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2. Trauma MCQs

Practice Set 492 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 9821

Topic: 2. Trauma

What is a potential pitfall of intramedullary nailing for a very proximal humeral shaft fracture (e.g., within 2-3 cm of the surgical neck)?

. Increased risk of radial nerve injury
. Difficulty achieving adequate distal locking
. High risk of shoulder impingement due to nail entry point
. Poor rotational control for spiral fractures
. Higher rates of infection

Correct Answer & Explanation

. High risk of shoulder impingement due to nail entry point

Explanation

For very proximal humeral shaft fractures, especially those extending close to the surgical neck, the entry point for antegrade intramedullary nailing becomes critical. Too lateral or prominent an entry point can lead to significant shoulder impingement, rotator cuff damage, and postoperative shoulder pain or stiffness. While rotational control can be challenging for some IMNs, and distal locking can be tricky, the primary concern for very proximal fractures with antegrade nailing is the proximal entry site and its consequences for shoulder function. Radial nerve injury risk is generally lower than with plating for proximal fractures, and infection rates are comparable to other internal fixation methods.

Question 9822

Topic: 2. Trauma

A 72-year-old female presents with a closed, spiral mid-shaft humeral fracture. She is relatively sedentary but lives independently. She has significant comorbidities, including severe chronic obstructive pulmonary disease (COPD) and heart failure, making general anesthesia high-risk. What is the most appropriate treatment option?

. Open reduction and internal fixation with a plate
. Intramedullary nailing
. Functional bracing with careful follow-up
. External fixation under local anesthesia
. Skeletal traction

Correct Answer & Explanation

. Functional bracing with careful follow-up

Explanation

Given the patient's severe comorbidities and high anesthetic risk, non-operative management with a functional brace is the most appropriate initial treatment. While surgery (plating or nailing) might provide more rigid fixation, the risks associated with general anesthesia in a patient with severe COPD and heart failure outweigh the potential benefits for a fracture type (spiral) that is generally amenable to conservative management. Functional bracing has high success rates for spiral fractures, even in the elderly. External fixation, while possible under local, is rarely the first choice for a closed, non-comminuted fracture and has its own set of complications. Skeletal traction is largely historical for humeral shaft fractures.

Question 9823

Topic: 2. Trauma

Which of the following is a common early complication of a hanging cast for a humeral shaft fracture?

. Distal humerus fracture
. Elbow stiffness
. Shoulder stiffness
. Apex anterior angulation (sagging)
. Radial nerve palsy

Correct Answer & Explanation

. Apex anterior angulation (sagging)

Explanation

A common complication of hanging casts, particularly if the cast is too heavy or the elbow is kept in too much flexion, is apex anterior angulation (sagging) of the fracture. The weight of the cast can cause the distal fragment to sag anteriorly, creating an anterior bow. This is a primary reason why functional braces, which provide circumferential compression, are preferred over hanging casts for most humeral shaft fractures. Elbow/shoulder stiffness and radial nerve palsy are less directly attributable to the hanging cast itself compared to the typical anterior angulation.

Question 9824

Topic: 2. Trauma

A 58-year-old patient undergoes ORIF with a locked compression plate for a humeral shaft fracture. Six weeks post-op, radiographs show an intact plate but a wide fracture gap with minimal callus. The patient reports pain at the fracture site. What is the most likely cause of this radiographic finding?

. Infection
. Stress shielding
. Radial nerve irritation
. Hardware failure
. Excessive compression at the fracture site

Correct Answer & Explanation

. Stress shielding

Explanation

A wide fracture gap with minimal callus despite intact hardware, especially with a rigid plate, is a classic sign of stress shielding. Locked compression plates (LCPs) are very rigid and can take up too much of the load, preventing the necessary stress at the fracture site that stimulates callus formation and bone healing (Wolff's Law). This can lead to delayed union or nonunion. While infection is possible, a wide gap with minimal callus (rather than bone resorption or lysis around hardware) is more indicative of a mechanical problem like stress shielding. Hardware failure would typically show plate breakage or screw pullout. Excessive compression is generally beneficial, not detrimental, to healing.

Question 9825

Topic: 2. Trauma
Which of the following scenarios would most strongly favor plate osteosynthesis over intramedullary nailing for a humeral shaft fracture?
. Segmental comminuted fracture in an elderly patient
. Pathological fracture due to metastatic disease
. Fracture with significant bone loss requiring bone grafting
. Distal third transverse fracture with intra-articular extension into the elbow
. Open Gustilo-Anderson Type IIIA fracture

Correct Answer & Explanation

. Distal third transverse fracture with intra-articular extension into the elbow

Explanation

A distal third transverse humeral shaft fracture with intra-articular extension into the elbow joint (a condylar or supracondylar component) is best managed with plate osteosynthesis. This allows for precise anatomical reduction of the articular surface fragments under direct visualization and provides the necessary rigid fixation (often with two plates) to stabilize the intra-articular components and the shaft. Intramedullary nailing is generally less suitable for intra-articular involvement or fractures very close to the joint line where distal locking becomes difficult and precise articular reduction cannot be achieved. Segmental or pathological fractures often favor IMN. Open fractures might initially get external fixation.

Question 9826

Topic: 2. Trauma

For a patient presenting with an acute, closed humeral shaft fracture, which initial immobilization method provides the best immediate pain control and prevents further displacement prior to definitive treatment (operative or non-operative)?

. Sarmiento functional brace
. Hanging arm cast
. Coaptation splint (e.g., U-shaped splint)
. Skeletal traction
. Sling and swathe

Correct Answer & Explanation

. Coaptation splint (e.g., U-shaped splint)

Explanation

A coaptation splint (U-shaped splint or sugar-tong splint) provides excellent immediate immobilization for acute humeral shaft fractures. It extends from the axilla, around the elbow, and up to the shoulder on the lateral side, effectively stabilizing the fracture fragments against the chest wall. This is a critical first step for pain control and preventing further soft tissue injury or displacement before swelling subsides and a definitive treatment plan (e.g., functional brace or surgery) is implemented. A Sarmiento brace requires a reduced swelling, and a hanging cast is for definitive non-operative treatment, not initial immobilization. Sling and swathe is generally insufficient.

Question 9827

Topic: 2. Trauma

What is the primary advantage of minimally invasive plate osteosynthesis (MIPO) over traditional open reduction and internal fixation for humeral shaft fractures?

. Stronger fixation construct
. Reduced risk of infection
. Less soft tissue dissection and preservation of fracture hematoma
. Shorter operative time
. Complete visualization of the fracture site

Correct Answer & Explanation

. Less soft tissue dissection and preservation of fracture hematoma

Explanation

The primary advantage of MIPO is its biological approach: it involves less soft tissue dissection, particularly stripping of the periosteum, and aims to preserve the fracture hematoma. This theoretically leads to improved blood supply to the fracture fragments, promoting faster healing and reducing rates of nonunion. While MIPO can result in reduced infection rates due to less tissue exposure, the main biomechanical and biological rationale is tissue preservation. The fixation construct isn't inherently stronger, operative time can sometimes be longer due to careful indirect reduction, and complete visualization of the fracture site is intentionally avoided to minimize soft tissue trauma.

Question 9828

Topic: 2. Trauma

A 40-year-old male sustains a humeral shaft fracture in a motorcycle accident. He also has a severe open tibial fracture and a closed femoral fracture. Which surgical principle for the humeral fracture should be prioritized in this polytrauma patient?

. Achieve absolute anatomical reduction for cosmetic results
. Utilize a functional brace to minimize surgical invasiveness
. Provide stable fixation to facilitate patient mobilization and nursing care
. Delay definitive fixation until other injuries are healed
. Prioritize external fixation to avoid any hardware in the humerus

Correct Answer & Explanation

. Provide stable fixation to facilitate patient mobilization and nursing care

Explanation

In a polytrauma patient, early and stable fixation of long bone fractures (damage control orthopedics) is paramount. The primary goal is to provide stable fixation to allow for early mobilization of the patient, facilitate nursing care, reduce pain, minimize complications like ARDS, and decrease the systemic inflammatory response. While anatomical reduction is desirable, functional stability is prioritized in this setting. Functional bracing is generally not suitable for polytrauma patients. Delaying fixation can lead to increased morbidity. External fixation might be used initially for the open tibia, but internal fixation of the humerus is usually performed when the patient is stable enough.

Question 9829

Topic: 2. Trauma

When performing ORIF with a plate and screws for a humeral shaft fracture, what is the recommended position for the patient to allow for optimal access to the entire humeral shaft and facilitate imaging?

. Supine with the arm abducted 90 degrees on a hand table
. Lateral decubitus with the affected arm draped free
. Prone with the arm adducted
. Beach chair position with the arm draped across the chest
. Sitting upright with skeletal traction

Correct Answer & Explanation

. Lateral decubitus with the affected arm draped free

Explanation

The lateral decubitus position with the affected arm draped free is commonly recommended for ORIF of the humeral shaft. This position allows for full circumduction of the arm, providing excellent access to both the anterior and posterior aspects of the humerus as needed for different approaches. It also facilitates intraoperative fluoroscopy in multiple planes without repositioning the patient. Supine with abduction can be used but offers less versatility, especially for posterior aspects, and prone is less common. Beach chair is primarily for shoulder surgery.

Question 9830

Topic: 2. Trauma

A patient undergoes successful intramedullary nailing of a mid-shaft humeral fracture. What is the most common postoperative complication directly related to the antegrade entry point?

. Radial nerve palsy
. Nonunion
. Rotator cuff impingement or shoulder pain
. Infection
. Distal locking screw loosening

Correct Answer & Explanation

. Rotator cuff impingement or shoulder pain

Explanation

For antegrade intramedullary nailing, the entry point typically involves breaching the rotator cuff and potentially damaging the deltoid. This can lead to postoperative shoulder pain, stiffness, and impingement symptoms due to hardware prominence or direct injury to the rotator cuff. This is a well-recognized and common complication. Radial nerve palsy is less common with IMN than plating. Nonunion and infection are general complications of any surgery but not specific to the entry point issue of antegrade nailing.

Question 9831

Topic: 2. Trauma

What is a major advantage of using a locking plate system for a comminuted humeral shaft fracture in osteoporotic bone?

. It promotes primary bone healing without callus formation
. It requires fewer screws for stable fixation
. It provides angular stability, making screw purchase less dependent on bone quality
. It allows for early weight-bearing without any limitations
. It eliminates the need for bone grafting

Correct Answer & Explanation

. It provides angular stability, making screw purchase less dependent on bone quality

Explanation

Locking plate systems provide angular stability by creating a fixed-angle construct where the screws lock into the plate, forming a 'fixed-angle internal fixator.' This makes screw purchase less dependent on cortical bone quality (e.g., in osteoporotic bone) and improves fixation strength. This is particularly advantageous in comminuted fractures where screw purchase might be poor in the metaphysis or in osteoporotic bone. Locking plates allow for stable fixation even when bicortical screw purchase is compromised. While they promote stable healing, they don't necessarily eliminate callus or bone grafting (if needed for nonunion), nor do they allow unlimited early weight-bearing.

Question 9832

Topic: 2. Trauma

A patient with a humeral shaft fracture treated with a functional brace presents at 8 weeks post-injury with a palpable and visible gap at the fracture site, significant pain, and no signs of healing on radiographs. This describes a:

. Delayed union
. Early union
. Malunion
. Atrophic nonunion
. Hypertrophic nonunion

Correct Answer & Explanation

. Atrophic nonunion

Explanation

A palpable/visible gap, significant pain, and no radiographic signs of healing, particularly at 8 weeks which is past the expected initial callus formation phase, strongly suggests an atrophic nonunion. Atrophic nonunions are characterized by a lack of biological activity at the fracture site, often due to devascularization, leading to bone resorption and a 'gap' appearance. They typically require surgical intervention with bone grafting. A delayed union would still show some signs of progression, albeit slow. Malunion is healing in an unacceptable position. Hypertrophic nonunion would show abundant callus but no bridging.

Question 9833

Topic: 2. Trauma

What is the primary concern when treating a distal third humeral shaft fracture with an antegrade intramedullary nail?

. Radial nerve injury
. Shoulder impingement
. Difficulty achieving adequate distal locking due to canal widening
. Ulnar nerve irritation
. Brachial artery injury

Correct Answer & Explanation

. Difficulty achieving adequate distal locking due to canal widening

Explanation

For distal third humeral shaft fractures, a primary concern with antegrade intramedullary nailing is the difficulty in achieving adequate distal locking. The medullary canal naturally widens in the distal metaphysis, which can make it challenging to obtain a stable fit of the nail and secure distal screw fixation, leading to potential loss of rotational control or pullout. Shoulder impingement is more common with mid-shaft or proximal fractures. Radial nerve injury is less common with IMN than plating but always a risk. Ulnar nerve and brachial artery injury are less direct concerns with antegrade nailing for shaft fractures.

Question 9834

Topic: 2. Trauma

Which of the following conditions might necessitate consideration of a retrograde intramedullary nail for a mid-shaft humeral fracture?

. A concomitant ipsilateral proximal humeral fracture
. A history of previous rotator cuff repair in the ipsilateral shoulder
. Primary radial nerve palsy
. A severely comminuted fracture requiring extensive soft tissue stripping
. A pathological fracture due to metastatic disease

Correct Answer & Explanation

. A history of previous rotator cuff repair in the ipsilateral shoulder

Explanation

A history of previous rotator cuff repair or other ipsilateral shoulder pathology (e.g., shoulder arthritis requiring future arthroplasty, severe impingement) might make antegrade nailing undesirable due to the risk of further shoulder compromise. In such cases, a retrograde intramedullary nail, which spares the shoulder joint, could be a preferred option for a mid-shaft humeral fracture. A concomitant ipsilateral proximal humeral fracture would rule out antegrade nailing, making retrograde an option if fixation of the proximal fracture is also planned. Primary radial nerve palsy does not dictate the nailing approach. Severe comminution doesn't specifically point to retrograde, and pathological fractures are often best treated with antegrade nailing.

Question 9835

Topic: 2. Trauma

A 29-year-old male sustains a closed, isolated mid-shaft humeral fracture. He is a high-performance athlete (pitcher for a baseball team) and demands the absolute fastest and most reliable return to sport. What is the optimal treatment strategy?

. Functional bracing for 12 weeks
. Hanging cast for 8 weeks
. Open reduction and internal fixation with a compression plate
. Antegrade intramedullary nailing
. External fixation

Correct Answer & Explanation

. Antegrade intramedullary nailing

Explanation

For a high-demand athlete requiring the fastest and most reliable return to sport, operative management is typically preferred. Both plating and nailing offer good stability. However, intramedullary nailing is often favored in this scenario due to its load-sharing nature, which may allow for earlier controlled rehabilitation and return to strength training, and its minimal soft tissue disruption. Plate fixation is also an option, but IMN avoids significant periosteal stripping and has advantages in high-demand patients. Non-operative methods would involve a significantly longer recovery and return-to-sport timeline, which is unacceptable for a professional athlete.

Question 9836

Topic: 2. Trauma

Which specific biomechanical principle is primarily exploited by a Sarmiento-type functional brace for humeral shaft fractures?

. Distraction to maintain length
. Tension band principle to convert distraction to compression
. Hydraulic pressure of soft tissues and circumferential compression
. Articular conformity for stability
. Cantilever bending

Correct Answer & Explanation

. Hydraulic pressure of soft tissues and circumferential compression

Explanation

The Sarmiento-type functional brace primarily utilizes the hydraulic pressure of the surrounding soft tissues and circumferential compression to stabilize the fracture fragments. The brace acts as an external pneumatic splint, applying constant pressure to the soft tissues, which in turn compresses the fracture fragments, promoting union and maintaining alignment. It does not primarily rely on distraction, tension band, or articular conformity (as it's a shaft fracture).

Question 9837

Topic: 2. Trauma

A 60-year-old active female develops a symptomatic hypertrophic nonunion of a mid-shaft humeral fracture 8 months after treatment with a functional brace. Radiographs show abundant callus formation but a persistent fracture line. What is the most appropriate surgical management?

. Re-application of a functional brace with increased compression
. Intramedullary nailing without bone grafting
. Open reduction and internal fixation with a plate, decortication, and bone grafting
. External fixation with dynamic compression
. Percutaneous injection of corticosteroids

Correct Answer & Explanation

. Intramedullary nailing without bone grafting

Explanation

A hypertrophic nonunion is characterized by abundant callus formation, indicating biological healing potential, but a lack of mechanical stability for bridging. In this scenario, the primary issue is mechanical, not biological. Therefore, intramedullary nailing, which provides excellent load-sharing stability with minimal soft tissue stripping, is often the preferred treatment. Bone grafting is typically not required for hypertrophic nonunions because there is already sufficient biological activity. Plate fixation with decortication and grafting is generally reserved for atrophic nonunions. Re-bracing is unlikely to be effective for an established nonunion.

Question 9838

Topic: 2. Trauma

A 35-year-old patient undergoes ORIF of a humeral shaft fracture. Postoperatively, the patient develops signs of a compartment syndrome in the forearm (pain out of proportion, pain with passive stretch of fingers, paresthesia). What is the immediate next step?

. Elevate the arm and apply ice
. Administer opioid analgesics for pain relief
. Perform a forearm fasciotomy
. Obtain an urgent MRI of the forearm
. Loosen all dressings and splints, and monitor compartment pressures

Correct Answer & Explanation

. Loosen all dressings and splints, and monitor compartment pressures

Explanation

The immediate first step in suspected compartment syndrome is to release all external constrictive dressings, splints, or casts. This can sometimes alleviate pressure and prevent progression. Following this, compartment pressures should be measured immediately. If pressures are elevated above a critical threshold (typically within 30 mmHg of diastolic blood pressure or an absolute pressure >30-40 mmHg, depending on protocols), then an urgent forearm fasciotomy is indicated to prevent irreversible muscle and nerve damage. Elevating the arm is contraindicated as it reduces arterial perfusion. Analgesics mask symptoms. MRI is too slow for an acute emergency.

Question 9839

Topic: 2. Trauma

Which type of humeral shaft fracture typically involves the highest rate of vascular injury due to its location?

. Proximal third spiral fracture
. Mid-shaft transverse fracture
. Distal third oblique fracture
. Supracondylar humeral fracture extending into the shaft
. Segmental fracture of the mid-diaphysis

Correct Answer & Explanation

. Distal third oblique fracture

Explanation

Distal third humeral shaft fractures, particularly those extending into the supracondylar region or with significant displacement, are most closely associated with a risk of brachial artery injury. The brachial artery courses medially and anteriorly in the arm and is particularly vulnerable where it passes close to the humerus just proximal to the elbow joint. While any displaced fracture can potentially injure a vessel, the anatomical proximity makes distal third fractures and especially supracondylar fractures more prone to vascular compromise. Other fracture locations carry a lower risk.

Question 9840

Topic: 2. Trauma

What is the primary concern regarding rotational control when managing a transverse mid-shaft humeral fracture with a functional brace?

. Varus/valgus malunion
. Anterior/posterior angulation
. Shortening
. Lack of inherent stability against torsional forces
. Radial nerve impingement

Correct Answer & Explanation

. Lack of inherent stability against torsional forces

Explanation

For transverse mid-shaft humeral fractures, the lack of interdigitating fracture surfaces means there is very little inherent stability against rotational (torsional) forces. While functional braces provide good control against angulation and shortening due to circumferential compression, they offer less robust control over rotation compared to spiral or oblique fractures where fragment interdigitation resists rotation. This makes achieving and maintaining rotational alignment more challenging with non-operative management for transverse fractures. However, rotational malunion of the humerus is often well-tolerated due to shoulder mobility, so it is often a secondary concern compared to angulation and shortening.

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