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2. Trauma MCQs

Practice Set 491 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 9801

Topic: 2. Trauma

Which of the following factors is most strongly associated with an increased risk of nonunion following non-operative treatment of a humeral shaft fracture?

. Patient age over 60 years
. Distal third fracture location
. Transverse fracture pattern
. Initial fracture displacement of less than 1 cm
. Associated radial nerve palsy

Correct Answer & Explanation

. Transverse fracture pattern

Explanation

Transverse fracture patterns of the humeral shaft treated non-operatively have been identified as having a higher risk of nonunion compared to spiral or oblique patterns. This is primarily due to the inherent instability of transverse fractures, which makes achieving and maintaining satisfactory reduction and apposition more challenging in a non-operative setting. While other factors like age or location can influence outcomes, the fracture pattern itself is a significant biomechanical determinant of stability and healing potential with conservative management. Radial nerve palsy itself does not increase nonunion risk.

Question 9802

Topic: 2. Trauma

A 40-year-old male with a nonunion of a humeral shaft fracture previously treated with a functional brace presents with pain and instability. Radiographs show a sclerotic nonunion gap. Which surgical option is generally considered most appropriate for revision surgery in this scenario?

. Re-application of a functional brace
. Intramedullary nailing with reaming and bone grafting
. Plate osteosynthesis with compression and bone grafting
. External fixation
. Percutaneous pinning

Correct Answer & Explanation

. Plate osteosynthesis with compression and bone grafting

Explanation

For a sclerotic nonunion of a humeral shaft, plate osteosynthesis with compression and bone grafting (autograft or allograft) is widely considered the gold standard for revision surgery. Sclerotic nonunions are typically 'atrophic' and require biological stimulation (grafting) and mechanical stability (compression plating) to achieve union. Reaming and intramedullary nailing can be used for nonunions, but often require specific nail designs (e.g., larger diameter, specific locking options) and may be less effective for sclerotic nonunions with a significant gap or angulation where a plate provides better compression and contouring. External fixation is rarely the definitive treatment for established nonunions, and percutaneous pinning is inadequate.

Question 9803

Topic: 2. Trauma

What is a potential advantage of using a retrograde intramedullary nail for a distal third humeral shaft fracture?

. Reduced risk of radial nerve injury
. Less potential for shoulder impingement and rotator cuff injury
. Easier insertion technique compared to antegrade nailing
. Greater rotational stability than antegrade nailing
. Applicable for very proximal humeral fractures

Correct Answer & Explanation

. Less potential for shoulder impingement and rotator cuff injury

Explanation

A significant advantage of retrograde intramedullary nailing for distal humeral shaft fractures is the avoidance of the shoulder joint and its associated soft tissues. This minimizes the risk of shoulder pain, stiffness, and rotator cuff impingement/injury, which are well-known complications of antegrade nailing. However, retrograde nailing carries its own risks, such as elbow stiffness or distal humeral fracture propagation. It does not necessarily reduce the risk of radial nerve injury compared to antegrade nailing, nor is it inherently easier. Rotational stability depends on nail design and locking. It's not applicable for very proximal fractures.

Question 9804

Topic: 2. Trauma

A 22-year-old female presents with a closed humeral shaft fracture in the setting of severe osteogenesis imperfecta. Given her bone fragility, what is the most appropriate surgical approach to stabilize this fracture?

. Functional bracing
. Hanging cast
. Flexible intramedullary nailing (e.g., Fassier-Duval rods)
. Standard locked compression plating
. External fixation

Correct Answer & Explanation

. Flexible intramedullary nailing (e.g., Fassier-Duval rods)

Explanation

In patients with osteogenesis imperfecta (OI), bone fragility is extreme, and fractures are common. The optimal surgical approach for humeral shaft fractures in OI is often internal fixation with flexible intramedullary nails, such as Fassier-Duval rods or telescoping rods. These implants allow for continued bone growth and provide longitudinal stability while minimizing stress shielding and allowing for re-fracture prevention. Standard plating can be problematic due to poor screw purchase in osteoporotic bone and the stress-rising effect at plate ends. Non-operative management is often ineffective for achieving stable union in OI due to recurrent fractures and bone deformity. External fixation is generally not a long-term solution.

Question 9805

Topic: 2. Trauma

Which of the following scenarios is a strong contraindication for functional bracing in a humeral shaft fracture?

. Transverse mid-shaft fracture with 10 degrees of angulation
. Segmental fracture in a conscious, cooperative patient
. Oblique fracture in a patient with a primary radial nerve palsy
. Shortening of 1.5 cm in a spiral fracture
. Morbid obesity where brace fit is compromised

Correct Answer & Explanation

. Segmental fracture in a conscious, cooperative patient

Explanation

A segmental humeral shaft fracture is a relative contraindication to functional bracing and often an indication for operative management. Segmental fractures are inherently unstable and difficult to control with a functional brace, leading to higher rates of malunion or nonunion. While the patient is cooperative, the fracture pattern itself makes non-operative management challenging and less predictable. Other options generally fall within acceptable parameters for functional bracing or are not direct contraindications to the method itself, though obesity can make bracing challenging, it's not an absolute contraindication compared to the fracture pattern.

Question 9806

Topic: 2. Trauma

A 38-year-old male sustains a closed transverse mid-shaft humeral fracture. He is a smoker and poorly compliant. He reports persistent pain and lack of healing after 6 months of functional bracing, with radiographs showing a nonunion. What is the most appropriate next step in management?

. Continue functional bracing for another 3 months
. Perform open reduction and internal fixation with a plate and autogenous bone graft
. Recommend a course of pulsed electromagnetic fields (PEMF)
. Administer high-dose NSAIDs for pain control
. Perform intramedullary nailing without bone grafting

Correct Answer & Explanation

. Perform open reduction and internal fixation with a plate and autogenous bone graft

Explanation

Given the established nonunion after 6 months of failed non-operative treatment, surgical intervention is indicated. For a nonunion, particularly a transverse pattern which can be 'atrophic' and in a patient with risk factors for poor healing (smoking, poor compliance), open reduction and internal fixation with a compression plate and autogenous bone grafting is considered the gold standard. The bone graft provides biological stimulation for healing, and the plate provides stable mechanical fixation. Intramedullary nailing might also be an option, but bone grafting is critical for addressing the biological deficiency in a nonunion. Continuing bracing or using PEMF alone is unlikely to be successful for an established nonunion, and NSAIDs would hinder healing.

Question 9807

Topic: 2. Trauma

A 48-year-old male sustains a humeral shaft fracture that is associated with an ipsilateral forearm (both bone) fracture (a 'floating elbow'). What is the recommended management strategy for the humeral fracture?

. Functional bracing for both fractures
. Hanging cast for the humerus, ORIF for the forearm
. Intramedullary nailing or plate fixation for the humerus, ORIF for the forearm
. External fixation for the humerus, functional bracing for the forearm
. Skeletal traction for the humerus, ORIF for the forearm

Correct Answer & Explanation

. Intramedullary nailing or plate fixation for the humerus, ORIF for the forearm

Explanation

A 'floating elbow' (ipsilateral humeral and forearm fractures) is a compelling indication for operative fixation of both fractures. Stabilizing the humeral fracture, typically with intramedullary nailing or plate fixation, allows for earlier mobilization of the elbow and prevents prolonged immobilization that can lead to severe stiffness, especially when both segments are involved. Operative stabilization of the forearm fracture is also typically indicated. Non-operative management of the humeral fracture in this scenario would complicate the management of the forearm fracture and significantly increase the risk of elbow stiffness and poor functional outcomes.

Question 9808

Topic: 2. Trauma

Which type of humeral shaft fracture is typically best suited for functional bracing due to its inherent stability once reduced?

. Comminuted fracture
. Segmental fracture
. Transverse fracture
. Spiral fracture
. Highly displaced oblique fracture

Correct Answer & Explanation

. Spiral fracture

Explanation

Spiral fractures of the humeral shaft are generally considered ideal for functional bracing. Once reduced and aligned, the long oblique fracture surfaces provide inherent stability and resist shortening and rotation, making them amenable to healing with external support. Comminuted, segmental, and highly displaced oblique fractures are inherently less stable and more challenging to manage non-operatively, often leading to higher rates of nonunion or malunion. Transverse fractures, while sometimes managed non-operatively, can be more prone to shortening and angular deformities due to their lack of interdigitating fragments.

Question 9809

Topic: 2. Trauma

A 30-year-old male with a closed, oblique mid-shaft humeral fracture is treated with a functional brace. At 3 weeks post-injury, he presents with increased pain and marked shortening (4 cm) on follow-up radiographs. He has intact neurovascular status. What is the most appropriate next step?

. Adjust the functional brace and continue observation
. Apply a hanging cast for better traction
. Proceed with open reduction and internal fixation with a plate
. Prescribe stronger analgesics and continue bracing
. Recommend physical therapy to improve alignment

Correct Answer & Explanation

. Proceed with open reduction and internal fixation with a plate

Explanation

The patient has developed significant shortening (4 cm), which exceeds the generally accepted limits for non-operative management (typically up to 3 cm). This indicates a failure of non-operative treatment to maintain adequate alignment. Therefore, operative intervention, such as open reduction and internal fixation with a plate or intramedullary nailing, is indicated to achieve anatomical reduction and stable fixation, preventing further displacement and promoting union. Simply adjusting the brace, using a hanging cast (which provides less stable control than bracing in the active phase, and is not for established failure), or prescribing analgesics would not address the underlying mechanical instability.

Question 9810

Topic: 2. Trauma

Which biomechanical property is a significant advantage of intramedullary nailing over plate fixation for highly comminuted humeral shaft fractures?

. Superior rotational stability
. Less risk of iatrogenic radial nerve injury
. Load-bearing fixation
. Load-sharing fixation
. Better for very distal fractures

Correct Answer & Explanation

. Load-sharing fixation

Explanation

Intramedullary nails are load-sharing devices. This means they share axial load with the bone, rather than bearing the entire load (as plates do). This property is particularly advantageous for highly comminuted fractures where there is significant cortical bone loss, as it reduces stress shielding, promotes callus formation, and can allow for earlier weight-bearing or functional use of the arm without risking implant failure. Plates are load-bearing and can lead to stress shielding. While IMNs often have a lower risk of iatrogenic radial nerve injury compared to direct plating, and can offer good stability, their primary biomechanical advantage for comminuted fractures is load-sharing.

Question 9811

Topic: 2. Trauma

A 50-year-old female presents with a pathological fracture of the humeral shaft due to metastatic breast cancer. She is expected to have a life expectancy of 6-12 months. What is the primary goal of treatment, and what is the most suitable fixation method?

. Achieve anatomical reduction and full union; plate fixation
. Pain relief and functional stability for palliation; intramedullary nailing
. Non-operative management with a functional brace due to limited life expectancy
. External fixation for ease of removal
. Radiation therapy alone

Correct Answer & Explanation

. Pain relief and functional stability for palliation; intramedullary nailing

Explanation

For pathological fractures, especially in patients with limited life expectancy, the primary goal of treatment is rapid pain relief, functional stability for palliation, and preventing further morbidity. Intramedullary nailing is often the preferred method as it provides immediate load-sharing stability, allows for early mobilization, and has a lower risk of implant failure. It also can be extended across the full length of the bone to protect against future fractures. While anatomical reduction is desired, the main emphasis is on durable fixation for comfort and function, rather than complete union, which may not occur due to the underlying disease. Functional bracing is often inadequate for pathological fractures due to poor bone quality.

Question 9812

Topic: 2. Trauma

A 25-year-old male sustains a closed, transverse mid-shaft humeral fracture. He also has a severe traumatic brain injury and is non-ambulatory. What is the optimal treatment for the humeral fracture?

. Functional bracing, as it is non-invasive
. Hanging cast for alignment
. Open reduction and internal fixation with a plate
. Intramedullary nailing
. External fixation

Correct Answer & Explanation

. Intramedullary nailing

Explanation

For a patient with a traumatic brain injury (TBI), early and stable fixation of long bone fractures is crucial. This minimizes pain, allows for easier nursing care, facilitates transfers, and prevents complications associated with prolonged immobilization. Furthermore, early fracture stabilization is thought to reduce the systemic inflammatory response, which can positively impact TBI recovery. While plating is also an option, intramedullary nailing is often preferred in this setting due to its load-sharing properties, which may allow for earlier mobilization, and less soft tissue disruption. Functional bracing and hanging casts are generally not suitable for uncooperative or non-ambulatory TBI patients.

Question 9813

Topic: 2. Trauma

What is the primary rationale for recommending a functional brace over a hanging cast for most humeral shaft fractures amenable to non-operative treatment?

. Hanging casts are more prone to skin irritation
. Functional braces provide better fracture compression and prevent shortening
. Hanging casts increase the risk of radial nerve palsy
. Functional braces are lighter and more comfortable for patients
. Hanging casts lead to higher rates of nonunion

Correct Answer & Explanation

. Functional braces provide better fracture compression and prevent shortening

Explanation

Functional braces (e.g., Sarmiento brace) are preferred over hanging casts because they provide circumferentially applied compression to the fracture site, which helps to maintain reduction, prevent shortening, and promote callus formation. Hanging casts rely on gravity for traction and alignment but offer poor rotational control and can exacerbate fracture angulation (especially apex anterior angulation) due to the weight. While comfort can be a factor, the primary biomechanical advantage of the functional brace is superior fracture control and compression. Neither method inherently increases radial nerve palsy risk. Nonunion rates are generally lower with functional bracing compared to hanging casts if the latter is improperly used or for inappropriate fracture patterns.

Question 9814

Topic: 2. Trauma

When performing ORIF with a plate and screws for a mid-shaft humeral fracture, what is the minimum number of cortices that should be engaged by screws both proximal and distal to the fracture to achieve adequate stability?

. 4 cortices (2 screws)
. 6 cortices (3 screws)
. 8 cortices (4 screws)
. 10 cortices (5 screws)
. 12 cortices (6 screws)

Correct Answer & Explanation

. 8 cortices (4 screws)

Explanation

For standard plate osteosynthesis of humeral shaft fractures, the accepted principle for achieving adequate stability is to have at least 8 cortices engaged (meaning 4 screws) both proximal and distal to the fracture site. This provides sufficient purchase and rigidity to resist bending, torsion, and axial forces, thereby promoting union. While more screws can provide additional stability, 4 bicortical screws per segment (8 cortices total) is generally considered the minimum for satisfactory fixation in most clinical scenarios. Less than 8 cortices significantly increases the risk of implant failure or loss of reduction.

Question 9815

Topic: 2. Trauma

A 65-year-old female sustains a closed, spiral mid-shaft humeral fracture. She has severe Parkinson's disease, leading to significant tremors and poor muscle control. What is the most appropriate treatment option?

. Functional bracing
. Hanging cast
. Open reduction and internal fixation with a plate
. Intramedullary nailing
. Expectant management with pain control only

Correct Answer & Explanation

. Intramedullary nailing

Explanation

For a patient with severe Parkinson's disease and tremors, maintaining reduction and alignment with non-operative methods like functional bracing or a hanging cast would be extremely challenging and likely result in malunion or nonunion due to uncontrolled movements. Therefore, operative stabilization is indicated. Intramedullary nailing is often preferred over plating in such patients as it is a load-sharing, less invasive method with good biomechanical stability, allowing for early protected movement despite tremors, and avoiding the need for strict cast/brace compliance. Plating could also work, but IMN often has advantages in such scenarios.

Question 9816

Topic: 2. Trauma

Which of the following is a common complication specific to retrograde intramedullary nailing of the humeral shaft?

. Shoulder impingement
. Radial nerve palsy
. Elbow stiffness or pain
. Nonunion of the proximal humerus
. Damage to the axillary nerve

Correct Answer & Explanation

. Elbow stiffness or pain

Explanation

Retrograde intramedullary nailing involves an entry point in the distal humerus, typically through the olecranon fossa or capitellum. While it avoids shoulder complications, it carries a risk of elbow stiffness, pain, or even iatrogenic fracture of the supracondylar region or olecranon during insertion. Shoulder impingement is a complication of antegrade nailing. Radial nerve palsy can occur with any humeral shaft surgery but is not specific to retrograde nailing. Nonunion of the proximal humerus and axillary nerve damage are not typical complications of retrograde nailing (which addresses the shaft distally).

Question 9817

Topic: 2. Trauma

In managing a delayed union of a humeral shaft fracture (e.g., 4 months post-injury with persistent fracture line but some callus), what adjunctive treatment might be considered before surgical intervention?

. High-dose NSAIDs
. Corticosteroid injections at the fracture site
. Pulsed electromagnetic fields (PEMF) or low-intensity pulsed ultrasound (LIPUS)
. Complete immobilization with a spica cast
. Immediate surgical plating without grafting

Correct Answer & Explanation

. Pulsed electromagnetic fields (PEMF) or low-intensity pulsed ultrasound (LIPUS)

Explanation

For a delayed union, especially when some callus is present but healing is slow, non-invasive bone stimulation methods like pulsed electromagnetic fields (PEMF) or low-intensity pulsed ultrasound (LIPUS) can be considered. These modalities are thought to promote bone healing and may help avoid surgery in some cases. NSAIDs inhibit bone healing, and corticosteroids would be detrimental. A spica cast is overly restrictive and typically not used for humeral shaft fractures, and immediate surgery might be premature if non-invasive options still exist. Surgical intervention with or without grafting is generally reserved for established nonunions or if non-invasive methods fail.

Question 9818

Topic: 2. Trauma

What is the primary concern when considering non-operative management for a high-energy, open (Gustilo-Anderson Type I) humeral shaft fracture?

. Inability to achieve anatomical reduction
. Increased risk of radial nerve palsy
. High risk of infection and nonunion if not stabilized operatively
. Excessive pain that cannot be managed conservatively
. Development of compartment syndrome

Correct Answer & Explanation

. High risk of infection and nonunion if not stabilized operatively

Explanation

Open fractures, even Gustilo-Anderson Type I, always carry a significantly higher risk of infection and subsequent nonunion if not appropriately managed. This necessitates surgical debridement and typically operative stabilization (often with internal fixation after appropriate debridement, or external fixation initially for more severe open injuries). While pain management is a factor, and reduction might be difficult, the overriding concern for any open fracture is preventing deep infection and promoting timely union. Compartment syndrome is rare in the arm, but infection is a constant threat with open injuries.

Question 9819

Topic: 2. Trauma

A 42-year-old male with a closed, spiral mid-shaft humeral fracture has been non-operatively managed in a functional brace for 12 weeks. Radiographs show a persistent fracture line and pain with activity. There is mild callus formation but no bridging. Which term best describes this situation?

. Malunion
. Nonunion
. Delayed union
. Infected union
. Stress fracture

Correct Answer & Explanation

. Delayed union

Explanation

This scenario describes a delayed union. A delayed union is diagnosed when a fracture has not healed in the expected timeframe for that particular fracture (typically 3-4 months for humeral shaft fractures) but still shows signs of biological healing potential (some callus formation). A nonunion is typically declared when there are no signs of progression toward healing for at least 3 consecutive months, or after 6-9 months total, with evidence of sclerosis and fracture gap. Malunion refers to healing in an unacceptable position. Infected union and stress fracture are distinct pathologies.

Question 9820

Topic: 2. Trauma

Which surgical technique for humeral shaft fracture fixation has the highest reported incidence of iatrogenic radial nerve injury?

. Antegrade intramedullary nailing
. Retrograde intramedullary nailing
. Minimally invasive plate osteosynthesis (MIPO)
. Conventional open reduction and internal fixation (ORIF) with plate
. External fixation

Correct Answer & Explanation

. Conventional open reduction and internal fixation (ORIF) with plate

Explanation

Conventional open reduction and internal fixation (ORIF) with a plate, particularly using direct posterior or anterolateral approaches, has the highest reported incidence of iatrogenic radial nerve injury. This is due to the extensive soft tissue dissection required, direct visualization, and manipulation of the fracture fragments and surrounding tissues, placing the nerve directly at risk of traction, compression, or transection. Minimally invasive techniques (MIPO, IMN) generally aim to reduce this risk by minimizing soft tissue dissection around the nerve, though radial nerve injury is still a known complication with all internal fixation methods.

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