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 11721
Topic: 2. Trauma
Which of the following describes the 'floating knee' injury?
Correct Answer & Explanation
. An ipsilateral fracture of the femoral shaft and tibia shaft.
Explanation
A 'floating knee' injury (C) refers to an ipsilateral fracture of the femoral shaft and the tibia shaft. It is a high-energy injury often associated with significant soft tissue damage, increased risk of complications (e.g., compartment syndrome, vascular injury, nerve injury), and often occurs in polytrauma patients. While option B describes fractures around the knee joint, the classic definition of a floating knee refers to the shaft fractures, effectively 'disconnecting' the knee joint from both proximal and distal segments.
Question 11722
Topic: 2. Trauma
A 33-year-old male presents with a closed mid-shaft tibia fracture. He is hemodynamically stable, and there is no evidence of compartment syndrome. What is the most appropriate definitive management strategy?
Correct Answer & Explanation
. Reamed intramedullary nailing.
Explanation
For most adult, closed, diaphyseal tibia fractures, reamed intramedullary nailing (D) is the gold standard for definitive management. It provides rigid fixation, allows for early weight-bearing and mobilization, has high union rates, and minimizes soft tissue stripping. While casting (A) or bracing (B) can be used for very stable, non-displaced fractures, IMN is preferred for most mid-shaft fractures. Plate and screw fixation (C) is generally reserved for fractures with articular extension, severe comminution precluding nailing, or nonunions. External fixation (E) is usually temporary, especially in closed fractures, due to pin tract infection risk and patient discomfort.
Question 11723
Topic: 2. Trauma
What is the most common mechanism of injury for a posterior wall acetabular fracture?
Correct Answer & Explanation
. Dashboard injury in a motor vehicle accident (hip flexed, adducted, internally rotated).
Explanation
A posterior wall acetabular fracture (C) typically results from a 'dashboard injury' in a motor vehicle accident. This mechanism involves a direct axial load to the flexed, adducted, and internally rotated hip, driving the femoral head posteriorly into the posterior column and wall of the acetabulum. This often causes an associated posterior hip dislocation. Direct blow to the greater trochanter (A) would typically cause a lateral wall or column fracture. Falls onto outstretched hand (B) cause upper extremity injuries. Lateral compression to the pelvis (E) causes pelvic ring injuries.
Question 11724
Topic: 2. Trauma
A 70-year-old male sustains an open Schatzker V tibial plateau fracture (bicondylar). He is a smoker with peripheral vascular disease. What is the most appropriate initial management for this complex injury?
Correct Answer & Explanation
. Debridement, external fixation, and delayed ORIF.
Explanation
This patient has a complex, high-energy open tibial plateau fracture (Schatzker V/bicondylar) complicated by significant comorbidities (smoking, PVD), which impair wound healing and increase infection risk. Immediate definitive ORIF (A) is contraindicated in open fractures with soft tissue compromise due to high infection and wound complication rates. The principles of damage control orthopedics apply: thorough debridement, temporary external fixation to stabilize the knee and allow soft tissues to recover, followed by delayed definitive ORIF (C) once the soft tissue envelope is favorable. External fixation across the knee (B) is a temporary measure, but the emphasis on debridement is critical. Skeletal traction (D) is largely historical for these types of fractures and carries its own risks. Amputation (E) is not an initial consideration unless there is unsalvageable limb injury (e.g., complete neurovascular disruption).
Question 11725
Topic: 2. Trauma
A 25-year-old female presents with a transverse femoral shaft fracture. During reamed intramedullary nailing, she experiences sudden hypoxia, hypotension, and petechial rash. What is the most likely diagnosis?
Correct Answer & Explanation
. Fat embolism syndrome.
Explanation
The triad of sudden hypoxia, hypotension, and a petechial rash, occurring during or shortly after intramedullary nailing of a long bone fracture (especially femoral shaft), is highly suggestive of Fat Embolism Syndrome (FES) (D). Reaming and nail insertion increase intramedullary pressure, forcing fat globules into the venous circulation, which can then travel to the lungs and brain, causing systemic inflammatory response. Pulmonary embolism (A) would typically present with hypoxia and hypotension but usually without the classic petechial rash. Myocardial infarction (B), anaphylaxis (C), and sepsis (E) would have different clinical presentations.
Question 11726
Topic: 2. Trauma
What is the most appropriate imaging modality to evaluate for a missed acetabular fracture in a patient who previously sustained a posterior hip dislocation and now complains of persistent hip pain?
Correct Answer & Explanation
. CT scan of the pelvis with 3D reconstructions.
Explanation
Following a posterior hip dislocation, a CT scan of the pelvis with 3D reconstructions (C) is the most appropriate and sensitive imaging modality to evaluate for a missed acetabular fracture or incarcerated osteochondral fragments. Plain radiographs (A) can miss subtle fractures. Dynamic stress radiographs (B) are not used for acetabular fractures. MRI (D) is excellent for soft tissue injuries (labrum, cartilage) but less sensitive for acute bony details. Bone scan (E) indicates metabolic activity but is not specific for acute fracture morphology.
Question 11727
Topic: 2. Trauma
A 55-year-old male with chronic alcoholism and poor nutrition sustains a Grade II open tibia shaft fracture. He is planned for definitive intramedullary nailing. What is the most important pre-operative intervention to reduce the risk of nonunion and infection?
Correct Answer & Explanation
. Nutritional optimization and smoking cessation counseling.
Explanation
Chronic alcoholism and poor nutrition significantly compromise wound healing, immune function, and bone quality, substantially increasing the risk of nonunion and infection in open fractures. Nutritional optimization (e.g., protein, vitamins) and smoking cessation counseling (B) are critical pre-operative interventions that can improve patient physiology and wound healing potential. While prophylactic fasciotomy (C) can prevent compartment syndrome, it's not a primary intervention for reducing nonunion/infection risk directly. Higher dose antibiotics (D) are important but secondary to systemic health. Choice of reamed vs. unreamed nail (E) depends on fracture specifics and surgeon preference but doesn't override systemic health issues. Aggressive physical therapy (A) is premature.
Question 11728
Topic: 2. Trauma
Which of the following describes the mechanism of injury for a 'reverse obliquity' intertrochanteric hip fracture?
Correct Answer & Explanation
. High-energy adduction force causing a fracture line from superomedial to inferolateral.
Explanation
A 'reverse obliquity' intertrochanteric hip fracture (D) is characterized by a fracture line that runs from superomedial to inferolateral. This pattern is inherently unstable and often caused by high-energy adduction forces. It is particularly problematic for fixation with a sliding hip screw (DHS) because the oblique fracture line tends to convert shear forces into compressive forces, leading to medialization of the distal fragment and cut-out of the screw from the femoral head. Intramedullary nailing is generally the preferred fixation for these unstable fractures. Option A, B, C, D (medial impaction) are typically associated with more common intertrochanteric fracture patterns.
Question 11729
Topic: 2. Trauma
In a patient with an open Gustilo-Anderson IIIB tibia fracture, after initial debridement and external fixation, which imaging modality is most useful for assessing the extent of soft tissue and periosteal stripping before definitive coverage?
Correct Answer & Explanation
. MRI.
Explanation
MRI (C) is the most useful imaging modality for assessing the extent of soft tissue and periosteal stripping in an open Gustilo-Anderson IIIB tibia fracture. It provides excellent soft tissue contrast, allowing visualization of muscle damage, fascial integrity, and periosteal disruption, which are crucial for planning definitive soft tissue coverage and predicting healing potential. Plain radiographs (A) show bone only. CT scan (B) shows bony detail better than MRI, but less soft tissue detail. Angiography (D) is for vascular assessment. Ultrasound (E) can assess superficial soft tissues but has limitations in deep structures.
Question 11730
Topic: 2. Trauma
What is the most common classification system used for intra-articular calcaneal fractures?
Correct Answer & Explanation
. Sanders classification.
Explanation
The Sanders classification (E) is the most commonly used system for intra-articular calcaneal fractures. It is based on coronal CT images and divides fractures into types I-IV based on the number and location of articular fragments in the posterior facet. This classification helps guide surgical management and prognosis. Gustilo-Anderson (A) is for open fractures. AO/OTA (B) is a general long bone classification. Schatzker (C) is for tibial plateau fractures. Essex-Lopresti (D) describes a specific forearm injury (radial head fracture with DRUJ dissociation).
Question 11731
Topic: 2. Trauma
A 40-year-old male presents with a Grade II open pilon fracture. The initial debridement is performed, and an external fixator is applied. Two weeks later, the soft tissues have 'wrinkled', and the skin appears healthy. The articular surface is comminuted. What is the most appropriate next step for definitive management?
Correct Answer & Explanation
. Application of a circular external fixator for definitive management.
Explanation
For a comminuted open pilon fracture, even after initial debridement and temporary external fixation, severe articular comminution may preclude safe and stable fixation with traditional plates and screws, especially if there is significant bone loss or soft tissue compromise. In such cases, a circular external fixator (D) (e.g., Ilizarov or Taylor Spatial Frame) can be a powerful tool for definitive management. It allows for gradual reduction, compression, distraction, and potential bone transport, while providing rigid stability and access for wound care. Limited ORIF (B) is common for less comminuted Pilon fractures. Intramedullary nailing (A) is generally contraindicated for articular Pilon fractures. Cast immobilization (C) is insufficient for stability. Observation (E) is not definitive.
Question 11732
Topic: 2. Trauma
Which complication is unique to a Type III fibular collateral ligament (FCL) avulsion fracture of the fibular head (Segond-like lesion) associated with posterolateral corner injury?
Correct Answer & Explanation
. Common peroneal nerve injury.
Explanation
A Type III fibular collateral ligament (FCL) avulsion fracture of the fibular head (often indicative of a posterolateral corner injury) is uniquely associated with common peroneal nerve injury (A). The common peroneal nerve courses directly around the fibular neck, making it highly susceptible to stretch, contusion, or laceration during injuries to this region. Popliteal artery injury (B) is associated with knee dislocations, but less specifically with isolated FCL avulsions. DVT (C), compartment syndrome (D), and osteoarthritis (E) are more general complications or sequelae of knee trauma.
Question 11733
Topic: 2. Trauma
A 28-year-old male presents with a posterior wall acetabular fracture with a stable hip joint after closed reduction. There is a 4 mm step-off on the post-reduction CT scan. The patient is otherwise healthy. What is the most appropriate management?
Correct Answer & Explanation
. Open reduction and internal fixation (ORIF).
Explanation
For an acetabular fracture with even a minimal articular step-off or gap (typically >1-2 mm) following reduction, open reduction and internal fixation (ORIF) (C) is generally indicated in a young, healthy patient. Unreduced articular incongruity significantly increases the risk of post-traumatic osteoarthritis. A 4 mm step-off is considered an absolute indication for surgical correction. Non-weight-bearing (A) or skeletal traction (B) are insufficient to address articular incongruity. Percutaneous screw fixation (D) is typically for certain types of pelvic ring injuries or very simple acetabular fractures, not displaced posterior wall fractures. Delayed total hip arthroplasty (E) is a salvage procedure for established arthritis.
Question 11734
Topic: 2. Trauma
Which of the following is an absolute indication for immediate operative exploration in a patient with a lower extremity trauma?
Correct Answer & Explanation
. Absent distal pulses with expanding hematoma.
Explanation
An absent distal pulse combined with an expanding hematoma (A) is an absolute indication for immediate operative exploration (fasciotomy and vascular repair). This suggests an acute arterial injury, which, if not promptly addressed, will lead to limb ischemia and loss. While open fracture with gross contamination (C) requires urgent debridement, it's not 'immediate exploration' in the same sense as a vascular emergency. Pain out of proportion (D) suggests compartment syndrome, requiring pressure measurement and potentially fasciotomy, but not necessarily immediate exploration without definitive diagnosis. Decreased sensation (B) is a sign of nerve injury but not an immediate limb-threatening emergency. Minor laceration (E) indicates a Grade I open fracture needing debridement but not immediate exploration in this context.
Question 11735
Topic: 2. Trauma
A 60-year-old obese female with diabetes sustains a comminuted ipsilateral femoral neck and shaft fracture. What is the most appropriate management for this 'floating hip' injury?
Correct Answer & Explanation
. Long cephalomedullary nail.
Explanation
For ipsilateral femoral neck and shaft fractures (a 'floating hip'), a long cephalomedullary nail (D) is often the most appropriate and biomechanically sound fixation method. This single implant can stabilize both the femoral neck and shaft fractures, providing a stable construct that allows for early mobilization. It avoids the need for two separate implants and associated stress risers or complex plating. Hemiarthroplasty (B) or THA (C) for the neck with separate shaft fixation would be more invasive and complex. Cannulated screws (A) are generally not adequate for displaced neck fractures in this age group, and plate fixation for the shaft is often less preferred than nailing. External fixation (E) is typically temporary.
Question 11736
Topic: 2. Trauma
What is the most common nerve injured in association with a fracture of the fibular neck?
Correct Answer & Explanation
. Common peroneal nerve.
Explanation
The common peroneal nerve (D) courses directly around the fibular neck, making it highly susceptible to injury (stretch, compression, or direct trauma) in fractures of the fibular neck. Injury to this nerve typically results in foot drop (weakness of ankle dorsiflexion and eversion) and sensory loss in the dorsum of the foot. The tibial nerve (A) and posterior tibial nerve (E) are located medially and deep, while the sural (B) and saphenous (C) nerves are sensory only and less commonly injured in this specific fracture.
Question 11737
Topic: 2. Trauma
What is the most crucial consideration in preventing deep infection in a Grade IIIB open tibia fracture?
Correct Answer & Explanation
. Adequate and timely surgical debridement of devitalized tissue.
Explanation
Adequate and timely surgical debridement of devitalized tissue is unequivocally the most crucial factor in preventing deep infection in open fractures, especially Gustilo-Anderson IIIB injuries. Devitalized tissue (skin, muscle, bone) serves as a nidus for bacterial growth, hindering the body's immune response and antibiotic penetration. While antibiotics are essential, they are adjunctive to debridement. Anatomical reduction is important for function but secondary to infection control. External fixation provides stability but does not address the biological environment. Early weight-bearing is post-operative and does not directly prevent infection.
Question 11738
Topic: 2. Trauma
A 25-year-old male sustains a spiral fracture of the distal tibia extending into the ankle joint (Pilon fracture). The fracture is closed, but the ankle is severely swollen. What is the most appropriate immediate definitive fixation strategy?
Correct Answer & Explanation
. Application of a spanning external fixator, followed by delayed ORIF.
Explanation
For a closed Pilon fracture with severe soft tissue swelling, a staged approach is generally preferred. The initial step is to stabilize the joint and reduce swelling with a spanning external fixator (B), often with fibular fixation. This allows the soft tissue envelope to recover ('wrinkle sign') before definitive open reduction and internal fixation (ORIF). Immediate ORIF (A) in the presence of severe swelling carries a high risk of wound complications and infection. Intramedullary nailing (C) is generally not suitable for articular fractures. Long leg cast (D) does not provide adequate stability or allow for soft tissue monitoring. Percutaneous screws (E) are insufficient for complex articular fractures.
Question 11739
Topic: 2. Trauma
Which of the following is an accepted indication for acute knee arthroscopy in the setting of an acute tibial plateau fracture?
Correct Answer & Explanation
. All of the above.
Explanation
Acute knee arthroscopy can be a valuable adjunct in the management of tibial plateau fractures. It allows for direct visualization and evaluation of articular cartilage integrity (A), repair of associated meniscal tears (B) (which are common), removal of incarcerated intra-articular fragments (C), and assessment of associated ligamentous injuries (D). Therefore, 'All of the above' (E) is the most accurate answer, highlighting the utility of arthroscopy in these complex injuries.
Question 11740
Topic: 2. Trauma
What is the most common complication following surgical repair of a high-energy Lisfranc injury?
Correct Answer & Explanation
. Post-traumatic arthritis.
Explanation
The most common and debilitating complication following surgical repair of a high-energy Lisfranc injury is post-traumatic arthritis (D). Despite meticulous anatomical reduction and stable fixation, the initial severe cartilage damage and persistent subtle incongruity can lead to degenerative changes, chronic pain, and functional limitations, often requiring a fusion procedure. While hardware failure (B) and nonunion (A) can occur, post-traumatic arthritis is far more prevalent as a long-term sequela. Infection (C) and nerve injury (E) are less common.
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