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2. Trauma MCQs

Practice Set 360 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 7181

Topic: 2. Trauma

A 13-year-old boy who recently underwent intramedullary nailing for a femur fracture via a piriformis fossa entry point presents for a follow-up 2 years later. What is the most likely complication associated with this specific entry point in a skeletally immature patient?

. Overgrowth of the femur
. Nonunion of the fracture
. Avascular necrosis of the femoral head
. Premature closure of the distal femoral physis
. Slipped capital femoral epiphysis

Correct Answer & Explanation

. Overgrowth of the femur

Explanation

Use of a piriformis fossa entry point for rigid intramedullary nailing in skeletally immature patients carries a significant risk of iatrogenic avascular necrosis of the femoral head. A lateral trochanteric entry is strongly preferred.

Question 7182

Topic: Pelvic & Acetabular Trauma

A 3-year-old girl is diagnosed with unilateral DDH. Closed reduction was unsuccessful. During an open reduction, an innominate osteotomy is planned to address acetabular dysplasia. Which of the following osteotomies hinges on the pubic symphysis to provide anterolateral coverage?

. Pemberton
. Dega
. Salter
. Chiari
. Shelf

Correct Answer & Explanation

. Pemberton

Explanation

The Salter innominate osteotomy involves a complete cut through the ilium and hinges on the pubic symphysis to redirect the acetabulum. This provides anterolateral coverage for the femoral head.

Question 7183

Topic: 2. Trauma

A 9-month-old infant is brought to the emergency department with a swollen and deformed left thigh. Radiographs reveal a spiral fracture of the femoral shaft. Assuming no other injuries, which of the following is the most appropriate initial orthopedic management?

. Flexible intramedullary nailing
. Rigid antegrade intramedullary nailing
. Pavlik harness application
. Spica casting
. Open reduction and internal fixation

Correct Answer & Explanation

. Flexible intramedullary nailing

Explanation

Spica casting is the standard of care for isolated femur fractures in children aged 6 months to 5 years. While child abuse must be ruled out, the orthopedic management of the fracture relies on cast immobilization.

Question 7184

Topic: 2. Trauma

A 6-year-old boy sustains an isolated diaphyseal femur fracture and is treated with flexible intramedullary nailing. To anticipate the most common complication related to leg length, how much overgrowth is typically expected after a femur fracture in this age group?

. 0.5 cm
. 1.0 to 2.0 cm
. 3.0 to 4.0 cm
. 5.0 cm
. No overgrowth is expected with surgical stabilization

Correct Answer & Explanation

. 0.5 cm

Explanation

In children aged 2 to 10 years, a femur fracture typically stimulates overgrowth of 1 to 2 cm due to hyperemia of the physes. Surgeons may intentionally leave the fractured limb slightly short to compensate.

Question 7185

Topic: 2. Trauma

A 6-year-old boy sustains a completely displaced midshaft femur fracture. If treated with a spica cast, what is the acceptable amount of shortening to aim for during reduction to account for expected overgrowth?

. No shortening is acceptable
. 1 to 1.5 cm
. 2 to 3 cm
. 3 to 4 cm
. 4 to 5 cm

Correct Answer & Explanation

. No shortening is acceptable

Explanation

In children aged 2 to 10 years, femur fractures often stimulate longitudinal overgrowth due to hyperemia. An initial shortening of 1 to 1.5 cm is accepted and expected to correct over time.

Question 7186

Topic: 2. Trauma

A 12-year-old boy sustains a transverse midshaft femur fracture. He is treated with a rigid intramedullary nail using a piriformis fossa starting point. Which of the following is the most devastating complication associated with this specific surgical technique in this age group?

. Nonunion
. Coxa vara
. Avascular necrosis of the femoral head
. Premature closure of the greater trochanteric apophysis
. Leg length discrepancy

Correct Answer & Explanation

. Nonunion

Explanation

Using a piriformis fossa entry point for rigid nailing in skeletally immature patients carries a high risk of iatrogenic avascular necrosis. This is due to injury to the ascending branches of the medial femoral circumflex artery.

Question 7187

Topic: 2. Trauma

A 9-month-old infant is brought to the pediatric emergency department with swelling and deformity of the left thigh. Radiographs demonstrate a spiral fracture of the femoral diaphysis. Which of the following factors in this patient's presentation is the strongest indicator of non-accidental trauma (child abuse)?

. The spiral fracture pattern
. Involvement of the femoral diaphysis
. The patient's age and ambulatory status
. Absence of an associated tibia fracture
. Presence of an overlying skin abrasion

Correct Answer & Explanation

. The spiral fracture pattern

Explanation

Femur fractures in non-ambulatory infants (typically under 1 year of age) have a high association with non-accidental trauma (up to 80%). While spiral fractures were historically deemed suspicious, recent studies show age and ambulatory capability are the most reliable indicators of abuse.

Question 7188

Topic: 2. Trauma

A 3-year-old boy sustains an isolated, closed midshaft femur fracture with 2 cm of shortening after falling from a playground structure. His neurovascular exam is intact. What is the most appropriate definitive management for this patient?

. Pavlik harness application
. Early hip spica casting
. Flexible intramedullary nailing
. Submuscular bridge plating
. Rigid antegrade intramedullary nailing

Correct Answer & Explanation

. Pavlik harness application

Explanation

For children aged 6 months to 5 years with an isolated femur fracture and acceptable shortening (<2-3 cm), early hip spica casting is the gold standard treatment. Operative interventions like flexible nailing are generally reserved for children older than 5 years.

Question 7189

Topic: 2. Trauma

An 8-year-old boy, weighing 35 kg, underwent flexible intramedullary nailing for a transverse midshaft femur fracture 6 months ago. The fracture has healed well radiographically, but he now complains of knee pain and a slight limp. What is the most common complication of this procedure causing his current symptoms?

. Avascular necrosis of the femoral head
. Nonunion of the fracture site
. Symptomatic prominent hardware at the distal insertion site
. Premature closure of the distal femoral physis
. Deep surgical site infection

Correct Answer & Explanation

. Avascular necrosis of the femoral head

Explanation

The most common complication following titanium elastic nailing for pediatric femur fractures is symptomatic hardware prominence at the distal insertion site, leading to soft tissue irritation and knee pain. This typically resolves after implant removal once the fracture is fully healed.

Question 7190

Topic: 2. Trauma

An 11-year-old boy weighing 65 kg (143 lbs) sustains a length-unstable, comminuted midshaft femur fracture. He is planned for rigid intramedullary nailing. To minimize the risk of iatrogenic avascular necrosis (AVN) of the femoral head, which entry point is strictly recommended in this pediatric age group?

. Piriformis fossa
. Greater trochanter (lateral entry)
. Medial femoral epicondyle
. Lesser trochanter
. Femoral neck base

Correct Answer & Explanation

. Piriformis fossa

Explanation

Piriformis fossa entry in children carries a significant risk of injuring the medial circumflex femoral artery anastomosis, leading to AVN of the femoral head. A lateral greater trochanteric entry point avoids this blood supply and is the standard for rigid nailing in older children.

Question 7191

Topic: 2. Trauma

A 4-year-old boy sustains an isolated, closed midshaft femur fracture and is treated with immediate spica casting. To appropriately account for anticipated post-traumatic limb overgrowth, what is the ideal amount of initial fracture shortening accepted in the cast?

. 0 mm (anatomic reduction)
. 5 to 10 mm
. 15 to 20 mm
. 25 to 30 mm
. Greater than 30 mm

Correct Answer & Explanation

. 0 mm (anatomic reduction)

Explanation

In children aged 2 to 10 years, femoral shaft fractures often stimulate physeal overgrowth. Accepting 15 to 20 mm (1.5 to 2 cm) of initial shortening in the spica cast helps prevent ultimate leg length discrepancy.

Question 7192

Topic: 2. Trauma

A 12-year-old male who weighs 65 kg (143 lbs) presents with a length-unstable, comminuted midshaft femur fracture. His greater trochanteric physis remains open. To minimize the risk of avascular necrosis of the femoral head while providing stable fixation, what is the preferred starting point if a rigid intramedullary nail is selected?

. Piriformis fossa
. Lateral aspect of the greater trochanter
. Intertrochanteric line
. Medial to the piriformis fossa
. Distal femoral metaphysis

Correct Answer & Explanation

. Piriformis fossa

Explanation

In adolescents with open physes, a rigid lateral entry nail utilizing the lateral aspect of the greater trochanter avoids the medial femoral circumflex artery's ascending branch. This effectively minimizes the risk of iatrogenic avascular necrosis compared to piriformis fossa entry.

Question 7193

Topic: 2. Trauma

A 5-year-old boy presents with a lateral condyle fracture of the distal humerus that was treated with a long-arm cast at an outside facility 4 weeks ago. Radiographs now demonstrate 4 mm of displacement of the fracture fragment and no evidence of callus formation. What is the most appropriate next step in management?

. Continued cast immobilization for an additional 4 weeks
. Closed reduction and percutaneous pinning
. Open reduction and internal fixation
. Excision of the lateral condyle fragment
. Physical therapy to regain elbow range of motion

Correct Answer & Explanation

. Continued cast immobilization for an additional 4 weeks

Explanation

Lateral condyle fractures with displacement greater than 2 mm or those that displace secondarily in a cast require operative intervention. Because this injury involves the articular surface and the physis, and has poor healing potential due to the pull of the extensor origin and bathing in synovial fluid, delayed presentation with >2 mm of displacement should be treated with open reduction and internal fixation (ORIF) to prevent nonunion, progressive cubitus valgus, and subsequent tardy ulnar nerve palsy.

Question 7194

Topic: 2. Trauma

A 10-year-old boy presents to the emergency department after sustaining a minor twisting injury to his right arm while throwing a baseball. Radiographs reveal a minimally displaced pathologic fracture through a centrally located, completely radiolucent lesion in the proximal humerus metaphysis. The lesion demonstrates a 'fallen leaf' sign. What is the most appropriate initial management?

. Immediate curettage and bone grafting
. Immobilization in a sling to allow the fracture to heal
. Intralesional injection of methylprednisolone
. Flexible intramedullary nailing
. En bloc resection

Correct Answer & Explanation

. Immediate curettage and bone grafting

Explanation

The clinical presentation and radiographic finding of a 'fallen leaf' sign (a fragment of cortical bone sitting at the dependent portion of a cystic lesion) are pathognomonic for a unicameral bone cyst (UBC). When a UBC presents with a pathologic fracture, the initial management is conservative immobilization (e.g., a sling) to allow the fracture to heal. In many cases, the cyst may undergo partial or complete spontaneous healing during fracture consolidation. If the cyst persists and is large enough to pose a risk of recurrent fracture, elective interventions such as injections or curettage/grafting can be considered later.

Question 7195

Topic: 2. Trauma

A 3-year-old boy presents to the emergency department after falling off a slide. He has a closed, isolated midshaft femur fracture with 1.5 cm of shortening. He is normally developing and has no other injuries. What is the most appropriate definitive management for this patient?

. Submuscular plating
. External fixation
. Pavlik harness
. Immediate hip spica casting
. Flexible intramedullary nailing

Correct Answer & Explanation

. Submuscular plating

Explanation

For children aged 6 months to 5 years with isolated, closed femur fractures with acceptable shortening (typically <2 cm), early hip spica casting is the standard of care. Flexible intramedullary nailing is typically reserved for children older than 5 years (or heavier than 50 lbs), while the Pavlik harness is indicated for infants under 6 months of age. Submuscular plating and external fixation are generally reserved for older patients, polytrauma, open fractures, or unstable fracture patterns where length cannot be maintained.

Question 7196

Topic: 2. Trauma

A 3-year-old child sustains a closed, isolated midshaft femur fracture with 2 cm of shortening after falling from a playground slide. Which of the following is the most appropriate definitive management?

. Immediate spica cast application
. Flexible intramedullary nailing
. Rigid locked intramedullary nailing
. Open reduction and internal fixation with a compression plate
. External fixation

Correct Answer & Explanation

. Immediate spica cast application

Explanation

The standard of care for an isolated, closed midshaft femur fracture in a 3-year-old child with acceptable shortening (less than 2 cm) is early spica casting. Surgical management, such as flexible intramedullary nailing, is typically reserved for children aged 5 to 11 years or in cases of polytrauma, open fractures, or inability to achieve or maintain acceptable alignment in a cast. Immediate spica cast application in young children yields excellent clinical and radiographic outcomes with minimal complications.

Question 7197

Topic: 2. Trauma

A 9-year-old boy presents to the emergency department after a minor fall with right arm pain. Radiographs reveal a centrally located, lucent metaphyseal lesion in the proximal humerus with a nondisplaced pathologic fracture. A 'fallen leaf' sign is noted within the lesion.

What is the most appropriate initial management?

. Immediate curettage and autologous bone grafting
. Immobilization in a sling followed by observation to allow the fracture to heal
. Intralesional methylprednisolone injection immediately in the emergency department
. Prophylactic flexible intramedullary nailing
. Wide excision and structural allograft reconstruction

Correct Answer & Explanation

. Immediate curettage and autologous bone grafting

Explanation

The clinical and radiographic presentation is classic for a unicameral bone cyst (UBC) complicated by a pathologic fracture. The 'fallen leaf' (or 'fallen fragment') sign is pathognomonic for a UBC. When a UBC presents with a nondisplaced fracture, the initial treatment is immobilization to allow the fracture to heal. Up to 15-20% of UBCs may go on to spontaneous resolution after a fracture. Surgical intervention or injections are typically reserved for cysts that fail to resolve and pose a persistent risk of re-fracture after the initial fracture has healed.

Question 7198

Topic: 2. Trauma

A 5-year-old girl falls onto an outstretched hand and complains of elbow pain. Radiographs demonstrate a lateral condyle fracture of the distal humerus.

The fracture fragment is displaced by 4 millimeters. What is the most appropriate definitive management?

. Long-arm cast immobilization in 90 degrees of flexion and forearm supination
. Closed reduction and percutaneous pinning without joint visualization
. Open reduction and internal fixation to restore the articular surface
. Excision of the displaced lateral condyle fragment
. Observation in a sling for 3 weeks

Correct Answer & Explanation

. Long-arm cast immobilization in 90 degrees of flexion and forearm supination

Explanation

Lateral condyle fractures of the humerus are intra-articular injuries. Displacement of greater than 2 mm is an indication for open reduction and internal fixation (ORIF) to anatomically restore the joint surface and prevent complications such as nonunion, malunion, cubitus valgus, and tardy ulnar nerve palsy. Closed reduction is often inadequate because the fracture fragment is subjected to the deforming pull of the common extensor origin.

Question 7199

Topic: 2. Trauma

An 8-year-old boy weighing 35 kg sustains a closed, length-stable, transverse midshaft fracture of the femur. His neurovascular examination is intact. What is the most appropriate definitive management?

. Pavlik harness
. Early spica casting
. Titanium elastic nailing (TENs)
. Rigid locked intramedullary nailing through the piriformis fossa
. Open reduction and plate osteosynthesis

Correct Answer & Explanation

. Pavlik harness

Explanation

For pediatric length-stable midshaft femur fractures in children aged 5 to 11 years (typically weighing less than 50 kg), flexible intramedullary nailing (e.g., Titanium Elastic Nails, or TENs) is the standard of care. It provides excellent alignment, allows early mobilization, and avoids the complications of prolonged immobilization. Early spica casting is generally reserved for children under 5 years of age. Rigid nailing through the piriformis fossa is contraindicated in this age group due to the high risk of iatrogenic avascular necrosis of the femoral head.

Question 7200

Topic: 2. Trauma
A 32-year-old man sustains a highly displaced, Pauwels type III femoral neck fracture in a motor vehicle collision. Which of the following fixation constructs provides the greatest biomechanical stability against vertical shear forces for this fracture pattern?
. Three parallel partially threaded cannulated screws
. Dynamic hip screw (sliding hip screw) with a derotational cannulated screw
. Two parallel fully threaded cannulated screws
. Proximal femoral locking plate
. Long cephalomedullary nail

Correct Answer & Explanation

. Dynamic hip screw (sliding hip screw) with a derotational cannulated screw

Explanation

Pauwels type III fractures have a highly vertical orientation, subjecting them to massive shear forces. A dynamic hip screw with a derotational screw provides superior biomechanical stability compared to multiple cannulated screws by converting shear forces into compressive forces.

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