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2. Trauma MCQs

Practice Set 37 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 721

Topic: 2. Trauma

A 78-year-old female presents with a periprosthetic femoral fracture around a polished taper-slip cemented stem. Radiographs show a fracture at the tip of the stem with subsidence of the implant, but excellent bone stock in the diaphysis. What is the most appropriate surgical management?

. Open reduction internal fixation with a lateral locking plate and cables
. Revision to a long cemented stem
. Revision to an extensively porous-coated cylindrical stem bypassing the fracture by two cortical diameters
. Revision to a modular fluted tapered stem bypassing the fracture by two cortical diameters
. Cortical strut allografting only

Correct Answer & Explanation

. Revision to a modular fluted tapered stem bypassing the fracture by two cortical diameters

Explanation

This is a Vancouver B2 periprosthetic fracture (fracture around the stem, loose implant, good bone stock). The standard of care is revision of the femoral component using a long cementless stem, typically a fluted tapered or extensively porous-coated stem, bypassing the most distal defect by at least two cortical diameters.

Question 722

Topic: 2. Trauma

A patient falls from a height and sustains a transforaminal sacral fracture (Denis Zone II). Which neurologic structures are most directly at risk of injury from this specific fracture pattern?

. L4 and L5 nerve roots
. S1 and S2 nerve roots
. Sacral plexus leading to isolated bladder dysfunction
. Superior gluteal nerve
. Pudendal nerve

Correct Answer & Explanation

. S1 and S2 nerve roots

Explanation

Denis Zone II sacral fractures pass through the sacral foramina, placing the exiting S1 and S2 nerve roots at the greatest risk, often causing radicular pain or sciatica.

Question 723

Topic: 2. Trauma

A 72-year-old female presents to the emergency department after a low-energy fall onto her outstretched arm, sustaining a closed, non-comminuted midshaft humerus fracture. She has no neurovascular deficits. Radiographs show a transverse fracture pattern with 15 degrees of varus angulation, 10 degrees of anterior angulation, and 1 cm of shortening. Based on the provided case material, what is the MOST appropriate initial management strategy for this patient?

. Immediate open reduction and internal fixation with a locking compression plate via a posterior approach.
. Urgent intramedullary nailing to facilitate early mobilization due to her age.
. Application of a functional humerus brace with close clinical and radiographic follow-up.
. Surgical exploration of the radial nerve due to the risk of delayed palsy.
. Admission for skeletal traction followed by delayed surgical fixation.

Correct Answer & Explanation

. Application of a functional humerus brace with close clinical and radiographic follow-up.

Explanation

Correct Answer: CThe case material explicitly states that for the vast majority of closed, non-comminuted midshaft humerus fractures,functional bracing remains a highly effective initial treatment, with union rates often exceeding 90%. The acceptable alignment criteria for non-operative treatment are less than 20 degrees of anterior angulation, less than 30 degrees of varus angulation, and less than 3 cm of shortening. This patient's fracture falls well within these acceptable parameters (15 degrees varus, 10 degrees anterior, 1 cm shortening). Her low-energy mechanism and lack of neurovascular deficit further support non-operative management.Option A (Immediate ORIF with LCP via posterior approach)is incorrect. While ORIF is an option for certain indications, it is not the most appropriate initial management for a stable, closed fracture within acceptable alignment parameters, especially given the higher complication rates associated with operative management compared to non-operative care for suitable fractures.Option B (Urgent intramedullary nailing)is incorrect for similar reasons. While IM nailing is a valid operative technique, it is not indicated as the primary treatment for this stable fracture. Furthermore, IM nailing can be associated with shoulder or elbow pain from entry portals.Option D (Surgical exploration of the radial nerve)is incorrect. The patient has no neurovascular deficits. The case material clearly states that radial nerve palsy in closed humerus fractures should initially be observed, as spontaneous recovery occurs in 70-90% of cases. Immediate exploration is reserved for specific scenarios like open fractures with nerve deficits or evolving palsy with increasing soft tissue compromise, none of which apply here.Option E (Admission for skeletal traction)is an outdated and generally not indicated primary treatment for midshaft humerus fractures in the modern era, especially for a stable, closed fracture amenable to functional bracing.

Question 724

Topic: 2. Trauma

A 40-year-old male sustains a highly comminuted midshaft humerus fracture (AO/OTA 12-C3) after a fall from a height. He has no neurovascular deficits. The surgeon opts for operative fixation. Considering the biomechanical principles discussed in the case, which fixation strategy is generally preferred for this fracture pattern to promote secondary bone healing and why?

. Dynamic compression plating (DCP) with interfragmentary lag screws for absolute stability.
. Intramedullary nailing with static locking, as it is a load-sharing device that resists bending and axial loads effectively.
. External fixation to allow for staged reconstruction and soft tissue healing.
. Minimally invasive plate osteosynthesis (MIPO) with a locking compression plate (LCP) applying the principle of relative stability.
. Tension band wiring for robust compression across the comminuted zone.

Correct Answer & Explanation

. Minimally invasive plate osteosynthesis (MIPO) with a locking compression plate (LCP) applying the principle of relative stability.

Explanation

Correct Answer: DThe case material states that for comminuted fractures, "bridging principles to restore length and alignment without direct compression of fragments" are required. It also highlights that "Plate fixation offers superior resistance to bending and torsional forces, especially with longer plates and more screws (increasing working length). The principle of relative stability (bridging plates) is often employed for comminuted fractures." Furthermore, the summary mentions that "For comminuted midshaft fractures, MIPO plating techniques using LCPs are gaining popularity due to their potential to preserve soft tissue and provide stable fixation with relative stability principles." MIPO with an LCP applying relative stability (bridging) is ideal for comminuted fractures as it preserves periosteal blood supply and allows for secondary bone healing.Option A (Dynamic compression plating (DCP) with interfragmentary lag screws for absolute stability)is incorrect. Absolute stability with lag screws and compression plating is typically used for simple transverse or short oblique fractures to achieve primary bone healing, not for highly comminuted fractures where direct compression would devitalize fragments and a bridging technique is preferred.Option B (Intramedullary nailing with static locking, as it is a load-sharing device that resists bending and axial loads effectively)is a plausible option, as IM nailing is a load-sharing device promoting secondary healing. However, the question asks for the generally preferred strategy for ahighly comminutedfracture, and the case specifically mentions MIPO plating for comminuted fractures. While nailing is effective for bending and axial loads, it is "less effective against rotational forces unless adequately locked proximally and distally." Plate fixation offers superior resistance to bending and torsional forces, making MIPO plating often preferred for highly comminuted patterns where precise alignment and rotational control are critical, especially when considering the potential for shoulder/elbow pain with nailing.Option C (External fixation)is generally reserved for open fractures with severe soft tissue damage, highly contaminated wounds, or as a temporary measure in polytrauma, not typically as a definitive fixation for a closed comminuted midshaft humerus fracture.Option E (Tension band wiring)is primarily used for avulsion fractures or fractures around joints (e.g., olecranon, patella) where muscle pull creates a tension force, converting it into compression. It is not suitable for stabilizing a highly comminuted midshaft humerus fracture.

Question 725

Topic: 2. Trauma

A 60-year-old male with a history of morbid obesity and poorly controlled diabetes sustains a closed, segmental midshaft humerus fracture. He is non-compliant with medical advice and has a poor social support system. Initial attempts at functional bracing have failed to maintain acceptable alignment, with radiographs showing progressive varus angulation exceeding 35 degrees. Based on the case material, which of the following is the MOST compelling indication for operative management in this patient?

. The presence of a segmental fracture alone.
. The patient's morbid obesity and non-compliance making functional bracing challenging.
. The failure of non-operative treatment to maintain acceptable alignment.
. The patient's poorly controlled diabetes, increasing the risk of nonunion.
. All of the above are compelling indications for operative management.

Correct Answer & Explanation

. All of the above are compelling indications for operative management.

Explanation

Correct Answer: EThe case material lists several factors that, individually or in combination, serve as strong indications for operative management:Failed non-operative treatment:"Persistent unacceptable alignment, nonunion, or patient intolerance of brace." This patient has progressive varus angulation exceeding 35 degrees, which is well beyond the acceptable 30 degrees.Segmental fractures:These are listed as a relative indication for operative intervention.Morbid obesity or non-compliant patients:"Where functional bracing is challenging." This patient fits both descriptions.While poorly controlled diabetes (Option D) is a risk factor for nonunion, it is not listed as a direct indication for operative management itself, but rather a comorbidity that influences the decision-making process and prognosis. However, the combination of failed non-operative treatment, a segmental fracture, and patient factors (morbid obesity, non-compliance) makes operative management the most appropriate choice. Therefore, 'All of the above' (considering the individual factors as contributing to the overall decision) is the best answer.Option A (The presence of a segmental fracture alone)is a relative indication, but not the sole compelling factor here.Option B (The patient's morbid obesity and non-compliance)are relative indications, making bracing difficult, but not the only reasons for surgery.Option C (The failure of non-operative treatment)is a strong indication, but combined with the other factors, the decision is even more robust.Since all listed factors (A, B, C, and the underlying risk from D) contribute significantly to the decision for operative management, 'All of the above' is the most comprehensive and accurate answer.

Question 726

Topic: 2. Trauma

A 55-year-old male presents with a midshaft humerus fracture following a high-energy trauma. On initial assessment, he has diminished radial pulses and an expanding hematoma in the arm. He also has a complete radial nerve palsy. Which of the following pre-operative imaging studies is MOST critical to obtain immediately for this patient?

. Standard AP and lateral radiographs of the humerus.
. Computed Tomography (CT) scan of the humerus.
. Angiography of the affected limb.
. Electromyography (EMG) and nerve conduction studies (NCS).
. Magnetic Resonance Imaging (MRI) of the brachial plexus.

Correct Answer & Explanation

. Angiography of the affected limb.

Explanation

Correct Answer: CThe case material explicitly states under Pre-Operative Planning: "Angiography: Indicated if vascular injury is suspected (e.g., diminished pulses, expanding hematoma)." This patient presents with both diminished radial pulses and an expanding hematoma, which are classic signs of a vascular injury requiring urgent assessment and potential repair. Vascular injury is an absolute indication for operative intervention, and its identification is paramount.Option A (Standard AP and lateral radiographs)are essential for fracture characterization but will not provide information about the vascular status. While they are always obtained, they are not themost criticalimmediate study for the suspected vascular injury.Option B (Computed Tomography (CT) scan)is useful for complex comminuted fractures or articular involvement but is not the primary study for acute vascular injury. A CT angiogram (CTA) could be an alternative to conventional angiography, but the question specifically asks about angiography, which is the gold standard for detailed vascular assessment.Option D (Electromyography (EMG) and nerve conduction studies (NCS))are used to assess nerve function and prognosis, typically 6-8 weeks after injury, not for acute assessment of vascular compromise. The radial nerve palsy, while present, is secondary to the immediate life-threatening vascular concern.Option E (Magnetic Resonance Imaging (MRI) of the brachial plexus)is not indicated in the acute setting for a midshaft humerus fracture with suspected vascular injury. It might be considered for complex brachial plexus injuries, but not as the immediate critical study here.

Question 727

Topic: 2. Trauma

A surgeon is planning an open reduction and internal fixation of a midshaft humerus fracture via a posterior approach (Henry triceps split). The patient is being positioned for surgery. Which of the following patient positions is MOST commonly used for this approach, and what is a key advantage of this position?

. Supine position with the arm draped over an arm board; advantage is excellent access to the shoulder joint for antegrade nailing.
. Lateral decubitus position on the unaffected side with the affected arm draped free over an overhead bar; advantage is excellent access to the entire posterior and posterolateral aspects of the humerus, allowing for easy identification and protection of the radial nerve.
. Beach chair position with the backrest at 45 degrees; advantage is comfortable for the patient and facilitates anterior plating.
. Prone position with the arm draped free; advantage is direct posterior access and minimal risk to the brachial plexus.
. Semi-Fowler position with a bump under the ipsilateral scapula; advantage is improved visualization for anterolateral approaches.

Correct Answer & Explanation

. Lateral decubitus position on the unaffected side with the affected arm draped free over an overhead bar; advantage is excellent access to the entire posterior and posterolateral aspects of the humerus, allowing for easy identification and protection of the radial nerve.

Explanation

Correct Answer: BThe case material explicitly states under 'Patient Positioning': "Lateral Decubitus Position:Most commonly used for posterior plating approaches (Henry or triceps splitting). ...Advantages: Excellent access to the entire posterior and posterolateral aspects of the humerus, allowing for easy identification and protection of the radial nerve. Good visualization for direct reduction." This directly matches the description in Option B.Option A (Supine position with the arm draped over an arm board)is primarily indicated for antegrade intramedullary nailing or anterior plating, not typically for a posterior approach. The advantage listed is for antegrade nailing, not posterior plating.Option C (Beach chair position)is a variation of the supine position, primarily used for antegrade nailing or shoulder surgery, not for posterior midshaft humerus plating.Option D (Prone position)can be used for posterior plating but is less common than lateral decubitus due to anesthetic challenges and increased patient risks. While it offers direct posterior access, the claim of 'minimal risk to the brachial plexus' is not a unique advantage over lateral decubitus, and prone positioning has its own set of risks.Option E (Semi-Fowler position)is similar to the beach chair and is used for shoulder procedures or antegrade nailing, not typically for posterior midshaft humerus plating.

Question 728

Topic: 2. Trauma

During a posterior approach (Henry triceps split) for open reduction and internal fixation of a midshaft humerus fracture, the surgeon has incised the skin and subcutaneous tissue and is proceeding with deep dissection. What is the MOST critical step to perform next to ensure patient safety and prevent iatrogenic injury?

. Incise the deep fascia and immediately expose the fracture site for reduction.
. Identify the interval between the lateral and long heads of the triceps and then meticulously identify and protect the radial nerve.
. Reflect the brachialis and biceps brachii muscles medially to expose the anterior aspect of the humerus.
. Perform a fasciotomy of the forearm to prevent compartment syndrome.
. Apply a distractor to the fracture fragments to restore length and alignment.

Correct Answer & Explanation

. Identify the interval between the lateral and long heads of the triceps and then meticulously identify and protect the radial nerve.

Explanation

Correct Answer: BThe case material emphasizes: "Radial Nerve Protection:This is the cardinal rule for midshaft humerus fracture surgery. Regardless of the approach, the radial nerve must be identified and protected." Under the 'Posterior Approach Henry Triceps Split' section, it states: "Deep Dissection & Internervous Plane: ...Crucially, identify the radial nerve. It typically lies within the spiral groove, deep to the lateral head of the triceps and medial to the lateral intermuscular septum. Trace the nerve proximally and distally, isolating it with vessel loops. Protect the profunda brachii artery accompanying the nerve. This step is critical and often performed first before further fracture exposure." Therefore, identifying the triceps interval and then the radial nerve is the most critical immediate next step.Option A (Incise the deep fascia and immediately expose the fracture site)is incorrect because it bypasses the crucial step of radial nerve identification, significantly increasing the risk of iatrogenic injury.Option C (Reflect the brachialis and biceps brachii muscles medially)describes a step in an anterolateral approach, not a posterior approach.Option D (Perform a fasciotomy of the forearm)is not indicated unless there is clinical evidence of compartment syndrome, which is not mentioned in the vignette. It is not a routine step in midshaft humerus fracture fixation.Option E (Apply a distractor to the fracture fragments)is a step in fracture reduction and fixation, which occurs after the nerve has been identified and protected, and the fracture site exposed. It is not the immediate next step after superficial dissection.

Question 729

Topic: 2. Trauma

A 48-year-old male underwent open reduction and internal fixation with a locking compression plate for a comminuted midshaft humerus fracture 8 months ago. He continues to experience pain at the fracture site, and recent radiographs show no evidence of callus formation with persistent fracture lines. Clinically, there is motion at the fracture site. He is a smoker and has poorly controlled nutrition. What is the MOST appropriate management strategy for this established nonunion?

. Continue observation for another 4 months, as bone healing can be slow in smokers.
. Initiate a course of oral bisphosphonates to stimulate bone formation.
. Revision surgery involving exchange nailing with autogenous bone grafting and addressing modifiable risk factors.
. Removal of the existing plate and application of a larger, stronger plate without bone grafting.
. Aggressive physical therapy to mobilize the fracture site and promote healing.

Correct Answer & Explanation

. Revision surgery involving exchange nailing with autogenous bone grafting and addressing modifiable risk factors.

Explanation

Correct Answer: CThe case material defines nonunion as "Failure of radiographic healing by 6-9 months post-fracture, often accompanied by pain or instability." This patient meets the criteria (8 months, pain, motion, no callus). The management section for nonunion states: "For established nonunions, revision surgery often involves combining mechanical stabilization (e.g., exchange nailing, conversion from plate to nail, or vice versa, dual plating) with biological augmentation (autogenous bone grafting). Addressing underlying risk factors (e.g., smoking cessation, nutritional optimization) is also crucial." Therefore, revision surgery with exchange nailing (a form of mechanical enhancement) and autogenous bone grafting (biological enhancement), along with addressing smoking and nutrition, is the most comprehensive and appropriate strategy.Option A (Continue observation)is incorrect. At 8 months with no signs of healing and persistent pain/motion, it is an established nonunion, and further observation without intervention is unlikely to lead to union, especially with risk factors present.Option B (Initiate bisphosphonates)is incorrect. Bisphosphonates are used for osteoporosis and to reduce fracture risk, not to stimulate healing of an established nonunion. They can even inhibit bone remodeling in some contexts.Option D (Removal of the existing plate and application of a larger plate without bone grafting)is partially correct regarding mechanical enhancement but critically misses the biological component. For an established nonunion, especially with risk factors like smoking and poor nutrition, biological augmentation with bone grafting is almost always necessary to stimulate healing.Option E (Aggressive physical therapy)is incorrect. Aggressive mobilization of an unstable nonunion will not promote healing and may exacerbate pain and instability. Activity should be restricted until definitive treatment for the nonunion is performed.

Question 730

Topic: 2. Trauma

A 22-year-old male sustains an open midshaft humerus fracture (Gustilo-Anderson Type II) with significant soft tissue contamination after a motorcycle accident. He has no neurovascular deficits. Based on the provided case material, which of the following is an absolute indication for operative management in this patient?

. The patient's young age, favoring early return to activity.
. The presence of an open fracture, requiring urgent debridement and stabilization.
. The high-energy mechanism of injury, suggesting inherent instability.
. The absence of neurovascular deficits, allowing for immediate surgical intervention.
. The potential for a segmental fracture, which is a relative indication for surgery.

Correct Answer & Explanation

. The presence of an open fracture, requiring urgent debridement and stabilization.

Explanation

Correct Answer: BThe case material clearly lists "Open fractures:Require urgent debridement and stabilization to prevent infection" as anabsolute indicationfor operative intervention. This patient has an open midshaft humerus fracture (Gustilo-Anderson Type II), which mandates immediate surgical management.Option A (The patient's young age)is not an absolute indication for surgery. While it might influence the choice of fixation, it does not mandate surgery in itself.Option C (The high-energy mechanism)often leads to more severe fractures, but it is not an absolute indication for surgery unless it results in specific complications (e.g., open fracture, vascular injury, severe comminution making non-op impossible).Option D (The absence of neurovascular deficits)is a positive finding, but it does not, by itself, constitute an indication for surgery. In fact, for closed fractures, the absence of deficits often supports non-operative management.Option E (The potential for a segmental fracture)is listed as arelativeindication for surgery, not an absolute one. The definitive presence of an open fracture is a much stronger and absolute indication.

Question 731

Topic: 2. Trauma

A patient presents with a fight bite over the fifth MCP joint. The x-ray shows a fracture of the fifth metacarpal neck (Boxer's fracture). What implications does this fracture have on managing the bite wound?

. A. The fracture takes precedence; the bite wound can be closed primarily.
. B. The fracture must be definitively fixed immediately, even if the wound is infected.
. C. The presence of a fracture necessitates thorough debridement and management of the bite wound as an open fracture, with careful consideration for delayed fracture stabilization.
. D. The fracture indicates a non-infected injury, thus antibiotics are not needed.
. E. The fracture should be ignored, and only the bite wound addressed.

Correct Answer & Explanation

. C. The presence of a fracture necessitates thorough debridement and management of the bite wound as an open fracture, with careful consideration for delayed fracture stabilization.

Explanation

Correct Answer: CA fracture of the fifth metacarpal neck associated with a fight bite means the fracture is an open fracture (communicating with the outside environment through the bite wound). This significantly complicates management. The bite wound requires meticulous debridement and copious irrigation, and the fracture must be treated as an open, contaminated injury. Definitive fracture stabilization (e.g., with internal hardware) is often delayed until the infection is controlled and the wound is clean, or performed with external fixation if immediate stability is required and internal fixation is deemed too risky in the acute infected setting. Primary closure of the bite wound (A) is contraindicated. Immediate definitive internal fixation (B) is dangerous in an infected field due to high risk of hardware infection. A fracture does not negate infection risk (D); in fact, it increases the risk of osteomyelitis. Ignoring the fracture (E) is malpractice.

Question 732

Topic: 2. Trauma

A 25-year-old male presents to the emergency department after a direct blow to his upper arm. Radiographs confirm a closed transverse midshaft humerus fracture. On examination, he is unable to actively extend his wrist or digits, and has decreased sensation over the dorsal first web space. This deficit was present immediately following the injury. What is the most appropriate initial management for this patient?

. Immediate surgical exploration and nerve repair
. Functional bracing and observation of the neurologic deficit
. Urgent electromyography (EMG) to assess baseline nerve function
. External fixation of the humerus to protect the nerve
. Open reduction and internal fixation with prophylactic radial nerve decompression

Correct Answer & Explanation

. Functional bracing and observation of the neurologic deficit

Explanation

Closed humeral shaft fractures presenting with a primary radial nerve palsy are managed initially with functional bracing and observation. Spontaneous nerve recovery occurs in the vast majority of cases, and immediate surgical exploration is not indicated.

Question 733

Topic: 2. Trauma

A 34-year-old female sustains a distal third spiral humerus fracture (Holstein-Lewis type).

On initial presentation, she has a completely normal neurovascular examination. Following a closed reduction and splinting attempt in the emergency department, she suddenly loses active wrist and thumb extension. What is the most appropriate next step in management?

. Application of a Sarmiento brace and close follow-up
. Serial electromyography (EMG) starting at 3 weeks
. Immediate surgical exploration of the radial nerve and fracture fixation
. Removal of the splint and re-manipulation under procedural sedation
. Corticosteroid injection into the spiral groove

Correct Answer & Explanation

. Immediate surgical exploration of the radial nerve and fracture fixation

Explanation

A secondary radial nerve palsy that develops immediately following closed reduction of a humeral shaft fracture strongly suggests iatrogenic nerve entrapment within the fracture site. This is an absolute indication for immediate surgical exploration and internal fixation.

Question 734

Topic: 2. Trauma

A 45-year-old male sustains a closed humeral shaft fracture following a low-energy fall. A functional fracture brace (Sarmiento) is prescribed. Which of the following defines the maximum acceptable deformity for nonoperative management of this fracture?

. 10 degrees varus, 10 degrees anterior angulation, 1 cm shortening
. 20 degrees varus, 20 degrees anterior angulation, 3 cm shortening
. 30 degrees varus, 20 degrees anterior angulation, 3 cm shortening
. 30 degrees varus, 30 degrees anterior angulation, 4 cm shortening
. 15 degrees varus, 15 degrees anterior angulation, 2 cm shortening

Correct Answer & Explanation

. 20 degrees varus, 20 degrees anterior angulation, 3 cm shortening

Explanation

Acceptable alignment for nonoperative management of humeral shaft fractures includes up to 20 degrees of anterior angulation, 30 degrees of varus angulation, and 3 cm of shortening. The shoulder and elbow joints have a wide range of motion that easily compensates for this degree of malalignment without functional deficits.

Question 735

Topic: 2. Trauma

A 28-year-old female presents with a closed distal-third spiral fracture of the humerus. On initial evaluation, she has intact wrist and finger extension. Following a closed reduction and application of a coaptation splint, she develops a complete radial nerve palsy. What is the most appropriate next step in management?

. Obtain an MRI of the humerus to evaluate the nerve
. Observation and application of a functional brace
. Perform electromyography (EMG) immediately
. Surgical exploration and internal fixation
. Corticosteroid injection into the radial nerve groove

Correct Answer & Explanation

. Surgical exploration and internal fixation

Explanation

A secondary radial nerve palsy that develops after a closed reduction attempt of a humeral shaft fracture is an absolute indication for surgical exploration. This presentation is classic for a Holstein-Lewis fracture, where the radial nerve can become tethered or entrapped between the fracture fragments during reduction.

Question 736

Topic: 2. Trauma
A 45-year-old male sustains a closed midshaft humerus fracture. He is managed non-operatively in a functional Sarmiento brace. When evaluating his standing AP and lateral radiographs at 2 weeks, what is the maximum acceptable varus angulation for successful non-operative management of a humeral shaft fracture?
. 10 degrees
. 20 degrees
. 25 degrees
. 30 degrees
. 45 degrees

Correct Answer & Explanation

. 30 degrees

Explanation

Acceptable alignment parameters for non-operative management of humeral shaft fractures include up to 30 degrees of varus/valgus angulation, 20 degrees of anterior/posterior angulation, and up to 3 cm of shortening. The extensive mobility of the shoulder and elbow joints compensates for these deformities without significant functional loss.

Question 737

Topic: 2. Trauma

A 28-year-old female presents with a closed spiral fracture of the distal third of the humeral shaft (Holstein-Lewis fracture) and an associated primary radial nerve palsy. At what specific anatomical location is the radial nerve most susceptible to tethering and injury in this fracture pattern?

. Within the spiral groove of the posterior humerus
. As it pierces the lateral intermuscular septum
. Between the brachialis and brachioradialis muscles
. At the arcade of Frohse
. Within the quadrangular space

Correct Answer & Explanation

. As it pierces the lateral intermuscular septum

Explanation

In a Holstein-Lewis fracture, the radial nerve is particularly vulnerable to injury as it is tethered tightly while piercing the lateral intermuscular septum to pass from the posterior to the anterior compartment. This occurs approximately 10 cm proximal to the lateral epicondyle.

Question 738

Topic: 2. Trauma
Which of the following scenarios is considered an absolute indication for operative stabilization of a humeral shaft fracture?
. Transverse fracture in a 25-year-old athlete
. Primary complete radial nerve palsy following a closed fracture
. Concomitant ipsilateral distal radius fracture
. Associated "floating elbow" (ipsilateral humerus and both-bone forearm fractures)
. Fracture with 15 degrees of anterior angulation

Correct Answer & Explanation

. Associated "floating elbow" (ipsilateral humerus and both-bone forearm fractures)

Explanation

Absolute indications for operative fixation of a humeral shaft fracture include an associated vascular injury requiring repair, a "floating elbow" (ipsilateral forearm fractures), bilateral humerus fractures, and compartment syndrome. Primary radial nerve palsy in a closed fracture is generally treated with observation.

Question 739

Topic: 2. Trauma

A 65-year-old female undergoes antegrade intramedullary nailing for a pathologic fracture of the proximal humeral shaft. Postoperatively, she achieves union but continues to have significant functional limitation. What is the most common long-term complication associated with this specific surgical approach?

. Iatrogenic axillary nerve injury
. Nonunion of the fracture site
. Shoulder pain and rotator cuff dysfunction
. Complex regional pain syndrome
. Hardware failure of the locking screws

Correct Answer & Explanation

. Shoulder pain and rotator cuff dysfunction

Explanation

The most common and significant complication of antegrade intramedullary nailing of the humerus is shoulder pain and dysfunction, often due to violation of the rotator cuff (supraspinatus tendon) and prominent proximal hardware.

Question 740

Topic: 2. Trauma
A 45-year-old patient with a humeral shaft fracture is managed non-operatively. Which of the following specific fracture characteristics places this patient at the highest risk for developing a nonunion?
. Distal third spiral fracture
. Midshaft oblique fracture
. Proximal third transverse fracture
. Comminuted midshaft fracture
. Butterfly fragment fracture

Correct Answer & Explanation

. Proximal third transverse fracture

Explanation

Transverse fractures, particularly those in the proximal third of the humerus, have the highest risk of nonunion when treated non-operatively. This is due to a smaller cross-sectional area for healing, lack of interdigitation, and distracting forces from the arm's weight.

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