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2. Trauma MCQs

Practice Set 88 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 1741

Topic: 2. Trauma

A 32-year-old male sustains a high-energy distal humerus fracture (AO/OTA Type C2) involving both columns and the articular surface. Surgical fixation is planned via a posterior approach with an olecranon osteotomy. The surgeon opts for an orthogonal plating strategy. Which of the following biomechanical principles BEST describes the advantage of this construct for distal humerus fractures?

. Orthogonal plating primarily provides superior axial compression across the fracture site, enhancing primary bone healing.
. Orthogonal plating allows for easier placement of interfragmentary lag screws compared to parallel plating.
. Orthogonal plating offers superior stiffness, particularly in torsion and bending, by capturing fragments of the lateral column and bridging the olecranon fossa effectively.
. Orthogonal plating minimizes soft tissue stripping, thereby preserving blood supply to the fracture fragments.
. Orthogonal plating is exclusively indicated for extra-articular fractures, as it provides less articular visualization.

Correct Answer & Explanation

. Orthogonal plating offers superior stiffness, particularly in torsion and bending, by capturing fragments of the lateral column and bridging the olecranon fossa effectively.

Explanation

Correct Answer: CThe 'Summary of Key Literature / Guidelines' section states: 'Biomechanically, both orthogonal (medial and posterior/posterolateral) and parallel (medial and lateral) plating constructs provide sufficient stability. Several studies, including cadaveric biomechanical analyses and clinical series, suggest thatorthogonal plating may offer superior stiffness, particularly in torsion and bending, especially when the posterior plate is positioned to capture fragments of the lateral column and bridge the olecranon fossa effectively.' This directly supports the advantage described in option C.Option A is incorrectbecause while compression is important, the primary biomechanical advantage highlighted for orthogonal plating is its stiffness in torsion and bending, not exclusively axial compression. Lag screws provide interfragmentary compression.Option B is incorrectbecause the ability to place interfragmentary lag screws is dependent on the fracture pattern and surgical technique, not inherently easier or harder with orthogonal versus parallel plating. Both strategies aim to incorporate lag screws.Option D is incorrectbecause both orthogonal and parallel plating strategies for complex DHFs via a posterior approach typically involve significant soft tissue dissection to expose the fracture and apply plates, so one does not inherently minimize stripping more than the other.Option E is incorrectbecause orthogonal plating is widely used and often preferred for complex intra-articular fractures (AO/OTA Type C), as described in the case, due to its robust fixation and ability to capture articular fragments. It does not limit articular visualization, especially when combined with an olecranon osteotomy.

Question 1742

Topic: 2. Trauma

A 72-year-old osteoporotic female presents with a highly comminuted, intra-articular distal humerus fracture (AO/OTA Type C3) after a low-energy fall. Given her bone quality and the complexity of the fracture, the surgeon is considering the optimal triceps management strategy for a posterior approach. Which of the following statements regarding triceps management is MOST appropriate for this patient?

. A triceps-splitting approach (Campbell) is preferred to minimize surgical morbidity and avoid a second fracture in osteoporotic bone.
. An olecranon osteotomy is the gold standard for complex intra-articular fractures, providing unrivaled exposure for anatomical reduction, despite adding a second fracture to manage.
. A paratricipital approach (Bryan-Morrey) offers superior exposure of the articular surface compared to an olecranon osteotomy, especially for highly comminuted patterns.
. Triceps-sparing approaches are generally indicated for all distal humerus fractures to prevent complications associated with olecranon osteotomy.
. The triceps reflecta (Kocher) approach is primarily used for lateral column fractures and provides limited access to the medial column.

Correct Answer & Explanation

. An olecranon osteotomy is the gold standard for complex intra-articular fractures, providing unrivaled exposure for anatomical reduction, despite adding a second fracture to manage.

Explanation

Correct Answer: BThe 'Detailed Surgical Approach / Technique' section, under 'Triceps Management', states: 'Olecranon Osteotomy: Indications: Gold standard for complex intra-articular fractures (AO/OTA C-type) requiring maximal visualization and direct access to the articular surface.' It further notes its advantage: 'Unrivaled exposure of the articular surface and both medial and lateral columns. Allows direct visualization of the fracture pattern and facilitates anatomical reduction.' While it 'Adds a second fracture to manage, potential for nonunion, symptomatic hardware, or pain at the osteotomy site,' for a highly comminuted intra-articular fracture, the benefit of optimal visualization for anatomical reduction often outweighs these risks, especially with modern osteotomy fixation techniques.Option A is incorrectbecause while a triceps split avoids an osteotomy, it provides more limited exposure, which can compromise anatomical reduction of a highly comminuted intra-articular fracture. The case states that olecranon osteotomy is the gold standard for such complex fractures.Option C is incorrectbecause the paratricipital approach is a triceps-sparing technique that offers more limited exposure compared to an olecranon osteotomy, especially for the entire articular surface and both columns. It is not superior for highly comminuted patterns.Option D is incorrectbecause triceps-sparing approaches are suitable for 'extra-articular (AO/OTA A-type) or less comminuted intra-articular fractures where full articular exposure is not mandatory,' not generally for all DHFs, especially complex ones.Option E is incorrectbecause the triceps reflecta (Kocher) is a more extensile triceps-sparing approach that provides good access to both columns, not primarily limited to lateral column fractures. However, it still does not offer the 'unrivaled exposure' of an olecranon osteotomy for complex articular fractures.

Question 1743

Topic: 2. Trauma

A 48-year-old male undergoes ORIF of a distal humerus fracture via a posterior approach with olecranon osteotomy. Post-operatively, he develops new onset paresthesia and weakness in the small finger and ulnar half of the ring finger, along with intrinsic muscle weakness. This complication is most consistent with ulnar neuropathy. Based on the case, what is the MOST appropriate initial management strategy for this patient?

. Immediate surgical exploration and neurolysis of the ulnar nerve.
. Observation, as many cases of post-operative ulnar neuropathy are transient neurapraxias.
. Administration of high-dose corticosteroids to reduce nerve inflammation.
. Revision ORIF to remove any hardware impinging on the ulnar nerve.
. Initiation of aggressive physical therapy focusing on elbow flexion and extension to stretch the nerve.

Correct Answer & Explanation

. Observation, as many cases of post-operative ulnar neuropathy are transient neurapraxias.

Explanation

Correct Answer: BThe 'Complications & Management' section, under 'Management Considerations for Specific Complications', states: 'Ulnar Neuropathy: Most often presents as paresthesia or weakness in the ulnar nerve distribution. Many cases are transient neurapraxias. If symptoms persist beyond 3-6 months, worsen, or present as a new deficit, EMG/NCS studies are warranted. Surgical exploration, neurolysis, and re-transposition may be indicated.'Option A is incorrectbecause immediate surgical exploration is generally not the first step unless there is clear evidence of acute, severe nerve transection or entrapment. Most post-operative neuropathies are transient and resolve with observation.Option C is incorrectbecause while corticosteroids can reduce inflammation, there is no specific evidence presented in the case or general guidelines recommending high-dose corticosteroids as the primary initial management for post-operative ulnar neuropathy.Option D is incorrectbecause revision ORIF for hardware removal is premature. Hardware removal is considered if symptoms persist and are clearly attributable to hardware irritation after fracture union, or if the nerve was not transposed and is now compressed by hardware. Initial management is observation.Option E is incorrectbecause aggressive physical therapy, especially focusing on stretching the nerve, could potentially exacerbate an irritated nerve. Rehabilitation should be guided by the nerve's status and the fracture's healing, with caution regarding nerve symptoms.

Question 1744

Topic: 2. Trauma

A 65-year-old male presents to the emergency department after a motor vehicle accident with a severely comminuted distal humerus fracture. Clinical examination reveals significant swelling and tenderness around the elbow. Initial radiographs are difficult to interpret due to the comminution. Which of the following pre-operative imaging modalities is MOST essential for surgical planning in this case?

. Magnetic Resonance Imaging (MRI) to assess soft tissue and ligamentous injuries.
. Standard AP and lateral radiographs with additional oblique views only.
. Computed Tomography (CT) scan with axial, sagittal, coronal, and 3D reconstructions.
. Arteriography to rule out vascular injury, given the high-energy mechanism.
. Ultrasound to evaluate for joint effusion and guide aspiration.

Correct Answer & Explanation

. Computed Tomography (CT) scan with axial, sagittal, coronal, and 3D reconstructions.

Explanation

Correct Answer: CThe 'Pre-Operative Planning & Patient Positioning' section, under 'Radiographic Evaluation', states: 'Computed Tomography (CT) Scan: Essential for nearly all complex DHFs. Axial, sagittal, and coronal reconstructions, along with 3D reconstructions, are invaluable for understanding fracture morphology, articular involvement, degree of comminution, and fragment orientation. This guides implant selection and surgical strategy.'Option A is incorrectbecause while MRI can assess soft tissues, it is not the primary or most essential imaging for detailed bone fracture morphology in complex DHFs. CT is superior for bony detail.Option B is incorrectbecause while standard radiographs are the initial assessment, the case states they are 'difficult to interpret due to the comminution,' highlighting the need for more advanced imaging like CT.Option D is incorrectbecause arteriography is indicated 'if vascular injury is suspected (e.g., absent pulses, expanding hematoma),' which is not explicitly stated as the primary concern in the vignette, although it might be considered if vascular compromise were present. CT is essential for fracture planning regardless.Option E is incorrectbecause ultrasound is not the primary imaging modality for detailed fracture assessment or surgical planning for complex distal humerus fractures.

Question 1745

Topic: 2. Trauma

A 40-year-old construction worker undergoes ORIF for a complex intra-articular distal humerus fracture. The surgeon achieves stable bicondylar fixation with an orthogonal plating construct. Post-operatively, the patient is placed in a posterior splint. Which of the following principles is MOST critical for the immediate post-operative rehabilitation protocol in this patient?

. Strict immobilization for 6-8 weeks to ensure complete fracture union before initiating any motion.
. Early, controlled active and passive range of motion (ROM) to prevent stiffness and heterotopic ossification.
. Immediate full weight-bearing through the affected extremity to promote bone healing.
. Aggressive strengthening exercises starting on post-operative day 1 to regain muscle mass.
. Continuous passive motion (CPM) machine use for 24 hours a day for the first 2 weeks.

Correct Answer & Explanation

. Early, controlled active and passive range of motion (ROM) to prevent stiffness and heterotopic ossification.

Explanation

Correct Answer: BThe 'Post-Operative Rehabilitation Protocols' section, under 'General Principles', states: 'Early, Controlled Motion: The overarching goal is to prevent stiffness and heterotopic ossification by initiating controlled active and passive range of motion (ROM) as soon as safely possible.' Under 'Phase 1: Immediate Post-Operative / Early Protection (Weeks 0-3)', it specifies: 'Passive Range of Motion (PROM): Gentle, gravity-assisted flexion and extension within a pain-free arc, typically starting the first post-operative day if fixation is stable. Avoid forceful manipulation. Active-Assisted Range of Motion (AAROM): Patient uses the unaffected arm to assist the injured arm. Active Range of Motion (AROM): Gentle active flexion/extension, pronation/supination within comfort limits.'Option A is incorrectbecause the case explicitly states that 'prolonged immobilization is detrimental' and that the goal is 'early, controlled motion' to prevent stiffness.Option C is incorrectbecause the protocol specifies 'Strictly non-weight-bearing through the upper extremity' in Phase 1, and 'Still no significant weight-bearing or heavy lifting' in Phase 2.Option D is incorrectbecause strengthening exercises are initiated gradually, with 'gentle isometric exercises' starting in Phase 2 (Weeks 3-6/8), not aggressive exercises on day 1.Option E is incorrectbecause while CPM can be used, the case emphasizes active and passive ROM exercises. The specific duration and necessity of 24-hour CPM are not highlighted as the MOST critical principle, and its routine use is debated.

Question 1746

Topic: 2. Trauma

A 28-year-old male presents with an open, displaced intra-articular distal humerus fracture (AO/OTA Type C1) after a motorcycle accident. He has no significant comorbidities. Which of the following factors is the MOST compelling indication for operative management in this patient?

. The patient's young age and high activity level.
. The presence of an open fracture requiring urgent debridement and stabilization.
. The intra-articular nature of the fracture, necessitating anatomical reduction.
. The displaced nature of the fracture, increasing the risk of malunion.
. The absence of significant comorbidities, making him a good surgical candidate.

Correct Answer & Explanation

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

Explanation

Correct Answer: BThe 'Indications for Operative Management' section lists: 'Open Fractures: Require urgent debridement and stabilization.' While all other options are also valid indications or contributing factors, an open fracture is an urgent surgical indication due to the high risk of infection and the need for immediate debridement and stabilization to prevent further contamination and facilitate healing.Option A is incorrectbecause while young age and high activity level are factors favoring operative management to restore function, they are not as immediately compelling as an open fracture.Option C is incorrectbecause the intra-articular nature is a strong indication for ORIF to restore joint congruity, but an open fracture adds an element of urgency and necessity for immediate intervention beyond just the fracture pattern.Option D is incorrectbecause displacement is a general indication for operative management in many fractures, but an open fracture carries additional, more immediate risks that mandate surgery.Option E is incorrectbecause being a good surgical candidate (absence of comorbidities) facilitates surgery but is not an indication for surgery itself; rather, it allows for the treatment of existing indications.

Question 1747

Topic: 2. Trauma

During definitive fixation of a complex distal humerus fracture via a posterior approach, the surgeon is applying an orthogonal plating construct. A medial plate is applied to the medial column, and a posterior/posterolateral plate is applied to the lateral column. To maximize bone purchase and construct stability, what is the MOST effective screw trajectory strategy for the distal fragments?

. All screws from both plates should be directed parallel to the humeral shaft axis for maximum length.
. Screws from the medial plate should be directed medially, and screws from the posterior plate should be directed posteriorly.
. Screws from the medial plate should be directed laterally, and screws from the posterior/posterolateral plate should be directed medially.
. Screws should be placed only in unicortical fashion to avoid neurovascular injury.
. Screws should be directed perpendicular to the plate to ensure maximum compression.

Correct Answer & Explanation

. Screws from the medial plate should be directed laterally, and screws from the posterior/posterolateral plate should be directed medially.

Explanation

Correct Answer: CThe 'Detailed Surgical Approach / Technique' section, under 'Definitive Fixation' and 'Screw Trajectories', states: 'The key is to direct screws from each plate to avoid collision and to maximize bone purchase, ideally interlocking each column distally. Screws from the medial plate are directed laterally, and screws from the posterior/posterolateral plate are directed medially. Bicortical purchase is desirable where anatomically safe.' This describes the 'omega' configuration mentioned in the 'Summary of Key Literature / Guidelines' section, which maximizes interfragmentary purchase.Option A is incorrectbecause directing all screws parallel to the humeral shaft axis would not effectively capture the distal articular fragments in a cross-columnar fashion, which is crucial for bicondylar fixation.Option B is incorrectbecause directing screws medially from the medial plate and posteriorly from the posterior plate would not achieve the desired interlocking and cross-columnar fixation, potentially leading to inadequate stability.Option D is incorrectbecause the case states 'Bicortical purchase is desirable where anatomically safe' to maximize stability, not unicortical purchase to avoid neurovascular injury. While neurovascular protection is paramount, bicortical purchase is preferred when safe.Option E is incorrectbecause while some screws may be perpendicular, the primary strategy for distal humerus fixation is to direct screws to maximize purchase and interlock the columns, which often involves varying angles, not strictly perpendicular to the plate.

Question 1748

Topic: 2. Trauma

A 55-year-old male undergoes ORIF of a complex distal humerus fracture. Despite stable fixation and a diligent rehabilitation protocol, he develops significant elbow stiffness with a limited range of motion (30-90 degrees) and radiographic evidence of heterotopic ossification (HO) 4 months post-operatively. Which of the following is the MOST appropriate next step in managing his elbow stiffness and HO?

. Immediate surgical excision of the heterotopic ossification and capsular release.
. Intensified physical therapy, static progressive or dynamic splinting, and consideration of manipulation under anesthesia (MUA).
. Prolonged immobilization in a cast to allow the HO to mature and resorb.
. Initiation of systemic antibiotics to address potential low-grade infection contributing to stiffness.
. Prescription of high-dose NSAIDs indefinitely to prevent further HO formation.

Correct Answer & Explanation

. Intensified physical therapy, static progressive or dynamic splinting, and consideration of manipulation under anesthesia (MUA).

Explanation

Correct Answer: BThe 'Complications & Management' section, under 'Management Considerations for Specific Complications' for 'Stiffness', states: 'If stiffness develops, a stepwise approach is taken: intensive physical therapy, static progressive or dynamic splinting, and if conservative measures fail, manipulation under anesthesia (MUA) or open capsular release (often combined with hardware removal).' For HO, it states: 'surgical excision after maturation (usually 6-12 months post-injury).'At 4 months, the HO is likely not fully mature, and a conservative, stepwise approach to stiffness is indicated before considering aggressive surgical excision of HO. Intensified therapy and splinting are the next logical steps, with MUA as a potential escalation if conservative measures fail.Option A is incorrectbecause surgical excision of HO is generally recommended 'after maturation (usually 6-12 months post-injury)' to reduce recurrence risk. At 4 months, it is likely too early for surgical excision of HO, though capsular release might be considered later if conservative measures fail.Option C is incorrectbecause prolonged immobilization is a known cause of stiffness and would worsen the current situation, directly contradicting the principle of early motion.Option D is incorrectbecause there is no mention of signs of infection in the vignette. Stiffness and HO are common complications of DHF, and infection is not the primary assumption without other clinical signs.Option E is incorrectbecause while NSAIDs are used for HO prophylaxis, indefinite high-dose NSAID use is not a primary treatment for established HO and carries significant side effects. Prophylaxis is typically initiated perioperatively, not indefinitely post-HO formation.

Question 1749

Topic: 2. Trauma

A 68-year-old female presents with a non-displaced extra-articular distal humerus fracture (AO/OTA Type A1) after a fall. She has multiple comorbidities, including severe cardiac disease and poorly controlled diabetes. Which of the following is the MOST appropriate initial management strategy for this patient?

. Open reduction internal fixation (ORIF) with an orthogonal plating construct to ensure stable fixation.
. Non-operative management with immobilization in a posterior splint and early protected range of motion.
. External fixation to provide stability while minimizing surgical invasiveness.
. Total elbow arthroplasty (TEA) due to her age and comorbidities.
. Immediate referral for a second opinion regarding surgical candidacy due to her comorbidities.

Correct Answer & Explanation

. Non-operative management with immobilization in a posterior splint and early protected range of motion.

Explanation

Correct Answer: BThe 'Indications for Non-Operative Management' section states: 'Non-displaced or Minimally Displaced Extra-Articular Fractures (AO/OTA Type A): Especially in elderly or low-demand patients.' It also lists 'Non-displaced or Minimally Displaced Intra-Articular Fractures (rare): In elderly, frail, low-demand patients with significant comorbidities where surgical risks outweigh potential benefits...' The patient in the vignette has a non-displaced extra-articular fracture and significant comorbidities, making non-operative management the most appropriate initial strategy.Option A is incorrectbecause ORIF is typically indicated for displaced fractures, especially intra-articular ones. For a non-displaced extra-articular fracture, especially in a patient with severe comorbidities, the risks of surgery likely outweigh the benefits.Option C is incorrectbecause external fixation is generally reserved for open fractures with severe soft tissue compromise or as a temporary measure in polytrauma, not typically for a non-displaced extra-articular fracture.Option D is incorrectbecause total elbow arthroplasty is a salvage procedure for severe comminuted fractures in elderly, low-demand patients, or for post-traumatic arthritis, not for a non-displaced extra-articular fracture.Option E is incorrectbecause while a second opinion is always an option, the case provides clear guidelines that support non-operative management for this specific fracture type and patient profile, making it the most appropriate initial strategy.

Question 1750

Topic: 2. Trauma

A 7-year-old boy presents with a closed Bado Type I Monteggia fracture-dislocation. Following successful closed reduction of the ulnar shaft and radial head, the examiner notes the patient is unable to actively extend his thumb or the metacarpophalangeal joints of his fingers. What is the most appropriate management of this neurologic deficit?

. Immediate surgical exploration of the posterior interosseous nerve
. Magnetic resonance imaging of the elbow
. Observation and expectant management for 3 to 6 months
. Electromyography (EMG) within 24 hours
. Revision closed reduction with the forearm in full pronation

Correct Answer & Explanation

. Observation and expectant management for 3 to 6 months

Explanation

Posterior interosseous nerve (PIN) palsy is the most common neurologic complication of anterior Monteggia fractures. It is almost always a neuropraxia that resolves spontaneously, making observation for 3 to 6 months the recommended management.

Question 1751

Topic: 2. Trauma

When comparing parallel versus orthogonal double-plating techniques for intra-articular distal humerus fractures (AO/OTA type 13-C), biomechanical studies have demonstrated which of the following regarding construct stiffness?

. Parallel plating is vastly superior in both sagittal and coronal planes.
. Orthogonal plating has significantly higher failure rates under axial load.
. Both configurations provide comparable biomechanical stability for early range of motion.
. Orthogonal plating requires routine ulnar nerve transposition to achieve adequate stability.
. Parallel plating prevents the need for an olecranon osteotomy.

Correct Answer & Explanation

. Both configurations provide comparable biomechanical stability for early range of motion.

Explanation

Biomechanical and clinical studies have shown that both parallel and orthogonal plating configurations provide comparable and adequate stability to allow for early active range of motion in distal humerus fractures.

Question 1752

Topic: 2. Trauma
A 35-year-old male presents after a fall on an outstretched hand. Radiographs show a proximal third ulnar shaft fracture with an anterior dislocation of the radial head. What is the Bado classification and the most commonly associated nerve injury?
. Bado I, Posterior Interosseous Nerve (PIN)
. Bado II, Anterior Interosseous Nerve (AIN)
. Bado III, Ulnar Nerve
. Bado IV, Radial Nerve Proper
. Bado I, Ulnar Nerve

Correct Answer & Explanation

. Bado I, Posterior Interosseous Nerve (PIN)

Explanation

Bado type I Monteggia fractures involve an anterior radial head dislocation with an ulnar shaft fracture and are most commonly associated with a posterior interosseous nerve (PIN) neurapraxia.

Question 1753

Topic: 2. Trauma

In managing a Galeazzi fracture, which radiographic or clinical finding is the most reliable predictor of distal radioulnar joint (DRUJ) instability following anatomic plate fixation of the radius?

. A radial shaft fracture located within 7.5 cm of the radiocarpal articular surface
. The presence of an ulnar styloid base fracture
. Dorsal translation of the ulna on a lateral radiograph in supination
. Palmar translation of the radius in pronation
. Widening of the interosseous space by 1 mm

Correct Answer & Explanation

. A radial shaft fracture located within 7.5 cm of the radiocarpal articular surface

Explanation

A radial shaft fracture located within 7.5 cm of the radiocarpal joint (distal third) is the most reliable predictor of inherent DRUJ instability after rigid fixation of the radius in Galeazzi fractures.

Question 1754

Topic: 2. Trauma

An active 68-year-old female sustains a highly comminuted intercondylar distal humerus fracture. To gain maximum articular exposure, the surgeon chooses a transolecranon approach. Where should the olecranon osteotomy be ideally placed to minimize articular damage?

. Through the center of the trochlear notch
. At the base of the coronoid process
. In the "bare area" of the greater sigmoid notch
. Distal to the sublime tubercle
. Proximal to the triceps insertion

Correct Answer & Explanation

. In the "bare area" of the greater sigmoid notch

Explanation

A chevron olecranon osteotomy should be directed into the "bare area" of the greater sigmoid notch. This region is naturally devoid of articular cartilage, thereby minimizing iatrogenic articular damage.

Question 1755

Topic: 2. Trauma

Which of the following is considered an absolute indication for operative fixation of an isolated ulnar shaft (nightstick) fracture in an adult?

. Displacement greater than 50% of the shaft diameter
. Angulation of 5 degrees in any plane
. A closed fracture with 2 mm of shortening
. A concomitant nondisplaced radial head fracture
. Fracture located at the junction of the middle and distal thirds

Correct Answer & Explanation

. Displacement greater than 50% of the shaft diameter

Explanation

Absolute indications for surgical fixation of an isolated ulnar shaft fracture include displacement >50%, angulation >10 degrees, or proximal third fractures which are prone to displacement and nonunion.

Question 1756

Topic: 2. Trauma

During open reduction and internal fixation of a both-bone forearm fracture, the surgeon applies dynamic compression plates to the radius and ulna. What is the minimum recommended number of diaphyseal cortices that should be engaged on each side of the fracture?

. 4 cortices
. 6 cortices
. 8 cortices
. 10 cortices
. 12 cortices

Correct Answer & Explanation

. 6 cortices

Explanation

For diaphyseal forearm fractures, biomechanical studies demonstrate that engaging a minimum of 6 cortices (using a 3.5 mm plate) on both sides of the fracture provides optimal torsional and bending stability.

Question 1757

Topic: 2. Trauma

A 75-year-old female with profound osteoporosis presents with a severely comminuted, intra-articular distal humerus fracture (AO/OTA 13-C3) and pre-existing symptomatic elbow osteoarthritis. What is the preferred surgical treatment?

. Nonoperative management with a hinged elbow brace
. Open reduction and internal fixation with dual orthogonal plates
. Total elbow arthroplasty
. Distal humerus hemiarthroplasty
. Spanning external fixation

Correct Answer & Explanation

. Total elbow arthroplasty

Explanation

Total elbow arthroplasty is the preferred treatment for elderly patients with complex, unreconstructible intra-articular distal humerus fractures, particularly those with pre-existing osteoarthritis, as it allows for immediate mobilization.

Question 1758

Topic: 2. Trauma

To minimize the risk of radioulnar cross-union (synostosis) during the surgical fixation of a diaphyseal fracture of both the radius and ulna, what is the most critical technical principle?

. Using a single dorsal incision to approach both fractures simultaneously
. Delaying surgery for at least 14 days post-injury
. Avoiding the placement of bone graft or hardware in the interosseous space
. Utilizing a single specialized plate that spans both bones
. Routinely repairing the interosseous membrane

Correct Answer & Explanation

. Avoiding the placement of bone graft or hardware in the interosseous space

Explanation

The risk of radioulnar synostosis is minimized by using separate surgical incisions for the radius and ulna, and meticulously avoiding the placement of any bone graft or hardware in the interosseous space.

Question 1759

Topic: 2. Trauma

A 22-year-old sustains a both-bone forearm fracture treated with ORIF. Two years later, the patient requests hardware removal. Which factor is most strongly associated with an increased risk of refracture following plate removal in the forearm?

. Plate removal prior to 15-18 months post-injury
. The initial use of dynamic compression plates
. The initial use of locking compression plates
. Plate removal performed more than 3 years post-injury
. Patient age greater than 40 years

Correct Answer & Explanation

. Plate removal prior to 15-18 months post-injury

Explanation

Removing forearm plates prior to 15-18 months post-fixation is associated with a significantly higher risk of refracture, as the diaphyseal bone requires adequate time for remodeling to regain normal tensile strength.

Question 1760

Topic: 2. Trauma

What is the primary deforming force that causes supination of the proximal radius fragment in a fracture located in the proximal third of the radial diaphysis?

. Pronator teres
. Pronator quadratus
. Combined pull of the supinator and biceps brachii
. Brachioradialis
. Extensor carpi radialis brevis

Correct Answer & Explanation

. Combined pull of the supinator and biceps brachii

Explanation

In proximal third radius fractures, the proximal fragment is strongly supinated by the combined pull of the supinator and biceps brachii, which is unresisted because the pronator teres attaches to the middle third.

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