Menu

Pediatric Hip MCQs

Practice Set 37 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 721

Topic: Pediatric Hip
Which of the following is NOT considered one of Catterall's classic 'head-at-risk' radiographic signs in Legg-Calvé-Perthes disease?
. Gage sign
. Lateral calcification
. Lateral subluxation of the femoral head
. Coxa magna
. Metaphyseal cysts

Correct Answer & Explanation

. Coxa magna

Explanation

Catterall's 'head-at-risk' signs predict a poor outcome and hinge abduction in Perthes disease. They include Gage's sign (V-shaped defect in the lateral epiphysis), lateral calcification, lateral subluxation of the head, horizontal growth plate, and diffuse metaphyseal reaction (cysts). Coxa magna (enlarged head) is a later sequela, not a predictive 'head-at-risk' sign.

Question 722

Topic: Pediatric Hip

A 14-year-old obese boy presents with an acute-on-chronic slipped capital femoral epiphysis (SCFE) of the right hip. He is unable to bear weight even with the use of crutches. He is treated with single in-situ screw fixation. Which of the following clinical factors places him at the highest risk for developing avascular necrosis (AVN) of the femoral head?

. Obesity
. Use of a single screw instead of two
. Inability to bear weight before surgery
. Male gender
. Age greater than 12 years

Correct Answer & Explanation

. Inability to bear weight before surgery

Explanation

The inability to bear weight defines an 'unstable' SCFE according to the Loder classification. Unstable SCFE is the single greatest predictor for the development of AVN, with rates up to nearly 50%, due to the increased risk of disruption to the retinacular blood supply.

Question 723

Topic: Pediatric Hip

A 9-year-old boy presents with a left-sided Slipped Capital Femoral Epiphysis (SCFE) and undergoes in situ single-screw fixation. Under which of the following conditions is prophylactic pinning of the contralateral, asymptomatic right hip most strongly indicated?

. If the patient has a body mass index (BMI) in the 85th percentile
. If the left-sided SCFE was graded as mild (less than 33% slip)
. If the patient has a known diagnosis of renal osteodystrophy
. If the patient is of African American descent
. If the initial presentation was a chronic slip rather than acute

Correct Answer & Explanation

. If the patient has a known diagnosis of renal osteodystrophy

Explanation

Prophylactic pinning of the contralateral hip in SCFE is controversial but is universally recommended in patients with endocrine or metabolic disorders (e.g., hypothyroidism, renal osteodystrophy, growth hormone supplementation) due to the exceedingly high risk of bilateral involvement. Age at presentation (boys <10, girls <8) is also a strong indication.

Question 724

Topic: Pediatric Hip

A 4-week-old female infant is diagnosed with developmental dysplasia of the hip (DDH) and placed in a Pavlik harness. Ultrasound confirms the hip is completely dislocated. After 3 weeks of strict, full-time wear, repeat ultrasound demonstrates that the hip remains persistently dislocated. What is the next best step in management?

. Continue Pavlik harness for an additional 3 weeks
. Adjust the harness to increase hip flexion beyond 120 degrees
. Discontinue the Pavlik harness and transition to a rigid abduction orthosis or proceed to closed reduction
. Perform immediate open reduction with pelvic osteotomy
. Transition to a Denis Browne bar

Correct Answer & Explanation

. Discontinue the Pavlik harness and transition to a rigid abduction orthosis or proceed to closed reduction

Explanation

If a hip remains completely dislocated after 3 to 4 weeks of proper Pavlik harness treatment, the harness should be discontinued. Prolonged use of a harness on an irreducible hip leads to 'Pavlik harness disease' (excoriation/flattening of the posterior acetabulum) and increases the risk of avascular necrosis. The next step is a rigid abduction orthosis (e.g., Ilfeld or von Rosen) or proceeding directly to closed reduction and spica casting.

Question 725

Topic: Pediatric Hip

A 14-year-old obese male presents with an acute exacerbation of chronic left knee pain and a severe limp. Examination reveals obligate external rotation of the hip during passive flexion. He is completely unable to bear weight on the left leg. Radiographs confirm a severe, acute-on-chronic slipped capital femoral epiphysis (SCFE). Which of the following is the most serious and highly prevalent complication specifically associated with this patient's inability to bear weight?

. Chondrolysis of the hip joint
. Avascular necrosis (AVN) of the femoral head
. Femoroacetabular impingement (FAI)
. Slipped capital femoral epiphysis of the contralateral hip
. Premature spontaneous closure of the physis

Correct Answer & Explanation

. Avascular necrosis (AVN) of the femoral head

Explanation

This patient's inability to bear weight defines his condition as an 'unstable' SCFE. Unstable SCFE is associated with a markedly higher risk of avascular necrosis (AVN) of the femoral head—reported to be up to 50% in some series. While chondrolysis, FAI, and contralateral slips are also complications of SCFE, AVN is the most devastating complication intrinsically tied to the vascular insult that occurs during an unstable slip.

Question 726

Topic: Pediatric Hip

A 12-year-old boy with obesity presents with left hip pain and an obligatory external rotation during hip flexion. He is diagnosed with a slipped capital femoral epiphysis (SCFE). Which of the following is the strongest indication for prophylactic pinning of the asymptomatic contralateral hip?

. Age older than 14 years
. Endocrine disorder (e.g., hypothyroidism)
. Female sex
. Chronic presentation of the slip
. Grade I slip

Correct Answer & Explanation

. Endocrine disorder (e.g., hypothyroidism)

Explanation

Prophylactic pinning of the contralateral hip in SCFE is controversial but is generally recommended in patients with a high risk of developing a contralateral slip. Strong indications include the presence of an endocrine disorder (such as hypothyroidism, panhypopituitarism, or renal osteodystrophy), prior radiation therapy, or presentation at a particularly young age (e.g., males <12 years, females <10 years). Age older than 14, female sex alone, chronicity, or severity of the current slip are not primary indications.

Question 727

Topic: Pediatric Hip

A 13-year-old boy with a BMI of 32 presents with 3 weeks of left knee pain and an antalgic gait. He is able to bear weight on the affected limb. Radiographs demonstrate a mild left slipped capital femoral epiphysis (SCFE). Which of the following accurately describes the anatomic displacement that occurs in SCFE?

. The epiphysis displaces anteriorly and superiorly relative to the metaphysis
. The metaphysis displaces anteriorly and externally rotates relative to the epiphysis
. The metaphysis displaces posteriorly and internally rotates relative to the epiphysis
. The epiphysis displaces laterally and internally rotates relative to the metaphysis
. The metaphysis displaces medially and superiorly relative to the epiphysis

Correct Answer & Explanation

. The metaphysis displaces anteriorly and externally rotates relative to the epiphysis

Explanation

In a slipped capital femoral epiphysis (SCFE), the epiphysis actually remains held within the acetabulum by the ligamentum teres, while the femoral neck (metaphysis) displaces anteriorly and externally rotates relative to the epiphysis. On radiographs, this makes the epiphysis appear to have displaced posteriorly and inferiorly relative to the neck.

Question 728

Topic: Pediatric Hip

A 13-year-old obese male presents with 3 weeks of left knee pain and a limp. Examination reveals obligate external rotation of the left hip with passive flexion. Radiographs confirm a mild stable slipped capital femoral epiphysis (SCFE). Which of the following is the most appropriate definitive management?

. Immediate closed reduction and spica casting
. In situ fixation with a single cannulated screw in the center of the epiphysis
. Open reduction and internal fixation through a surgical dislocation approach
. Prophylactic pinning of the contralateral hip only
. Non-weight bearing with crutches and close observation

Correct Answer & Explanation

. In situ fixation with a single cannulated screw in the center of the epiphysis

Explanation

The gold standard for a mild, stable SCFE is in situ fixation using a single cannulated screw placed in the center of the epiphysis. Closed reduction is contraindicated due to the high risk of precipitating avascular necrosis. Open reduction (e.g., modified Dunn procedure) is typically reserved for severe or unstable slips to correct the deformity acutely while protecting the blood supply. Prophylactic pinning of the contralateral hip is performed in certain high-risk demographics, but the affected hip must be treated.

Question 729

Topic: Pediatric Hip

A 13-year-old obese boy is brought to the clinic due to left groin pain and an absolute inability to bear weight on the left leg, even with the assistance of crutches, for the past 2 days following a minor fall. Pelvic radiographs confirm a severe slipped capital femoral epiphysis (SCFE). According to the Loder classification, this patient is at the highest risk for developing which of the following complications?

. Chondrolysis
. Avascular necrosis (AVN)
. Slip progression
. Contralateral slip
. Deep infection

Correct Answer & Explanation

. Avascular necrosis (AVN)

Explanation

The Loder classification divides SCFE into stable (able to bear weight with or without crutches) and unstable (unable to bear weight). Unstable SCFE has a notoriously high rate of avascular necrosis (AVN) of the femoral head, historically reported up to 47%, compared to a near 0% AVN rate in stable slips. Prompt recognition and appropriate operative planning are required to mitigate this risk.

Question 730

Topic: Pediatric Hip

A 12-year-old boy presents with right hip pain and an obligatory external rotation with hip flexion. Radiographs confirm a stable slipped capital femoral epiphysis (SCFE) on the right. In which of the following clinical scenarios is prophylactic in situ pinning of the asymptomatic, contralateral (left) hip most strongly indicated?

. Body mass index > 95th percentile
. Age greater than 14 years at presentation
. Concomitant hypothyroidism
. Right slip angle > 50 degrees
. African American ethnicity

Correct Answer & Explanation

. Concomitant hypothyroidism

Explanation

Prophylactic pinning of the contralateral hip in patients presenting with a unilateral SCFE is strongly recommended for those with underlying endocrine disorders (such as hypothyroidism, panhypopituitarism, and renal osteodystrophy) or a history of pelvic radiation. These patients have an exceptionally high rate of developing bilateral disease (often approaching 100%). Other relative indications include presentation at an age less than 10 years or the inability to reliably follow up.

Question 731

Topic: Pediatric Hip

An obese 10-year-old boy has had left groin pain and a limp for the past 2 months. Examination reveals decreased abduction and internal rotation. Laboratory studies show normal renal function and an elevated thyroid-stimulating hormone (TSH) level. AP and frog lateral radiographs of the pelvis are shown in Figures 30a and 30b. What is the best course of action?

. Traction followed by reduction and pinning
. In situ pinning of the left hip
. In situ pinning of both hips
. No weight bearing on the left side and nonsteroidal anti-inflammatory drugs
. Femoral realignment osteotomy

Correct Answer & Explanation

. In situ pinning of both hips

Explanation

The radiographs show a grade I slipped capital femoral epiphysis (SCFE) that is classified as stable because the child is able to bear weight. The elevated TSH level indicates possible hypothyroidism. SCFE usually occurs in boys age 12 to 14 years. Because of the patient's young age and hypothyroidism, he is at increased risk for slippage of the contralateral hip; therefore, prophylactic pinning of the uninvolved side also should be considered. Because of the risk of slip progression, crutch treatment and nonsteroidal anti-inflammatory drugs are not indicated. Realignment osteotomy is not indicated for grade I SCFE. Traction to reduce the slip, followed by pinning, has been advocated for unstable slips but is not indicated here. Loder RT, Wittenberg B, DeSilva G: Slipped capital femoral epiphysis associated with endocrine disorders. J Pediatr Orthop 1995;15:349-356.

Question 732

Topic: Pediatric Hip

A 6-year-old boy is diagnosed with Legg-Calve-Perthes disease. In evaluating the pathogenesis of avascular necrosis in this age group, which of the following arteries provides the predominant blood supply to the capital femoral epiphysis?

. Artery of the ligamentum teres
. Lateral epiphyseal branches of the medial femoral circumflex artery
. Inferior metaphyseal arteries
. Anterior ascending branches of the lateral femoral circumflex artery
. Internal pudendal artery

Correct Answer & Explanation

. Lateral epiphyseal branches of the medial femoral circumflex artery

Explanation

In children over the age of 3-4 years and persisting into adulthood, the predominant blood supply to the femoral head is provided by the lateral epiphyseal branches of the medial femoral circumflex artery (MFCA).

Question 733

Topic: Pediatric Hip

A 3-month-old girl is being treated for developmental dysplasia of the hip (DDH) with a Pavlik harness. During a follow-up visit, the parents report that the child has stopped actively extending her knee on the treated side. On examination, the patellar reflex is diminished. What is the most appropriate next step in management?

. Continue the harness and add physical therapy
. Adjust the anterior strap to increase hip flexion
. Remove the harness and observe for spontaneous recovery
. Transition immediately to a rigid hip spica cast
. Perform an urgent ultrasound to rule out deep vein thrombosis

Correct Answer & Explanation

. Remove the harness and observe for spontaneous recovery

Explanation

The clinical presentation is consistent with a femoral nerve palsy, a known complication of excessive hip flexion in a Pavlik harness. Management requires immediate removal of the harness to allow for spontaneous neurological recovery.

Question 734

Topic: Pediatric Hip

A 6-week-old infant presents for a routine screening hip ultrasound due to a breech presentation. The ultrasound report indicates an alpha angle of 48 degrees and a beta angle of 75 degrees. Which of the following is the most appropriate interpretation and management?

. Normal hip; no further follow-up needed
. Physiologic immaturity; repeat ultrasound in 4 weeks
. Developmental dysplasia; initiate Pavlik harness treatment
. Severe dysplasia; schedule for closed reduction and spica casting
. Borderline dysplasia; recommend double-diapering

Correct Answer & Explanation

. Developmental dysplasia; initiate Pavlik harness treatment

Explanation

An alpha angle less than 60 degrees and a beta angle greater than 55 degrees on a coronal ultrasound indicate developmental dysplasia of the hip (Graf Type IIc or worse). Initiation of a Pavlik harness is the standard of care for an infant at this age with these parameters.

Question 735

Topic: Pediatric Hip

A 13-year-old obese boy presents with 2 days of severe left hip pain and inability to bear weight after a minor fall. Radiographs confirm a severe slipped capital femoral epiphysis (SCFE). According to the Loder classification, what is the most significant prognostic factor associated with his presentation?

. A high risk of chondrolysis
. A 10% to 50% risk of avascular necrosis (AVN)
. A high likelihood of contralateral slip
. The need for prophylactic pinning of the right hip
. Guaranteed premature osteoarthritis

Correct Answer & Explanation

. A 10% to 50% risk of avascular necrosis (AVN)

Explanation

Under the Loder classification, a SCFE is unstable if the patient cannot bear weight, even with crutches. Unstable SCFE has a much higher rate of avascular necrosis (10% to 50%) compared to stable SCFE (less than 10%).

Question 736

Topic: Pediatric Hip

An 8-year-old boy whose weight is in the 40th percentile presents with groin pain and an altered gait. Radiographs reveal a mild stable slipped capital femoral epiphysis (SCFE). Given the patient's age and body habitus, which of the following is the most appropriate next step in evaluation?

. Genetic testing for Down syndrome
. DEXA scan
. Endocrine laboratory workup (TSH, free T4, BUN, Cr)
. MRI of the lumbosacral spine
. Rheumatoid factor and ANA testing

Correct Answer & Explanation

. Endocrine laboratory workup (TSH, free T4, BUN, Cr)

Explanation

SCFE typically occurs in obese adolescents during the pubertal growth spurt. Presentation in patients younger than 10 years or those who are not overweight strongly warrants an endocrine workup to rule out hypothyroidism or renal osteodystrophy.

Question 737

Topic: Pediatric Hip

Which of the following radiographic signs is most sensitive for detecting an early, subtle Slipped Capital Femoral Epiphysis (SCFE) on an anteroposterior (AP) pelvis radiograph?

. The femoral head is displaced medially to the ilioischial line
. Klein's line fails to intersect a portion of the lateral femoral epiphysis
. The epiphyseal-diaphyseal angle is greater than 50 degrees
. A "crescent sign" is visible in the subchondral bone
. The teardrop distance is widened by more than 2 mm

Correct Answer & Explanation

. Klein's line fails to intersect a portion of the lateral femoral epiphysis

Explanation

Klein's line is drawn along the superior edge of the femoral neck on an AP radiograph. In a normal hip, it should intersect the lateral portion of the femoral epiphysis; failure to do so (Trethowan's sign) indicates a SCFE.

Question 738

Topic: Pediatric Hip

A 4-month-old female with developmental dysplasia of the hip (DDH) is being treated with a Pavlik harness. At a follow-up visit, the mother notes the child is no longer kicking her left leg. On exam, there is an absent patellar reflex and decreased active knee extension. Which of the following is the most appropriate next step in management?

. Adjust the anterior straps to increase hip flexion
. Discontinue the Pavlik harness
. Switch to a rigid abduction orthosis
. Perform immediate closed reduction and spica casting
. Obtain an emergent MRI of the lumbar spine

Correct Answer & Explanation

. Discontinue the Pavlik harness

Explanation

The patient has developed a femoral nerve palsy, a known complication of hyperflexion in a Pavlik harness. The most appropriate immediate management is to discontinue the harness and observe for neurologic recovery.

Question 739

Topic: Pediatric Hip

A 13-year-old obese male presents to the emergency department with acute left groin pain and inability to bear weight. He reports a 3-month history of mild intermittent knee pain. Radiographs reveal a left slipped capital femoral epiphysis (SCFE). Which of the following factors is the strongest predictor of developing avascular necrosis (AVN) in this patient?

. Duration of prodromal symptoms
. Degree of slip angle on the lateral radiograph
. Inability to bear weight with or without crutches
. The patient's body mass index (BMI)
. Associated endocrine abnormalities

Correct Answer & Explanation

. Inability to bear weight with or without crutches

Explanation

The Loder classification defines an unstable SCFE by the patient's inability to bear weight, even with crutches. Unstable slips have a significantly higher risk of developing avascular necrosis compared to stable slips.

Question 740

Topic: Pediatric Hip

An 18-month-old female with neglected developmental dysplasia of the hip is scheduled for an open reduction via an anterior Smith-Petersen approach. During the procedure, several anatomical structures must be addressed to allow concentric reduction. Which of the following represents an extra-articular block to reduction?

. Ligamentum teres
. Transverse acetabular ligament
. Inverted limbus
. Iliopsoas tendon
. Pulvinar

Correct Answer & Explanation

. Iliopsoas tendon

Explanation

Blocks to reduction in DDH are categorized as extra-articular or intra-articular. The iliopsoas tendon and capsular constriction (hourglass capsule) are extra-articular blocks, whereas the ligamentum teres, transverse acetabular ligament, pulvinar, and inverted limbus are intra-articular blocks.

Test Yourself

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

On this Page