Menu

Pediatric Hip MCQs

Practice Set 58 of 104

This practice set contains high-yield board review questions covering key concepts in Pediatric Hip. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.

Question 1141

Topic: Pediatric Hip

An 8-year-old boy with Legg-Calve-Perthes disease presents with hip pain and a limp. Radiographs reveal greater than 50% maintenance of the lateral pillar height (Herring B). According to the Herring lateral pillar classification, what is the most appropriate management?

. Symptomatic management and observation only
. Pelvic or femoral osteotomy for surgical containment
. Core decompression of the femoral head
. Epiphysiodesis of the greater trochanter
. Application of an A-frame abduction orthosis

Correct Answer & Explanation

. Pelvic or femoral osteotomy for surgical containment

Explanation

For patients 8 years and older with Herring group B or B/C border Perthes disease, surgical containment (pelvic or femoral osteotomy) is indicated. This approach yields better radiographic and clinical outcomes compared to nonoperative treatment in this older age group.

Question 1142

Topic: Pediatric Hip

A 13-year-old obese male presents with acute-on-chronic left groin pain after a minor fall. He is completely unable to bear weight on the affected extremity. Radiographs reveal a slipped capital femoral epiphysis (SCFE). Compared to a patient who is able to bear weight, this patient is at the highest risk for developing which of the following complications?

. Chondrolysis
. Avascular necrosis
. Femoroacetabular impingement
. Slipped capital femoral epiphysis of the contralateral hip
. Premature physeal closure

Correct Answer & Explanation

. Avascular necrosis

Explanation

This patient has an unstable SCFE, clinically defined by the inability to bear weight even with crutches. Unstable SCFE has a substantially higher risk of avascular necrosis (up to 47%) compared to stable SCFE.

Question 1143

Topic: Pediatric Hip

A 4-month-old female infant is undergoing treatment with a Pavlik harness for developmental dysplasia of the hip (DDH). After 3 weeks of strict full-time wear, an ultrasound reveals that the hip remains dislocated. What is the most appropriate next step in management?

. Continue the Pavlik harness for an additional 3 weeks
. Transition to a rigid abduction orthosis
. Perform an immediate open reduction
. Perform a varus derotational osteotomy
. Wait until skeletal maturity for surgical reconstruction

Correct Answer & Explanation

. Transition to a rigid abduction orthosis

Explanation

Failure to achieve reduction in a Pavlik harness after 3 to 4 weeks necessitates abandoning the harness to prevent 'Pavlik disease' (posterior acetabular wear). The next appropriate step is typically a trial of a rigid abduction orthosis or proceeding to closed reduction with spica casting.

Question 1144

Topic: Pediatric Hip

An 8-year-old boy is diagnosed with Legg-Calve-Perthes disease. Radiographs show greater than 50% collapse of the lateral pillar. According to the Herring lateral pillar classification, what is his prognosis and recommended treatment?

. Pillar A, excellent prognosis, observation only
. Pillar B, fair prognosis, symptomatic treatment
. Pillar C, poor prognosis, surgical containment
. Pillar C, poor prognosis, immediate total hip arthroplasty
. Pillar B/C border, good prognosis, abduction bracing

Correct Answer & Explanation

. Pillar C, poor prognosis, surgical containment

Explanation

This patient has Lateral Pillar C disease (>50% collapse). Children older than 8 years at the time of onset with Pillar B/C or C involvement have a poorer prognosis and generally benefit from surgical containment (femoral or pelvic osteotomy).

Question 1145

Topic: Pediatric Hip

An 18-month-old girl presents with a painless limp and a positive Trendelenburg sign. Pelvic radiographs show a unilaterally dislocated left hip with an acetabular index of 40 degrees. What is the most appropriate management?

. Pavlik harness trial
. Rigid hip abduction orthosis
. Closed reduction and spica cast
. Open reduction and spica cast with possible pelvic osteotomy
. Observation until skeletal maturity

Correct Answer & Explanation

. Open reduction and spica cast with possible pelvic osteotomy

Explanation

In a child older than 18 months presenting with DDH and significant dysplasia (acetabular index >30-35), closed reduction has a high failure and AVN rate. Open reduction, often combined with a pelvic osteotomy (e.g., Salter or Pemberton) and capsulorrhaphy, is typically required.

Question 1146

Topic: Pediatric Hip

A 5-month-old girl has been treated with a Pavlik harness for an initially irreducible, dislocated right hip for 4 weeks. Repeat ultrasound shows the hip remains persistently dislocated. What is the next best step in management?

. Continue Pavlik harness for 2 more weeks
. Transition to a rigid abduction orthosis (e.g., Rhino cruiser)
. Closed reduction and spica casting
. Immediate open reduction
. Observation until skeletal maturity

Correct Answer & Explanation

. Closed reduction and spica casting

Explanation

Continued use of a Pavlik harness for a dislocated hip after 3-4 weeks without successful reduction leads to 'Pavlik harness disease', which causes posterior wear of the acetabulum. Transitioning to a rigid orthosis is indicated for residual dysplasia but not for a dislocated hip, which requires closed (or open) reduction and spica casting.

Question 1147

Topic: Pediatric Hip

A 12-year-old obese boy presents with right thigh pain and inability to bear weight after a minor trip 2 days ago. Radiographs reveal a severe, unstable right slipped capital femoral epiphysis (SCFE). During management, what is the most significant clinical risk associated with this specific type of injury?

. Chondrolysis
. Avascular necrosis of the femoral head
. Femoroacetabular impingement
. Premature hip osteoarthritis
. Nonunion of the proximal femoral physis

Correct Answer & Explanation

. Avascular necrosis of the femoral head

Explanation

Unstable SCFE is defined by the inability to bear weight even with crutches and carries a high risk of avascular necrosis (AVN), ranging from 10-50%. Prompt, gentle reduction and stabilization are crucial to minimize capsular tension and preserve the tenuous blood supply.

Question 1148

Topic: Pediatric Hip
A 7-year-old boy presents with a painless limp of 3 months duration. Radiographs show fragmentation of the capital femoral epiphysis consistent with Legg-Calvé-Perthes disease. According to the Herring lateral pillar classification, which radiographic feature is most predictive of the final functional outcome?
. Extent of the subchondral fracture (Crescent sign)
. Degree of metaphyseal cysts
. Height of the lateral portion of the capital femoral epiphysis
. Amount of epiphyseal extrusion
. Premature closure of the capital femoral physis

Correct Answer & Explanation

. Height of the lateral portion of the capital femoral epiphysis

Explanation

The Herring lateral pillar classification divides the femoral head into three pillars. The height of the lateral pillar on an AP radiograph during the fragmentation stage is the most reliable prognostic indicator for long-term outcome in Legg-Calvé-Perthes disease.

Question 1149

Topic: Pediatric Hip

A 13-year-old boy undergoes in-situ percutaneous pinning of a stable slipped capital femoral epiphysis (SCFE) on the left side. Which of the following is considered an absolute indication for prophylactic pinning of the asymptomatic contralateral right hip?

. Patient age > 14 years at presentation
. Presence of an underlying endocrine disorder (e.g., hypothyroidism)
. Severe obesity (BMI > 99th percentile)
. Male gender
. Severe slip angle (> 60 degrees) on the symptomatic left side

Correct Answer & Explanation

. Presence of an underlying endocrine disorder (e.g., hypothyroidism)

Explanation

Prophylactic pinning of the contralateral hip in SCFE is strongly recommended for patients with an underlying endocrine disorder (such as hypothyroidism or renal osteodystrophy) or a history of radiation therapy, as their risk of eventual bilateral involvement approaches 100%.

Question 1150

Topic: Pediatric Hip

A 3-month-old female is being treated with a Pavlik harness for Developmental Dysplasia of the Hip (DDH). At her 2-week follow-up, she is noted to have decreased active knee extension on the affected side. What is the most appropriate next step in management?

. Continue the harness and observe
. Stop the harness temporarily and observe for neurologic recovery
. Loosen the posterior straps of the harness
. Perform a closed reduction and spica casting
. Switch to a rigid abduction orthosis

Correct Answer & Explanation

. Stop the harness temporarily and observe for neurologic recovery

Explanation

Decreased active knee extension in a Pavlik harness indicates femoral nerve palsy due to excessive hyperflexion. The harness must be discontinued temporarily until neurologic function returns to prevent permanent damage.

Question 1151

Topic: Pediatric Hip

A 12-year-old obese boy presents with left thigh pain and a limp. Radiographs confirm a stable left slipped capital femoral epiphysis (SCFE). Which of the following is an absolute indication for prophylactic pinning of the contralateral right hip?

. Patient age younger than 10 years
. Presence of an endocrine disorder such as hypothyroidism
. Body Mass Index > 35
. Closure of the triradiate cartilage
. Presentation with a stable slip

Correct Answer & Explanation

. Presence of an endocrine disorder such as hypothyroidism

Explanation

Prophylactic pinning of the contralateral hip is strongly recommended in patients with endocrine or metabolic disorders, as well as in patients presenting prior to age 10 or those undergoing radiation therapy. Obesity is a risk factor but not an absolute indication.

Question 1152

Topic: Pediatric Hip
In the evaluation of a 7-year-old boy with Legg-Calvé-Perthes disease, which of the following is the most significant prognostic radiographic factor according to the Herring classification?
. Extent of medial metaphyseal cysts
. Presence of the Gage sign
. Height of the lateral pillar of the capital femoral epiphysis
. Subchondral radiolucency (crescent sign)
. Degree of coxa magna

Correct Answer & Explanation

. Height of the lateral pillar of the capital femoral epiphysis

Explanation

The Herring (lateral pillar) classification assesses the height of the lateral aspect of the capital femoral epiphysis during the fragmentation phase. It is widely considered the most reliable prognostic indicator for long-term hip outcome in Legg-Calvé-Perthes disease.

Question 1153

Topic: Pediatric Hip

A 13-year-old boy undergoes in-situ percutaneous pinning for an unstable slipped capital femoral epiphysis (SCFE). At 6 months post-op, he develops severe hip stiffness, pain, and joint space narrowing on radiographs. The hardware does not penetrate the joint. What is the most likely diagnosis?

. Avascular necrosis (AVN)
. Chondrolysis
. Septic arthritis
. Hardware failure
. Unrecognized contralateral SCFE

Correct Answer & Explanation

. Chondrolysis

Explanation

Chondrolysis is a devastating complication of SCFE, characterized by acute loss of articular cartilage, joint space narrowing, and severe stiffness. It can occur idiopathically, especially in severe or unstable slips, even without hardware penetration.

Question 1154

Topic: Pediatric Hip

A 12-year-old obese boy presents with acute onset of right hip pain and inability to bear weight after tripping. Radiographs confirm a slipped capital femoral epiphysis (SCFE). He is completely unable to ambulate even with crutches. What is the most common severe complication directly associated with the unstable nature of this specific diagnosis?

. Chondrolysis
. Avascular necrosis of the femoral head
. Septic arthritis
. Femoral neck nonunion
. Early-onset osteoarthritis

Correct Answer & Explanation

. Avascular necrosis of the femoral head

Explanation

This patient has an unstable SCFE, defined clinically by the inability to bear weight even with crutches. Unstable SCFE carries a significantly higher risk of avascular necrosis (AVN) compared to stable SCFE, with rates historically reported up to 50%.

Question 1155

Topic: Pediatric Hip

An 18-month-old girl presents with a limp. Clinical examination and pelvic radiographs reveal an untreated, dislocated right hip with a dysplastic acetabulum consistent with developmental dysplasia of the hip (DDH). What is the most appropriate initial management for this patient?

. Pavlik harness application
. Closed reduction and spica casting
. Open reduction, pelvic osteotomy, and spica casting
. Proximal femoral varus derotation osteotomy
. Observation and physical therapy

Correct Answer & Explanation

. Closed reduction and spica casting

Explanation

In children aged 6 to 18 months with untreated DDH, the standard first-line treatment is typically an attempt at closed reduction and spica casting under general anesthesia. Open reduction is reserved for cases where a stable and concentric closed reduction cannot be achieved.

Question 1156

Topic: Pediatric Hip

A 9-year-old boy is diagnosed with Legg-Calve-Perthes disease. Pelvic radiographs demonstrate that more than 50% of the lateral pillar of the femoral head has collapsed. According to the Herring lateral pillar classification, what group does this represent and what is the expected outcome?

. Group B, favorable outcome
. Group B, poor outcome
. Group C, favorable outcome
. Group C, poor outcome
. Group A, favorable outcome

Correct Answer & Explanation

. Group C, poor outcome

Explanation

Herring Group C is characterized by greater than 50% loss of lateral pillar height. In children over the age of 8, Group C presentation is strongly associated with a poor long-term clinical and radiographic outcome regardless of the treatment modality.

Question 1157

Topic: Pediatric Hip

A 45-year-old woman with Crowe type IV developmental dysplasia of the hip is undergoing a primary THA (

). During reconstruction, the true acetabulum is prepared. Which nerve is at greatest risk of injury when the femur is subsequently brought down to the true center of rotation?

. Femoral nerve
. Sciatic nerve
. Obturator nerve
. Superior gluteal nerve
. Lateral femoral cutaneous nerve

Correct Answer & Explanation

. Sciatic nerve

Explanation

The sciatic nerve is at the greatest risk of stretch injury during femoral lengthening in THA for high-riding DDH (Crowe IV). To prevent this, a subtrochanteric shortening osteotomy is frequently necessitated to safely reduce the hip.

Question 1158

Topic: Pediatric Hip

A 12-year-old obese boy presents with a 3-week history of right thigh and knee pain. Radiographs confirm a stable slipped capital femoral epiphysis (SCFE) of the right hip. Under what circumstance is prophylactic in situ pinning of the contralateral left hip most strongly indicated?

. Body mass index > 35
. Presentation in the summer months
. Underlying diagnosis of renal osteodystrophy
. Posterior tilt angle greater than 30 degrees
. Patient age older than 14 years

Correct Answer & Explanation

. Underlying diagnosis of renal osteodystrophy

Explanation

Prophylactic pinning of the contralateral hip in SCFE is highly recommended for patients with underlying endocrine or metabolic disorders (such as renal osteodystrophy or hypothyroidism). These conditions carry a significantly elevated risk for bilateral involvement.

Question 1159

Topic: Pediatric Hip

An 8-year-old boy is diagnosed with Legg-Calve-Perthes disease. Which of the following radiographic findings represents the greatest risk for a poor long-term outcome?

. Crescent sign
. Central pillar involvement
. Lateral subluxation of the femoral head
. Metaphyseal cysts
. Gage sign

Correct Answer & Explanation

. Lateral subluxation of the femoral head

Explanation

Lateral subluxation (extrusion) of the femoral head causes it to abut the lateral acetabular margin, leading to hinge abduction. This mechanical block severely deforms the head during the healing phase, resulting in a poor long-term outcome.

Question 1160

Topic: Pediatric Hip
A 38-year-old woman with severe bilateral developmental dysplasia of the hip (DDH) is planned for THA. Radiographs show proximal migration of the femoral head with the inferomedial aspect of the femoral head articulating with the false acetabulum. The native acetabular teardrop is located 55% of the femoral head height inferiorly. Which Crowe classification best describes this hip?
. Crowe I
. Crowe II
. Crowe III
. Crowe IV
. Crowe V

Correct Answer & Explanation

. Crowe III

Explanation

The Crowe classification is based on the proximal migration of the femoral head. Proximal subluxation of 50-75% of the femoral head height (or 10-15% of the pelvic height) characterizes a Crowe III dysplasia.

Test Yourself

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

On this Page