Menu

2. Trauma MCQs

Practice Set 421 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 8401

Topic: 2. Trauma
A 29-year-old male falls from a height of 15 feet and sustains an isolated, vertically oriented, displaced femoral neck fracture with an angle of 75 degrees relative to the horizontal (Pauwels Type III). He is brought to the operating room for urgent fixation. To minimize the risk of varus collapse and nonunion, which of the following internal fixation constructs provides the most biomechanically stable fixation for this fracture pattern?
. Three parallel cancellous screws placed in an inverted triangle configuration
. A sliding hip screw (dynamic hip screw) with an anti-rotation screw
. A short cephalomedullary nail
. Two parallel cancellous screws
. Bipolar hemiarthroplasty

Correct Answer & Explanation

. A sliding hip screw (dynamic hip screw) with an anti-rotation screw

Explanation

Pauwels Type III femoral neck fractures are highly vertical and experience massive shear forces, leading to high rates of varus collapse, shortening, and nonunion when treated with multiple cancellous screws alone. Biomechanical studies have consistently shown that a fixed-angle construct, such as a sliding hip screw (DHS) supplemented with a derotation screw, provides superior stability against vertical shear forces compared to multiple parallel cancellous screws.

Question 8402

Topic: 2. Trauma

A 35-year-old skier sustains a high-energy medial tibial plateau fracture (Schatzker IV). Upon arrival at the emergency department, his knee is grossly swollen. The foot is warm and pink, and a dorsalis pedis pulse is palpable. However, an Ankle-Brachial Index (ABI) is performed and measured at 0.8. The calf compartments are soft and compressible. What is the most appropriate next step in management?

. Immediate four-compartment fasciotomy of the leg
. CT angiography of the lower extremity
. Observation with serial ABI measurements every 4 hours
. Immediate open exploration of the popliteal artery
. Application of a spanning external fixator and discharge

Correct Answer & Explanation

. CT angiography of the lower extremity

Explanation

High-energy knee injuries, such as knee dislocations and Schatzker IV (medial) tibial plateau fractures, have a high association with popliteal artery injuries. Even in the presence of palpable pulses and a well-perfused extremity, an asymmetric or abnormal ABI (< 0.9) warrants further definitive vascular imaging. CT angiography is indicated to rule out flow-limiting lesions, intimal flaps, or pseudoaneurysms. Fasciotomy is not indicated if the compartments are soft and there are no clinical signs of compartment syndrome.

Question 8403

Topic: 2. Trauma

A 45-year-old male is brought to the trauma bay after being crushed by heavy machinery. He is hemodynamically stable. Radiographs reveal an 'open-book' anterior-posterior compression (APC-II) pelvic ring injury. During the secondary survey, blood is noted at the urethral meatus, and a high-riding prostate is palpated on digital rectal examination. What is the most appropriate immediate step in the urologic evaluation?

. Placement of a standard transurethral Foley catheter
. Retrograde urethrogram
. Intravenous pyelogram
. CT cystogram
. Immediate suprapubic catheter placement

Correct Answer & Explanation

. Retrograde urethrogram

Explanation

Blood at the urethral meatus, a high-riding/non-palpable prostate, or perineal hematoma in the setting of pelvic trauma are classic cardinal signs of a urethral injury. A retrograde urethrogram (RUG) must be performed to evaluate urethral integrity before any attempt is made to pass a transurethral catheter, as blind catheterization can convert a partial urethral tear into a complete transection.

Question 8404

Topic: 2. Trauma
A 50-year-old male sustains a displaced, intra-articular calcaneus fracture (Sanders Type III) after falling from a roof. He is scheduled for open reduction and internal fixation via an extensile lateral approach once the soft tissue swelling subsides. When counseling the patient preoperatively, which of the following patient-specific factors should be identified as the single greatest independent risk factor for postoperative wound healing complications?
. Diabetes mellitus
. Active cigarette smoking
. Age greater than 60 years
. Body mass index greater than 30
. Delaying surgery beyond 14 days

Correct Answer & Explanation

. Active cigarette smoking

Explanation

Wound breakdown and infection are devastating complications following the extensile lateral approach to the calcaneus. Multiple large orthopedic trauma studies have consistently identified active smoking as the most significant independent risk factor for wound healing complications, increasing the risk up to threefold compared to non-smokers due to nicotine-induced microvascular vasoconstriction and delayed cellular healing.

Question 8405

Topic: 2. Trauma

A 35-year-old male is brought to the emergency department after a high-speed motorcycle collision. He is hemodynamically unstable with a blood pressure of 80/50 mmHg and a heart rate of 120 beats per minute. Primary survey reveals a mechanically unstable pelvic ring injury with a widened symphysis pubis. A pelvic binder is applied, but his blood pressure only marginally improves to 85/55 mmHg. A Focused Assessment with Sonography for Trauma (FAST) scan is negative. What is the most appropriate next step in management?

. CT abdomen and pelvis with IV contrast
. Retrograde urethrogram
. Immediate internal fixation of the anterior ring
. Pelvic angiography and embolization or preperitoneal pelvic packing
. Application of a supracondylar femoral traction pin

Correct Answer & Explanation

. Pelvic angiography and embolization or preperitoneal pelvic packing

Explanation

In a hemodynamically unstable patient with a mechanically unstable pelvic fracture and a negative FAST scan, the source of bleeding is highly likely to be the presacral venous plexus or pelvic arterial injury. Once a binder is placed, if the patient remains hemodynamically unstable, immediate hemorrhage control is required. Depending on institutional protocol, this is achieved via pelvic packing or emergent angiography and embolization.

Question 8406

Topic: 2. Trauma
A 28-year-old man sustains a closed Hawkins Type III fracture of the talar neck after falling from a height. He undergoes urgent open reduction and internal fixation. Six weeks postoperatively, an anteroposterior radiograph of the ankle shows a subchondral radiolucent band in the talar dome. What does this radiographic finding most likely indicate?
. Early onset of avascular necrosis (AVN) of the talar body
. Presence of subchondral osteomyelitis
. Intact vascularity of the talar body
. Nonunion of the talar neck fracture
. Post-traumatic osteoarthritis

Correct Answer & Explanation

. Intact vascularity of the talar body

Explanation

The presence of a subchondral radiolucent band in the talar dome at 6 to 8 weeks post-injury is known as the Hawkins sign. It represents subchondral atrophy (osteopenia) resulting from disuse. Because bone resorption is an active process that requires an intact blood supply, this finding is a favorable prognostic indicator, indicating that the talar body has intact vascularity and is unlikely to develop avascular necrosis.

Question 8407

Topic: 2. Trauma
A 30-year-old woman sustains a displaced, highly vertical (Pauwels type III) femoral neck fracture after a motor vehicle collision. Which of the following fixation constructs provides the greatest biomechanical stability for this specific fracture pattern?
. Three parallel cancellous screws in an inverted triangle configuration
. Sliding hip screw (SHS) with an anti-rotation screw
. Two fully threaded cortical screws
. Cephalomedullary nail with a single lag screw
. Smooth Steinmann pins

Correct Answer & Explanation

. Sliding hip screw (SHS) with an anti-rotation screw

Explanation

Pauwels type III fractures are vertically oriented and subject to high shear forces during weight-bearing. Biomechanical studies have consistently demonstrated that for vertical, high-shear femoral neck fractures in young adults, a fixed-angle construct such as a sliding hip screw (often supplemented with a derotational screw) provides superior biomechanical stability and a lower risk of varus collapse compared to multiple parallel cancellous screws.

Question 8408

Topic: 2. Trauma

A 45-year-old male presents with a high-energy closed bicondylar tibial plateau fracture (Schatzker VI). Examination reveals severe soft tissue swelling, hemorrhagic fracture blisters, and a tense calf compartment. Compartment pressures are measured at 15 mmHg, with a diastolic blood pressure of 80 mmHg. The most appropriate initial surgical management is:

. Immediate single-incision open reduction and internal fixation with a lateral locked plate
. Immediate dual-incision open reduction and internal fixation
. Spanning external fixation and delayed internal fixation once soft tissues allow
. Four-compartment lower leg fasciotomies
. Intramedullary nailing of the tibia

Correct Answer & Explanation

. Spanning external fixation and delayed internal fixation once soft tissues allow

Explanation

Schatzker VI fractures involve severe high-energy soft tissue injury. The presence of significant swelling and fracture blisters precludes early definitive internal fixation due to an unacceptably high risk of wound breakdown and deep infection. The standard of care is a staged protocol: initial temporization with a spanning external fixator across the knee to maintain length, alignment, and joint distraction, followed by delayed definitive open reduction and internal fixation (usually 1-3 weeks later) once the soft tissue envelope has healed.

Question 8409

Topic: 2. Trauma
A 34-year-old man sustains a Gustilo-Anderson Type IIIA open tibia fracture. In the evidence-based management of open fractures, which of the following interventions has been shown to have the most significant impact on reducing the patient's overall risk of deep fracture-related infection?
. Time to operative debridement of less than 6 hours
. Early administration of systemic intravenous antibiotics
. Use of high-pressure pulsatile lavage instead of low-pressure lavage
. Application of a vacuum-assisted closure (VAC) dressing
. Staged definitive fixation rather than immediate fixation

Correct Answer & Explanation

. Early administration of systemic intravenous antibiotics

Explanation

Extensive orthopedic literature (including foundational studies by Patzakis et al.) demonstrates that the single most critical factor in reducing the infection rate in open fractures is the early administration of systemic intravenous antibiotics (ideally within the first hour after injury). The historic '6-hour rule' for operative debridement has been largely challenged by modern evidence, which shows that a delay beyond 6 hours does not significantly increase infection rates as long as antibiotics are administered promptly.

Question 8410

Topic: 2. Trauma

A 42-year-old woman is involved in a motor vehicle collision and sustains a highly comminuted intra-articular distal femur fracture. A CT scan confirms a displaced coronal shear fracture of the lateral femoral condyle (Hoffa fragment). When planning surgical fixation, what is the most biomechanically sound and appropriate technique to stabilize the Hoffa fragment?

. Anterior-to-posterior positional cortical screws
. Posterior-to-anterior positional cortical screws
. Anterior-to-posterior countersunk interfragmentary lag screws
. A single lateral locking plate capturing the fragment with locking screws
. Spanning external fixation alone

Correct Answer & Explanation

. Anterior-to-posterior countersunk interfragmentary lag screws

Explanation

A Hoffa fragment is a coronal plane shear fracture of the femoral condyle. Being an intra-articular fracture, it requires precise anatomical reduction and absolute stability. This is best achieved using anterior-to-posterior (or posterior-to-anterior depending on exposure) interfragmentary lag screws placed perpendicular to the fracture line. These screws must be countersunk beneath the articular cartilage if placed through the joint surface. A lateral locking plate alone provides inadequate compression across a coronal fracture and is used mainly to neutralize the supracondylar component.

Question 8411

Topic: 2. Trauma

A 28-year-old man is brought to the emergency department after a motorcycle collision resulting in a comminuted midshaft tibia fracture. He is currently intubated and sedated for head injuries. His blood pressure is 110/70 mmHg. The orthopedic surgeon is concerned about acute compartment syndrome and measures intracompartmental pressures (ICP) of the leg. Which of the following findings is an absolute indication for a four-compartment fasciotomy in this patient?

. Absolute ICP of 25 mmHg in the anterior compartment
. Absolute ICP of 30 mmHg in the deep posterior compartment
. A difference of 25 mmHg between the diastolic blood pressure and the highest ICP measured
. A difference of 40 mmHg between the mean arterial pressure and the highest ICP measured
. A difference of 35 mmHg between the systolic blood pressure and the highest ICP measured

Correct Answer & Explanation

. A difference of 25 mmHg between the diastolic blood pressure and the highest ICP measured

Explanation

The diagnosis of acute compartment syndrome in an obtunded or intubated patient is heavily reliant on objective pressure measurements. The widely accepted threshold for performing a fasciotomy is a Delta P (Diastolic Blood Pressure - Intracompartmental Pressure) of less than 30 mmHg. In this scenario, a difference of 25 mmHg between the diastolic blood pressure and the highest measured ICP falls below the 30 mmHg threshold, indicating inadequate tissue perfusion and an absolute need for emergency fasciotomy.

Question 8412

Topic: 2. Trauma
A 30-year-old man sustains a completely displaced, vertically oriented (Pauwels Type III) femoral neck fracture. He is medically stable and taken to the operating room for closed reduction and internal fixation. To maximize the biomechanical stability of the construct and minimize the risk of varus collapse, which of the following fixation strategies is most appropriate?
. Three parallel fully threaded cancellous screws placed in an inverted triangle configuration
. A sliding hip screw (dynamic hip screw) with a derotational screw
. Two partially threaded cancellous screws on the central axis
. An antegrade intramedullary nail with a single cephalomedullary screw
. Bipolar hemiarthroplasty

Correct Answer & Explanation

. A sliding hip screw (dynamic hip screw) with a derotational screw

Explanation

Pauwels Type III femoral neck fractures are characterized by a highly vertical fracture line, which creates massive shear forces across the fracture site. Multiple cancellous screws alone offer poor resistance to these shear forces, leading to a high rate of varus collapse, nonunion, and failure. A fixed-angle device such as a sliding hip screw (often supplemented with an anti-rotation screw) provides superior biomechanical stability by converting shear forces into compressive forces, making it the preferred construct for young patients with vertical femoral neck fractures.

Question 8413

Topic: 2. Trauma
A 40-year-old male is brought to the trauma bay after a high-speed motor vehicle collision. He is hemodynamically unstable with a blood pressure of 75/40 mmHg. Pelvic radiographs demonstrate an anteroposterior compression (APC) type III pelvic ring injury. The trauma team decides to apply a circumferential pelvic binder. Where should the pelvic binder be centered to most effectively reduce the pelvic volume and stabilize the fracture?
. Over the iliac crests
. Over the anterior superior iliac spines (ASIS)
. Over the greater trochanters
. Over the symphysis pubis and L5 vertebral body
. Over the mid-thighs

Correct Answer & Explanation

. Over the greater trochanters

Explanation

To optimally reduce pelvic volume and stabilize an "open-book" pelvic ring injury, the pelvic binder must be applied directly over the greater trochanters. Applying the binder over the iliac crests is a common error; it can paradoxically push the superior hemipelvis inward while flaring the inferior aspect outward, failing to reduce the volume of the true pelvis and potentially exacerbating bleeding.

Question 8414

Topic: 2. Trauma

A 45-year-old woman presents with a Schatzker type IV tibial plateau fracture involving a large posteromedial coronal shear fragment. Which of the following surgical approaches is most appropriate for direct visualization and buttress plating of this specific fragment?

. Standard anterolateral approach
. Posteromedial approach
. Direct posterior approach
. Anteromedial approach
. Lateral approach with a tibial tubercle osteotomy

Correct Answer & Explanation

. Posteromedial approach

Explanation

Schatzker IV fractures commonly involve the medial plateau. When a coronal shear fragment is present posteriorly (posteromedial fragment), traditional anteromedial or anterolateral approaches do not allow adequate access for reduction or perpendicular implant application. A posteromedial approach allows direct visualization of the apex of the fracture and permits the application of a posterior buttress plate, which mechanically opposes the posteroinferior shear forces during weight-bearing.

Question 8415

Topic: 2. Trauma
A 25-year-old man sustains a Gustilo-Anderson Type IIIB open tibia fracture in a motorcycle collision. According to current evidence and trauma guidelines regarding the management of open fractures, which of the following factors has the greatest impact on reducing the rate of deep infection?
. Surgical debridement strictly within 6 hours of the injury
. High-pressure pulsatile lavage during the index debridement
. Administration of systemic intravenous antibiotics as soon as possible after the injury
. Prophylactic application of local antibiotic beads during the first debridement
. Immediate primary closure of the wound during the index procedure

Correct Answer & Explanation

. Administration of systemic intravenous antibiotics as soon as possible after the injury

Explanation

Extensive literature, notably supported by findings from the LEAP (Lower Extremity Assessment Project) study, has shifted the paradigm of open fracture management. The most critical determinant for reducing infection rates is the early administration of systemic antibiotics (ideally within 1 hour of injury). The historical '6-hour rule' for surgical debridement has been shown to be less strongly correlated with infection rates compared to the prompt initiation of antibiotic therapy.

Question 8416

Topic: 2. Trauma

An 82-year-old woman with severe osteoporosis and pre-existing tricompartmental osteoarthritis of the knee sustains a comminuted, intra-articular distal femur fracture (OTA/AO 33-C2). Prior to the injury, she was an independent community ambulator. What is the most appropriate definitive management to allow for immediate weight-bearing and minimize complications?

. Open reduction and internal fixation with a lateral locked plate
. Retrograde intramedullary nailing
. Distal femoral replacement (megaprosthesis)
. External fixation followed by delayed internal fixation
. Non-operative management with a hinged knee brace

Correct Answer & Explanation

. Distal femoral replacement (megaprosthesis)

Explanation

In elderly patients with severe osteopenia, comminuted intra-articular distal femur fractures, and pre-existing severe osteoarthritis, internal fixation (ORIF) carries a notoriously high risk of failure, nonunion, and prolonged immobility. Distal femoral replacement (DFR) successfully addresses both the fracture and the underlying arthritis in a single procedure, reliably allowing for immediate post-operative weight-bearing and early mobilization, which is vital for survival in the geriatric population.

Question 8417

Topic: 2. Trauma

A 42-year-old male falls from a ladder and sustains a closed, highly comminuted intra-articular distal tibia fracture (Tscherne Grade 2). Initial management includes application of a spanning external fixator. What is the most appropriate indicator that the patient's soft tissue envelope is ready for definitive open reduction and internal fixation (ORIF)?

. Resolution of fracture blisters and appearance of skin wrinkles
. Normalization of serum inflammatory markers (ESR, CRP)
. Strictly reaching post-injury day 7
. Decreased pain with passive range of motion of the toes
. Formation of early soft callus on follow-up radiographs

Correct Answer & Explanation

. Resolution of fracture blisters and appearance of skin wrinkles

Explanation

The timing of definitive fixation for high-energy pilon fractures is dictated by the condition of the soft tissue envelope, not a strict timeline. The 'wrinkle sign' (appearance of skin wrinkles and re-epithelialization of fracture blisters) indicates that acute edema has subsided enough to safely allow surgical incisions with a minimized risk of wound dehiscence and deep infection. Normalization of inflammatory markers or reaching day 7 are not reliable standalone indicators of soft tissue readiness.

Question 8418

Topic: Pelvic & Acetabular Trauma
A 28-year-old male presents in hemorrhagic shock following a high-speed motorcycle crash. A pelvic radiograph reveals an anterior-posterior compression type III (APC-III) pelvic ring injury. A pelvic binder is immediately applied, and a massive transfusion protocol is initiated. A FAST (Focused Assessment with Sonography for Trauma) scan is negative. His blood pressure remains 70/40 mm Hg. What is the most appropriate next step in management?
. Exploratory laparotomy
. Computed tomography (CT) scan of the abdomen and pelvis
. Placement of a supra-acetabular external fixator
. Retroperitoneal pelvic packing and/or angioembolization
. Definitive open reduction and internal fixation of the symphysis pubis

Correct Answer & Explanation

. Retroperitoneal pelvic packing and/or angioembolization

Explanation

In a hemodynamically unstable patient with a mechanically unstable pelvic ring injury and a negative FAST scan, the primary source of hemorrhage is presumed to be the retroperitoneal venous plexus or pelvic arterial branches. Following initial volume reduction with a binder, the next most appropriate step in a patient who remains hypotensive is retroperitoneal pelvic packing (RPP) or pelvic angioembolization to achieve direct hemostasis. CT scanning is contraindicated in hemodynamically unstable patients. Laparotomy is indicated if the FAST scan is positive (intra-abdominal bleeding).

Question 8419

Topic: 2. Trauma
A 30-year-old female sustains a completely displaced, vertical femoral neck fracture (Pauwels Type III, 70-degree angle) following a motor vehicle collision. The fracture is closed. Which of the following fixation constructs provides the most biomechanically stable construct to resist the high shear forces inherent to this specific fracture pattern?
. Three parallel cancellous screws in an inverted triangle configuration
. A sliding hip screw (fixed-angle device) with an anti-rotation screw
. Cemented bipolar hemiarthroplasty
. Intramedullary cephalomedullary nail with a single lag screw
. Fully threaded cannulated screws with washers

Correct Answer & Explanation

. A sliding hip screw (fixed-angle device) with an anti-rotation screw

Explanation

Pauwels Type III fractures are highly vertical and experience significant vertical shear forces during loading. Multiple parallel cancellous screws have a high failure rate in this pattern because they cannot adequately resist vertical shear, often leading to varus collapse and nonunion. A fixed-angle device, such as a sliding hip screw (SHS), provides superior biomechanical stability against vertical shear. An additional derotational screw is often used to prevent rotation of the femoral head during insertion. Arthroplasty is generally reserved for older, low-demand patients.

Question 8420

Topic: 2. Trauma

A 25-year-old male is intubated in the ICU following a severe traumatic brain injury and a closed, comminuted midshaft tibia fracture. The limb is splinted. On examination, the calf is tense and non-compressible. The patient is obtunded and unable to report pain. The patient's blood pressure is 110/70 mm Hg (MAP 83 mm Hg). Compartment pressure monitoring is initiated. Which of the following intracompartmental pressure findings is an absolute indication for an emergent four-compartment fasciotomy?

. An absolute compartment pressure of 25 mm Hg
. An absolute compartment pressure of 35 mm Hg
. A differential pressure (Diastolic BP minus Compartment Pressure) of 40 mm Hg
. A differential pressure (MAP minus Compartment Pressure) of 45 mm Hg
. A differential pressure (Diastolic BP minus Compartment Pressure) of 20 mm Hg

Correct Answer & Explanation

. A differential pressure (Diastolic BP minus Compartment Pressure) of 20 mm Hg

Explanation

The diagnosis of compartment syndrome in an obtunded patient relies heavily on objective pressure measurements. The generally accepted threshold for fasciotomy is a differential pressure (Delta P) of 30 mm Hg or less (Delta P = Diastolic Blood Pressure minus Compartment Pressure). A Delta P of 20 mm Hg indicates critically impaired local tissue perfusion and is an absolute indication for emergent fasciotomy. Relying solely on absolute pressures can be misleading, particularly in hypotensive patients.

Test Yourself

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

On this Page