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2. Trauma MCQs

Practice Set 588 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 11741

Topic: 2. Trauma

A 20-year-old male presents with a Grade II open femoral shaft fracture. He is hemodynamically stable. After initial debridement and external fixation, what is the ideal timing for conversion to intramedullary nailing?

. Within 6 hours.
. Within 24-48 hours.
. Within 3-5 days.
. When the wound is clean and healthy (typically 7-14 days).
. After 3 months, once initial healing has occurred.

Correct Answer & Explanation

. When the wound is clean and healthy (typically 7-14 days).

Explanation

For a Gustilo-Anderson Grade II open femoral shaft fracture, after thorough initial debridement and external fixation, the ideal timing for conversion to intramedullary nailing is typically when the wound is clean, healthy, and showing signs of granulation, usually within 7-14 days (D). This staged approach minimizes the risk of infection associated with early definitive fixation in an open wound while providing stability and promoting healing. Converting too early (A, B, C) increases infection risk. Waiting too long (E) can lead to difficulties with reduction and nonunion.

Question 11742

Topic: 2. Trauma

A 65-year-old female sustains a comminuted distal femur fracture (AO/OTA 33-C3). She has severe osteoporosis. What is the most appropriate definitive surgical management?

. Skeletal traction.
. Retrograde intramedullary nail.
. Antegrade intramedullary nail.
. Open reduction and internal fixation with a locking plate.
. Total knee arthroplasty.

Correct Answer & Explanation

. Open reduction and internal fixation with a locking plate.

Explanation

For a comminuted distal femur fracture, especially in an osteoporotic patient, open reduction and internal fixation with a locking plate (D) is generally the preferred definitive surgical management. Locking plates provide angular stability, which is crucial in osteoporotic bone, allowing for fixation of comminuted fragments without relying on screw purchase in poor bone stock. While intramedullary nailing (B, C) can be used for some distal femur fractures, they are less suitable for highly comminuted articular fractures where anatomical reduction and stability of the condyles are paramount. Skeletal traction (A) is not definitive. Total knee arthroplasty (E) is a salvage procedure for severe articular destruction, not typically an acute fracture fixation.

Question 11743

Topic: 2. Trauma

A 40-year-old male sustains a traumatic posterior hip dislocation. Which of the following conditions mandates open reduction, even after an attempt at closed reduction has failed?

. A concomitant femoral shaft fracture.
. Incarcerated intra-articular fragments seen on CT scan.
. An associated avulsion fracture of the greater trochanter.
. Sciatic nerve palsy.
. Patient obesity.

Correct Answer & Explanation

. Incarcerated intra-articular fragments seen on CT scan.

Explanation

If closed reduction of a traumatic hip dislocation is unsuccessful or if post-reduction imaging (CT scan) reveals incarcerated intra-articular fragments (B), then open reduction is mandated. Incarcerated fragments prevent concentric reduction and significantly increase the risk of post-traumatic arthritis and re-dislocation. They must be removed. A concomitant femoral shaft fracture (A) is a 'floating hip' but doesn't necessarily contraindicate successful closed reduction of the hip. Avulsion fracture of the greater trochanter (C) is usually managed differently. Sciatic nerve palsy (D) is a complication, not an indication for open reduction itself. Obesity (E) makes reduction difficult but doesn't mandate open reduction on its own.

Question 11744

Topic: 2. Trauma

A 50-year-old male sustains a comminuted subtrochanteric femur fracture. He has stable vital signs. What is the preferred method of surgical fixation?

. Dynamic hip screw (DHS) with side plate.
. 95-degree condylar blade plate.
. Intramedullary nail (IMN).
. External fixation.
. Open reduction with 3.5mm reconstruction plate.

Correct Answer & Explanation

. Intramedullary nail (IMN).

Explanation

Intramedullary nails (IMNs) are the preferred treatment for most subtrochanteric femur fractures due to their load-sharing capabilities, high union rates, and minimally invasive insertion. They resist varus collapse and provide better biomechanical stability than plates, especially in comminuted fractures. A Dynamic Hip Screw (DHS) is generally used for intertrochanteric fractures. Blade plates are used for certain distal femur fractures or occasionally proximal femur fractures but are less common for subtrochanteric. External fixation is reserved for open fractures with significant contamination or as a temporizing measure in polytrauma. A 3.5mm reconstruction plate is too weak for a subtrochanteric femur fracture.

Question 11745

Topic: 2. Trauma

A 40-year-old female sustains a high-energy pilon fracture (distal tibia intra-articular) with significant soft tissue swelling and blistering. What is the most appropriate initial management strategy?

. Immediate open reduction and internal fixation (ORIF).
. Closed reduction and long-leg casting.
. External fixation with ankle-spanning frame, with delayed definitive ORIF.
. Urgent CT scan for surgical planning.
. Application of a walking boot and non-weight bearing.

Correct Answer & Explanation

. External fixation with ankle-spanning frame, with delayed definitive ORIF.

Explanation

Pilon fractures often involve severe soft tissue injury, and attempting immediate ORIF in the setting of significant swelling and blistering can lead to wound complications, infection, and skin necrosis. The most appropriate initial management involves a staged approach: initial closed reduction and application of an ankle-spanning external fixator to restore length, alignment, and indirectly reduce the articular surface, thereby allowing the soft tissues to recover. Definitive ORIF is then performed once the 'wrinkle sign' is present and soft tissue edema has subsided (typically 7-14 days later). Urgent CT is important for surgical planning but not the immediate management of the soft tissue envelope.

Question 11746

Topic: 2. Trauma

Which of the following absolute compartment pressure readings, in a normotensive patient with suspected acute compartment syndrome of the lower leg, is generally considered diagnostic and an indication for fasciotomy?

. Greater than 10 mmHg.
. Greater than 20 mmHg.
. Greater than 30 mmHg.
. Greater than 40 mmHg.
. Greater than 50 mmHg.

Correct Answer & Explanation

. Greater than 30 mmHg.

Explanation

While clinical suspicion remains paramount, an absolute compartment pressure greater than 30-40 mmHg is generally considered indicative of acute compartment syndrome and an indication for emergent fasciotomy. More precisely, the 'delta pressure' (diastolic blood pressure minus compartment pressure) less than 30 mmHg is often used, as it accounts for the patient's perfusion pressure. However, a consistent absolute pressure >30-40 mmHg is a common benchmark regardless of delta pressure, especially in a normotensive patient.

Question 11747

Topic: 2. Trauma
A 40-year-old male sustains a Gustilo-Anderson Type II open distal tibial shaft fracture. He receives tetanus prophylaxis and IV antibiotics (cefazolin and gentamicin) in the ED. Which of the following is the most appropriate next step in antibiotic management?
. Continue cefazolin and gentamicin for 24 hours post-surgery.
. Switch to oral antibiotics after debridement.
. Add vancomycin for broad-spectrum coverage.
. Continue IV antibiotics for 48-72 hours post-surgery, or until wound is closed/clean.
. Discontinue antibiotics if wound cultures are negative.

Correct Answer & Explanation

. Continue IV antibiotics for 48-72 hours post-surgery, or until wound is closed/clean.

Explanation

For Gustilo-Anderson Type II open fractures, initial IV antibiotics with a first-generation cephalosporin (e.g., cefazolin) and an aminoglycoside (e.g., gentamicin) or a fluoroquinolone are appropriate for gram-positive and gram-negative coverage. The recommended duration for Type II fractures is typically 48-72 hours post-initial debridement, or until the wound is deemed clean and closed. Extending beyond 72 hours for Type I and II is generally not recommended unless there are signs of infection. Vancomycin is added for Type III fractures or if MRSA is suspected. Switching to oral antibiotics too early is inappropriate given the severity of open fractures.

Question 11748

Topic: 2. Trauma

A 25-year-old male polytrauma patient sustains a comminuted femoral shaft fracture, blunt abdominal trauma, and a closed head injury (GCS 13). His hemodynamic status is stable after initial resuscitation. What is the optimal timing for definitive fixation of his femoral shaft fracture?

. Within 6 hours of injury (emergency fixation).
. Within 12-24 hours of injury (early appropriate care).
. Delayed fixation after 5-7 days.
. After the closed head injury has resolved (GCS 15).
. Only after all other injuries are fully assessed by MRI.

Correct Answer & Explanation

. Within 12-24 hours of injury (early appropriate care).

Explanation

For stable polytrauma patients, early appropriate care (EAC) with definitive fixation of long bone fractures, particularly femoral shaft fractures, is recommended within 12-24 hours. This has been shown to decrease the incidence of systemic complications such as ARDS, fat embolism, and pneumonia. While immediate fixation (damage control orthopedics, DCO) might be considered for unstable patients, this patient is stable. Delayed fixation (after 5-7 days) or waiting for full resolution of head injury can increase systemic complications. MRI is not required for timing of femoral shaft fixation.

Question 11749

Topic: 2. Trauma

A 60-year-old male falls directly onto his knee. He presents with severe pain and inability to actively extend his knee. X-rays confirm a transverse patellar fracture with 1 cm of displacement between the superior and inferior poles. What is the most appropriate surgical management?

. Closed reduction and long-leg casting for 6 weeks.
. Partial patellectomy.
. Tension band wiring.
. Patellectomy and quadriceps tendon repair.
. Lag screw fixation.

Correct Answer & Explanation

. Tension band wiring.

Explanation

Transverse patellar fractures with disruption of the extensor mechanism (manifested by inability to actively extend the knee) and displacement require surgical fixation. Tension band wiring is the classic and most commonly used technique for these fractures. It converts tensile forces across the fracture into compressive forces, promoting healing and allowing early range of motion. Partial patellectomy is reserved for highly comminuted fragments that cannot be reconstructed. Total patellectomy is a salvage procedure. Lag screws alone are insufficient for transverse fractures and risk pull-out. Non-operative treatment is for non-displaced fractures with intact extensor mechanism.

Question 11750

Topic: 2. Trauma

A 30-year-old female runner complains of insidious onset of increasing pain in her left anterior lower leg that worsens with running and improves with rest. Initial X-rays are normal. What is the most likely diagnosis?

. Shin splints (medial tibial stress syndrome).
. Acute compartment syndrome.
. Chronic exertional compartment syndrome.
. Stress fracture of the tibia.
. Peroneal tendonitis.

Correct Answer & Explanation

. Stress fracture of the tibia.

Explanation

The description of localized pain that worsens with activity, improves with rest, and normal initial X-rays in a runner is highly suggestive of a stress fracture of the tibia. Shin splints typically involve diffuse pain along the posteromedial tibia. Chronic exertional compartment syndrome is characterized by exertional pain, but often with sensory changes and tightness, and typically requires compartment pressure measurements for diagnosis. Acute compartment syndrome is an emergency after trauma. Peroneal tendonitis would cause lateral ankle pain. While shin splints are possible, the 'increasing pain' and localized nature points more towards a stress fracture as a more serious diagnosis to rule out.

Question 11751

Topic: 2. Trauma

A 28-year-old male sustains a high-energy femoral shaft fracture and undergoes intramedullary nailing. He has a history of head injury. What is the most effective prophylactic measure against heterotopic ossification (HO) in this patient?

. Indomethacin (NSAID) post-operatively.
. Radiation therapy to the fracture site pre-operatively.
. Early continuous passive motion (CPM).
. High-dose corticosteroids post-operatively.
. Serial X-rays to monitor for HO formation.

Correct Answer & Explanation

. Indomethacin (NSAID) post-operatively.

Explanation

Heterotopic ossification (HO) is the abnormal formation of bone in soft tissues where bone does not normally exist. It is a known complication following severe trauma, especially in patients with associated head injury or burns, and particularly around the hip. The most effective prophylactic measures are NSAIDs (like indomethacin) given post-operatively for 2-6 weeks or localized low-dose radiation therapy. Radiation is often reserved for high-risk cases or those who cannot tolerate NSAIDs. Early CPM does not prevent HO, though it's important for mobility. Corticosteroids are not standard prophylaxis. Serial X-rays are for monitoring, not prevention.

Question 11752

Topic: 2. Trauma

A 35-year-old male develops a painful nonunion of his mid-shaft tibia fracture, 9 months after intramedullary nailing. There are no signs of infection, and the fracture gap is less than 1 cm. What is the most appropriate management strategy?

. Revision IMN with dynamization.
. Plate fixation with bone grafting.
. External fixation with bone transport.
. Excision of the nonunion and short-leg casting.
. Stimulation with pulsed electromagnetic fields (PEMF) alone.

Correct Answer & Explanation

. Plate fixation with bone grafting.

Explanation

For aseptic tibial shaft nonunions after IMN, several options exist. If the nail is biomechanically stable but healing is stalled, dynamization of the nail (removing locking screws) can be considered. However, for a persistent nonunion at 9 months, especially with a gap or if the nail is deemed inadequate, revision surgery is often necessary. Exchange nailing (removing the old nail and inserting a larger one, often with reaming and bone grafting) is a common and effective strategy. Plate fixation with bone grafting is another excellent option, especially if deformity correction is needed. External fixation with bone transport is typically reserved for large bone defects or infected nonunions. PEMF can be an adjunct but is less likely to achieve union as a standalone treatment for established nonunion.

Question 11753

Topic: 2. Trauma

A 45-year-old male sustains a high-energy trauma to his ankle, resulting in a comminuted, intra-articular fracture of the distal tibia extending into the ankle joint (pilon fracture). Which of the following principles is paramount for achieving optimal long-term functional outcome?

. Early full weight-bearing to promote bone healing.
. Aggressive soft tissue debridement and delayed closure.
. Accurate anatomical reduction of the articular surface.
. Application of external fixation as definitive treatment.
. Fusion of the ankle joint to eliminate pain.

Correct Answer & Explanation

. Accurate anatomical reduction of the articular surface.

Explanation

For intra-articular fractures like pilon fractures, accurate anatomical reduction of the articular surface is paramount. Malreduction, even by a few millimeters, significantly increases the risk of post-traumatic arthritis, pain, and poor functional outcomes. While soft tissue management (staged approach) is critical for preventing complications, and external fixation may be used initially, the ultimate goal of definitive fixation is articular congruence. Early full weight-bearing is contraindicated. Ankle fusion is a salvage procedure, not an initial goal.

Question 11754

Topic: 2. Trauma

A 25-year-old football player sustains a non-displaced fracture of the base of the 5th metatarsal after a twisting injury to his foot. The fracture is located 1.5 cm distal to the tuberosity. This fracture is most appropriately classified as a:

. Avulsion fracture of the styloid process.
. Jones fracture.
. Stress fracture of the 5th metatarsal.
. Diaphyseal stress fracture.
. March fracture.

Correct Answer & Explanation

. Jones fracture.

Explanation

Fractures of the 5th metatarsal base are categorized into three zones. Zone 1 involves the styloid process (tuberosity) and is typically an avulsion fracture (peroneus brevis insertion). Zone 2 is the metaphyseal-diaphyseal junction, typically 1.5-3 cm distal to the tuberosity, and is known as a Jones fracture. Zone 3 is a diaphyseal stress fracture more distal. A fracture 1.5 cm distal to the tuberosity falls squarely into Zone 2, making it a Jones fracture. These fractures have a higher risk of nonunion due to watershed vascularity and typically require non-weight bearing immobilization or surgical fixation.

Question 11755

Topic: 2. Trauma

A 30-year-old triathlete complains of calf pain that predictably starts during running, progressively worsens, and resolves completely within 15-20 minutes after stopping activity. Physical exam is normal at rest. What is the most appropriate diagnostic test?

. Plain X-rays of the tibia and fibula.
. MRI of the lower leg.
. Measurement of intracompartmental pressures before and after exercise.
. Electromyography (EMG) and nerve conduction studies (NCS).
. Doppler ultrasound of the lower leg arteries.

Correct Answer & Explanation

. Measurement of intracompartmental pressures before and after exercise.

Explanation

The classic presentation of exertional pain that resolves with rest, especially in athletes, is highly suggestive of chronic exertional compartment syndrome (CECS). The definitive diagnostic test for CECS is the measurement of intracompartmental pressures before and after exercise. A pressure increase to >30 mmHg during exercise or a sustained elevation of >15 mmHg at 1 minute or >10 mmHg at 5 minutes post-exercise is diagnostic. X-rays and MRI are typically normal in CECS and are used to rule out other pathology (e.g., stress fracture). EMG/NCS are for nerve impingement, and Doppler for vascular insufficiency, which are less likely given the immediate post-exertional resolution.

Question 11756

Topic: 2. Trauma

A 30-year-old male suffers a traumatic knee dislocation. After reduction, he has palpable dorsalis pedis and posterior tibial pulses, but the ankle-brachial index (ABI) is 0.7 on the injured side. What is the most appropriate next step in management?

. Observe the pulses and ABI for 24 hours.
. Obtain an urgent CT angiogram (CTA) of the lower extremity.
. Start prophylactic anticoagulation.
. Perform an emergent fasciotomy.
. Measure compartment pressures.

Correct Answer & Explanation

. Obtain an urgent CT angiogram (CTA) of the lower extremity.

Explanation

A knee dislocation, even with palpable pulses, has a high risk of popliteal artery injury, often involving intimal tears that can lead to delayed thrombosis. An ABI <0.9 (or an absolute difference >0.1 in some guidelines) is considered abnormal and warrants further investigation for vascular injury. The most appropriate next step is an urgent CT angiogram to definitively diagnose and localize any arterial injury, which may then require surgical repair. Observation is unsafe given the ABI. Fasciotomy and compartment pressure measurements are for compartment syndrome, a separate but potentially coexisting issue. Anticoagulation is not the primary treatment for an acute arterial injury.

Question 11757

Topic: 2. Trauma

A 40-year-old female develops severe, disproportionate pain, swelling, allodynia, and trophic changes in her foot after an ankle fracture. This clinical picture is most consistent with:

. Peripheral neuropathy.
. Acute compartment syndrome.
. Complex Regional Pain Syndrome (CRPS) Type I.
. Deep vein thrombosis (DVT).
. Infection.

Correct Answer & Explanation

. Complex Regional Pain Syndrome (CRPS) Type I.

Explanation

The constellation of symptoms (disproportionate pain, swelling, allodynia (pain from non-painful stimuli), and trophic changes like skin/nail/hair alterations) after an injury, without a specific nerve lesion, is classic for Complex Regional Pain Syndrome (CRPS) Type I (formerly Reflex Sympathetic Dystrophy). Peripheral neuropathy would typically have a specific nerve distribution. Acute compartment syndrome would be an acute, limb-threatening emergency with specific '5 Ps' signs. DVT involves swelling and pain but not allodynia or trophic changes. Infection would typically have systemic signs and purulence.

Question 11758

Topic: 2. Trauma

Which of the following conditions is the highest risk factor for developing avascular necrosis (AVN) of the femoral head following a traumatic event?

. Intertrochanteric hip fracture.
. Acetabular fracture (posterior wall).
. Subcapital femoral neck fracture with displacement.
. Femoral shaft fracture.
. Posterior hip dislocation with reduction within 6 hours.

Correct Answer & Explanation

. Subcapital femoral neck fracture with displacement.

Explanation

Subcapital femoral neck fractures, especially when displaced, sever the crucial retinacular vessels (branches of the medial circumflex femoral artery) that supply the femoral head. This places the femoral head at the highest risk for avascular necrosis (AVN), often exceeding 30-50%. While posterior hip dislocations also carry a risk of AVN, especially with delayed reduction, a displaced subcapital femoral neck fracture inherently compromises the blood supply more severely. Intertrochanteric and femoral shaft fractures are extracapsular and generally do not disrupt the femoral head blood supply. Acetabular fractures do not directly affect femoral head vascularity unless there is concomitant dislocation.

Question 11759

Topic: 2. Trauma

When performing intramedullary nailing for a femoral shaft fracture, which of the following is considered the primary advantage of reamed nailing compared to unreamed nailing?

. Decreased risk of fat embolism.
. Reduced operative time.
. Stronger implant-bone interface due to larger diameter nail.
. Lower incidence of compartment syndrome.
. Preservation of endosteal blood supply.

Correct Answer & Explanation

. Stronger implant-bone interface due to larger diameter nail.

Explanation

Reamed intramedullary nailing involves gradually increasing the intramedullary canal diameter with reamers before nail insertion. The primary advantage of reamed nailing is that it allows for the insertion of a larger diameter nail, which provides a stronger implant-bone interface and increased biomechanical stability, leading to higher union rates and improved construct stiffness. The disadvantage is the theoretical increased risk of fat embolism and disruption of endosteal blood supply. Unreamed nails typically involve less operative time and less disruption to endosteal blood supply, but their smaller diameter may offer less rotational stability and a higher risk of nonunion.

Question 11760

Topic: 2. Trauma

A 28-year-old male sustains an open comminuted tibial shaft fracture. You decide to apply an external fixator as a temporizing measure. Which of the following is a critical principle for pin care and prevention of pin tract infection?

. Tight dressing around the pin sites to limit motion.
. Daily cleaning of pin sites with hydrogen peroxide.
. Prophylactic systemic antibiotics throughout the duration of fixation.
. Leaving pin sites open to air after initial dressing changes.
. Aggressive debridement of any pin tract erythema with oral antibiotics.

Correct Answer & Explanation

. Leaving pin sites open to air after initial dressing changes.

Explanation

Proper pin care is crucial to prevent pin tract infection, a common complication of external fixation. Leaving pin sites open to air after initial dressing changes (once bleeding has stopped) is often recommended to prevent moisture accumulation and bacterial proliferation. If dressings are used, they should be loose to allow air circulation. Daily cleaning with saline or chlorhexidine (not hydrogen peroxide which can be cytotoxic) is also important. Prophylactic systemic antibiotics are not indicated for the entire duration of fixation unless there's an active infection. Aggressive debridement is needed for severe infection, but not routine erythema, which might be managed with local care and observation or oral antibiotics for minor infection.

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