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 2301
Topic: 2. Trauma
A 40-year-old male presents with a volar shear fracture of the distal radius (volar Barton's fracture). The carpus is subluxated volarly with the intra-articular fracture fragment. What is the primary biomechanical function of a volar plate utilized for this specific fracture pattern?
Correct Answer & Explanation
. Buttress fixation
Explanation
A volar Barton fracture is inherently unstable due to powerful palmar shear forces. A volar plate applied in this setting acts primarily as a buttress to neutralize these shear forces, effectively preventing volar subluxation of the fragment and the carpus.
Question 2302
Topic: 2. Trauma
A 6-year-old child presents with a Bado Type I Monteggia fracture-dislocation. Closed reduction of the ulnar shaft fracture is achieved, but the radial head remains anteriorly dislocated despite appropriate maneuvers. What is the most common anatomic structure blocking radial head reduction in this pediatric scenario?
Correct Answer & Explanation
. Annular ligament
Explanation
In pediatric Monteggia injuries, failure to achieve closed reduction of the radial head is most commonly caused by an interposed annular ligament or intact joint capsule. Open reduction to clear the interposition is required if closed maneuvers fail.
Question 2303
Topic: 2. Trauma
A 35-year-old male sustains an isolated, non-displaced fracture of the distal third of the ulnar shaft (nightstick fracture) after raising his forearm to block a blunt object. What is the most appropriate initial management?
Correct Answer & Explanation
. Functional bracing with early active range of motion
Explanation
Non-displaced or minimally displaced isolated ulnar shaft fractures are best managed non-operatively. Functional bracing with early active range of motion yields excellent union rates while avoiding joint stiffness.
Question 2304
Topic: 2. Trauma
A 50-year-old smoker underwent ORIF for a midshaft both-bone forearm fracture 8 months ago. Radiographs now demonstrate an atrophic nonunion of the radius with broken hardware, while the ulna has fully healed. What is the most appropriate definitive management?
Correct Answer & Explanation
. Revision ORIF of the radius with autologous bone grafting
Explanation
Aseptic atrophic nonunion of a diaphyseal forearm fracture requires both mechanical stabilization and biological stimulation. Revision ORIF with stable plate fixation and autologous bone grafting is the gold standard treatment.
Question 2305
Topic: 2. Trauma
A 32-year-old male presents to the emergency department after a high-speed motor vehicle collision, sustaining a bilateral C6-C7 facet dislocation. He is neurologically intact but complains of severe neck pain and inability to move his head. Which of the following statements accurately describes the typical mechanism of injury and associated ligamentous damage in this patient's condition?
Correct Answer & Explanation
. Hyperflexion with distraction resulting in complete disruption of the posterior ligamentous complex and often the posterior longitudinal ligament.
Explanation
Correct Answer: CBilateral cervical facet dislocations are severe, high-energy injuries typically resulting from a combination of hyperflexion and distraction forces. This mechanism leads to complete, catastrophic disruption of the posterior ligamentous complex (PLC), which includes the ligamentum flavum, interspinous ligaments, supraspinous ligaments, and facet joint capsules. The posterior longitudinal ligament (PLL) and the intervertebral disc annulus are also frequently compromised. This aligns with Stage 3 or Stage 4 of the Allen and Ferguson mechanistic classification for Distraction-Flexion injuries.Option A describes the typical mechanism for a unilateral facet dislocation, which involves flexion-rotation and generally less severe ligamentous disruption. Option B describes a hyperextension injury, which primarily affects the anterior column and ligaments. Option D describes a burst fracture, which is an axial compression injury. Option E describes a shear injury, which is less common for isolated bilateral facet dislocations.
Question 2306
Topic: 2. Trauma
A 72-year-old female presents to the emergency department after a low-energy fall onto her outstretched arm. Radiographs reveal a displaced fracture of the surgical neck of the humerus with the humeral head in a valgus-impacted position, demonstrating less than 1 cm displacement and approximately 30 degrees of angulation. She has a past medical history of well-controlled hypertension and osteoporosis. She lives independently and has moderate functional demands, enjoying gardening and light housework. On examination, she has intact neurovascular status, but significant pain with any shoulder movement. Based on the Neer classification system and the provided case details, what is the most appropriate initial management strategy for this patient?
Correct Answer & Explanation
. Non-operative management with sling immobilization and early passive range of motion.
Explanation
The patient presents with a displaced surgical neck fracture, but the description notes it is 'valgus-impacted' with 'less than 1 cm displacement and approximately 30 degrees of angulation.' According to the case content, non-operative management is the treatment of choice for the majority of proximal humerus fractures, particularly one-part fractures, and often for two-part surgical neck fractures in elderly, low-demand patients with minimal displacement. Minimally displaced or nondisplaced fractures are generally defined as <1 cm displacement and <45 degrees angulation. Stable, valgus-impacted fractures also fall under non-operative indications.
Question 2307
Topic: 2. Trauma
A 62-year-old male undergoes open reduction and internal fixation (ORIF) with a locking plate for a displaced three-part proximal humerus fracture. Post-operatively, radiographs show good reduction and hardware placement. However, at his 6-month follow-up, he presents with increasing pain, loss of reduction, and new varus collapse of the humeral head, with screws appearing to have migrated through the superior aspect of the humeral head. Which of the following is the most likely primary cause of this complication?
Correct Answer & Explanation
. Inadequate medial calcar support during initial fixation.
Explanation
Correct Answer: BThe patient's presentation of 'loss of reduction, and new varus collapse of the humeral head, with screws appearing to have migrated through the superior aspect of the humeral head' is a classic description of screw cutout and construct failure due to varus collapse. The case content explicitly states under 'Complications': 'Screw Cutout / Implant Failure... Etiology / Risk Factors: Osteoporotic bone, inadequate medial support (calcar screws), varus collapse, premature weight-bearing, poor screw purchase, poor reduction.' Inadequate medial calcar support is a critical factor in resisting varus collapse and preventing screw cutout.Option A (Iatrogenic axillary nerve injury during surgery):Axillary nerve injury would cause deltoid weakness and sensory loss, but not directly lead to varus collapse or screw cutout.Option C (Development of a deep surgical site infection):While infection is a serious complication, it typically presents with signs of inflammation, fever, and wound drainage, and while it can lead to nonunion or implant loosening, it's not the primary mechanism for acute varus collapse and screw cutout as described.Option D (Premature and aggressive post-operative rehabilitation):While this can contribute to implant failure, the fundamental structural weakness often stems from inadequate initial fixation, particularly medial support, which allows the varus collapse to initiate.Option E (Failure to repair the rotator cuff tendons to the plate):Suture augmentation of tuberosities is important for tuberosity healing and stability, but its absence is less directly linked to varus collapse of the humeral head and screw cutout than the lack of medial calcar support.
Question 2308
Topic: 2. Trauma
A 28-year-old male sustains a high-energy Neer four-part fracture-dislocation of the proximal humerus. He is scheduled for urgent open reduction and internal fixation. During pre-operative planning, the surgeon reviews the imaging, including a CT scan with 3D reconstructions. What is the primary advantage of using a CT scan with 3D reconstructions in this specific fracture pattern?
Correct Answer & Explanation
. To provide detailed information on comminution, articular involvement, glenoid impression fractures, and precise tuberosity displacement.
Explanation
Correct Answer: CThe case content, under 'Pre-Operative Planning - Imaging,' states: 'Computed Tomography (CT) Scan: Indispensable for complex fractures, particularly three- and four-part fractures, fracture-dislocations, and head-splitting injuries. Provides detailed information on comminution, articular involvement, glenoid impression fractures, and precise tuberosity displacement. 3D reconstructions are invaluable for understanding fracture morphology and planning reduction maneuvers.'Option A (To assess for rotator cuff integrity and associated ligamentous injuries):MRI is generally better for assessing soft tissue structures like the rotator cuff and ligaments.Option B (To evaluate for brachial plexus pathology):While CT can show bony impingement, MRI or electrodiagnostic studies are more definitive for brachial plexus pathology.Option D (To confirm the presence of a fracture-dislocation, which is typically missed on standard radiographs):While CT can confirm, standard radiographs (AP, scapular Y, axillary lateral) are usually sufficient for initial diagnosis of fracture-dislocation. CT provides more detail, not just confirmation.Option E (To determine the extent of avascular necrosis (AVN) of the humeral head):AVN is a complication that develops over time. While CT can show signs of AVN in later stages, it's not the primary acute indication for CT in a fresh fracture-dislocation.
Question 2309
Topic: 2. Trauma
A 65-year-old male underwent open reduction and internal fixation (ORIF) of a two-part surgical neck fracture 3 weeks ago. He is now in the initial phase of his post-operative rehabilitation. Which of the following activities is most appropriate for him at this stage, according to the general principles of proximal humerus fracture rehabilitation?
Correct Answer & Explanation
. Gentle pendulum exercises and passive range of motion (PROM) below 90 degrees of flexion.
Explanation
The case content, under 'Post-Operative Rehabilitation Protocols - Phase I Immobilization and Early Passive Motion,' states: 'Goals: Protect surgical repair, minimize pain and swelling, initiate early passive range of motion (PROM) to prevent stiffness... Exercises: Pendulum Exercises: Gentle, gravity-assisted swings... Initiated early, often within the first week... Passive Range of Motion (PROM): Forward Elevation (Flexion): Supine patient, therapist assists arm into flexion, staying below 90 degrees initially... Precautions: No active shoulder movement. No lifting, pushing, or pulling.'
Question 2310
Topic: 2. Trauma
Recent anatomical studies have fundamentally changed the understanding of the vascular supply to the proximal humerus. Which of the following vessels is now recognized as the primary blood supply to the humeral head, particularly relevant when assessing the risk of avascular necrosis following a fracture?
Correct Answer & Explanation
. Posterior humeral circumflex artery
Explanation
Historically, the arcuate branch of the anterior humeral circumflex artery was thought to provide the main blood supply to the humeral head. Recent quantitative studies have demonstrated that the posterior humeral circumflex artery provides the vast majority (approx. 64%) of the blood supply to the humeral head.
Question 2311
Topic: 2. Trauma
A 75-year-old male presents with a displaced Type II odontoid fracture after a ground-level fall. He has a history of severe COPD and ischemic heart disease. What is the most significant risk factor for nonunion if this injury is treated nonoperatively in a hard cervical collar?
Correct Answer & Explanation
. Initial fracture displacement greater than 5 mm
Explanation
The strongest predictors for nonunion of a Type II odontoid fracture are initial displacement > 5 mm, angulation > 10 degrees, and age > 50 years. Halo vest immobilization in the elderly is associated with high morbidity and mortality, making collar or surgery (if tolerable) the preferred choices.
Question 2312
Topic: 2. Trauma
According to the Hertel criteria, which of the following radiographic findings is the most reliable predictor of subsequent ischemia and avascular necrosis of the humeral head following a proximal humerus fracture?
Correct Answer & Explanation
. Disruption of the lateral periosteum
Explanation
Hertel et al. identified specific predictors of humeral head ischemia. A metaphyseal head extension (calcar length) < 8 mm, disruption of the medial hinge, and an anatomic neck fracture pattern are the most accurate predictors of avascular necrosis.
Question 2313
Topic: 2. Trauma
A 62-year-old osteoporotic female undergoes open reduction and internal fixation of a 3-part proximal humerus fracture with a locking plate. Postoperatively, she develops severe shoulder pain and crepitus with motion. Radiographs reveal varus collapse of the humeral head. What is the most frequent complication directly associated with this specific mode of failure?
Correct Answer & Explanation
. Intra-articular screw penetration
Explanation
Varus collapse of the humeral head after locked plating frequently leads to intra-articular screw penetration (screw cut-out). Placing inferior medial calcar screws during surgery provides crucial inferomedial support to prevent this specific complication.
Question 2314
Topic: 2. Trauma
A 45-year-old male sustains an anteriorly translated, 3-part proximal humerus fracture. Which of the following clinical findings would best indicate an injury to the nerve most commonly affected by this fracture pattern?
Correct Answer & Explanation
. Numbness over the lateral aspect of the proximal arm
Explanation
The axillary nerve is the most commonly injured nerve in proximal humerus fractures. It supplies motor function to the deltoid and teres minor, and sensation to the lateral aspect of the proximal arm (superior lateral brachial cutaneous nerve).
Question 2315
Topic: 2. Trauma
When applying a locking plate for the treatment of a proximal humerus fracture, what is the optimal superior-inferior positioning of the plate relative to the greater tuberosity to minimize complications?
Correct Answer & Explanation
. 5-8 mm distal to the superior tip of the greater tuberosity
Explanation
To minimize the risk of subacromial impingement while ensuring adequate proximal screw purchase, the optimal position of a proximal humerus locking plate is 5-8 mm distal to the superior tip of the greater tuberosity.
Question 2316
Topic: 2. Trauma
A 55-year-old female sustains a minimally displaced 2-part surgical neck fracture of the humerus. Non-operative management is chosen. What is the most important rehabilitation principle to optimize her final functional outcome and minimize complications?
Correct Answer & Explanation
. Early initiation of passive range of motion within 7 to 14 days
Explanation
The vast majority of minimally displaced proximal humerus fractures are treated successfully with a sling. Early initiation of passive range of motion exercises (typically within 1 to 2 weeks) is crucial to prevent adhesive capsulitis and ensure optimal functional recovery.
Question 2317
Topic: 2. Trauma
A 72-year-old female sustains a 4-part proximal humerus fracture after a fall from a standing height. Radiographs demonstrate significant varus angulation. According to the Hertel criteria, which of the following radiographic findings is most predictive of humeral head ischemia?
Correct Answer & Explanation
. Calcar segment length attached to the articular fragment of less than 8 mm
Explanation
Hertel et al. identified that a calcar length of less than 8 mm attached to the articular segment, disruption of the medial hinge, and an anatomical neck fracture are the most reliable predictors of humeral head ischemia. The posterior circumflex humeral artery is the primary blood supply to the humeral head.
Question 2318
Topic: 2. Trauma
During open reduction and internal fixation of a proximal humerus fracture using a locked plate, which technical step is most critical to prevent varus collapse and subsequent intra-articular screw cutout?
Correct Answer & Explanation
. Insertion of inferomedial calcar screws
Explanation
Placement of inferomedial calcar screws provides structural support to the medial column of the proximal humerus. This mechanically resists varus settling of the humeral head, which is the most common reason for secondary intra-articular screw cutout.
Question 2319
Topic: 2. Trauma
A 60-year-old male with a 4-part proximal humerus fracture is indicated for a hemiarthroplasty. To achieve the best functional outcome, which of the following variables must be restored most accurately?
Correct Answer & Explanation
. Humeral head height relative to the superior border of the pectoralis major tendon
Explanation
Restoring appropriate humeral head height and version is critical in proximal humerus hemiarthroplasty. The superior border of the pectoralis major insertion is a highly reliable landmark, consistently located approximately 5.6 cm distal to the top of the humeral head.
Question 2320
Topic: 2. Trauma
A 28-year-old male sustains an isolated greater tuberosity fracture of the proximal humerus with 7 mm of superior displacement following a seizure. What is the most appropriate management for this injury?
Correct Answer & Explanation
. Open reduction and internal fixation
Explanation
Greater tuberosity fractures displaced more than 5 mm (and sometimes >3 mm in active overhead athletes) superiorly require surgical fixation. Nonoperative management of superiorly displaced fractures leads to severe subacromial impingement and loss of abduction.
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