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2. Trauma MCQs

Practice Set 102 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 2021

Topic: 2. Trauma

When comparing intramedullary nailing to lateral locked plating for the treatment of subtrochanteric femur fractures, intramedullary nailing is biomechanically advantageous primarily due to:

. A larger bending moment on the implant
. A shorter lever arm from the mechanical axis of the femur
. Placement on the tension side of the bone
. Increased absolute torsional rigidity compared to bilateral plating
. Direct anatomical reduction of the medial cortex

Correct Answer & Explanation

. A shorter lever arm from the mechanical axis of the femur

Explanation

Intramedullary nails are load-sharing devices located centrally within the medullary canal. This decreases the distance (lever arm) between the implant and the mechanical axis of the lower extremity, significantly reducing the bending moments compared to laterally applied plates.

Question 2022

Topic: 2. Trauma

A 40-year-old male sustains a high-energy Gustilo-Anderson Type I open pilon fracture. If immediate open reduction and internal fixation through a standard anterior approach is performed on the day of injury, what is the most likely severe complication?

. Nonunion of the fibula
. Sural nerve injury
. Deep wound infection and soft tissue necrosis
. Avascular necrosis of the talus
. Malunion of the tibial plafond

Correct Answer & Explanation

. Deep wound infection and soft tissue necrosis

Explanation

Immediate open reduction and internal fixation of high-energy pilon fractures through swollen, compromised soft tissues historically carries an unacceptably high rate (up to 30-50%) of catastrophic wound dehiscence and deep infection. A staged protocol (external fixation followed by delayed ORIF) minimizes this risk.

Question 2023

Topic: 2. Trauma

A patient sustains a non-displaced fracture of the patella 5 years after an uncomplicated total knee arthroplasty. The patellar component remains radiographically well-fixed, and the patient has an intact active straight leg raise. What is the recommended treatment?

. Immediate operative fixation with tension band wiring
. Revision of the patellar component
. Non-operative management with a knee immobilizer or hinged brace
. Patellectomy and extensor mechanism allograft reconstruction
. Arthroscopic debridement and synovectomy

Correct Answer & Explanation

. Non-operative management with a knee immobilizer or hinged brace

Explanation

This is an Ortiguera and Berry Type I periprosthetic patella fracture (stable implant, intact extensor mechanism). These fractures are treated successfully with non-operative management, typically using a knee immobilizer or extension brace for a period of restricted flexion.

Question 2024

Topic: 2. Trauma

During the reduction of a comminuted subtrochanteric femur fracture prior to intramedullary nailing, the surgeon notes persistent flexion and external rotation of the proximal fragment. Which of the following techniques is most effective for directly controlling this multiplanar deformity during reaming and nail insertion?

. Placing the patient in the lateral decubitus position
. Applying longitudinal skin traction
. Inserting a Schanz pin percutaneously into the proximal fragment as a joystick
. Applying a ball-spiked pusher directed medially on the greater trochanter
. Clamping a low-profile plate provisionally to the lateral cortex

Correct Answer & Explanation

. Inserting a Schanz pin percutaneously into the proximal fragment as a joystick

Explanation

The powerful deforming forces on the proximal fragment (iliopsoas, abductors, external rotators) often cannot be overcome by positioning alone. A Schanz pin or a collinear reduction clamp applied directly to the proximal fragment provides the leverage needed to manually correct the flexion and external rotation during guidewire passage.

Question 2025

Topic: 2. Trauma

A 30-year-old male undergoes successful open reduction and internal fixation for a closed, displaced tibial pilon fracture. Even with a near-anatomic articular reduction confirmed by postoperative CT, what is the most common long-term complication he should be counseled about?

. Tibiotalar arthrodesis nonunion
. Chronic osteomyelitis
. Post-traumatic ankle arthrosis
. Complex regional pain syndrome
. Tarsal tunnel syndrome

Correct Answer & Explanation

. Post-traumatic ankle arthrosis

Explanation

Despite anatomic reduction of the articular surface, the initial impact damages the chondrocytes of the tibial plafond. Post-traumatic ankle arthrosis remains the most common long-term complication following severe pilon fractures.

Question 2026

Topic: 2. Trauma

When treating a complex tibial pilon fracture with significant articular impaction and an associated fibula fracture, what is a potential disadvantage of rigidly fixing the fibula first?

. It completely blocks visualization of the lateral tibial plafond
. It may tether the tibial reduction and prevent accurate restoration of the tibial articular surface
. It dramatically increases the risk of sural nerve neuroma
. It permanently disrupts the syndesmosis
. It prevents the use of a posteromedial surgical approach

Correct Answer & Explanation

. It may tether the tibial reduction and prevent accurate restoration of the tibial articular surface

Explanation

While fixing the fibula first can restore length, in severely comminuted pilon fractures with massive impaction, a rigid fibular fixation can act as a tether. This can hold the distal tibia in an over-distracted or malaligned position, making anatomic reduction of the articular surface much more difficult.

Question 2027

Topic: 2. Trauma

A 45-year-old male sustains a severe closed pilon fracture. The surgeon elects to use an anterolateral approach to the distal tibia. The incision is made in line with the 4th ray. Which of the following neurologic structures is at highest risk of iatrogenic injury during the distal extent of this exposure?

. Deep peroneal nerve
. Sural nerve
. Saphenous nerve
. Intermediate dorsal cutaneous branch of the superficial peroneal nerve
. Medial plantar nerve

Correct Answer & Explanation

. Intermediate dorsal cutaneous branch of the superficial peroneal nerve

Explanation

The anterolateral approach to the pilon places the superficial peroneal nerve, specifically its intermediate dorsal cutaneous branch, at significant risk as it crosses the surgical field from medial to lateral. Careful superficial dissection is required to identify and protect it.

Question 2028

Topic: 2. Trauma

A 30-year-old male sustains a highly comminuted subtrochanteric femur fracture following a motorcycle collision. Preoperatively, the proximal fracture fragment is noted to be severely flexed, abducted, and externally rotated. Which muscle group is primarily responsible for the external rotation deformity of this proximal segment?

. Iliopsoas
. Gluteus medius
. Gluteus minimus
. Short external rotators (e.g., piriformis, obturator internus)
. Adductor magnus

Correct Answer & Explanation

. Short external rotators (e.g., piriformis, obturator internus)

Explanation

In subtrochanteric fractures, the proximal fragment is acted upon by multiple deforming forces. The short external rotators pull the fragment into external rotation, while the iliopsoas causes flexion and the gluteus medius/minimus cause abduction.

Question 2029

Topic: 2. Trauma

A 68-year-old female on bisphosphonate therapy for 9 years presents with unremitting right thigh pain. Radiographs reveal lateral cortical thickening and an incomplete transverse lucency. According to current guidelines, which of the following radiographic parameters is an absolute indication for prophylactic intramedullary nailing of this atypical femur fracture?

. Lateral cortical thickness > 5 mm
. Anterior bowing > 15 degrees
. Medial spike formation
. Radiolucent line extending > 50% across the cortex
. Presence of a "dreaded black line" on the medial cortex

Correct Answer & Explanation

. Radiolucent line extending > 50% across the cortex

Explanation

Prophylactic intramedullary nailing of an atypical femur fracture is indicated if the patient has clinical pain or if the incomplete fracture (radiolucent line) extends greater than 50% through the lateral cortex.

Question 2030

Topic: 2. Trauma

According to classical AO/OTA principles for the operative sequence of a severe, comminuted pilon fracture with associated fibula fracture, what is the initial step in definitive surgical reconstruction?

. Bone grafting of the metaphyseal void
. Anatomic reduction of the tibial articular surface
. Fixation of the fibula to restore length and rotation
. Bridging the metadiaphyseal junction with a locked plate
. Placement of an anterior spanning external fixator

Correct Answer & Explanation

. Fixation of the fibula to restore length and rotation

Explanation

The classic four-step AO sequence for pilon fractures begins with fibular reconstruction to restore limb length and rotational alignment. This is followed by tibial articular reconstruction, metaphyseal bone grafting, and finally connecting the joint block to the diaphysis.

Question 2031

Topic: 2. Trauma

During cephalomedullary nailing of a subtrochanteric femur fracture, the surgeon utilizes a greater trochanter entry point. If the starting awl is placed too laterally on the greater trochanter, what is the most predictable malreduction of the proximal fragment?

. Valgus alignment
. Varus alignment
. Procurvatum deformity
. Recurvatum deformity
. Internal rotation deformity

Correct Answer & Explanation

. Varus alignment

Explanation

A lateral starting point on the greater trochanter during intramedullary nailing forces the proximal segment into varus as the nail is inserted. Achieving a colinear starting point or slightly medial on the tip is critical to prevent this common malreduction.

Question 2032

Topic: 2. Trauma

Following a high-energy mechanism, a 35-year-old male sustains a pilon fracture. CT imaging (

) is obtained to evaluate the articular comminution. A large, displaced posterolateral articular fragment (Volkmann's fragment) is identified. Which ligamentous structure remains attached to this specific fragment?

. Anterior inferior tibiofibular ligament
. Posterior inferior tibiofibular ligament
. Deltoid ligament
. Interosseous membrane
. Calcaneofibular ligament

Correct Answer & Explanation

. Posterior inferior tibiofibular ligament

Explanation

The posterolateral articular fragment in a pilon or ankle fracture is known as the Volkmann fragment. The posterior inferior tibiofibular ligament (PITFL) securely attaches to this fragment, often causing it to avulse during injury.

Question 2033

Topic: 2. Trauma

A 40-year-old male sustains a transverse subtrochanteric femur fracture. What is the primary biomechanical advantage of utilizing a cephalomedullary nail compared to a laterally based fixed-angle locking plate for this injury?

. Increased construct stiffness in torsion
. Decreased implant bending moment due to a shorter lever arm
. Complete elimination of varus deforming forces
. Enhanced periosteal blood supply preservation via open techniques
. Ability to reliably lock the implant dynamically

Correct Answer & Explanation

. Decreased implant bending moment due to a shorter lever arm

Explanation

An intramedullary device is a load-sharing implant located closer to the mechanical axis of the femur. This creates a shorter lever arm from the hip joint center to the implant compared to a lateral plate, significantly decreasing the bending moment and risk of implant failure.

Question 2034

Topic: 2. Trauma

A 50-year-old male sustains a high-energy closed pilon fracture. Initial management consists of a spanning external fixator due to massive soft tissue swelling and fracture blisters. What is the most reliable clinical indicator that the soft tissue envelope has recovered sufficiently to proceed with definitive open reduction and internal fixation?

. Re-epithelialization of hemorrhagic blisters
. Normalization of serum ESR and CRP levels
. Appearance of skin wrinkles (the "wrinkle test")
. A 50% reduction in calf circumference based on tape measurement
. Clear drainage from the external fixator pin sites

Correct Answer & Explanation

. Appearance of skin wrinkles (the "wrinkle test")

Explanation

The return of skin wrinkles (a positive wrinkle test) is the most reliable clinical sign that edema has adequately subsided. Operating through maximally swollen tissues carries an unacceptably high risk of wound dehiscence and deep infection.

Question 2035

Topic: 2. Trauma

A 68-year-old male with a well-functioning posterior-stabilized TKA falls onto a flexed knee and sustains a highly comminuted patella fracture. Radiographs demonstrate displacement and a completely loose patellar component, but active straight leg raise confirms an intact extensor mechanism. According to the Ortiguera and Berry classification, what is the most appropriate management?

. Nonoperative management with cast immobilization in extension
. Open reduction and internal fixation with tension band wiring
. Removal of the loose component and retained fragments with patelloplasty
. Revision of the patellar component with bone grafting
. Total patellectomy and advancement of the quadriceps tendon

Correct Answer & Explanation

. Removal of the loose component and retained fragments with patelloplasty

Explanation

This is an Ortiguera and Berry Type II periprosthetic patella fracture (intact extensor mechanism, loose component). The recommended treatment is surgical excision of the loose component and bone fragments (patelloplasty) while preserving the extensor mechanism.

Question 2036

Topic: 2. Trauma

A 45-year-old male involved in a high-speed motor vehicle collision presents with a closed subtrochanteric femur fracture. During closed reduction and intramedullary nailing, the proximal fragment is found to be consistently flexed, abducted, and externally rotated. Which muscle is primarily responsible for the abduction deformity of the proximal fragment?

. Iliopsoas
. Gluteus medius
. Gluteus maximus
. Adductor longus
. Piriformis

Correct Answer & Explanation

. Iliopsoas

Explanation

In subtrochanteric femur fractures, the proximal fragment is typically abducted by the pull of the gluteus medius and minimus. It is flexed by the iliopsoas and externally rotated by the short external rotators.

Question 2037

Topic: 2. Trauma
A 38-year-old male falls from a ladder and sustains a severely comminuted closed tibial plafond fracture (Rรผedi-Allgรถwer Type III). On exam, the anterior ankle skin is tense, shiny, and demonstrates hemorrhagic fracture blisters. What is the most appropriate initial management for this patient?
. Immediate open reduction and internal fixation through an anterior approach
. Immediate minimally invasive plate osteosynthesis (MIPO)
. Joint-spanning external fixation and elevation
. Primary tibiotalar arthrodesis
. Cast immobilization for 6 weeks

Correct Answer & Explanation

. Joint-spanning external fixation and elevation

Explanation

High-energy pilon fractures with severe soft tissue compromise are initially managed with a joint-spanning external fixator. This allows soft tissue swelling to resolve and blisters to heal before definitive open reduction and internal fixation is attempted.

Question 2038

Topic: 2. Trauma

A 60-year-old male sustains a subtrochanteric femur fracture. The surgeon elects to use a trochanteric entry cephalomedullary nail.

What is the most common complication associated with an entry point that is too lateral on the greater trochanter during this procedure?

. Varus malalignment
. Valgus malalignment
. Anterior cortical perforation
. Iatrogenic femoral neck fracture
. Nonunion of the greater trochanter

Correct Answer & Explanation

. Varus malalignment

Explanation

A lateral starting point on the greater trochanter forces the rigid nail medially as it advances down the canal, pushing the proximal fragment into varus. To avoid this malreduction, the starting point should be slightly medial to the tip of the greater trochanter.

Question 2039

Topic: 2. Trauma

A 45-year-old male is undergoing definitive ORIF for a highly comminuted tibial pilon fracture using an anterolateral approach to the ankle.

Which nerve is at greatest risk of iatrogenic injury during the superficial dissection of the anterolateral approach to the distal tibia?

. Deep peroneal nerve
. Superficial peroneal nerve
. Sural nerve
. Saphenous nerve
. Tibial nerve

Correct Answer & Explanation

. Superficial peroneal nerve

Explanation

The superficial peroneal nerve courses from medial to lateral over the anterior aspect of the ankle and lies in the superficial subcutaneous tissues. It is at significant risk during the superficial dissection and mobilization for the anterolateral approach.

Question 2040

Topic: 2. Trauma

An 80-year-old female presents after a fall with a supracondylar femur fracture just proximal to a posterior-stabilized total knee arthroplasty. Radiographs indicate a displaced fracture with an intact, well-fixed femoral component. Based on the Rorabeck classification, which of the following is the most appropriate management?

. Revision to a rotating hinge knee prosthesis
. Retrograde intramedullary nailing or locking plate fixation
. Long leg cast for 6 weeks
. Distal femoral replacement
. Hinged knee brace with immediate weight-bearing

Correct Answer & Explanation

. Retrograde intramedullary nailing or locking plate fixation

Explanation

This is a Rorabeck Type II fracture, characterized by a displaced fracture with a well-fixed prosthesis. Standard treatment includes stable internal fixation using either a retrograde intramedullary nail or a laterally applied locking plate to permit early range of motion.

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