Menu

2. Trauma MCQs

Practice Set 419 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 8361

Topic: Pelvic & Acetabular Trauma

A 42-year-old hemodynamically unstable male presents after a high-speed motor vehicle collision. A pelvic AP radiograph reveals a symphyseal diastasis of 4 cm and disruption of the anterior sacroiliac ligaments bilaterally. He is tachycardic (130 bpm) and hypotensive (80/50 mmHg). FAST exam is negative. What is the most appropriate initial step in management?

. Angiography with embolization
. Application of a pelvic binder centered over the greater trochanters
. Exploratory laparotomy
. External fixation of the pelvis
. Retrograde urethrogram

Correct Answer & Explanation

. Application of a pelvic binder centered over the greater trochanters

Explanation

In a hemodynamically unstable patient with an anteroposterior compression (APC) type pelvic ring injury (often presenting as an 'open book' pelvis), the immediate priority is mechanical stabilization to reduce pelvic volume. A pelvic binder, properly centered over the greater trochanters (not the iliac crests), is the most rapid and effective initial non-invasive step. If instability persists despite adequate volume reduction and fluid resuscitation, angiography with embolization or pre-peritoneal packing is indicated.

Question 8362

Topic: 2. Trauma
A 28-year-old female sustains a displaced, vertical (Pauwels type III) femoral neck fracture. She is brought to the operating room for internal fixation. Which of the following biomechanical constructs provides the most stable fixation for this specific fracture pattern?
. Three parallel cancellous screws placed in an inverted triangle
. Sliding hip screw with a derotational cancellous screw
. Two fully threaded cortical screws
. Cephalomedullary nail
. Hemiarthroplasty

Correct Answer & Explanation

. Sliding hip screw with a derotational cancellous screw

Explanation

Pauwels type III femoral neck fractures are characterized by a vertical fracture line (angle > 50 degrees from horizontal), resulting in high shear forces and marked instability. Biomechanical studies have consistently demonstrated that a fixed-angle device, such as a sliding hip screw (SHS), provides superior resistance to vertical shear compared to multiple parallel cancellous screws. A derotational screw is often added superiorly to prevent rotational displacement of the head during SHS insertion.

Question 8363

Topic: 2. Trauma
A 45-year-old male sustains a closed, displaced intra-articular calcaneus fracture. A CT scan shows a Sanders Type III fracture. The surgeon plans an extensile lateral approach for open reduction and internal fixation. To minimize the risk of wound complications, when should the surgery ideally be performed?
. Within 24 hours of injury
. After the 'wrinkle sign' appears, typically 10-14 days post-injury
. Immediately after the resolution of fracture blisters at 4 weeks
. As a delayed reconstruction at 3 months
. Within 48 hours of injury

Correct Answer & Explanation

. After the 'wrinkle sign' appears, typically 10-14 days post-injury

Explanation

The extensile lateral approach to the calcaneus is associated with a high rate of wound healing complications (up to 25%). To mitigate this risk, surgery must be delayed until post-traumatic soft tissue swelling has adequately subsided. The appearance of the 'wrinkle sign' (skin wrinkling on the lateral aspect of the hindfoot) typically occurs between 10 to 14 days post-injury and is a highly reliable clinical indicator that the soft tissue envelope is ready for surgical intervention.

Question 8364

Topic: 2. Trauma

A 72-year-old female with osteoporosis presents with a closed, displaced extra-articular distal femur fracture (OTA/AO 33-A). She is scheduled for open reduction and internal fixation with a lateral locking plate. What is the primary mechanical advantage of a locked plating construct over conventional non-locked plating in this specific scenario?

. Decreased incidence of delayed nonunion
. Improved resistance to screw pullout
. Ability to provide absolute stability via primary bone healing
. Reduced need for supplemental bone grafting
. Shorter operative time

Correct Answer & Explanation

. Improved resistance to screw pullout

Explanation

Locking plates are fixed-angle constructs where the screw head threads lock into the plate, creating a single beam construct. This design bypasses the need for friction between the plate and bone for stability. This offers a distinct biomechanical advantage in osteoporotic bone by significantly increasing resistance to screw pullout and toggle. Non-locking screws rely on cortical bite and plate-to-bone compression, which frequently fail in weak, osteoporotic bone.

Question 8365

Topic: 2. Trauma

A 29-year-old male is admitted with a closed midshaft tibia fracture. Twelve hours post-injury, he complains of severe leg pain out of proportion to the injury, exacerbated by passive toe stretch. His pedal pulses are palpable. Intracompartmental pressure testing reveals a pressure of 45 mmHg with a diastolic blood pressure of 65 mmHg. Which of the following is the most appropriate definitive management?

. Elevation of the leg above the level of the heart and reassess in 2 hours
. Administration of intravenous mannitol and dexamethasone
. Immediate four-compartment fasciotomy
. Application of a long-leg cast to immobilize the fracture
. Emergent CT angiography to rule out arterial injury

Correct Answer & Explanation

. Immediate four-compartment fasciotomy

Explanation

Acute compartment syndrome is a surgical emergency. The diagnosis is confirmed clinically and supported by intracompartmental pressure measurements. A Delta P (diastolic blood pressure minus intracompartmental pressure) of less than 30 mmHg is an absolute indication for emergent fasciotomy. In this patient, the Delta P is 20 mmHg (65 - 45). Elevation above the heart is contraindicated because it further decreases local arterial perfusion pressure, worsening ischemia.

Question 8366

Topic: 2. Trauma

A 38-year-old female presents with a spiral fracture of the distal third of the humeral shaft. On examination, she is unable to extend her wrist or fingers. Radiographs confirm a Holstein-Lewis fracture. What is the most appropriate initial management of her nerve palsy?

. Immediate surgical exploration of the radial nerve and fracture fixation
. Closed reduction and functional bracing with clinical observation of nerve recovery
. Electromyography (EMG) to determine the extent of nerve injury
. Primary nerve grafting
. Tendon transfers to restore wrist and finger extension

Correct Answer & Explanation

. Closed reduction and functional bracing with clinical observation of nerve recovery

Explanation

The Holstein-Lewis fracture is a spiral fracture of the distal one-third of the humeral shaft, which places the radial nerve at high risk for injury as it passes through the lateral intermuscular septum. However, a primary radial nerve palsy in the setting of a closed humeral shaft fracture is typically a neuropraxia. The standard management is observation and functional bracing. Surgical exploration is reserved for open fractures, secondary palsies (occurring after closed reduction), or failure to clinically or electromyographically improve after 3 to 4 months.

Question 8367

Topic: 2. Trauma
A 25-year-old intubated polytrauma patient is admitted to the intensive care unit with a comminuted closed tibial shaft fracture. The nursing staff notes the leg is exquisitely swollen and tense. Intracompartmental pressure testing of the anterior compartment reveals a pressure of 35 mm Hg. The patient's current blood pressure is 90/50 mm Hg (mean arterial pressure 63 mm Hg). What is the most appropriate next step in management?
. Immediate four-compartment fasciotomy of the leg
. Elevate the leg above the level of the heart and reassess in 2 hours
. Administer a bolus of intravenous fluids and recheck pressures in 1 hour
. Apply a long leg cast to stabilize the fracture and reduce soft-tissue trauma
. Intravenous administration of mannitol

Correct Answer & Explanation

. Immediate four-compartment fasciotomy of the leg

Explanation

The diagnosis of acute compartment syndrome in an obtunded or intubated patient relies heavily on objective pressure measurements. The classic threshold for surgical intervention is a delta pressure (ΔP) of less than 30 mm Hg. Delta pressure is calculated as the Diastolic Blood Pressure minus the Intracompartmental Pressure. In this patient, the ΔP is 50 mm Hg - 35 mm Hg = 15 mm Hg. A ΔP < 30 mm Hg is a definitive indication for an immediate four-compartment fasciotomy to prevent irreversible muscle and nerve necrosis.

Question 8368

Topic: 2. Trauma

A 45-year-old male sustains a high-energy Schatzker VI tibial plateau fracture. He is initially managed with a spanning external fixator. At 2 weeks, the soft-tissue envelope improves, and he undergoes definitive open reduction and internal fixation utilizing an anterolateral locking plate and a direct medial plate. Three months postoperatively, radiographs demonstrate a varus collapse of the medial plateau. What technical error is most likely responsible for this failure mechanism?

. Failure to place a subchondral raft of screws in the lateral plateau
. Failure to specifically recognize and buttress a posteromedial shear fragment
. Over-distraction of the joint space during the initial application of the external fixator
. Use of non-locking screws in the metaphyseal segment of the medial plate
. Placement of the lateral plate too distal on the tibial shaft

Correct Answer & Explanation

. Failure to specifically recognize and buttress a posteromedial shear fragment

Explanation

Medial tibial plateau fractures frequently involve a posteromedial shear fragment with a vertical fracture line that exits the posteromedial cortex. A direct medial or anteromedial plate will often fail to adequately capture or buttress this posterior fragment. Biomechanical and clinical studies have shown that failure to specifically support this fragment with a posteromedial anti-glide or buttress plate leads to proximal migration of the fragment and subsequent varus collapse of the joint.

Question 8369

Topic: 2. Trauma
A 28-year-old agricultural worker sustains an open midshaft tibia fracture heavily contaminated with soil and manure after being pinned by a tractor. The soft-tissue wound is 12 cm long with extensive muscle devitalization, corresponding to a Gustilo-Anderson Type IIIB injury. According to established orthopedic trauma guidelines, what is the most appropriate initial empiric antibiotic regimen?
. A first-generation cephalosporin alone
. A first-generation cephalosporin and an aminoglycoside
. A third-generation cephalosporin and vancomycin
. A first-generation cephalosporin, an aminoglycoside, and high-dose penicillin
. A fluoroquinolone and clindamycin

Correct Answer & Explanation

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

Explanation

In the setting of a severe open fracture heavily contaminated with soil or organic farm material (a classic high-risk environment for Clostridium species), empiric antibiotic coverage must be broadened. Standard coverage for Type III open fractures includes a first-generation cephalosporin (for Gram-positive organisms) and an aminoglycoside (for Gram-negative organisms). The addition of high-dose penicillin (or metronidazole) is critical specifically to provide anaerobic coverage and prevent gas gangrene (Clostridium perfringens) in agricultural or highly contaminated soil injuries.

Question 8370

Topic: 2. Trauma
A 35-year-old male is brought to the emergency department after a high-speed motorcycle collision. He is hypotensive (BP 80/40 mmHg) and tachycardic (HR 130 bpm). Primary survey reveals an unstable pelvis with an anteroposterior compression (APC) type III pattern on a plain anteroposterior radiograph. A pelvic binder is appropriately applied, but he remains hemodynamically unstable despite receiving 2 units of uncrossmatched blood. A FAST exam is negative for intra-abdominal fluid. What is the most appropriate next step in management?
. CT abdomen and pelvis with IV contrast
. Retrograde urethrogram to evaluate for urologic injury
. Preperitoneal pelvic packing and/or pelvic angiography with embolization
. Exploratory laparotomy
. Application of an anterior pelvic external fixator in the ED

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 (ruling out massive intra-abdominal hemorrhage), the source of bleeding is presumed to be the pelvis (venous plexus or arterial injury). Current ATLS and orthopedic trauma guidelines recommend preperitoneal pelvic packing (PPP) and/or pelvic angiography with embolization as the primary interventions for hemorrhage control. A CT scan is contraindicated in a hemodynamically unstable patient. While an external fixator can help reduce pelvic volume, PPP or angioembolization provides definitive intervention for the hemorrhage.

Question 8371

Topic: 2. Trauma
A 28-year-old male sustains a completely displaced, vertically oriented (Pauwels type III) femoral neck fracture after a fall from a height. He has no significant past medical history. He is taken to the operating room 6 hours after the injury. What is the most biomechanically appropriate surgical management to preserve the native hip?
. Closed reduction and percutaneous pinning with three parallel cancellous screws
. Open reduction and internal fixation with a sliding hip screw and an anti-rotation screw
. Bipolar hemiarthroplasty
. Total hip arthroplasty
. Open reduction and internal fixation with a cephalomedullary nail

Correct Answer & Explanation

. Open reduction and internal fixation with a sliding hip screw and an anti-rotation screw

Explanation

In a young adult with a Pauwels type III (high shear angle) displaced femoral neck fracture, preservation of the native hip is the absolute goal. Parallel cancellous screws are associated with a high failure rate for vertically oriented shear fractures due to inadequate biomechanical stability. A sliding hip screw (SHS) with an adjunctive anti-rotation screw, or a length-stable construct, provides superior biomechanical stability against vertical shear forces compared to multiple cancellous screws. Arthroplasty is reserved for older, lower-demand patients or unfixable highly comminuted fractures.

Question 8372

Topic: 2. Trauma

A 40-year-old female sustains a high-energy supracondylar distal femur fracture (OTA/AO 33-C2). The CT scan demonstrates an associated coronal plane fracture of the lateral femoral condyle. When planning internal fixation for this specific coronal plane fragment, what biomechanical force must primarily be addressed by the implant construct?

. Varus angulation
. Valgus angulation
. Vertical shear forces
. Torsional forces
. Tension forces

Correct Answer & Explanation

. Vertical shear forces

Explanation

A coronal plane fracture of the femoral condyle is known as a Hoffa fracture (OTA/AO 33-B3). By nature of its coronal orientation, it is primarily subjected to vertical shear forces during weight-bearing and physiologic knee motion. Fixation typically requires anterior-to-posterior (or posterior-to-anterior) directed lag screws to compress the fracture and effectively resist these shear forces. An adjunctive antiglide plate is frequently utilized for supplemental stability.

Question 8373

Topic: 2. Trauma

A 32-year-old male is recovering on the surgical ward 12 hours after reamed intramedullary nailing of a closed diaphyseal tibia fracture. He complains of severe, escalating leg pain that is out of proportion to the injury and unresponsive to IV opioids. On examination, he experiences extreme pain with passive stretch of the hallux and has diminished sensation in the first web space. His blood pressure is 110/70 mmHg. Intracompartmental pressure of the anterior compartment is measured at 45 mmHg. What is the delta pressure, and what is the most appropriate next step in management?

. Delta pressure is 25 mmHg; continue close observation with extremity elevation.
. Delta pressure is 25 mmHg; perform an emergent four-compartment fasciotomy.
. Delta pressure is 45 mmHg; administer IV mannitol and apply ice.
. Delta pressure is 25 mmHg; perform an emergent two-compartment fasciotomy.
. Delta pressure is 65 mmHg; discharge with oral analgesics.

Correct Answer & Explanation

. Delta pressure is 25 mmHg; perform an emergent four-compartment fasciotomy.

Explanation

Acute compartment syndrome is a surgical emergency. The delta pressure is calculated as the Diastolic Blood Pressure minus the Intracompartmental Pressure (70 - 45 = 25 mmHg). A delta pressure of 30 mmHg or less is generally accepted as an absolute indication for fasciotomy. Furthermore, this patient exhibits classic clinical signs (pain out of proportion, pain on passive stretch, and sensory deficit in the deep peroneal nerve distribution). The standard of care for tibial compartment syndrome is an emergent four-compartment fasciotomy.

Question 8374

Topic: 2. Trauma
A 25-year-old agricultural worker sustains a severe open tibia fracture after his leg gets caught in a tractor power take-off. The wound measures 12 cm with extensive muscle devitalization, and there is gross contamination with soil and organic farm debris. The patient has normal renal function and no known drug allergies. According to standard orthopedic trauma guidelines, what is the most appropriate initial empiric antibiotic regimen?
. A first-generation cephalosporin alone
. A first-generation cephalosporin and an aminoglycoside
. A first-generation cephalosporin, an aminoglycoside, and high-dose penicillin
. A third-generation cephalosporin alone
. Vancomycin and piperacillin-tazobactam

Correct Answer & Explanation

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

Explanation

This is a Gustilo-Anderson Type III open fracture with heavy soil/farm contamination. Traditional guidelines strongly recommend a first-generation cephalosporin (e.g., cefazolin) for Gram-positive coverage, an aminoglycoside (e.g., gentamicin) for expanded Gram-negative coverage, and high-dose penicillin specifically to cover Clostridium species to mitigate the risk of gas gangrene associated with agricultural or soil injuries.

Question 8375

Topic: 2. Trauma

A 50-year-old male presents to the trauma bay after a high-energy motor vehicle collision. Radiographs demonstrate a highly comminuted bicondylar tibial plateau fracture with metaphyseal-diaphyseal dissociation (Schatzker VI). Examination reveals a tensely swollen calf, multiple fracture blisters, and a delta pressure of 45 mmHg. What is the most appropriate initial orthopedic management of this injury?

. Immediate open reduction and internal fixation with dual locking plates
. Immediate closed reduction and percutaneous screw fixation
. Application of a knee-spanning external fixator
. Application of a long leg plaster cast
. Primary total knee arthroplasty with a hinged prosthesis

Correct Answer & Explanation

. Application of a knee-spanning external fixator

Explanation

High-energy tibial plateau fractures (Schatzker V and VI) frequently present with severe soft tissue envelope compromise. Immediate open reduction and internal fixation in the presence of severe swelling and fracture blisters carries an unacceptably high risk of catastrophic wound breakdown and deep infection. The standard of care ('damage control orthopedics') mandates the application of a knee-spanning external fixator to temporarily stabilize the fracture and restore length/alignment, allowing the soft tissues to adequately recover prior to definitive ORIF 10 to 14 days later.

Question 8376

Topic: 2. Trauma

A 38-year-old male sustains a closed, highly comminuted tibial pilon fracture (OTA/AO 43-C3) with an associated displaced distal third fibula fracture following a 15-foot fall. The treating surgeon plans a standard two-stage protocol. During the initial application of the joint-spanning external fixator, what is the current consensus regarding the role of immediate open reduction and internal fixation of the fibula?

. It must always be performed to provide an anatomical template for subsequent tibial reconstruction.
. It should be avoided if the surgical incision will compromise soft tissue bridges for a future definitive tibial approach.
. It is absolutely required to prevent valgus collapse of the tibial articular surface during the temporization phase.
. It guarantees the distal tibiofibular syndesmosis will heal without further operative intervention.
. It eliminates the need for future complex articular reconstruction of the tibia.

Correct Answer & Explanation

. It should be avoided if the surgical incision will compromise soft tissue bridges for a future definitive tibial approach.

Explanation

In the staged management of severe pilon fractures, early fibular fixation was traditionally advocated to restore length and act as a template. However, modern consensus indicates that immediate open fibular fixation should be avoided if the lateral incision will compromise the angiosomes or adequate skin bridges needed for future definitive anterior, anterolateral, or posterolateral approaches to the tibia. Many surgeons now rely entirely on the spanning external fixator to maintain length and alignment during the damage control phase to minimize additional soft tissue insults.

Question 8377

Topic: 2. Trauma
A 26-year-old male polytrauma patient sustains a severe traumatic brain injury, multiple rib fractures, and a closed comminuted midshaft femur fracture. He is initially treated with Damage Control Orthopedics (DCO) using a spanning external fixator for his femur. Before converting the external fixator to a definitive intramedullary nail, which of the following physiological parameters is the most reliable indicator of adequate resuscitation?
. Urine output greater than 0.5 mL/kg/hr for 2 hours
. Hemoglobin greater than 10 g/dL
. Normalization of serum lactate to less than 2.0 mmol/L
. Platelet count greater than 100,000/μL
. Glasgow Coma Scale score greater than 10

Correct Answer & Explanation

. Normalization of serum lactate to less than 2.0 mmol/L

Explanation

Normalization of serum lactate (typically < 2.0 or 2.5 mmol/L) and/or resolution of base deficit are considered the most reliable objective markers of adequate global tissue perfusion and resuscitation in polytrauma patients. Proceeding with definitive major surgery (Early Total Care or conversion from DCO) in an under-resuscitated patient with elevated lactate or high base deficit significantly increases the risk of acute respiratory distress syndrome (ARDS), multiple organ failure (MOF), and mortality.

Question 8378

Topic: 2. Trauma

A 72-year-old woman with an 8-year history of alendronate use presents with a 3-month history of insidious onset right lateral thigh pain. Radiographs demonstrate lateral cortical thickening and a transverse radiolucent line in the subtrochanteric region of the right femur, without complete displacement. What is the most appropriate management?

. Discontinue alendronate and begin weight bearing as tolerated
. Discontinue alendronate and perform prophylactic intramedullary nailing
. Continue alendronate and restrict weight bearing
. Discontinue alendronate and begin extracorporeal shockwave therapy
. Switch to denosumab and apply a cast brace

Correct Answer & Explanation

. Discontinue alendronate and perform prophylactic intramedullary nailing

Explanation

This patient is presenting with an impending atypical femur fracture (AFF), which is strongly associated with long-term bisphosphonate use (usually > 5 years). The classic radiographic findings are lateral cortical thickening ("beaking") and a transverse radiolucent line. If the patient has prodromal pain (impending fracture), the recommended treatment is discontinuation of the bisphosphonate and prophylactic intramedullary nailing to prevent a complete fracture, which has a significantly higher complication and nonunion rate.

Question 8379

Topic: 2. Trauma

A 45-year-old man falls from a ladder and sustains a high-energy closed tibial pilon fracture. On examination in the emergency department, the ankle is grossly deformed with tense soft tissues and early fracture blister formation. No open wounds are present. What is the most appropriate initial management?

. Immediate open reduction and internal fixation of the tibia and fibula
. Application of a spanning external fixator with or without fibular fixation
. Closed reduction and application of a well-molded short leg cast
. Immediate intramedullary nailing of the tibia
. Minimally invasive percutaneous plate osteosynthesis (MIPPO) of the tibia

Correct Answer & Explanation

. Application of a spanning external fixator with or without fibular fixation

Explanation

High-energy tibial pilon fractures are associated with profound soft tissue injury. Early definitive open reduction and internal fixation (ORIF) in the presence of compromised soft tissues (tense swelling, blisters) is associated with unacceptably high rates of wound breakdown and deep infection. The standard of care is a staged approach: initial application of a joint-spanning external fixator to restore length and alignment (with or without definitive fibular fixation), followed by definitive tibial ORIF once the soft tissues have recovered (usually 10 to 21 days later), marked by the reappearance of skin wrinkles.

Question 8380

Topic: Pelvic & Acetabular Trauma
A 28-year-old male is brought to the trauma bay after a high-speed motorcycle collision. His blood pressure is 80/50 mmHg, and his heart rate is 130 bpm. FAST examination is negative. Pelvic radiographs demonstrate an anteroposterior compression type III (APC-III) pelvic ring injury. A pelvic binder is applied appropriately, and he receives 2 units of uncrossmatched packed RBCs, but his blood pressure remains 85/55 mmHg. What is the most appropriate next step in management?
. Diagnostic peritoneal lavage
. Computed tomography of the abdomen and pelvis
. Pre-peritoneal pelvic packing and/or pelvic angiography with embolization
. Immediate open reduction and internal fixation of the anterior and posterior pelvic ring
. Application of a hip spica cast

Correct Answer & Explanation

. Pre-peritoneal pelvic packing and/or pelvic angiography with embolization

Explanation

This patient is hemodynamically unstable due to a major pelvic ring disruption (likely venous plexus bleeding or arterial injury), with no evidence of intra-abdominal hemorrhage (negative FAST). Mechanical stabilization with a pelvic binder is the first step. If the patient remains hemodynamically unstable despite a binder and initial volume resuscitation, emergent hemorrhage control is required. According to advanced trauma protocols, this should be achieved via pre-peritoneal pelvic packing (PPP) and/or pelvic angiography with embolization. CT is contraindicated in a persistently hemodynamically unstable patient.

Test Yourself

Switch to an interactive, timed exam simulation to truly master this topic.

On this Page