Menu

2. Trauma MCQs

Practice Set 334 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 6661

Topic: Pelvic & Acetabular Trauma

A 4-year-old girl requires a pelvic osteotomy for residual acetabular dysplasia following prior closed reduction. The planned procedure aims to change the acetabular volume by hinging through the flexible triradiate cartilage. Which osteotomy fits this description?

. Salter osteotomy
. Pemberton osteotomy
. Steel triple osteotomy
. Chiari osteotomy
. Ganz periacetabular osteotomy

Correct Answer & Explanation

. Pemberton osteotomy

Explanation

The Pemberton osteotomy is an incomplete, pericapsular osteotomy that hinges on the triradiate cartilage, reducing acetabular volume and improving anterolateral coverage. In contrast, the Salter osteotomy is a complete innominate osteotomy that hinges at the pubic symphysis.

Question 6662

Topic: Pelvic & Acetabular Trauma

A 5-year-old girl with an untreated developmental dysplasia of the left hip requires an open reduction and pelvic osteotomy. The surgeon plans a redirectional osteotomy that hinges at the pubic symphysis to improve anterolateral coverage. Which of the following osteotomies is being described?

. Pemberton osteotomy
. Dega osteotomy
. Salter osteotomy
. Chiari osteotomy
. Shelf osteotomy

Correct Answer & Explanation

. Salter osteotomy

Explanation

The Salter innominate osteotomy is a redirectional osteotomy that hinges at the pubic symphysis, primarily providing anterior and lateral coverage. The Pemberton and Dega are incomplete, reshaping osteotomies that hinge at the flexible triradiate cartilage.

Question 6663

Topic: 2. Trauma

An 11-year-old boy sustains a transverse diaphyseal femur fracture. The surgeon elects to proceed with rigid intramedullary nailing. To minimize the risk of iatrogenic avascular necrosis (AVN) of the femoral head, which entry point is most appropriate?

. Piriformis fossa
. Medial to the piriformis fossa
. Tip of the greater trochanter
. Intertrochanteric notch
. Anterior femoral neck

Correct Answer & Explanation

. Tip of the greater trochanter

Explanation

In pediatric patients with open physes, a trochanteric entry point (specifically the lateral edge or tip of the greater trochanter) is preferred for rigid nailing. Utilizing the piriformis fossa disrupts the medial circumflex femoral artery anastomosis, significantly increasing the risk of AVN.

Question 6664

Topic: 2. Trauma

A 3-year-old child sustains an isolated spiral fracture of the femoral shaft and is managed with a hip spica cast. During reduction, how much initial fracture shortening is most appropriate to accept to compensate for anticipated overgrowth?

. 0 mm (anatomic length)
. 15 mm
. 30 mm
. 45 mm
. 60 mm

Correct Answer & Explanation

. 15 mm

Explanation

In children aged 2 to 10 years, femoral fractures typically stimulate a hyperemic response leading to 1 to 2 cm of overgrowth. Therefore, accepting 10 to 15 mm of bayonet apposition (shortening) during casting is optimal to prevent long-term leg length discrepancy.

Question 6665

Topic: 2. Trauma

An 8-year-old boy is treated with titanium elastic nails for a midshaft transverse femur fracture.

What is the most commonly reported complication associated with this specific surgical intervention?

. Nonunion
. Avascular necrosis of the femoral head
. Symptomatic hardware at the insertion site
. Leg length discrepancy greater than 2 cm
. Deep surgical site infection

Correct Answer & Explanation

. Symptomatic hardware at the insertion site

Explanation

Insertion site pain or skin irritation from prominent nail ends at the distal femur is the most common complication of flexible intramedullary nailing in pediatric femur fractures. It often necessitates premature or planned hardware removal.

Question 6666

Topic: Pelvic & Acetabular Trauma

A 4-year-old girl with residual DDH requires an open reduction and pelvic osteotomy. The surgeon plans a Salter innominate osteotomy. This osteotomy relies on a hinge at which of the following structures to provide anterolateral coverage?

. Triradiate cartilage
. Sacroiliac joint
. Pubic symphysis
. Ischial spine
. Obturator foramen

Correct Answer & Explanation

. Pubic symphysis

Explanation

The Salter osteotomy is a complete, redirectional transiliac osteotomy that redirects the entire acetabulum to improve anterolateral coverage. It hinges symmetrically on the pubic symphysis to achieve its corrective rotation.

Question 6667

Topic: 2. Trauma

A 6-year-old girl sustains a closed, completely displaced subtrochanteric femur fracture.

What is the most appropriate fixation strategy to minimize complications while facilitating early mobilization?

. Spica casting in the 90-90 position
. Titanium elastic nails
. Rigid antegrade locked intramedullary nail
. Open or submuscular plating
. External fixation

Correct Answer & Explanation

. Open or submuscular plating

Explanation

Submuscular or open plating is preferred for pediatric subtrochanteric fractures. Elastic nails have a high rate of failure, malunion, and varus collapse in the subtrochanteric region due to poor biomechanical control, and rigid nails carry AVN risk in young children.

Question 6668

Topic: 2. Trauma

A 10-year-old boy weighing 55 kg (121 lbs) sustains a length-unstable, comminuted midshaft femur fracture. Which of the following surgical options is most appropriate?

. Retrograde elastic stable intramedullary nailing (ESIN)
. Antegrade trochanteric entry rigid intramedullary nail
. Submuscular bridge plating
. External fixation
. Piriformis entry rigid intramedullary nail

Correct Answer & Explanation

. Submuscular bridge plating

Explanation

Submuscular plating is ideal for length-unstable femur fractures in children weighing over 50 kg. ESIN in children over 50 kg is associated with unacceptable rates of loss of reduction and malunion.

Question 6669

Topic: 2. Trauma

A 3-year-old child sustains a closed midshaft femur fracture and is treated with a one-and-a-half spica cast. What is the maximum acceptable amount of fracture overriding to anticipate the overgrowth phenomenon?

. 0 cm (anatomic reduction is required)
. 1.5 cm
. 3.0 cm
. 4.5 cm
. 6.0 cm

Correct Answer & Explanation

. 1.5 cm

Explanation

In children aged 2 to 10 years, femoral shaft fractures typically stimulate a hyperemic response causing 1 to 2 cm of overgrowth. Accepting 1.5 cm of overriding in a cast prevents a clinically significant leg length discrepancy.

Question 6670

Topic: 2. Trauma

An 11-year-old boy requires rigid intramedullary nailing for a transverse femur fracture. To minimize the risk of iatrogenic avascular necrosis (AVN), what is the optimal entry point?

. Piriformis fossa
. Tip of the greater trochanter
. Lesser trochanter
. Intertrochanteric line
. Medial femoral condyle

Correct Answer & Explanation

. Tip of the greater trochanter

Explanation

In pediatric and adolescent patients, a piriformis entry portal risks damaging the medial circumflex femoral artery, leading to AVN. A trochanteric entry (tip or lateral to it) minimizes this risk.

Question 6671

Topic: 2. Trauma

A 2-year-old child is placed in a 90/90 spica cast for a midshaft femur fracture. This specific positioning (90 degrees hip flexion, 90 degrees knee flexion) is primarily chosen to control which of the following?

. Axial shortening
. Varus angulation
. Valgus angulation
. Rotational alignment
. Knee stiffness

Correct Answer & Explanation

. Rotational alignment

Explanation

The 90/90 spica cast position effectively controls rotational alignment of the femur. It also helps lock the pelvis to prevent the child from sliding distally within the cast, maintaining overall fracture reduction.

Question 6672

Topic: 2. Trauma

A 6-year-old boy sustains a midshaft femur fracture and is treated with flexible intramedullary nails. Which of the following is the most common complication associated with this treatment modality?

. Nonunion
. Nail prominence at the insertion site causing soft-tissue irritation
. Deep infection requiring hardware removal
. Avascular necrosis of the femoral head
. Malunion requiring corrective osteotomy

Correct Answer & Explanation

. Nail prominence at the insertion site causing soft-tissue irritation

Explanation

The most common complication of flexible intramedullary nailing for pediatric femur fractures is soft-tissue irritation at the insertion site, occurring in up to 15% of cases. Avascular necrosis is rare unless a rigid antegrade nail with a piriformis entry is improperly used in a child.

Question 6673

Topic: 2. Trauma

A 9-month-old boy presents with a spiral fracture of the femoral shaft. He is not yet walking independently. What is the most appropriate next step in management?

. Immediate spica casting and discharge to home
. Flexible intramedullary nailing
. Skeletal survey and child protective services consultation
. Pavlik harness application
. Open reduction and plate osteosynthesis

Correct Answer & Explanation

. Skeletal survey and child protective services consultation

Explanation

A femur fracture in a non-ambulatory infant is highly suspicious for non-accidental trauma (child abuse). A full skeletal survey and mandatory reporting to child protective services must be initiated before or concurrently with definitive orthopedic management.

Question 6674

Topic: Pelvic & Acetabular Trauma

When evaluating a 4-week-old infant's hip using Graf's ultrasound method, an alpha angle of 45 degrees is noted. What does this angle primarily measure?

. Cartilaginous roof coverage
. Bony roof acetabular depth
. Femoral head sphericity
. Labral version
. Capsular laxity

Correct Answer & Explanation

. Cartilaginous roof coverage

Explanation

The alpha angle reflects the bony concavity (roof) of the acetabulum, with a normal angle being greater than 60 degrees. An alpha angle of 45 degrees indicates significant bony dysplasia. The beta angle measures the cartilaginous roof coverage.

Question 6675

Topic: 2. Trauma

A 13-year-old boy weighing 65 kg sustains a length-unstable transverse femoral shaft fracture. If a rigid locked intramedullary nail is selected, which entry point minimizes the risk of iatrogenic avascular necrosis?

. Piriformis fossa
. Lateral aspect of the greater trochanter
. Medial femoral condyle
. Lesser trochanter
. Intertrochanteric line

Correct Answer & Explanation

. Lateral aspect of the greater trochanter

Explanation

To avoid iatrogenic avascular necrosis from damage to the medial circumflex femoral artery branches, rigid nailing in adolescents should use a lateral trochanteric entry point. A piriformis fossa entry is strictly contraindicated in skeletally immature patients.

Question 6676

Topic: Pelvic & Acetabular Trauma

A 4-year-old girl with untreated DDH is scheduled for open reduction and an innominate osteotomy. The planned procedure involves a complete transiliac osteotomy that redirects the entire acetabulum by hinging on the pubic symphysis. Which osteotomy is being described?

. Pemberton osteotomy
. Dega osteotomy
. Salter osteotomy
. Chiari osteotomy
. Shelf procedure

Correct Answer & Explanation

. Salter osteotomy

Explanation

The Salter osteotomy is a complete transiliac osteotomy that redirects the acetabulum to improve anterolateral coverage, hinging at the pubic symphysis. Pemberton and Dega are incomplete osteotomies that hinge on the triradiate cartilage.

Question 6677

Topic: 2. Trauma

A 3-year-old boy is treated in a 90-90 hip spica cast for a femoral shaft fracture. He presents 2 weeks later with excessive crying, bilious vomiting, and food refusal. What is the most likely diagnosis?

. Compartment syndrome of the thigh
. Superior mesenteric artery (SMA) syndrome
. Avascular necrosis of the hip
. Slipped capital femoral epiphysis
. Deep vein thrombosis

Correct Answer & Explanation

. Superior mesenteric artery (SMA) syndrome

Explanation

SMA syndrome (cast syndrome) occurs when the third portion of the duodenum is compressed by the SMA, often precipitated by body casts or rapid weight loss. Symptoms include severe abdominal pain, vomiting, and food refusal, requiring cast univalving or bi-valving.

Question 6678

Topic: 2. Trauma

A 7-year-old child weighing 45 kg sustains a highly comminuted, length-unstable femur fracture. What is the most appropriate fixation method to maintain length and alignment?

. Flexible intramedullary nailing
. Immediate hip spica casting
. Submuscular bridge plating
. Open reduction and dynamic compression plating
. Antegrade piriformis entry rigid nail

Correct Answer & Explanation

. Submuscular bridge plating

Explanation

For length-unstable, comminuted femur fractures in heavier school-aged children, submuscular bridge plating provides excellent stability and maintains length while preserving the fracture hematoma. Flexible nails are relatively contraindicated here due to a high risk of unacceptable shortening.

Question 6679

Topic: 2. Trauma

A 4-year-old boy undergoes application of a hip spica cast for a transverse midshaft femur fracture. The surgeon intentionally positions the fracture with 1.5 cm of overlap. What is the primary rationale for this?

. To promote secondary bone healing
. To counteract post-traumatic overgrowth
. To prevent atrophic nonunion
. To avoid superior mesenteric artery syndrome
. To intentionally create a leg length discrepancy

Correct Answer & Explanation

. To counteract post-traumatic overgrowth

Explanation

In children aged 2 to 10 years, a femur fracture stimulates longitudinal overgrowth (averaging 1-2 cm) due to fracture hyperemia. Bayonet apposition with 1-1.5 cm of overlap is intentionally accepted to compensate for this expected overgrowth.

Question 6680

Topic: 2. Trauma

A 12-year-old boy weighing 55 kg (121 lbs) sustains a midshaft femur fracture. The plan is to proceed with antegrade rigid intramedullary nailing. Which entry point is recommended to minimize the risk of iatrogenic avascular necrosis (AVN) of the femoral head?

. Piriformis fossa
. Tip of the greater trochanter
. Lateral to the tip of the greater trochanter
. Medial to the piriformis fossa
. Intertrochanteric line

Correct Answer & Explanation

. Lateral to the tip of the greater trochanter

Explanation

In pediatric patients, using a piriformis fossa entry point risks damaging the medial circumflex femoral artery, leading to AVN. A lateral entry point to the tip of the greater trochanter is recommended to avoid the retinacular vessels and minimize this devastating complication.

Test Yourself

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

On this Page