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2. Trauma MCQs

Practice Set 415 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 8281

Topic: 2. Trauma

An 82-year-old woman with severe rheumatoid arthritis and baseline limited household mobility sustains a highly comminuted, intra-articular distal femur fracture (OTA/AO 33-C3) after a fall. Her bone stock is extremely osteopenic. What is the primary advantage of choosing a distal femoral replacement (DFR) over open reduction and internal fixation (ORIF) with a lateral locking plate in this specific patient?

. Decreased intraoperative blood loss
. Shorter operative time
. Ability to allow immediate full weight-bearing
. Lower risk of periprosthetic joint infection
. Superior long-term survivorship of the implant

Correct Answer & Explanation

. Ability to allow immediate full weight-bearing

Explanation

In elderly, osteoporotic patients with complex, comminuted intra-articular distal femur fractures, achieving stable fixation for early mobilization via ORIF is challenging and often requires a period of restricted weight-bearing. Distal femoral replacement (DFR) bypasses the fracture and allows for immediate full weight-bearing. This faster mobilization is critical in the frail elderly population to prevent the severe medical complications of prolonged immobility. DFR generally carries a higher risk of blood loss and infection compared to ORIF.

Question 8282

Topic: 2. Trauma

A 19-year-old competitive cyclist falls onto his left shoulder. Radiographs reveal a completely displaced midshaft clavicle fracture. Which of the following radiographic findings is the strongest relative indication for operative intervention (ORIF) over nonoperative management to optimize functional recovery and minimize the risk of symptomatic nonunion?

. Shortening of 10 mm
. Presence of a butterfly fragment measuring 5 mm
. Fracture shortening greater than 20 mm
. Inferior displacement of the lateral fragment by 5 mm
. An associated non-displaced fracture of the scapular spine

Correct Answer & Explanation

. Fracture shortening greater than 20 mm

Explanation

Complete displacement, particularly with shortening greater than 20 mm (or 2 cm), is a strong relative indication for operative fixation of midshaft clavicle fractures. Multiple prospective studies have shown that shortening >2 cm treated nonoperatively is associated with significantly higher rates of nonunion, symptomatic malunion, altered shoulder kinematics, and residual weakness, particularly in highly active patients or laborers.

Question 8283

Topic: 2. Trauma

A 22-year-old man sustains a low-velocity handgun wound to the right thigh. His hemodynamics are stable, and neurovascular examination is entirely intact. Radiographs show a midshaft femur fracture with a retained bullet fragment situated within the vastus intermedius muscle belly. There is no evidence of intra-articular extension or compartment syndrome. What is the most appropriate initial management?

. Immediate operative exploration with bullet removal and fracture fixation
. Local wound care, a short course of systemic antibiotics, and fracture splinting while leaving the bullet in place
. Extensive prophylactic fasciotomies of all thigh compartments
. Local wound care without the administration of systemic antibiotics
. Immediate external fixation with delayed primary closure of the bullet track

Correct Answer & Explanation

. Local wound care, a short course of systemic antibiotics, and fracture splinting while leaving the bullet in place

Explanation

For low-velocity gunshot wounds resulting in a fracture without vascular compromise, compartment syndrome, or intra-articular extension, standard management includes local wound care (superficial debridement of the entry and exit sites), a short course of systemic antibiotics (often a first-generation cephalosporin), and appropriate fracture stabilization (which can be delayed or immediate depending on the fracture pattern and hospital protocol). The bullet fragment itself does not routinely need to be extracted unless it is intra-articular (risk of lead arthropathy), compressing a neurovascular structure, or superficial enough to cause skin irritation.

Question 8284

Topic: 2. Trauma
A 45-year-old man is brought to the trauma bay after a high-speed motorcycle collision. His blood pressure is 80/40 mm Hg and his heart rate is 135 bpm. Despite receiving 2 units of uncrossmatched packed red blood cells, he remains hemodynamically unstable. A pelvic binder has been applied. The FAST exam is negative. An AP pelvis radiograph reveals an APC-III (open-book) pelvic ring injury with wide disruption of the pubic symphysis and bilateral sacroiliac joints. What is the most appropriate next step in management?
. Immediate transfer to the operating room for pre-peritoneal pelvic packing and external fixation
. CT scan of the abdomen and pelvis to identify the source of bleeding
. Removal of the pelvic binder and application of a pelvic C-clamp in the trauma bay
. Administration of high-dose vasopressors and observation in the surgical intensive care unit
. Immediate exploratory laparotomy

Correct Answer & Explanation

. Immediate transfer to the operating room for pre-peritoneal pelvic packing and external fixation

Explanation

In a hemodynamically unstable patient with an open-book pelvic ring injury and a negative FAST exam, the primary source of bleeding is presumed to be the retroperitoneal venous plexus or cancellous bone from the pelvic fracture. Current advanced trauma guidelines recommend mechanical stabilization (e.g., pelvic binder or external fixator) followed by immediate pre-peritoneal pelvic packing and/or pelvic angioembolization. A CT scan is contraindicated in an unstable patient, and laparotomy is generally not indicated for retroperitoneal pelvic bleeding unless there is concurrent intra-abdominal injury.

Question 8285

Topic: 2. Trauma
A 28-year-old male sustains a vertically oriented, displaced femoral neck fracture (Pauwels type III) in a motor vehicle accident. He is scheduled for surgical fixation. According to biomechanical studies, which of the following constructs provides the greatest stability for this specific fracture pattern?
. Three parallel fully-threaded cancellous screws
. A fixed-angle sliding hip screw with an additional superior derotational screw
. A dynamic condylar screw system
. Two parallel partially-threaded cancellous screws
. A standard short cephalomedullary nail

Correct Answer & Explanation

. A fixed-angle sliding hip screw with an additional superior derotational screw

Explanation

Pauwels type III femoral neck fractures are characterized by a vertically oriented fracture line, which exposes the fracture to high shear forces and a greater risk of varus collapse and nonunion. Biomechanical studies have consistently shown that a fixed-angle construct, such as a sliding hip screw (SHS), provides superior biomechanical stability and resistance to shear forces compared to multiple cancellous screws. Adding a superior derotational screw helps control rotation of the femoral head during insertion and weight-bearing.

Question 8286

Topic: 2. Trauma
A 35-year-old construction worker sustains a highly comminuted midshaft tibia fracture with a 12 cm anterior soft-tissue defect exposing bone (Gustilo-Anderson type IIIB) after a crush injury. He undergoes emergent irrigation, debridement, and placement of an external fixator. Serial debridements render the wound bed clean. To minimize the risk of deep infection and flap failure, what is the optimal timing for definitive soft-tissue coverage?
. Immediate soft-tissue coverage within 24 hours, regardless of wound bed status
. Within 7 days of the initial injury
. Between 14 and 21 days to allow for complete soft-tissue demarcation
. After 4 weeks when healthy granulation tissue completely covers the exposed bone
. Application of negative pressure wound therapy until spontaneous secondary intention closure occurs

Correct Answer & Explanation

. Within 7 days of the initial injury

Explanation

The timing of soft-tissue coverage for Gustilo type IIIB open tibia fractures is critical. The LEAP (Lower Extremity Assessment Project) study and subsequent meta-analyses have demonstrated that definitive soft-tissue coverage performed within 7 days (and ideally within 72 hours) of the injury is associated with significantly lower rates of deep infection, flap failure, and nonunion compared to coverage performed after 7 days, provided the wound has been adequately debrided.

Question 8287

Topic: 2. Trauma

A 32-year-old male is admitted with a closed diaphyseal tibia fracture. Twelve hours later, he complains of severe, unrelenting leg pain that is exacerbated by passive stretch of his toes. The clinical suspicion for acute compartment syndrome is high, and continuous compartment pressure monitoring is initiated. Which of the following pressure measurements is the most widely accepted threshold indicating the need for an emergent fasciotomy?

. Absolute compartment pressure > 30 mm Hg
. Delta pressure (Systolic blood pressure minus compartment pressure) < 30 mm Hg
. Delta pressure (Mean Arterial Pressure minus compartment pressure) < 40 mm Hg
. Delta pressure (Diastolic blood pressure minus compartment pressure) < 30 mm Hg
. Delta pressure (Diastolic blood pressure minus compartment pressure) > 45 mm Hg

Correct Answer & Explanation

. Delta pressure (Diastolic blood pressure minus compartment pressure) < 30 mm Hg

Explanation

McQueen et al. established that utilizing a delta pressure—calculated as the diastolic blood pressure minus the absolute compartment pressure—is the most reliable threshold for diagnosing acute compartment syndrome. A delta pressure of less than 30 mm Hg indicates critically impaired tissue perfusion and is a universally accepted threshold for proceeding with an emergent fasciotomy. Absolute pressure alone can lead to unnecessary fasciotomies or missed diagnoses depending on the patient's systemic blood pressure.

Question 8288

Topic: 2. Trauma

An 80-year-old woman with severe osteoporosis presents to the emergency department after a fall. Radiographs reveal a highly comminuted, intra-articular distal femur fracture (AO/OTA 33-C3) with profoundly poor bone stock. Prior to the injury, she used a walker for short-distance ambulation. Which of the following surgical interventions will best allow for immediate, full weight-bearing in this patient?

. Open reduction and internal fixation with a lateral locking plate
. Retrograde intramedullary nailing with interlocking screws
. Distal femoral replacement (megaprosthesis)
. Fine wire circular external fixation
. Nonoperative management in a hinged knee brace

Correct Answer & Explanation

. Distal femoral replacement (megaprosthesis)

Explanation

In elderly, osteoporotic patients presenting with severely comminuted intra-articular distal femur fractures, achieving stable internal fixation is challenging, and postoperative restricted weight-bearing is usually necessary with ORIF. Distal femoral replacement (megaprosthesis) bypasses the compromised bone, providing immediate stability and allowing the patient to weight-bear fully right after surgery. This significantly reduces the risks associated with prolonged immobility in the geriatric population.

Question 8289

Topic: 2. Trauma

A 34-year-old male who sustained a Hawkins type II talar neck fracture 8 weeks ago returns for a follow-up clinic visit. His AP ankle radiograph reveals a distinct subchondral radiolucent band in the dome of the talus. What does this radiographic finding indicate?

. Impending collapse of the talar dome
. Intact vascularity to the talar body
. Established avascular necrosis of the talar body
. Nonunion of the talar neck
. Septic arthritis of the ankle joint

Correct Answer & Explanation

. Intact vascularity to the talar body

Explanation

The presence of a subchondral radiolucent band in the talar dome, visible on an AP or mortise radiograph 6 to 8 weeks after a talar neck fracture, is known as the Hawkins sign. This radiolucency represents subchondral bone resorption (osteopenia) secondary to disuse. Because bone resorption requires an active blood supply, a positive Hawkins sign is a highly reliable prognostic indicator that the vascularity to the talar body is intact, making the development of avascular necrosis highly unlikely.

Question 8290

Topic: 2. Trauma
A 28-year-old farmer sustains a Gustilo-Anderson Type IIIA open tibia fracture after his leg is caught in a tractor implement. The wound is heavily contaminated with soil and manure. He is brought to the emergency department for initial resuscitation. In addition to prompt surgical debridement, which of the following prophylactic antibiotic regimens is classically recommended for this specific injury pattern?
. Cefazolin monotherapy
. Cefazolin and Gentamicin
. Cefazolin, Gentamicin, and Penicillin G
. Ceftriaxone and Vancomycin
. Ciprofloxacin monotherapy

Correct Answer & Explanation

. Cefazolin, Gentamicin, and Penicillin G

Explanation

Open fractures in agricultural environments or those with heavy soil contamination are at high risk for infection with anaerobic organisms, most notably Clostridium perfringens, which can cause gas gangrene. The classic board-tested prophylactic antibiotic regimen for such injuries involves a first-generation cephalosporin (Cefazolin) to cover Gram-positives, an aminoglycoside (Gentamicin) for Gram-negatives, and the addition of high-dose Penicillin G to specifically target anaerobic clostridial species.

Question 8291

Topic: Pelvic & Acetabular Trauma
A 45-year-old man is brought to the trauma bay after a high-speed motorcycle collision. He has a heart rate of 130 bpm and a blood pressure of 80/50 mm Hg. A pelvic radiograph demonstrates an anteroposterior compression type III (APC-III) pelvic ring injury. A pelvic binder is applied, but his blood pressure remains 85/50 mm Hg after initial fluid resuscitation. A Focused Assessment with Sonography for Trauma (FAST) examination is negative. What is the next best step in management?
. Immediate CT scan of the abdomen and pelvis
. Emergent exploratory laparotomy
. Preperitoneal pelvic packing and/or pelvic angiography with embolization
. Application of an anterior external fixator and immediate symphyseal plating
. Administration of tranexamic acid (TXA) and continued observation in the ICU

Correct Answer & Explanation

. Preperitoneal pelvic packing and/or pelvic angiography with embolization

Explanation

In a hemodynamically unstable patient with a pelvic ring injury and a negative FAST exam (which rules out massive intra-abdominal hemorrhage), the source of bleeding is presumed to be the pelvis (venous plexus or arterial injury). Management dictates immediate mechanical stabilization (e.g., pelvic binder), followed by interventions to control the hemorrhage directly, such as preperitoneal pelvic packing or angioembolization. A CT scan is contraindicated in a hemodynamically unstable patient.

Question 8292

Topic: 2. Trauma

A 35-year-old woman sustains a high-energy Schatzker VI tibial plateau fracture. Upon admission, her leg is severely swollen and tense. Her current diastolic blood pressure is 60 mm Hg. Intracompartmental pressure measurement of the anterior compartment of the lower leg is 35 mm Hg. What is the most appropriate management of her lower extremity?

. Elevation of the leg above heart level and serial clinical examinations
. Immediate four-compartment fasciotomy of the leg
. Application of a spanning knee external fixator only
. Immediate open reduction and internal fixation of the tibial plateau
. Administration of intravenous mannitol and dexamethasone

Correct Answer & Explanation

. Immediate four-compartment fasciotomy of the leg

Explanation

The diagnosis of acute compartment syndrome is primarily clinical, but absolute pressure or delta pressure measurements are valuable, especially in polytraumatized or obtunded patients. A delta pressure (Diastolic BP - Compartment Pressure) of less than 30 mm Hg is a well-established threshold that is highly suggestive of acute compartment syndrome. In this patient, the delta pressure is 25 mm Hg (60 - 35). Immediate four-compartment fasciotomy is indicated to prevent irreversible muscle necrosis and nerve ischemia.

Question 8293

Topic: 2. Trauma
A 28-year-old man sustains a displaced, vertically oriented (Pauwels type III) femoral neck fracture after a fall from a height. He is an otherwise healthy construction worker. To minimize the risk of shear-related fixation failure and subsequent nonunion, which of the following is the most biomechanically appropriate surgical fixation construct?
. Three parallel cancellous screws placed in an inverted triangle configuration
. A sliding hip screw construct with or without an accessory derotational screw
. Bipolar hemiarthroplasty
. Total hip arthroplasty
. Antegrade cephalomedullary nailing

Correct Answer & Explanation

. A sliding hip screw construct with or without an accessory derotational screw

Explanation

Pauwels type III femoral neck fractures in young adults are highly unstable due to the vertical orientation of the fracture line, which subjects the fracture site to significant shear forces during weight-bearing. Biomechanical studies have shown that a fixed-angle construct, such as a sliding hip screw, provides superior stability against vertical shear forces compared to multiple cancellous screws. In young adults, head-preserving surgery is prioritized over arthroplasty.

Question 8294

Topic: 2. Trauma
A 42-year-old agricultural worker sustains a severe open tibia fracture (Gustilo-Anderson IIIB) that is heavily contaminated with soil and manure. He arrives at the emergency department within 1 hour of the injury. According to current trauma guidelines, what is the most appropriate initial intravenous antibiotic regimen?
. A first-generation cephalosporin alone
. A first-generation cephalosporin and an aminoglycoside
. A first-generation cephalosporin, an aminoglycoside, and high-dose penicillin
. Vancomycin alone
. A fluoroquinolone alone

Correct Answer & Explanation

. A first-generation cephalosporin, an aminoglycoside, and high-dose penicillin

Explanation

Standard antibiotic prophylaxis for severe open fractures (Gustilo Type III) includes a first-generation cephalosporin (for Gram-positive coverage) and an aminoglycoside or third-generation cephalosporin (for Gram-negative coverage). In the setting of gross agricultural or soil contamination, there is a high risk of anaerobic infection, particularly Clostridium species, which can cause gas gangrene. Therefore, high-dose penicillin (or metronidazole/ampicillin) must be added to the regimen to provide adequate anaerobic coverage.

Question 8295

Topic: 2. Trauma

A 60-year-old woman presents with persistent lower thigh pain 9 months after undergoing retrograde intramedullary nailing for a supracondylar distal femur fracture. Radiographs reveal a hypertrophic nonunion at the fracture site with abundant callus formation but a persistent fracture line. Laboratory markers for infection (CRP, ESR) are strictly normal. What is the most appropriate management?

. Exchange nailing with a smaller diameter intramedullary nail to increase flexibility
. Removal of hardware and application of a spanning external fixator
. Autologous iliac crest bone grafting alone, leaving the current nail in place
. Revision fixation using a fixed-angle locking plate to increase construct stiffness
. Extracorporeal shock wave therapy and continued observation

Correct Answer & Explanation

. Revision fixation using a fixed-angle locking plate to increase construct stiffness

Explanation

A hypertrophic nonunion indicates that the fracture site has adequate biological healing potential (excellent blood supply leading to callus formation) but lacks sufficient mechanical stability to bridge the gap. The treatment of choice for a hypertrophic nonunion is to improve the mechanical stability of the construct. Revision to a stiffer construct, such as exchanging to a larger nail or applying a fixed-angle locking plate, limits the excessive micro-motion and allows the fracture to heal. Bone grafting is unnecessary as the biology is already active.

Question 8296

Topic: 2. Trauma

A 72-year-old woman, who has been on alendronate therapy for 8 years, presents with atraumatic, persistent lateral thigh pain for the past 3 weeks. Radiographs reveal generalized cortical thickening and a transverse radiolucent line on the lateral cortex of the subtrochanteric femur. What is the most appropriate management to prevent a complete fracture?

. Immediate discontinuation of alendronate and weight-bearing restriction only
. Addition of teriparatide and continuation of full weight-bearing
. Prophylactic antegrade intramedullary nailing of the femur
. Application of a custom hinged fracture brace
. Core decompression of the femoral head and neck

Correct Answer & Explanation

. Prophylactic antegrade intramedullary nailing of the femur

Explanation

This patient presents with a symptomatic impending atypical femur fracture (AFF) associated with long-term bisphosphonate use. The classic radiographic signs include lateral cortical thickening and the 'dreaded black line' (a transverse radiolucent stress fracture). Because symptomatic impending AFFs have a very high rate of progressing to complete fractures with notoriously poor healing rates, prophylactic intramedullary nailing is the gold standard of care. Medical management (stopping bisphosphonates) must also occur, but mechanical stabilization is urgently required.

Question 8297

Topic: 2. Trauma

A 50-year-old construction worker falls from a ladder, sustaining a severely comminuted, displaced intra-articular calcaneus fracture with a 3-cm laceration on the medial hindfoot exposing the fracture site. After immediate irrigation and debridement in the operating room, what is the most appropriate strategy for definitive fracture stabilization once the soft tissues permit?

. Immediate open reduction and internal fixation through an extensile lateral approach
. Primary subtalar arthrodesis via a posterior approach
. Closed reduction and casting in equinus
. Minimally invasive percutaneous fixation or external fixation
. Total talocalcaneal arthroplasty

Correct Answer & Explanation

. Minimally invasive percutaneous fixation or external fixation

Explanation

Open calcaneus fractures, particularly those with medial wounds resulting from high-energy shear or inside-out forces, are associated with an exceedingly high rate of deep infection, osteomyelitis, and amputation. An extensile lateral approach in this setting further compromises the delicate soft tissue envelope and dramatically increases the risk of catastrophic wound complications. Therefore, definitive management relies on minimizing further soft tissue injury via minimally invasive percutaneous fixation, limited open reduction, or external fixation.

Question 8298

Topic: Pelvic & Acetabular Trauma
A 28-year-old male presents with a hemodynamically unstable APC III pelvic ring injury following a high-speed motorcycle collision. Despite application of a pelvic binder and initiation of a massive transfusion protocol, he remains hypotensive. A Focused Assessment with Sonography for Trauma (FAST) exam is negative. He is taken emergently to the operating room for preperitoneal pelvic packing. Which of the following is the most likely anatomic source of his hemorrhage?
. Superior gluteal artery
. Internal pudendal artery
. Presacral venous plexus
. Obturator artery
. External iliac vein

Correct Answer & Explanation

. Presacral venous plexus

Explanation

Up to 80-85% of massive bleeding in severe pelvic ring injuries is venous in origin, most commonly arising from the presacral venous plexus and prevesical veins. Arterial bleeding (such as from the superior gluteal or internal pudendal arteries) accounts for only 10-15% of cases. Preperitoneal pelvic packing is specifically highly effective in tamponading this diffuse venous bleeding.

Question 8299

Topic: 2. Trauma

A 32-year-old female undergoes open reduction and internal fixation of a displaced talar neck fracture (Hawkins Type II). At her 8-week postoperative follow-up, an anteroposterior radiograph of the ankle is obtained. Which of the following radiographic findings serves as a reliable prognostic indicator that she will not develop clinically significant avascular necrosis (AVN) of the talar body?

. Subchondral sclerosis of the talar dome
. Subchondral radiolucency of the talar dome
. Joint space narrowing of the subtalar joint
. Sclerosis of the talar body
. Osteopenia of the medial malleolus

Correct Answer & Explanation

. Subchondral radiolucency of the talar dome

Explanation

A subchondral radiolucency of the talar dome, known as the Hawkins sign, indicates active resorption of subchondral bone secondary to disuse osteopenia. The presence of this sign at 6 to 8 weeks post-injury confirms that the vascular supply to the talar body is intact, effectively ruling out the development of widespread avascular necrosis.

Question 8300

Topic: 2. Trauma

A 42-year-old man sustains a complex acetabular fracture in a motor vehicle collision. Radiographs include an anteroposterior pelvis and Judet views. On the obturator oblique radiograph, a prominent "spur sign" is visualized. This pathognomonic finding is diagnostic of which fracture pattern, and what anatomical structure does the spur represent?

. Both-column fracture; the spur represents the intact posterior ilium attached to the axial skeleton
. Anterior column/posterior hemitransverse fracture; the spur represents the displaced articular surface
. Posterior wall fracture; the spur represents the displaced posterior wall fragment
. T-type fracture; the spur represents the fractured quadrilateral plate
. Transverse fracture; the spur represents an ischial spine avulsion

Correct Answer & Explanation

. Both-column fracture; the spur represents the intact posterior ilium attached to the axial skeleton

Explanation

The "spur sign" on an obturator oblique radiograph is a classic finding of a both-column acetabular fracture. It represents the lowest extent of the intact posterior ilium that remains attached to the axial skeleton, while the articular segments of the acetabulum are displaced medially and anteriorly.

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