular involvement and the strong pull of the flexor tendons. Open reduction and internal fixation with a volar plate, which acts as a buttress, is the standard and most reliable treatment to restore articular congruity and stability. Closed reduction alone is rarely successful in maintaining reduction. Dorsal plating is inappropriate for a volar fragment. External fixation is less ideal for directly reducing and buttressing a single large volar fragment compared to a plate.

Question 9591

Topic: 2. Trauma

The principle of ligamentotaxis, commonly utilized in external fixation for distal radius fractures, primarily achieves fracture reduction by:

. Direct manipulation of fracture fragments
. Applying compression across the fracture site
. Distraction across the radiocarpal joint, allowing intact ligaments to pull fragments into place
. Providing a stable platform for K-wire insertion
. Resisting rotational forces

Correct Answer & Explanation

. Distraction across the radiocarpal joint, allowing intact ligaments to pull fragments into place

Explanation

Ligamentotaxis is the principle where continuous longitudinal traction (distraction) is applied across a joint via an external fixator. This tension, transmitted through the intact soft tissues (ligaments and joint capsule) attached to the distal fragments, indirectly pulls comminuted fracture fragments back into a more anatomical position. It does not directly manipulate fragments, apply compression, or primarily resist rotation, although it contributes to stability for K-wire fixation.

Question 9592

Topic: 2. Trauma

A patient presents with a displaced radial styloid fracture, often referred to as a Hutchinson or Chauffeur's fracture. What is the MOST appropriate treatment approach for this fracture pattern with significant displacement?

. Long-arm cast immobilization
. Open reduction and internal fixation with a screw or plate
. Percutaneous K-wire fixation without open reduction
. External fixation
. Short-arm cast immobilization

Correct Answer & Explanation

. Open reduction and internal fixation with a screw or plate

Explanation

Hutchinson (or Chauffeur's) fractures are intra-articular fractures of the radial styloid, typically caused by direct impaction of the scaphoid into the radial styloid. Due to the intra-articular nature and the strong pull of the brachioradialis, these fractures tend to displace. Significant displacement (>1-2mm articular step-off) or rotational malalignment usually warrants open reduction and internal fixation, often with screws (lag screw principle) or a small plate, to restore articular congruity and prevent post-traumatic arthritis. Closed reduction and casting are often insufficient to maintain reduction.

Question 9593

Topic: 2. Trauma
An open distal radius fracture, classified as Gustilo-Anderson Type II, is observed in the emergency department. What is the most appropriate initial management strategy?
. Immediate definitive volar plating
. Irrigation and debridement, antibiotics, tetanus prophylaxis, and temporary stabilization (e.g., external fixation)
. Closed reduction and cast application with oral antibiotics
. Delayed primary closure and internal fixation after 72 hours
. Amputation consultation

Correct Answer & Explanation

. Irrigation and debridement, antibiotics, tetanus prophylaxis, and temporary stabilization (e.g., external fixation)

Explanation

Open fractures require urgent attention to prevent infection and facilitate healing. The initial management for a Gustilo-Anderson Type II open fracture involves thorough irrigation and debridement in the operating theatre, administration of broad-spectrum antibiotics (IV), tetanus prophylaxis, and temporary stabilization of the fracture (e.g., with an external fixator or K-wires) to protect soft tissues and allow for swelling resolution. Definitive internal fixation (like volar plating) is often delayed until the soft tissue envelope is favorable, typically after several days. Closed reduction and casting are inappropriate for an open fracture. Amputation is generally reserved for Gustilo Type IIIC or unsalvageable limbs.

Question 9594

Topic: 2. Trauma

In the surgical management of a distal radius fracture, when is bone grafting most commonly indicated?

. Stable extra-articular fracture treated with volar plating
. Open fracture with minimal bone loss
. Highly comminuted intra-articular fracture with significant metaphyseal bone void after reduction
. Pediatric Salter-Harris Type I fracture
. Non-union of the ulnar styloid

Correct Answer & Explanation

. Highly comminuted intra-articular fracture with significant metaphyseal bone void after reduction

Explanation

Bone grafting is most commonly indicated in distal radius fractures when there is significant metaphyseal comminution or bone loss, creating a void that cannot be adequately filled by reduction alone. This void, if left unaddressed, can lead to secondary collapse and malunion. The graft (autograft or allograft) provides structural support and enhances healing. It's generally not needed for stable fractures, minimal bone loss, pediatric physeal fractures (unless significant defect), or isolated ulnar styloid non-union.

Question 9595

Topic: 2. Trauma

A patient 6 hours post-reduction and casting of a distal radius fracture reports progressively worsening pain, especially with passive extension of the fingers, despite adequate analgesia. On examination, the fingers are swollen and firm to palpation, and sensation in the median nerve distribution is diminished. The radial pulse is palpable. What is the MOST concerning diagnosis?

. Median nerve compression
. Complex Regional Pain Syndrome (CRPS)
. Tendonitis
. Acute compartment syndrome
. Delayed union

Correct Answer & Explanation

. Acute compartment syndrome

Explanation

The classic signs of acute compartment syndrome (ACS) are pain out of proportion to injury, pain on passive stretch of the digits (a very sensitive sign in the forearm/hand), paresthesias/nerve deficits, swelling, and a tense compartment. While median nerve compression is present, it's often a symptom of the elevated intracompartmental pressure rather than the primary diagnosis here. A palpable pulse does NOT rule out compartment syndrome. CRPS typically develops later. Tendonitis and delayed union are incorrect given the acute presentation. Urgent fasciotomy is required for ACS.

Question 9596

Topic: 2. Trauma

In older, less active patients with distal radius fractures, which of the following radiographic parameters is often considered more acceptable for achieving satisfactory functional outcomes compared to younger, active individuals?

. Intra-articular step-off >2mm
. Radial shortening >5mm
. Dorsal tilt >20 degrees
. Radial inclination 10 degrees
. Volar tilt 0 degrees

Correct Answer & Explanation

. Intra-articular step-off >2mm

Explanation

In older, less active patients, a certain degree of malunion, particularly increased dorsal tilt (up to 20-25 degrees), and some radial shortening (up to 5mm) can be tolerated with acceptable functional outcomes, especially if they have low functional demands. However, significant intra-articular step-off (>1-2mm) is still a strong predictor of post-traumatic arthritis and poor outcome, even in the elderly, and should generally be avoided if possible. While other parameters like radial inclination and volar tilt are important, dorsal tilt is often the most commonly accepted residual deformity in this demographic.

Question 9597

Topic: 2. Trauma

A distal radius fracture associated with a scaphoid impaction fracture (a compression injury to the scaphoid waist or pole) is best treated by:

. Isolated scaphoid screw fixation
. Closed reduction and casting for both
. Addressing the radial fracture, which typically decompresses the scaphoid
. External fixation with strong distraction
. Surgical intervention for both fractures

Correct Answer & Explanation

. Surgical intervention for both fractures

Explanation

A distal radius fracture associated with a scaphoid impaction fracture requires careful assessment of both injuries. While addressing the radial fracture can sometimes indirectly improve the scaphoid position, a significant or unstable scaphoid impaction fracture (e.g., involving articular surface, large fragment, or causing carpal instability) will likely require direct surgical fixation (e.g., with a screw or K-wires) in addition to fixation of the distal radius. Closed reduction and casting are often insufficient for complex scaphoid fractures. External fixation might distract the scaphoid, but doesn't directly stabilize an impaction fracture.

Question 9598

Topic: 2. Trauma

Non-union of a distal radius fracture is considered:

. A common complication
. Less common than malunion
. Always symptomatic
. More common in younger patients
. Typically requires vascularized bone graft

Correct Answer & Explanation

. Less common than malunion

Explanation

Non-union of the distal radius is a rare complication, significantly less common than malunion. The distal radius has an excellent blood supply. While it can occur, particularly with open fractures, severe comminution, infection, or poor surgical technique, it is not a common complication. Malunion is far more prevalent. Non-union is not always symptomatic. While vascularized graft can be used, standard bone graft and stable fixation are usually tried first for established non-unions. It's not more common in younger patients; factors like smoking, severe comminution, and poor fixation are greater risks.

Question 9599

Topic: 2. Trauma
Percutaneous K-wire fixation for distal radius fractures is generally most appropriate for which of the following scenarios?
. Highly comminuted C3 fracture
. Unstable extra-articular fracture with good bone quality
. Displaced volar Barton's fracture
. Open fracture Gustilo Type III
. Pediatric Salter-Harris Type V fracture

Correct Answer & Explanation

. Unstable extra-articular fracture with good bone quality

Explanation

Percutaneous K-wire fixation (often with closed reduction) is a good option for unstable extra-articular or simple intra-articular fractures, particularly in patients with good bone quality, where a stable reduction can be achieved and held with pins. It is less suitable for highly comminuted articular fractures (C3) which often require direct visualization and plating, displaced volar Barton's (requires buttressing), severe open fractures, or pediatric Salter-Harris V (crush injury with poor prognosis).

Question 9600

Topic: 2. Trauma

An 80-year-old active, independent female sustains a significantly displaced intra-articular distal radius fracture (AO 23-C2). She has no major comorbidities. What is the MOST appropriate treatment strategy given her functional status?

. Closed reduction and cast immobilization, allowing for some malunion
. External fixation without K-wires
. Volar locking plate fixation
. Percutaneous K-wire fixation
. Distal radius arthroplasty

Correct Answer & Explanation

. Volar locking plate fixation

Explanation

For an active and independent elderly patient with a significantly displaced intra-articular fracture, volar locking plate fixation is often the preferred treatment. While some malunion can be tolerated in less active elderly patients, an active individual will benefit significantly from anatomical reduction and stable fixation, allowing early mobilization and better functional outcomes. Closed reduction alone often fails to maintain reduction, especially in C2 fractures. External fixation alone may not adequately reduce and stabilize articular fragments. Percutaneous K-wires might not be sufficient for a C2 fracture. Distal radius arthroplasty is still investigational and not standard of care.

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