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 2541
Topic: 2. Trauma
A 60-year-old male sustains a completely displaced supracondylar distal femur fracture. Radiographs show a characteristic deformity where the distal articular fragment is extended. Which muscle is primarily responsible for this deforming force?
Correct Answer & Explanation
. Gastrocnemius
Explanation
In distal third femur fractures, the gastrocnemius muscles originate on the posterior aspect of the distal femoral condyles. They exert a strong posterior pull, causing the distal fragment to rotate into hyperextension, potentially endangering the popliteal artery.
Question 2542
Topic: 2. Trauma
A 68-year-old female presents with a complex proximal humerus fracture. Based on the Hertel radiographic criteria, which of the following features is most predictive of ischemia and subsequent avascular necrosis of the humeral head?
Correct Answer & Explanation
. Metaphyseal head extension (calcar length) less than 8 mm
Explanation
Hertel described several criteria predicting ischemia in proximal humerus fractures. A metaphyseal head extension (calcar length) of less than 8 mm and a disrupted medial hinge (>2mm displacement) are highly predictive of disruption of the blood supply to the humeral head.
Question 2543
Topic: 2. Trauma
A 26-year-old male is brought to the trauma bay with a 'floating knee' injury (ipsilateral closed fractures of the femoral shaft and tibial shaft). He is hemodynamically stable. What is the greatest systemic benefit of early operative stabilization (within 24 hours) of both fractures?
Correct Answer & Explanation
. Decreased incidence of Acute Respiratory Distress Syndrome (ARDS)
Explanation
In patients with major long bone fractures (like a floating knee), early operative stabilization significantly reduces the risk of fat embolism syndrome and Acute Respiratory Distress Syndrome (ARDS) by limiting the continuous release of marrow fat into the venous system.
Question 2544
Topic: 2. Trauma
A 25-year-old male sustains a vertically oriented femoral neck fracture (Pauwels Type III) after a fall from a height. Which of the following internal fixation constructs provides the greatest biomechanical stability against shear forces for this specific fracture pattern?
Correct Answer & Explanation
. Sliding hip screw with a derotational cancellous screw
Explanation
Pauwels Type III fractures experience high shear forces leading to varus collapse and nonunion. A sliding hip screw supplemented with a derotational screw provides superior biomechanical stability compared to multiple parallel cancellous screws for these vertical patterns.
Question 2545
Topic: 2. Trauma
A 42-year-old skier sustains a twisting injury to her knee. Radiographs reveal a depressed lateral tibial plateau fracture.
During the surgical approach for open reduction and internal fixation, the surgeon decides on an anterolateral approach. Which structure is at greatest risk of iatrogenic injury during meniscal elevation (submeniscal arthrotomy)?
Correct Answer & Explanation
. Inferior lateral geniculate artery
Explanation
The inferior lateral geniculate artery runs transversely along the lateral joint line between the lateral collateral ligament and the lateral meniscus. It is highly susceptible to injury during a submeniscal arthrotomy for lateral tibial plateau fractures.
Question 2546
Topic: 2. Trauma
A 28-year-old male is involved in a high-speed motor vehicle collision and sustains a Hawkins Type III talar neck fracture. What is the approximate rate of avascular necrosis (AVN) of the talar body associated with this specific injury pattern?
Correct Answer & Explanation
. 75-100%
Explanation
A Hawkins Type III fracture involves a talar neck fracture with dislocation of both the subtalar and tibiotalar joints, disrupting all three major blood supplies to the talar body. The risk of avascular necrosis in Type III fractures is classically cited as 75-100%.
Question 2547
Topic: 2. Trauma
A 30-year-old farmer sustains a severe open midshaft tibia fracture (Gustilo-Anderson IIIB) with gross soil contamination after a tractor accident. According to classic orthopedic trauma guidelines, which of the following is the most appropriate initial prophylactic antibiotic regimen?
Correct Answer & Explanation
. First-generation cephalosporin, an aminoglycoside, and high-dose penicillin
Explanation
For severe open fractures (Gustilo Type III) with heavy soil or farm contamination, classic guidelines recommend a first-generation cephalosporin, an aminoglycoside (for broader Gram-negative coverage), and high-dose penicillin to cover Clostridium species.
Question 2548
Topic: 2. Trauma
A 22-year-old male develops severe, unrelenting leg pain out of proportion to his injury 12 hours after intramedullary nailing of a closed tibial shaft fracture. Pain is exacerbated by passive stretch of the hallux. If intracompartmental pressures are measured, which of the following thresholds is the most widely accepted absolute indication for four-compartment fasciotomy?
The delta pressure, calculated as the diastolic blood pressure minus the intracompartmental pressure, is the most reliable indicator for acute compartment syndrome. A delta pressure of less than 30 mmHg is a universally accepted threshold for emergent fasciotomy.
Question 2549
Topic: 2. Trauma
A 32-year-old carpenter sustains a crush injury to his right index finger. Examination reveals a painful subungual hematoma covering 60% of the nail plate, an intact eponychial fold, and no obvious nail plate avulsion. Radiographs show a non-displaced tuft fracture. Based on the provided case, what is the most appropriate initial management?
Correct Answer & Explanation
. Nail plate removal, exploration, and repair of any underlying nail bed laceration, followed by splinting.
Explanation
Correct Answer: BTheIndications and Contraindicationssection, specifically underOperative IndicationsforSubungual Hematoma, states: 'Large, painful hematomas involving >50% of the nail plate. While simple trephination suffices for smaller, intact hematomas, larger collections often signify an underlying nail bed laceration, warranting nail plate removal and exploration.' The presence of a non-displaced tuft fracture further supports the need for exploration to ensure the nail bed is intact and to provide a stable foundation for healing. Nail plate removal allows for direct visualization and meticulous repair of any underlying nail bed laceration, which is crucial for preventing long-term deformities.Incorrect Options:A. Simple trephination of the hematoma and splinting:This is indicated for hematomas <50% of the nail plate with an intact nail plate and eponychial fold. For >50%, underlying nail bed laceration is highly suspected, requiring exploration.C. Observation with pain control and close follow-up:This is insufficient for a large hematoma with a suspected underlying nail bed laceration and an associated fracture, as it risks permanent nail deformity and potential complications.D. Incision and drainage of the hematoma without nail plate removal:This is not a standard or effective approach for subungual hematomas, as it does not allow for proper visualization or repair of the nail bed. Trephination is the method for drainage without removal.E. Immediate referral for advanced imaging (CT scan) to assess fracture stability:While CT can provide more detail, plain radiographs are typically sufficient for initial assessment of tuft fractures. The primary concern here is the nail unit injury and its management, not just fracture stability, which is often managed in conjunction with nail bed repair.
Question 2550
Topic: 2. Trauma
A 30-year-old patient undergoes nail bed repair for a laceration without an associated distal phalanx fracture. In the early healing phase (Weeks 1-4), what is the most appropriate recommendation regarding mobilization of the injured digit?
Correct Answer & Explanation
. Begin gentle active and passive range of motion exercises for the distal interphalangeal (DIP) joint once skin sutures are removed (10-14 days), if no fracture.
Explanation
Correct Answer: CUnder thePost Operative Rehabilitation Protocolssection, in theEarly Healing Phase (Weeks 1-4), it states: 'Suture Removal: Skin sutures are typically removed at 10-14 days post-op.' And under 'Early Mobilization': 'If no fracture, or once fracture stability is adequate (typically 3-4 weeks for simple fractures), begin gentle active and passive range of motion exercises for the distal interphalangeal (DIP) joint.' For a case without a fracture, the constraint of waiting for fracture stability is removed, allowing for earlier mobilization once the skin sutures are out and the wound is stable. Therefore, starting gentle ROM at 10-14 days post-op (after suture removal) is the most appropriate early mobilization for a non-fracture case.Incorrect Options:A. Complete immobilization of the digit for the entire 4-week period:Prolonged immobilization can lead to stiffness, especially without a fracture requiring rigid protection.B. Begin gentle active and passive range of motion exercises for the distal interphalangeal (DIP) joint once fracture stability is adequate (typically 3-4 weeks):This timing is for cases with fractures, not for a simple nail bed laceration without fracture.D. Initiate aggressive strengthening exercises immediately after suture removal:Aggressive strengthening is too early and could disrupt the healing nail bed. Gentle ROM precedes strengthening.E. Avoid all movement of the digit until the new nail plate has fully grown out (4-6 months):This would lead to severe stiffness and functional impairment. Early, gentle mobilization is crucial.
Question 2551
Topic: 2. Trauma
A 32-year-old presents with a painful subungual hematoma covering 40% of the nail plate following a crush injury. The nail margins are intact, and radiographs show no underlying fracture. What is the most appropriate treatment?
Correct Answer & Explanation
. Trephination of the nail plate
Explanation
For a painful, simple subungual hematoma with intact nail margins and no fracture, nail plate trephination (creating a hole in the nail to drain blood) is the treatment of choice to relieve pressure and pain.
Question 2552
Topic: 2. Trauma
A 28-year-old male sustains a high-energy pelvic ring injury after a motor vehicle collision. On initial assessment, he is hypotensive (BP 80/50 mmHg) and tachycardic (HR 125 bpm). Pelvic radiographs show an anterior-posterior compression (APC) Type III injury according to the Young-Burgess classification. What is the most appropriate initial management step after primary survey and resuscitation?
Correct Answer & Explanation
. Application of a pelvic binder or sheet
Explanation
For hemodynamically unstable patients with an APC Type III pelvic injury, immediate stabilization of the pelvic ring is paramount to reduce pelvic volume and tamponade venous hemorrhage. A pelvic binder or sheet is the quickest and most effective initial method to achieve this. It helps to close the disrupted pelvic ring, reducing the potential space for blood accumulation and providing mechanical stability.
Question 2553
Topic: 2. Trauma
A 35-year-old male presents with a Gustilo-Anderson Type IIIA open tibia shaft fracture. After initial debridement and external fixation, what is the most critical next step in management?
Correct Answer & Explanation
. Soft tissue coverage within 72 hours
Explanation
For Gustilo-Anderson Type IIIA open tibia fractures, achieving adequate soft tissue coverage within 72 hours (often referred to as the 'golden window') is crucial to minimize infection risk, promote bone healing, and prevent desiccation of exposed bone.
Question 2554
Topic: 2. Trauma
A 55-year-old female presents with a Schatzker Type IV tibial plateau fracture.
What is the most common associated neurovascular injury to be aware of with this fracture pattern?
Correct Answer & Explanation
. Peroneal nerve palsy
Explanation
Correct Answer: ASchatzker Type IV tibial plateau fractures involve the medial plateau, often resulting from high-energy valgus and axial forces. While popliteal artery injury can occur with any high-energy knee trauma, peroneal nerve palsy is classically associated with lateral knee trauma or significant displacement, especially involving the fibular head or proximal fibula. Although Type IV fractures primarily affect the medial side, the high-energy mechanism can lead to significant soft tissue injury and displacement of the lateral compartment, potentially compromising the peroneal nerve due to its superficial course around the fibular neck. Popliteal artery injury is more common with knee dislocations or severe posterior displacement. Femoral and saphenous nerve injuries are less commonly associated with tibial plateau fractures.
Question 2555
Topic: 2. Trauma
A 72-year-old male with a history of osteoporosis sustains a displaced intertrochanteric hip fracture (AO/OTA 31-A2).
What is the preferred surgical treatment?
Correct Answer & Explanation
. Intramedullary nail (IMN)
Explanation
Correct Answer: DFor displaced intertrochanteric fractures, particularly unstable patterns like AO/OTA 31-A2 (multifragmentary intertrochanteric), intramedullary nailing (IMN) is generally preferred over a dynamic hip screw (DHS). IMNs provide better biomechanical stability, especially in osteoporotic bone, due to their central load-sharing position and shorter lever arm. They also have lower rates of cut-out and fixation failure compared to DHS for unstable patterns. THA and hemiarthroplasty are typically reserved for femoral neck fractures or failed fixation of intertrochanteric fractures. Cannulated screws are inadequate for these comminuted and unstable fractures.
Question 2556
Topic: 2. Trauma
A 58-year-old female sustains a comminuted distal tibia fracture with articular involvement (Pilon fracture). The soft tissue envelope is significantly swollen with fracture blisters.
What is the most appropriate initial management strategy?
Correct Answer & Explanation
. Application of an external fixator and delayed definitive ORIF
Explanation
Correct Answer: BFor comminuted pilon fractures with significant soft tissue swelling and fracture blisters, the principle of 'staged' or 'damage control' orthopedic management is crucial. Initial management involves applying a temporary external fixator (typically spanning the ankle joint) to restore length, alignment, and stability. This helps to indirectly reduce swelling, improve the soft tissue condition, and allow fracture blisters to resolve. Definitive ORIF is then delayed until the soft tissue swelling has subsided and the skin is healthy (typically 7-14 days). Immediate ORIF in a severely swollen limb significantly increases the risk of wound complications, infection, and dehiscence. Casting alone is insufficient for unstable, comminuted pilon fractures. Continuous passive motion is not appropriate in the acute phase of an unstable fracture. Percutaneous screw fixation may be part of definitive management but is not the initial strategy for severe soft tissue compromise.
Question 2557
Topic: 2. Trauma
A 22-year-old male presents with a talar neck fracture (Hawkins Type II).
What is the primary concern and potential devastating complication associated with this fracture type?
Correct Answer & Explanation
. Avascular necrosis (AVN) of the talar body
Explanation
Correct Answer: CHawkins Type II talar neck fractures involve displacement of the subtalar joint, which disrupts a significant portion of the blood supply to the talar body (especially the artery of the tarsal canal). This places the talar body at a very high risk of avascular necrosis (AVN), a devastating complication that can lead to collapse of the talar dome, severe pain, and early degenerative arthritis. While post-traumatic arthritis and nonunion are also significant concerns with talar fractures, AVN is the most specific and severe complication directly related to the vascular compromise inherent in displaced talar neck fractures. Deep vein thrombosis and peroneal nerve palsy are general complications of lower limb trauma but not the primary, unique concern for this specific fracture type.
Question 2558
Topic: 2. Trauma
What is the primary concern for a missed or delayed diagnosis of a tibial shaft compartment syndrome?
Correct Answer & Explanation
. Volkmann's ischemic contracture (permanent muscle and nerve damage)
Explanation
Correct Answer: CThe most devastating and irreversible complication of a missed or delayed diagnosis of acute compartment syndrome, particularly in the tibia, is Volkmann's ischemic contracture. This condition results from permanent and irreversible damage to muscles and nerves within the affected compartment due to prolonged ischemia. It leads to severe functional impairment, muscle necrosis, fibrosis, and nerve damage, often requiring extensive reconstructive surgery or resulting in permanent disability. While other complications like nonunion or osteomyelitis can occur with tibial fractures, they are not the primary, immediate threat directly caused by unreleased compartment pressure. Deep vein thrombosis and fat embolism syndrome are systemic complications, not direct consequences of unreleased compartment pressure.
Question 2559
Topic: Lower Extremity Trauma
An MRI is performed for a suspected Non-Ossifying Fibroma in the distal femur of a 10-year-old. The lesion shows a characteristic sclerotic rim on plain radiographs. How would this sclerotic rim typically appear on both T1-weighted and T2-weighted MRI sequences?
Correct Answer & Explanation
. Dark on both T1 and T2.
Explanation
Correct Answer: CThe sclerotic rim surrounding a Non-Ossifying Fibroma is composed of dense cortical bone. Dense cortical bone, due to its very low water content and high mineral density, typically appears dark (low signal intensity) on all MRI sequences, including both T1-weighted and T2-weighted images. This is a consistent finding for cortical bone and helps delineate the lesion from surrounding marrow and soft tissues.
Question 2560
Topic: 2. Trauma
A 32-year-old male sustains a Hawkins Type III fracture of the talar neck. Six weeks postoperatively, a radiolucent band is seen beneath the subchondral bone of the talar dome on the AP radiograph. What does this finding indicate?
Correct Answer & Explanation
. Revascularization and intact blood supply
Explanation
The presence of subchondral radiolucency at 6-8 weeks, known as Hawkins sign, indicates subchondral atrophy secondary to hyperemia. This confirms that the blood supply to the talar body is intact, making avascular necrosis highly unlikely.
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