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Pediatric Hip MCQs

Practice Set 68 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 1341

Topic: Pediatric Hip

A 12-year-old overweight boy presents with sudden severe left hip pain and is completely unable to bear weight, even with crutches (Loder unstable SCFE). The exceptionally high risk of avascular necrosis (AVN) in this condition is primarily due to disruption of which of the following vessels?

. Artery of the ligamentum teres
. Medial femoral circumflex artery (lateral epiphyseal branches)
. Lateral femoral circumflex artery
. Inferior gluteal artery
. First perforating artery

Correct Answer & Explanation

. Medial femoral circumflex artery (lateral epiphyseal branches)

Explanation

An unstable Slipped Capital Femoral Epiphysis (SCFE) carries an AVN risk of up to 47%. The blood supply to the femoral head in this age group relies almost entirely on the posterosuperior and posteroinferior retinacular vessels, which are terminal lateral epiphyseal branches of the Medial Femoral Circumflex Artery (MFCA). These vessels are uniquely stretched or torn during the acute slip.

Question 1342

Topic: Pediatric Hip

A 4-year-old girl is brought to clinic due to a limping gait. Physical examination reveals a positive Trendelenburg sign on the left, leg length discrepancy (left shorter), and limited abduction of the left hip. Radiographs show significant dysplasia and a superolateral dislocation of the left hip. The most appropriate initial surgical management for this patient would be:

. Pavlik harness application.
. Closed reduction and spica cast application.
. Open reduction, femoral shortening osteotomy, and pelvic osteotomy.
. Traction followed by closed reduction.
. Arthroscopic reduction with capsular plication.

Correct Answer & Explanation

. Open reduction, femoral shortening osteotomy, and pelvic osteotomy.

Explanation

For developmental dysplasia of the hip (DDH) presenting in a 4-year-old child with a dislocated hip, the likelihood of successful closed reduction is very low due to soft tissue contractures and acetabular dysplasia. A Pavlik harness (Option A) is ineffective beyond 6-12 months of age. Closed reduction (Option B) or traction followed by closed reduction (Option D) are generally not successful in this age group without significant risk of avascular necrosis (AVN). Open reduction is required to release contractures (e.g., psoas, adductors) and reduce the femoral head. A femoral shortening osteotomy is crucial to reduce pressure on the femoral head after reduction, thereby minimizing the risk of AVN. A pelvic osteotomy (e.g., Dega, Salter, Pemberton) is necessary to provide adequate acetabular coverage for the femoral head (Option C). Arthroscopic reduction (Option E) is typically for much younger children or specific soft tissue interposition issues, not for a chronic dislocation with significant bony changes.

Question 1343

Topic: Pediatric Hip

An obese 13-year-old male presents with acute onset of severe left hip and knee pain and an inability to bear weight after stumbling. On examination, the left leg is externally rotated and shortened. He resists all attempts at passive hip motion. Radiographs reveal a significantly displaced left Slipped Capital Femoral Epiphysis (SCFE). Which of the following is the most appropriate urgent management step?

. Gentle closed reduction and spica casting.
. Percutaneous in situ pinning without reduction.
. Open reduction and internal fixation.
. Traction followed by percutaneous pinning.
. Non-weight-bearing and observation for stability.

Correct Answer & Explanation

. Percutaneous in situ pinning without reduction.

Explanation

This presentation describes an unstable Slipped Capital Femoral Epiphysis (SCFE), defined by the inability to bear weight. Unstable SCFE is an orthopedic emergency due to the high risk of avascular necrosis (AVN) of the femoral head. The most appropriate urgent management is percutaneous in situ pinning without reduction (Option B). The goal is to stabilize the physis and prevent further slip. Attempts at forceful closed reduction (Option A) carry a significantly increased risk of AVN due to disruption of the retinacular vessels, and are generally contraindicated. Open reduction and internal fixation (Option C) is typically reserved for severe chronic slips or failed in situ pinning. Traction (Option D) is not the primary intervention. Non-weight-bearing and observation (Option E) is insufficient and dangerous for an unstable slip.

Question 1344

Topic: Pediatric Hip

An 11-year-old obese male underwent in situ pinning for a stable, mild slipped capital femoral epiphysis (SCFE) of the left hip 6 months ago. He now presents with acute, severe, new onset left hip pain, limited range of motion, and a temperature of 38.5°C. Radiographs show no further slippage but evidence of joint space narrowing and subchondral lucency. What is the MOST likely complication, and what is the definitive diagnostic test?

. Progression of SCFE; repeat MRI.
. Contralateral SCFE; evaluate asymptomatic hip.
. Chondrolysis; hip aspiration and MRI.
. Avascular necrosis of the femoral head; CT scan.
. Osteomyelitis; blood cultures and bone biopsy.

Correct Answer & Explanation

. Chondrolysis; hip aspiration and MRI.

Explanation

This presentation (acute severe pain, limited ROM, fever, joint space narrowing, subchondral lucency) following SCFE treatment, especially in an obese adolescent, is highly suspicious for chondrolysis. Chondrolysis is a severe complication of SCFE, characterized by rapid destruction of articular cartilage, leading to joint space narrowing and stiffness. While AVN can also occur, the fever and rapid onset of severe pain along with joint space narrowing (rather than femoral head collapse seen later in AVN) point more towards chondrolysis.Option A (Progression of SCFE) is unlikely given the 'no further slippage' on radiographs.Option B (Contralateral SCFE) is common in SCFE patients but doesn't explain the acute symptoms and radiographic findings in the affected hip.Option C (Chondrolysis; hip aspiration and MRI) is the most likely diagnosis. Hip aspiration is crucial to rule out septic arthritis (which can mimic chondrolysis symptoms and sometimes coexist). MRI is excellent for evaluating cartilage status, synovitis, and ruling out other pathologies like avascular necrosis.Option D (Avascular necrosis) is a serious complication of SCFE, but the acute fever and the specific radiographic findings (joint space narrowing) make chondrolysis a stronger primary suspicion. CT is good for bone detail, but MRI is superior for cartilage and AVN in early stages.Option E (Osteomyelitis) is less likely to present primarily with joint space narrowing and subchondral lucency, and bone biopsy is more invasive than initially warranted. While septic arthritis should be ruled out (hence aspiration), osteomyelitis of the femoral head is a rarer primary complication here.

Question 1345

Topic: Pediatric Hip

A 3-year-old female is diagnosed with developmental dysplasia of the hip (DDH) after parents notice a limp and asymmetry in gait. Physical examination reveals a positive Trendelenburg sign and limited abduction of the left hip. Radiographs show a dislocated left hip with a shallow acetabulum and underdeveloped femoral head. What is the MOST likely initial treatment strategy?

. Pavlik harness application.
. Open reduction and Dega osteotomy.
. Closed reduction under anesthesia with hip spica cast application.
. Femoral osteotomy and Pemberton acetabuloplasty.
. Observation with serial ultrasounds.

Correct Answer & Explanation

. Open reduction and Dega osteotomy.

Explanation

The treatment for DDH is highly dependent on the patient's age and the severity of the dysplasia. A 3-year-old with a dislocated hip, limp, Trendelenburg sign, and radiographic evidence of a shallow acetabulum and underdeveloped femoral head represents a late presentation of DDH.Option A (Pavlik harness application) is effective for infants up to 6 months of age (and sometimes up to 12 months for reducible hips). It is contraindicated and ineffective for a dislocated hip in a 3-year-old, as the hip is unlikely to be reducible by gentle manipulation and the child is too old for this non-operative approach.Option B (Open reduction and Dega osteotomy) is a common and appropriate treatment for late-presenting DDH (typically 18 months to 8 years) where closed reduction is unlikely or has failed, and there is significant acetabular dysplasia. Open reduction is needed to place the femoral head into the true acetabulum, and an acetabuloplasty (like a Dega or Salter osteotomy) is performed to improve acetabular coverage and provide stability to the joint.Option C (Closed reduction under anesthesia with hip spica cast application) might be attempted in children under 18-24 months for reducible hips. For a 3-year-old with a chronically dislocated hip, closed reduction is often not possible due to soft tissue contractures (e.g., psoas, adductors), and even if achieved, the severe acetabular dysplasia would likely lead to redislocation without additional bony procedures.Option D (Femoral osteotomy and Pemberton acetabuloplasty) is also a valid surgical option for this age group, often combined with open reduction. The Pemberton is another type of acetabuloplasty. However, the Dega osteotomy is well-established for this age group to improve coverage. Both B and D are surgical options, but B is a common, well-described primary approach.Option E (Observation with serial ultrasounds) is appropriate only for mild dysplasia or hip instability in very young infants (e.g., Barlow/Ortolani positive) and is completely inappropriate for a 3-year-old with a dislocated hip and functional deficits.

Question 1346

Topic: Pediatric Hip

A 10-year-old boy presents with a sudden onset of left hip and knee pain, non-weight-bearing. Radiographs show a unilateral left Slipped Capital Femoral Epiphysis (SCFE). Further workup reveals a significantly elevated TSH and low T4 levels. What is the most important clinical implication of these endocrinological findings regarding his SCFE?

. The SCFE is likely chronic and requires a more aggressive surgical approach.
. He is at increased risk for contralateral SCFE and future slipped progression, even after surgical fixation.
. The SCFE is likely stable and will respond well to conservative management.
. He requires emergent endocrine consultation, but it does not impact SCFE management.
. The endocrinological disorder makes him a poor surgical candidate for in situ pinning.

Correct Answer & Explanation

. He is at increased risk for contralateral SCFE and future slipped progression, even after surgical fixation.

Explanation

Slipped Capital Femoral Epiphysis (SCFE) is more commonly associated with obesity and rapid growth. However, SCFE occurring at an atypical age (e.g., younger than 10 or older than 16) or in patients with unusual body habitus should raise suspicion for an underlying endocrine disorder. Hypothyroidism (elevated TSH, low T4) is one such disorder strongly associated with SCFE. The most important clinical implication of finding an endocrine disorder, particularly hypothyroidism, is that these patients have a significantly higher risk of contralateral SCFE (often synchronous or metachronous) and may be at increased risk of further slip progression even after initial surgical fixation. Therefore, prophylactic pinning of the contralateral hip is often recommended in these cases, and close follow-up is essential. The endocrine disorder itself does not necessarily make him a poor surgical candidate, nor does it mean the SCFE is stable or will respond to conservative management. The need for endocrine consultation is clear, but it directly impacts the management strategy for the SCFE, specifically regarding contralateral risk.

Question 1347

Topic: Pediatric Hip
A 4-year-old child presents with progressive bilateral hip pain and a limping gait. Radiographs show flattening and fragmentation of both femoral heads, consistent with Legg-Calvé-Perthes disease (LCPD). His Catterall classification is Group III on the right and Group II on the left. The right hip has signs of early subluxation. What is the most appropriate initial management for the right hip, given the severity?
. Strict bed rest and non-weight bearing until healing occurs.
. Observation with activity restriction and regular physiotherapy.
. Containment surgery, such as a varus osteotomy of the femur or Salter innominate osteotomy.
. Core decompression of the femoral head.
. Arthroscopic debridement of the joint capsule.

Correct Answer & Explanation

. Containment surgery, such as a varus osteotomy of the femur or Salter innominate osteotomy.

Explanation

LCPD management aims to contain the femoral head within the acetabulum to maintain its spherical shape during revascularization and remodeling. For a 4-year-old with Catterall Group III and early subluxation, containment surgery (Option C) is often indicated. A varus osteotomy of the femur or a Salter innominate osteotomy are common procedures to improve femoral head coverage. Strict bed rest (Option A) is rarely indicated now and has significant downsides. Observation (Option B) may be appropriate for very young children with limited involvement (e.g., Catterall I/II), but not for Group III with subluxation. Core decompression (Option D) is primarily for adult avascular necrosis. Arthroscopic debridement (Option E) is not a primary treatment for LCPD. Surgical containment offers the best chance to prevent severe deformity and osteoarthritis in this specific scenario.

Question 1348

Topic: Pediatric Hip

A 12-month-old infant is diagnosed with unilateral developmental dysplasia of the hip (DDH) after having failed a trial of Pavlik harness treatment initiated at 6 months of age. Clinical examination reveals a reducible but unstable hip. What is the most appropriate next step in management?

. Another trial of Pavlik harness for an extended duration
. Initiation of an abduction orthosis (e.g., hip abduction brace)
. Closed reduction under general anesthesia followed by spica cast application
. Open reduction with a capsulorrhaphy and possibly a pelvic osteotomy
. Observation with serial ultrasounds until 18 months

Correct Answer & Explanation

. Closed reduction under general anesthesia followed by spica cast application

Explanation

For a 12-month-old infant with DDH that has failed Pavlik harness treatment, the hip is past the age where harness treatment is typically effective. Given that the hip is reducible but unstable, closed reduction under general anesthesia followed by spica cast immobilization is the generally accepted next step. Open reduction with capsulorrhaphy and possibly a pelvic osteotomy is usually reserved for cases where closed reduction fails or for older children with more severe dysplasia. A second trial of Pavlik harness or an abduction orthosis is unlikely to be successful at this age and stage. Observation would risk further progression of the dysplasia.

Question 1349

Topic: Pediatric Hip

A 13-year-old obese male presents with left groin and knee pain that has been worsening over 6 months. Radiographs reveal a severe chronic Slipped Capital Femoral Epiphysis (SCFE). He undergoes in situ percutaneous pinning. What is the most significant recognized mechanical risk factor for developing chondrolysis in this patient?

. Patient obesity (BMI > 35)
. Unrecognized penetration of the hardware into the joint space
. Development of avascular necrosis (AVN) of the femoral head
. Performing a prophylactic pinning on the contralateral asymptomatic hip
. Use of a fully-threaded screw rather than a partially-threaded screw

Correct Answer & Explanation

. Unrecognized penetration of the hardware into the joint space

Explanation

Chondrolysis is a devastating complication of SCFE characterized by rapid destruction of the articular cartilage. Unrecognized penetration of the pin/screw into the hip joint space is the most significant mechanical risk factor for chondrolysis. To prevent this, careful fluoroscopic evaluation (e.g., the 'approach-withdraw' technique) is critical.

Question 1350

Topic: Pediatric Hip
A 6-week-old female infant, born in a breech presentation, is evaluated for Developmental Dysplasia of the Hip (DDH). A coronal ultrasound of the hip is performed. The alpha angle is measured at 40 degrees and the beta angle at 80 degrees. According to the Graf classification, what is the diagnosis and the most appropriate management?
. Type I hip; observe and reassure the parents
. Type IIa hip; observe with repeat ultrasound in 4 weeks
. Type IIc hip; immediate closed reduction in the operating room
. Type III hip; initiate treatment with a Pavlik harness
. Type IV hip; immediate open reduction and spica casting

Correct Answer & Explanation

. Type III hip; initiate treatment with a Pavlik harness

Explanation

According to Graf's ultrasound classification, a Type III hip has an alpha angle < 43 degrees and a beta angle > 77 degrees, indicating an eccentrically located (subluxated) femoral head with no structural alteration of the acetabular cartilage rim. The standard initial non-operative treatment for a Graf III hip in an infant < 6 months is a Pavlik harness.

Question 1351

Topic: Pediatric Hip

A 12-year-old male presents with acute severe groin pain after jumping off a swing. He is completely unable to bear weight, even with crutch assistance. Radiographs demonstrate a Slipped Capital Femoral Epiphysis (SCFE). What is the approximate risk of avascular necrosis (AVN) in this type of SCFE compared to a 'stable' slip?

. 0-5%
. 10-15%
. 25-50%
. 75-85%
. 95-100%

Correct Answer & Explanation

. 25-50%

Explanation

Loder classified SCFE into 'stable' (able to bear weight with or without crutches) and 'unstable' (unable to bear weight). Unstable SCFE is an acute emergency that carries a high risk of avascular necrosis (AVN), historically ranging from 25% to 50% (often cited around 47%), whereas stable SCFE has an AVN risk of nearly 0%.

Question 1352

Topic: Pediatric Hip
A 7-year-old boy is diagnosed with Legg-Calvé-Perthes disease. According to the Herring Lateral Pillar Classification, which of the following findings places him in Group C and predicts the poorest clinical outcome?
. No involvement of the lateral pillar on the AP radiograph
. Maintenance of greater than 50% of lateral pillar height
. Exactly 50% maintenance of lateral pillar height with early fragmentation
. Maintenance of less than 50% of lateral pillar height
. Flattening of the femoral head with a non-spherical congruency

Correct Answer & Explanation

. Maintenance of less than 50% of lateral pillar height

Explanation

The Herring Lateral Pillar Classification is highly prognostic in Legg-Calvé-Perthes disease. Group A involves no lateral pillar involvement. Group B involves >50% maintenance of lateral pillar height. Group C involves <50% maintenance of lateral pillar height, which portends a poor outcome with a high risk of developing an aspherical femoral head and early osteoarthritis.

Question 1353

Topic: Pediatric Hip

Which of the following patients presenting with a unilateral Slipped Capital Femoral Epiphysis (SCFE) has the strongest absolute indication for prophylactic in situ pinning of the contralateral hip?

. A 12-year-old boy with a BMI of 35
. A 14-year-old boy with a positive family history of SCFE
. A 10-year-old girl with end-stage renal disease and renal osteodystrophy
. A 13-year-old girl with a retroverted acetabulum
. An 11-year-old boy with delayed skeletal age

Correct Answer & Explanation

. A 10-year-old girl with end-stage renal disease and renal osteodystrophy

Explanation

Endocrine disorders (such as hypothyroidism) and metabolic bone diseases (like renal osteodystrophy) or a history of radiation therapy carry an exceptionally high risk (up to 50-100%) for the development of a bilateral SCFE. While obesity and delayed skeletal age are risk factors, a diagnosed underlying systemic endocrinopathy or metabolic disorder is considered a strong and almost absolute indication for prophylactic contralateral pinning.

Question 1354

Topic: Pediatric Hip

A 6-week-old female is treated with a Pavlik harness for an ultrasonographically confirmed irreducible right hip dislocation. At the 2-week follow-up, the parents report the infant is no longer kicking her right leg. Examination reveals absent active knee extension on the right, but active ankle dorsiflexion and plantarflexion are preserved. Ultrasound confirms the hip remains dislocated. What is the most appropriate next step in management?

. Continue the Pavlik harness and add targeted physical therapy for the quadriceps.
. Adjust the anterior straps to increase hip flexion past 100 degrees to facilitate reduction.
. Abandon the Pavlik harness and immediately transition to a rigid abduction orthosis.
. Remove the Pavlik harness and allow a period of rest to facilitate neurologic recovery before attempting alternative treatment.
. Perform an immediate closed reduction and application of a hip spica cast under general anesthesia.

Correct Answer & Explanation

. Remove the Pavlik harness and allow a period of rest to facilitate neurologic recovery before attempting alternative treatment.

Explanation

The patient has developed a femoral nerve palsy, a known complication of the Pavlik harness, typically caused by excessive hip flexion pressing the nerve against the inguinal ligament. If the hip is still dislocated and a femoral nerve palsy develops, the harness must be discontinued (the so-called 'Pavlik holiday'). A period of rest allows for neurologic recovery before pursuing alternative treatments, such as closed reduction and spica casting. Continuing the harness or increasing flexion risks permanent nerve damage and vascular compromise.

Question 1355

Topic: Pediatric Hip
An 8.5-year-old boy presents with a 4-month history of a painless limp. Radiographs demonstrate fragmentation of the capital femoral epiphysis with >50% maintenance of the lateral pillar height. He has 15 degrees of abduction and a 10-degree flexion contracture. Based on his age and radiographic classification, which treatment provides the best long-term radiographic outcome?
. Strict non-weight bearing in a wheelchair
. Application of an A-frame abduction orthosis
. Proximal femoral varus osteotomy
. In situ percutaneous pinning of the epiphysis
. Core decompression of the femoral head

Correct Answer & Explanation

. Proximal femoral varus osteotomy

Explanation

This patient has Legg-Calvé-Perthes disease with a Herring lateral pillar B classification (maintenance of >50% lateral pillar height). The Herring classification and age at onset dictate treatment. Studies have shown that for patients > 8 years old with Herring B or B/C border hips, surgical containment (such as a proximal femoral varus osteotomy or pelvic osteotomy) significantly improves radiographic outcomes (Stulberg classification) and reduces the risk of early osteoarthritis compared to nonoperative management.

Question 1356

Topic: Pediatric Hip

A 9-year-old male presents with bilateral knee pain and a waddling gait. He is in the 10th percentile for weight and 5th percentile for height. Radiographs reveal bilateral slipped capital femoral epiphyses (SCFE). Given the patient's age and bilateral presentation, an endocrine workup is initiated. Which of the following conditions is most commonly associated with this presentation?

. Hypothyroidism
. Hyperthyroidism
. Hyperparathyroidism
. Type 1 Diabetes Mellitus
. Cushing's disease

Correct Answer & Explanation

. Hypothyroidism

Explanation

Atypical Slipped Capital Femoral Epiphysis (SCFE) occurs in patients who fall outside the classic age range (boys <12 or >14), those who are underweight or short-statured, or those who present with synchronous bilateral involvement. These patients have a high likelihood of an underlying endocrine or metabolic disorder. Hypothyroidism is the single most common endocrine disorder associated with atypical SCFE. Other causes include panhypopituitarism, growth hormone deficiency, and renal osteodystrophy.

Question 1357

Topic: Pediatric Hip

A 12-year-old girl with primary hypothyroidism presents with a stable left Slipped Capital Femoral Epiphysis (SCFE) and undergoes in situ pinning. Her right hip is currently asymptomatic and radiographically normal. What is the most appropriate management regarding her contralateral right hip?

. Clinical and radiographic observation every 6 months
. Prophylactic pinning in situ of the right hip
. Application of a hip spica cast
. Prophylactic epiphysiodesis of the greater trochanter
. Arthroscopic capsulotomy of the right hip

Correct Answer & Explanation

. Prophylactic pinning in situ of the right hip

Explanation

Patients with endocrine disorders (such as hypothyroidism) have a significantly higher risk (up to 80-100%) of developing a contralateral SCFE. Prophylactic in situ pinning of the contralateral hip is highly recommended in these patients.

Question 1358

Topic: Pediatric Hip

A 3-month-old infant is being treated with a Pavlik harness for developmental dysplasia of the hip (DDH). At the 2-week follow-up, the mother reports the infant is not kicking the left leg as much. On examination, the infant exhibits absent active knee extension on the left. What is the most appropriate next step in management?

. Adjust the anterior straps to increase hip flexion
. Adjust the posterior straps to increase hip abduction
. Remove the harness for a period of rest and observation
. Switch immediately to a rigid abduction orthosis (e.g., Rhino cruiser)
. Perform a closed reduction and application of a spica cast

Correct Answer & Explanation

. Remove the harness for a period of rest and observation

Explanation

Decreased active knee extension in a Pavlik harness is the classic presentation of a femoral nerve palsy, typically caused by excessive hip flexion. The harness must be removed immediately to allow for neurologic recovery, which usually occurs within a few weeks.

Question 1359

Topic: Pediatric Hip
An 8-year-old boy is diagnosed with Legg-Calvé-Perthes disease. Radiographs demonstrate exactly 50% loss of lateral pillar height. According to the Herring lateral pillar classification and patient age, which treatment has been shown to provide the best long-term radiographic outcome (Stulberg I or II)?
. Strict weight-bearing restriction and crutches
. Physical therapy focusing on abduction exercises
. Surgical containment (e.g., femoral or pelvic osteotomy)
. Observation with serial radiographs
. Botulinum toxin injection to the adductors

Correct Answer & Explanation

. Surgical containment (e.g., femoral or pelvic osteotomy)

Explanation

This patient has Herring Group B/C border disease. Multicenter prospective studies have shown that children over 8 years of age at the onset of symptoms with Herring Group B or B/C border hips have significantly better radiographic outcomes with surgical containment compared to nonoperative treatment.

Question 1360

Topic: Pediatric Hip

A 6-week-old female is treated with a Pavlik harness for developmental dysplasia of the hip (DDH). At the 3-week follow-up, she exhibits decreased active extension of the knee on the affected side but cries when the leg is manipulated. What is the most likely cause of this clinical finding?

. Femoral nerve palsy
. Sciatic nerve palsy
. Obturator nerve palsy
. Avascular necrosis of the femoral head
. Missed patellar dislocation

Correct Answer & Explanation

. Femoral nerve palsy

Explanation

Femoral nerve palsy is a known complication of Pavlik harness treatment, typically resulting from excessive hyperflexion of the hip. Treatment involves adjusting the anterior straps to decrease hip flexion, which usually leads to spontaneous resolution of the palsy.

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