Menu

Pediatric Hip MCQs

Practice Set 44 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 861

Topic: Pediatric Hip

A 6-month-old infant was treated with a Pavlik harness for 3 months. Recent radiographs reveal fragmentation and delayed ossification of the left femoral head. Excessive positioning in which direction during treatment is most strongly associated with this complication?

. Flexion
. Extension
. Abduction
. Adduction
. Internal rotation

Correct Answer & Explanation

. Flexion

Explanation

Avascular necrosis (AVN) of the femoral head in DDH treatment is most commonly caused by excessive abduction. This position compresses the medial circumflex femoral artery, compromising blood flow to the epiphysis.

Question 862

Topic: Pediatric Hip

A 13-year-old obese male presents with left groin and knee pain. On physical examination, which finding is considered the classic pathognomonic sign during passive flexion of the affected hip?

. Obligate internal rotation
. Obligate external rotation
. Severe limitation of hip abduction
. Severe limitation of hip adduction
. A positive Trendelenburg sign

Correct Answer & Explanation

. Obligate internal rotation

Explanation

Obligate external rotation during passive hip flexion is the classic physical examination finding in Slipped Capital Femoral Epiphysis (SCFE). This occurs due to the anterior and superior translation of the femoral neck relative to the epiphysis.

Question 863

Topic: Pediatric Hip

A 9-year-old female presents with bilateral Slipped Capital Femoral Epiphysis (SCFE). She is in the 10th percentile for height and weight.

Which of the following laboratory investigations is most indicated for this patient?

. Hemoglobin A1c
. Free T4 and TSH
. Serum calcium and phosphate
. Growth hormone levels
. Serum parathyroid hormone

Correct Answer & Explanation

. Hemoglobin A1c

Explanation

Patients presenting with SCFE under the age of 10 years or with bilateral disease have a high incidence of underlying endocrine disorders, most commonly hypothyroidism. TSH and Free T4 are the primary screening tests indicated.

Question 864

Topic: Pediatric Hip

A 14-year-old male is unable to bear weight on his right leg after a minor fall. Radiographs demonstrate a severe, acute unstable SCFE. What is the primary advantage of the modified Dunn procedure via a surgical dislocation approach compared to in-situ pinning for this patient?

. It completely eliminates the risk of avascular necrosis
. It has a significantly shorter operative time
. It allows anatomical reduction while directly visualizing and protecting the retinacular vessels
. It avoids the need for an extensive capsulotomy
. It allows for earlier return to full contact sports

Correct Answer & Explanation

. It completely eliminates the risk of avascular necrosis

Explanation

The modified Dunn procedure involves a surgical hip dislocation to anatomically reduce the slipped epiphysis. Its main advantage is the direct visualization and protection of the posterior retinacular vessels, though it is technically demanding and AVN risk remains.

Question 865

Topic: Pediatric Hip

An 11-year-old boy undergoes in-situ pinning for a symptomatic left SCFE. Which of the following is the strongest clinical indication for prophylactic pinning of the asymptomatic right hip?

. A modified Southwick angle of 40 degrees on the left
. Patient age over 14 years
. Underlying diagnosis of renal osteodystrophy
. Obese body habitus
. Male sex

Correct Answer & Explanation

. A modified Southwick angle of 40 degrees on the left

Explanation

Prophylactic pinning of the contralateral hip is highly recommended in patients with underlying endocrine or metabolic disorders (such as renal osteodystrophy or hypothyroidism) because their risk of developing a subsequent contralateral slip is exceedingly high.

Question 866

Topic: Pediatric Hip

A 14-year-old male treated with in-situ pinning for a stable SCFE 6 months ago now presents with severe hip stiffness and worsening pain. Radiographs reveal global joint space narrowing to 2 mm. What is the most likely cause of this complication?

. Undiagnosed hypothyroidism
. Unrecognized hardware penetration into the joint space
. Avascular necrosis of the femoral head
. Secondary femoroacetabular impingement
. Subacute septic arthritis

Correct Answer & Explanation

. Undiagnosed hypothyroidism

Explanation

Chondrolysis presents with severe stiffness and diffuse joint space narrowing (< 3 mm). The most common iatrogenic cause is unrecognized pin penetration into the articular space during SCFE fixation.

Question 867

Topic: Pediatric Hip

A 12-year-old female presents with hip pain for 3 weeks but is able to ambulate into the clinic with a mild limp.

According to the Loder classification, what is her approximate risk of developing avascular necrosis (AVN) following in-situ pinning?

. Less than 5%
. 10 to 15%
. 25 to 30%
. 45 to 50%
. Greater than 75%

Correct Answer & Explanation

. Less than 5%

Explanation

The Loder classification divides SCFE into stable (patient can bear weight) and unstable (unable to bear weight). A stable SCFE carries a very low risk of AVN, historically less than 5%.

Question 868

Topic: Pediatric Hip

A 13-year-old male presents with vague knee pain. An AP pelvis radiograph is obtained. Which of the following radiographic signs strongly indicates a subtle SCFE?

. Intersection of the lateral epiphysis by Klein's line
. The entire epiphysis falling lateral to Klein's line
. Klein's line passing superior to the epiphysis without intersecting it
. Symmetric widening of the teardrop distance bilaterally
. An increased lateral center-edge angle of Wiberg

Correct Answer & Explanation

. Intersection of the lateral epiphysis by Klein's line

Explanation

Klein's line is drawn along the superior margin of the femoral neck on an AP radiograph. In a normal hip, it intersects the lateral portion of the epiphysis. Trethowan's sign in SCFE occurs when the line passes completely superior to the epiphysis.

Question 869

Topic: Pediatric Hip

In evaluating a patient with a slipped capital femoral epiphysis (SCFE), which of the following is considered an indication for prophylactic pinning of the contralateral asymptomatic hip?

. Age 14 years in a male
. Body mass index (BMI) > 30
. Renal osteodystrophy
. Mild slip angle on the affected side
. Acute presentation of the affected side

Correct Answer & Explanation

. Age 14 years in a male

Explanation

Prophylactic pinning of the contralateral hip is generally recommended for patients with endocrine or metabolic disorders (like renal osteodystrophy or hypothyroidism), prior radiation therapy, or age < 10 years.

Question 870

Topic: Pediatric Hip

A 9-year-old boy presents with an acute, unstable slipped capital femoral epiphysis (SCFE) after a minor fall. He is unable to bear weight. Which of the following complications is most highly associated with this specific type of SCFE compared to a stable SCFE?

. Chondrolysis
. Osteomyelitis
. Avascular necrosis (AVN) of the femoral head
. Femoroacetabular impingement (FAI)
. Leg length discrepancy

Correct Answer & Explanation

. Chondrolysis

Explanation

Unstable SCFE (defined as the inability to bear weight) has a significantly higher rate of avascular necrosis (up to 50%) compared to stable SCFE.

Question 871

Topic: Pediatric Hip

A 12-month-old girl is noted to have a painless limp. Examination reveals a positive Galeazzi sign and asymmetric thigh folds. Radiographs demonstrate a superolaterally displaced right femoral head with an acetabular index of 40 degrees. What is the most appropriate initial management?

. Pavlik harness
. Closed reduction and spica casting
. Open reduction and pelvic osteotomy
. Varus derotational osteotomy of the proximal femur
. Reassurance and follow-up

Correct Answer & Explanation

. Pavlik harness

Explanation

In a child aged 6 to 18 months with DDH, the initial treatment of choice is typically closed reduction and spica casting. A Pavlik harness is generally ineffective after 6 months of age.

Question 872

Topic: Pediatric Hip

During the surgical treatment of a slipped capital femoral epiphysis (SCFE) with in situ pinning, the surgeon must be careful to avoid joint penetration. Which complication is most directly associated with unrecognized pin penetration into the hip joint?

. Avascular necrosis
. Chondrolysis
. Subtrochanteric fracture
. Femoroacetabular impingement
. Slipped capital femoral epiphysis of the contralateral hip

Correct Answer & Explanation

. Avascular necrosis

Explanation

Unrecognized pin penetration during in situ fixation of SCFE is classically associated with chondrolysis, leading to severe stiffness and joint space narrowing.

Question 873

Topic: Pediatric Hip
A 3-week-old male infant undergoes ultrasound screening for developmental dysplasia of the hip (DDH). The alpha angle is measured at 40 degrees. According to the Graf classification, what does this alpha angle indicate?
. A normal, mature hip
. Physiologic immaturity
. Subluxation with structural deficiency
. An irreducible dislocation
. A normal variant requiring no treatment

Correct Answer & Explanation

. Subluxation with structural deficiency

Explanation

In the Graf classification, an alpha angle of less than 43 degrees (Type III) indicates a subluxated hip with poor bony roof coverage. This structural deficiency requires immediate treatment.

Question 874

Topic: Pediatric Hip

A 5-month-old infant is being treated with a Pavlik harness for DDH. The ultrasound at 4 weeks of treatment shows failure of reduction of the hip. What is the most appropriate next step in management?

. Continue Pavlik harness for an additional 4 weeks
. Switch to a rigid abduction orthosis (e.g., Ilfeld splint)
. Perform a closed reduction and spica casting
. Perform an open reduction and pelvic osteotomy
. Discontinue treatment and observe until skeletal maturity

Correct Answer & Explanation

. Continue Pavlik harness for an additional 4 weeks

Explanation

If a Pavlik harness fails to achieve reduction within 3 to 4 weeks, it should be discontinued to prevent "Pavlik harness disease" (abrading the posterior acetabulum). The next standard step is closed reduction and spica casting.

Question 875

Topic: Pediatric Hip

Which of the following radiographic findings on an AP pelvis is most indicative of developmental dysplasia of the hip (DDH) in an 8-month-old child?

. Acetabular index of 15 degrees
. Femoral head ossific nucleus located in the lower inner quadrant of Perkin and Hilgenreiner lines
. Disruption of Shenton's line
. Alpha angle greater than 60 degrees
. Presence of the teardrop sign

Correct Answer & Explanation

. Acetabular index of 15 degrees

Explanation

In DDH, the femoral head typically migrates superolaterally, causing a break in Shenton's line. A normal hip has the ossific nucleus in the lower inner quadrant formed by Perkin and Hilgenreiner lines.

Question 876

Topic: Pediatric Hip

A 6-week-old female is undergoing treatment for developmental dysplasia of the hip with a Pavlik harness. During a follow-up visit, the mother notes the child is no longer kicking her leg on the affected side. On examination, active knee extension is absent, but the hip remains well reduced. What is the most appropriate next step in management?

. Continue the harness and reassure the mother
. Adjust the anterior strap to increase hip flexion
. Remove the harness and give the family a brief holiday
. Switch to a rigid hip abduction orthosis
. Perform a closed reduction and spica casting

Correct Answer & Explanation

. Continue the harness and reassure the mother

Explanation

Absent knee extension indicates a femoral nerve palsy, the most common nerve palsy associated with the Pavlik harness. The harness should be removed temporarily to allow the nerve to recover, which usually happens within a few days to weeks.

Question 877

Topic: Pediatric Hip

An 8-year-old boy presents with an acute on chronic slipped capital femoral epiphysis. His height and weight are both at the 25th percentile for his age. Which of the following laboratory studies is most strongly indicated?

. Fasting blood glucose
. Thyroid-stimulating hormone (TSH)
. Rheumatoid factor
. HLA-B27
. Serum calcium

Correct Answer & Explanation

. Fasting blood glucose

Explanation

SCFE in atypical patients (age younger than 10, or weight below the 50th percentile) raises strong suspicion for an underlying endocrine or metabolic disorder. Hypothyroidism is a common cause, making TSH an essential screening test.

Question 878

Topic: Pediatric Hip

A 13-year-old obese boy presents to the emergency department with severe right hip pain after a minor fall. He is unable to bear weight on the right leg, even with crutches. Radiographs confirm a severe slipped capital femoral epiphysis (SCFE). Which of the following represents the highest risk of complication for this patient?

. Chondrolysis
. Femoroacetabular impingement
. Osteonecrosis (Avascular necrosis)
. Leg length discrepancy
. Contralateral SCFE

Correct Answer & Explanation

. Chondrolysis

Explanation

Inability to bear weight defines an unstable SCFE according to the Loder classification. Unstable SCFE carries a significantly higher risk of osteonecrosis (up to 47%) compared to stable SCFE.

Question 879

Topic: Pediatric Hip

A 12-year-old boy is scheduled for in situ pinning of a left-sided slipped capital femoral epiphysis. Prophylactic pinning of the asymptomatic right hip is most strongly recommended if the patient also has:

. Obesity
. Renal osteodystrophy
. A family history of SCFE
. A slip angle greater than 50 degrees on the left
. Open triradiate cartilage

Correct Answer & Explanation

. Obesity

Explanation

Prophylactic contralateral pinning is highly recommended in patients with endocrine or metabolic disorders, such as renal osteodystrophy or hypothyroidism, due to a very high risk of bilateral involvement.

Question 880

Topic: Pediatric Hip

When performing a closed reduction and spica casting for a 9-month-old with developmental dysplasia of the hip, a percutaneous adductor tenotomy is often performed. The primary purpose of this tenotomy is to:

. Prevent posterior subluxation
. Increase the safe zone of Ramsey
. Decrease the risk of femoral nerve palsy
. Prevent superior migration of the femoral head
. Improve acetabular remodeling

Correct Answer & Explanation

. Prevent posterior subluxation

Explanation

The adductor tenotomy relieves medial tension, allowing for adequate abduction without excessive pressure on the femoral head. This widens the "safe zone" of Ramsey and minimizes the risk of avascular necrosis.

Test Yourself

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

On this Page