Menu

2. Trauma MCQs

Practice Set 547 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 10921

Topic: 2. Trauma
A 38-year-old man sustains an open fracture of the tibia. There is a 12 cm laceration with extensive muscle stripping and a segmental fracture pattern. Pulses are non-palpable distally, and an angiogram demonstrates a complete transection of the popliteal artery requiring a saphenous vein graft repair. According to the Gustilo-Anderson classification, what is the grade of this open fracture?
. Grade II
. Grade IIIA
. Grade IIIB
. Grade IIIC
. Grade IV

Correct Answer & Explanation

. Grade IIIC

Explanation

The Gustilo-Anderson classification evaluates open fractures. Grade IIIC is defined as any open fracture associated with an arterial injury that requires formal surgical repair for limb salvage, regardless of the extent of the soft tissue injury.

Question 10922

Topic: 2. Trauma

In the polytraumatized patient, the concept of "Damage Control Orthopedics" (DCO) is often employed to minimize the "second hit" phenomenon. Which of the following physiologic parameters would most strongly indicate the need for DCO rather than Early Total Care (ETC) for a femoral shaft fracture?

. Serum lactate of 1.5 mmol/L
. Base excess of -1 mEq/L
. Core temperature of 36.5ยฐC
. Platelet count of 150,000/ยตL
. Serum pH of 7.15

Correct Answer & Explanation

. Serum lactate of 1.5 mmol/L

Explanation

Damage Control Orthopedics (DCO) involves rapid, temporary stabilization (such as external fixation) for patients "in extremis" or borderline. Indicators for DCO over ETC include severe acidemia (pH < 7.24), hypothermia (< 35ยฐC), coagulopathy (platelets < 90,000), prolonged shock (lactate > 2.5 mmol/L), and massive transfusion needs. A pH of 7.15 is a clear indication for DCO.

Question 10923

Topic: 2. Trauma
A 25-year-old male sustains a femoral neck fracture. The fracture line is oriented 75 degrees relative to the horizontal. According to the Pauwels classification, this is a Type III fracture. Which of the following statements best describes the biomechanical forces and optimal fixation strategy for this fracture?
. The fracture experiences primarily compressive forces; multiple parallel cancellous screws are ideal.
. The fracture experiences primarily tensile forces; an intramedullary nail is the only acceptable fixation method.
. The fracture experiences high shear forces; a dynamic hip screw (DHS) provides a biomechanically superior construct compared to multiple cancellous screws alone.
. The fracture experiences high shear forces; nonoperative management in a spica cast is recommended due to high AVN risk.
. The high angle provides intrinsic stability, requiring only a single lag screw.

Correct Answer & Explanation

. The fracture experiences high shear forces; a dynamic hip screw (DHS) provides a biomechanically superior construct compared to multiple cancellous screws alone.

Explanation

Pauwels Type III fractures (>50 degrees from the horizontal) are characterized by a vertically oriented fracture line. This results in high shear forces and varus instability. Biomechanical studies demonstrate that a fixed-angle device, such as a Dynamic Hip Screw (DHS) (often supplemented with an anti-rotation screw), provides superior stability against these shear forces compared to parallel cancellous screws.

Question 10924

Topic: 2. Trauma

A 45-year-old male presents with a high-energy medial tibial plateau fracture (Schatzker IV). This fracture pattern is frequently a result of a high-energy varus/axial load. Which of the following injuries is most strongly associated with this specific fracture pattern, requiring careful clinical assessment?

. Common peroneal nerve injury
. Quadriceps tendon rupture
. Lateral collateral ligament complex avulsion from the fibular head
. Popliteal artery injury secondary to knee subluxation/dislocation
. Posteromedial corner avulsion of the semimembranosus

Correct Answer & Explanation

. Common peroneal nerve injury

Explanation

Schatzker IV (medial tibial plateau) fractures often result from high-energy trauma and frequently represent a true fracture-dislocation of the knee. Due to the significant energy required to shear the dense medial column, there is a substantial risk of associated knee dislocation and subsequent popliteal artery injury. Peroneal nerve injuries are more commonly associated with high-energy lateral plateau injuries.

Question 10925

Topic: 2. Trauma

Proximal third tibial shaft fractures treated with intramedullary nailing in extension are classically associated with which of the following malalignments?

. Apex anterior and valgus
. Apex posterior and valgus
. Apex anterior and varus
. Apex posterior and varus
. Neutral alignment with significant shortening

Correct Answer & Explanation

. Apex anterior and valgus

Explanation

Proximal third tibia fractures nailed in extension classically fall into apex anterior (procurvatum) and valgus malalignment due to the pull of the extensor mechanism and an eccentric starting point. Techniques such as suprapatellar nailing or blocking screws help prevent this.

Question 10926

Topic: 2. Trauma

A 35-year-old polytrauma patient with bilateral femur fractures presents with a lactate of 4.5 mmol/L, pH 7.2, and base excess of -8. According to Damage Control Orthopedics (DCO) principles, what is the most appropriate initial management of the femur fractures?

. Bilateral reamed intramedullary nailing
. Bilateral unreamed intramedullary nailing
. Bilateral external fixation
. Unilateral nailing of the more severe side and external fixation of the other
. Open reduction and internal fixation with plates

Correct Answer & Explanation

. Bilateral reamed intramedullary nailing

Explanation

This patient is in extremis based on the high lactate, acidosis, and negative base excess. Under DCO principles, early definitive care with intramedullary nailing is contraindicated, and rapid temporary stabilization with external fixation is required.

Question 10927

Topic: 2. Trauma
A 40-year-old male sustains a Type IIIB open tibial shaft fracture. Following initial debridement and external fixation, when is the optimal time for definitive soft tissue coverage to minimize infection risk?
. Within 24 hours
. Between 5 to 7 days
. Within 72 hours
. Between 10 to 14 days
. After 3 weeks when mature granulation tissue forms

Correct Answer & Explanation

. Within 72 hours

Explanation

Early soft tissue coverage of Type IIIB open tibia fractures within 72 hours is associated with significantly lower rates of deep infection and flap failure. Delaying coverage beyond 5 to 7 days drastically increases the risk of nosocomial colonization.

Question 10928

Topic: 2. Trauma

In the management of a displaced Hoffa fracture (coronal shear fracture of the femoral condyle), what is the optimal direction of lag screw placement for maximum biomechanical stability against physiological forces?

. Anterior-to-posterior
. Posterior-to-anterior
. Medial-to-lateral
. Lateral-to-medial
. Distal-to-proximal

Correct Answer & Explanation

. Anterior-to-posterior

Explanation

Anterior-to-posterior (AP) lag screw placement provides superior biomechanical stability against vertical shear forces in Hoffa fractures compared to posterior-to-anterior screws. However, PA screws are often used concurrently to aid in articular congruity.

Question 10929

Topic: 2. Trauma

Eight weeks following open reduction and internal fixation of a Hawkins Type II talar neck fracture, an AP radiograph demonstrates a subchondral radiolucent band in the talar dome. What does this finding indicate?

. Osteonecrosis (AVN) of the talar body
. Impending nonunion of the talar neck
. Deep bone infection
. Intact vascularity to the talar body
. Post-traumatic osteoarthritis

Correct Answer & Explanation

. Osteonecrosis (AVN) of the talar body

Explanation

This subchondral radiolucent band is the Hawkins sign, representing subchondral osteopenia secondary to active hyperemia. It is a highly reliable indicator that the talar body has an intact vascular supply, making avascular necrosis unlikely.

Question 10930

Topic: 2. Trauma

A patient presents with severe leg pain following a closed tibial shaft fracture. Which of the following findings is the most reliable early clinical indicator of acute compartment syndrome?

. Absent dorsalis pedis pulse
. Pallor of the distal extremity
. Paralysis of the extensor hallucis longus
. Pain out of proportion to the injury exacerbated by passive stretch
. Decreased capillary refill time

Correct Answer & Explanation

. Absent dorsalis pedis pulse

Explanation

Pain out of proportion to the apparent injury and pain that is highly exacerbated by passive stretching of the involved muscles are the earliest and most reliable clinical signs of acute compartment syndrome. Pulselessness and paralysis are late, irreversible signs.

Question 10931

Topic: 2. Trauma

According to the Denis classification of sacral fractures, fractures occurring in Zone 3 are most commonly associated with which of the following complications?

. Sciatic nerve palsy
. Sural nerve neuropraxia
. Bowel, bladder, and sexual dysfunction
. Superior gluteal artery rupture
. High rate of aseptic nonunion

Correct Answer & Explanation

. Sciatic nerve palsy

Explanation

Denis Zone 3 sacral fractures involve the central sacral canal. They carry the highest risk (often over 50%) of cauda equina syndrome, which manifests as severe bowel, bladder, and sexual dysfunction due to bilateral sacral nerve root involvement.

Question 10932

Topic: 2. Trauma

A 65-year-old female sustains a subtrochanteric femur fracture. Biomechanically, what is the primary deforming force causing flexion and external rotation of the proximal fracture fragment?

. Gluteus medius
. Gluteus maximus
. Iliopsoas
. Adductor longus
. Tensor fasciae latae

Correct Answer & Explanation

. Gluteus medius

Explanation

In subtrochanteric femur fractures, the proximal fragment is predictably deformed into flexion and external rotation by the pull of the iliopsoas tendon on the lesser trochanter. Abduction is driven by the gluteus medius and minimus.

Question 10933

Topic: 2. Trauma
A 30-year-old patient with an open Type IIIA diaphyseal femur fracture undergoes immediate intramedullary nailing. What is the current consensus regarding the optimal duration of prophylactic antibiotic therapy after definitive wound closure?
. 24 to 72 hours
. 7 days
. 14 days
. 4 weeks
. Until the fracture demonstrates radiographic union

Correct Answer & Explanation

. 24 to 72 hours

Explanation

Current orthopedic trauma guidelines advocate limiting prophylactic antibiotics for severe open fractures to 24-72 hours after the injury, or 24 hours after definitive soft tissue closure. Prolonged antibiotics increase the risk of resistant organisms without decreasing infection rates.

Question 10934

Topic: 2. Trauma

A 22-year-old male presents with a gunshot wound to the right knee. Radiographs reveal a retained bullet directly within the intra-articular space, with a minimally displaced osteochondral fracture. What is the recommended management?

. Observation and protected weight-bearing
. Intra-articular steroid injection to suppress inflammation
. Surgical removal of the bullet and joint washout
. Immediate joint spanning external fixation
. Delayed removal after 6 months to allow encapsulation

Correct Answer & Explanation

. Observation and protected weight-bearing

Explanation

A retained bullet within a synovial joint requires surgical extraction. Lead bullets exposed to synovial fluid will dissolve, leading to systemic lead toxicity (plumbism) and severe localized mechanical and chemical joint destruction known as lead arthropathy.

Question 10935

Topic: 2. Trauma

A 40-year-old female sustains a distal femur fracture. CT imaging reveals a coronal plane fracture of the lateral femoral condyle (Hoffa fracture). Which of the following fixation strategies provides the most biomechanically stable construct for this specific fragment?

. A laterally applied distal femur locking plate alone
. Anterior-to-posterior directed lag screws
. Posterior-to-anterior directed lag screws
. An intramedullary nail with distal locking screws
. A single 6.5 mm fully threaded positioning screw

Correct Answer & Explanation

. A laterally applied distal femur locking plate alone

Explanation

Hoffa fractures are coronal shear fractures of the femoral condyles. Posterior-to-anterior (PA) directed lag screws have been shown biomechanically to provide superior fixation compared to anterior-to-posterior screws.

Question 10936

Topic: 2. Trauma

A 25-year-old male polytrauma patient with bilateral femoral shaft fractures and a severe pulmonary contusion has a serum lactate of 4.5 mmol/L and a base deficit of -8. According to damage control orthopedics (DCO) principles, what is the most appropriate initial skeletal management?

. Bilateral reamed intramedullary nailing
. Bilateral unreamed intramedullary nailing
. Bilateral spanning external fixation
. Open reduction and internal fixation with plates
. Skeletal traction and delayed fixation at 3 weeks

Correct Answer & Explanation

. Bilateral reamed intramedullary nailing

Explanation

In a borderline or unstable polytrauma patient (elevated lactate, high base deficit, severe chest trauma), damage control orthopedics dictates initial stabilization with spanning external fixation. This minimizes the systemic inflammatory response and avoids a 'second hit' phenomenon.

Question 10937

Topic: 2. Trauma

When treating a proximal third extra-articular tibia fracture with an intramedullary nail, the fracture is at highest risk for which of the following post-operative malalignments?

. Apex posterior (recurvatum) and varus
. Apex anterior (procurvatum) and valgus
. Apex posterior (recurvatum) and valgus
. Apex anterior (procurvatum) and varus
. Pure rotational malalignment

Correct Answer & Explanation

. Apex posterior (recurvatum) and varus

Explanation

Proximal third tibia fractures are notoriously difficult to control with intramedullary nailing. They commonly result in apex anterior (procurvatum) and valgus deformity due to the pull of the patellar tendon and the wide metaphyseal flare.

Question 10938

Topic: 2. Trauma

A 50-year-old male sustains a subtrochanteric femur fracture. During closed reduction, the proximal fragment is noted to be severely displaced. Which combination of muscles is responsible for the classic flexion, abduction, and external rotation deformity of the proximal segment?

. Iliopsoas, gluteus medius, and short external rotators
. Rectus femoris, gluteus maximus, and adductor longus
. Sartorius, adductor magnus, and piriformis
. Iliopsoas, adductor brevis, and hamstrings
. Gluteus minimus, pectineus, and vastus lateralis

Correct Answer & Explanation

. Iliopsoas, gluteus medius, and short external rotators

Explanation

The proximal fragment in a subtrochanteric fracture is deformed into flexion by the iliopsoas, abduction by the gluteus medius and minimus, and external rotation by the short external rotators.

Question 10939

Topic: 2. Trauma

According to the Lower Extremity Assessment Project (LEAP) study, which of the following is the most significant predictor of poor long-term functional outcome following severe, limb-threatening lower extremity trauma?

. Initial lack of plantar sensation
. Ischemia time greater than 6 hours
. Patient psychosocial factors, including poor social support and lower education level
. Gustilo-Anderson classification grade
. Presence of an associated major motor nerve injury

Correct Answer & Explanation

. Initial lack of plantar sensation

Explanation

The LEAP study demonstrated that initial plantar sensation, injury severity, and Gustilo grade did not definitively predict long-term functional outcomes. Instead, psychosocial factors such as social support, education level, and smoking status were the strongest predictors of poor functional recovery.

Question 10940

Topic: 2. Trauma

A 65-year-old female who has been taking alendronate for 8 years presents with severe, progressive right thigh pain. Radiographs reveal cortical thickening and a transverse radiolucent line on the lateral cortex of the subtrochanteric femur, but no complete fracture. What is the most appropriate management?

. Discontinue alendronate and prescribe strict non-weight bearing
. Prophylactic intramedullary nailing of the entire femur
. Plate osteosynthesis of the proximal femur
. Switching to denosumab and clinical observation
. Core decompression of the subtrochanteric region

Correct Answer & Explanation

. Discontinue alendronate and prescribe strict non-weight bearing

Explanation

This patient has an impending atypical femur fracture (AFF) associated with long-term bisphosphonate use. Because she has severe "prodromal" pain and a visible cortical defect, prophylactic intramedullary nailing is indicated to prevent completion of the fracture.

Test Yourself

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

On this Page