Menu

4. Pediatrics MCQs

Practice Set 145 of 334

This practice set contains high-yield board review questions covering key concepts in 4. Pediatrics. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.

Question 2881

Topic: Pediatric Upper Extremity & Spine

A 6-year-old boy sustains a completely displaced extension-type supracondylar humerus fracture. On presentation, the hand is pink but the radial pulse is absent. After closed reduction and percutaneous pinning, the fracture is anatomically reduced, the hand remains pink, but the radial pulse is still absent. What is the most appropriate next step in management?

. Observe and admit for serial neurovascular checks
. Immediate open exploration of the brachial artery
. Perform a brachial artery angiogram
. Remove pins and hyper-extend the elbow
. Consult vascular surgery for immediate bypass

Correct Answer & Explanation

. Observe and admit for serial neurovascular checks

Explanation

In a pulseless but well-perfused (pink) hand following reduction and pinning of a supracondylar humerus fracture, observation is recommended as collateral circulation is adequate. Exploration is indicated if the hand is pulseless and white (poorly perfused).

Question 2882

Topic: Pediatric Hip

A 4-month-old female with developmental dysplasia of the hip (DDH) is being treated with a Pavlik harness. During a follow-up visit, the parents report she has stopped kicking her right leg. Examination reveals decreased active extension of the right knee, but she withdraws to pain. What is the most likely cause, and what is the appropriate management?

. Femoral nerve palsy; discontinue harness
. Sciatic nerve palsy; discontinue harness
. Obturator nerve palsy; adjust harness
. Femoral nerve palsy; loosen anterior straps only
. Septic arthritis; immediate hip aspiration

Correct Answer & Explanation

. Femoral nerve palsy; discontinue harness

Explanation

Femoral nerve palsy is a known complication of Pavlik harness use, often due to hyperflexion. The appropriate management is temporary discontinuation of the harness until neurologic function returns.

Question 2883

Topic: Pediatric Upper Extremity & Spine

Which of the following factors represents the highest risk for curve progression in a 12-year-old girl with Adolescent Idiopathic Scoliosis (AIS)?

. Risser 0 with an open triradiate cartilage
. Risser 2 with a closed triradiate cartilage
. Menarche 1 year ago
. Double major curve of 20 degrees
. Lumbar curve of 25 degrees

Correct Answer & Explanation

. Risser 0 with an open triradiate cartilage

Explanation

Peak height velocity and maximal curve progression occur just before or during Risser 0 and open triradiate cartilages. An open triradiate cartilage is a strong predictor of high remaining growth potential and curve progression.

Question 2884

Topic: Pediatric Hip

A newborn girl with arthrogryposis multiplex congenita is found to have bilateral rigid, irreducible teratologic hip dislocations. What is the most appropriate management?

. Immediate application of a Pavlik harness
. Closed reduction and spica casting
. Open reduction prior to walking age
. Bilateral proximal femoral osteotomies at age 5
. Observation and supportive care only

Correct Answer & Explanation

. Immediate application of a Pavlik harness

Explanation

Teratologic hip dislocations (e.g., in arthrogryposis or spina bifida) are rigid and fail conservative management like Pavlik harnesses. Open reduction is typically required and is usually performed prior to walking age.

Question 2885

Topic: Pediatric Hip

A 13-year-old obese boy undergoes in-situ pinning for a unilateral stable slipped capital femoral epiphysis (SCFE). Which of the following is the strongest indication for prophylactic pinning of the contralateral hip?

. Male gender
. Obesity (>95th percentile BMI)
. Endocrine disorder (e.g., hypothyroidism)
. Age > 14 years
. African-American descent

Correct Answer & Explanation

. Male gender

Explanation

Prophylactic pinning of the contralateral hip is highly recommended in patients with SCFE associated with an underlying endocrine disorder (like hypothyroidism or renal osteodystrophy) due to the high risk of bilateral involvement.

Question 2886

Topic: Pediatric Upper Extremity & Spine

In the Lenke classification for Adolescent Idiopathic Scoliosis, a curve is considered "structural" if it fails to reduce to less than what Cobb angle on side-bending radiographs?

. 15 degrees
. 20 degrees
. 25 degrees
. 30 degrees
. 40 degrees

Correct Answer & Explanation

. 15 degrees

Explanation

According to the Lenke classification, a minor curve is structural if the Cobb angle is 25 degrees or greater on a side-bending radiograph, or if there is kyphosis of +20 degrees or more across the region.

Question 2887

Topic: 4. Pediatrics

An 11-year-old boy presents with progressive ulnar deviation of the wrist 18 months after sustaining a distal radius Salter-Harris II fracture. Radiographs show a complete premature closure of the distal radius physis, with continued growth of the distal ulna (ulnar plus variance). What is the most appropriate surgical treatment?

. Distal radius osteotomy with lengthening and ulnar epiphysiodesis
. Excision of the physeal bar with fat interposition
. Darrach procedure
. Suave-Kapandji procedure
. Ulnar lengthening only

Correct Answer & Explanation

. Distal radius osteotomy with lengthening and ulnar epiphysiodesis

Explanation

For a completely closed distal radius physis with symptomatic ulnar positive variance in a growing child, restoring alignment via distal radius lengthening and preventing further discrepancy by halting distal ulna growth is indicated. Bar excision is ineffective if the physis is completely closed.

Question 2888

Topic: 4. Pediatrics

On an AP pelvis radiograph of a 6-month-old infant evaluated for DDH, the femoral head ossific nucleus is absent. Which of the following describes the normal expected position of the proximal femoral metaphysis?

. Lateral to Perkin's line and superior to Hilgenreiner's line
. Medial to Perkin's line and inferior to Hilgenreiner's line
. Lateral to Perkin's line and inferior to Hilgenreiner's line
. Medial to Perkin's line and superior to Hilgenreiner's line
. Intersecting the teardrop centrally

Correct Answer & Explanation

. Lateral to Perkin's line and superior to Hilgenreiner's line

Explanation

In a normal hip, the proximal medial metaphysis should be situated in the lower inner quadrant. This quadrant is formed by the intersection of Perkin's line (vertical) and Hilgenreiner's line (horizontal).

Question 2889

Topic: 4. Pediatrics

A 14-year-old boy sustains a twisting injury to his ankle. Radiographs show a Salter-Harris III fracture of the anterolateral aspect of the distal tibial epiphysis. What is the anatomical rationale for this specific fracture pattern?

. The physis closes centrally first, then anterolaterally, then posteromedially.
. The physis closes centrally first, then posteromedially, then anterolaterally.
. The anterior tibiofibular ligament pulls off the closed physis.
. The deltoid ligament avulses the medial malleolus, propagating laterally.
. The physis closes uniformly, but the lateral aspect is mechanically weaker.

Correct Answer & Explanation

. The physis closes centrally first, then anterolaterally, then posteromedially.

Explanation

The distal tibial physis closes in a specific pattern: central, then posteromedial, and finally anterolateral. A juvenile Tillaux fracture occurs when the anterolateral portion is still open and is avulsed by the anterior inferior tibiofibular ligament.

Question 2890

Topic: 4. Pediatrics

A 6-week-old female is treated with a Pavlik harness for developmental dysplasia of the hip (DDH). At her 2-week follow-up, the mother notes that the child is no longer kicking her leg on the affected side. On examination, the infant has decreased active knee extension but normal ankle movements. What is the most appropriate next step in management?

. Adjust the anterior straps to increase hip flexion
. Remove the harness and observe
. Switch to a rigid abduction orthosis
. Proceed to closed reduction and spica casting
. Obtain an immediate MRI of the lumbar spine

Correct Answer & Explanation

. Adjust the anterior straps to increase hip flexion

Explanation

The child has developed a femoral nerve palsy, a known complication of hyperflexion in a Pavlik harness. The harness should be removed or the anterior straps loosened; typically, complete removal and observation is recommended until full neurologic function returns.

Question 2891

Topic: Pediatric Upper Extremity & Spine

A 12-year-old premenarchal girl presents with adolescent idiopathic scoliosis. Standing radiographs demonstrate a right thoracic curve of 32 degrees. Her Risser stage is 0. What is the most appropriate management?

. Observation with standing radiographs in 6 months
. Thoracolumbosacral orthosis (TLSO) bracing
. Physical therapy and Schroth exercises alone
. Posterior spinal fusion
. Anterior vertebral body tethering

Correct Answer & Explanation

. Observation with standing radiographs in 6 months

Explanation

Bracing is strictly indicated for skeletally immature patients (Risser 0-2, premenarchal) with curves between 25 and 45 degrees. The primary goal of a TLSO brace is to halt curve progression to a surgical magnitude during the rapid adolescent growth spurt.

Question 2892

Topic: Pediatric Upper Extremity & Spine

A 6-year-old boy sustains a completely displaced posteromedial supracondylar humerus fracture. On presentation, the hand is pink and warm, but the radial pulse is absent. Capillary refill is 2 seconds. What is the most appropriate initial management?

. Urgent closed reduction and percutaneous pinning
. Immediate CT angiography of the upper extremity
. Open exploration of the brachial artery
. Application of a long arm cast in 120 degrees of flexion
. Observation and admission for neurovascular checks

Correct Answer & Explanation

. Urgent closed reduction and percutaneous pinning

Explanation

A "pulseless, pink" hand in the setting of a completely displaced supracondylar humerus fracture indicates adequate collateral perfusion. The immediate next step is urgent closed reduction and percutaneous pinning, which often restores the pulse by removing pressure from the brachial artery.

Question 2893

Topic: 4. Pediatrics

A 3-year-old boy is diagnosed with congenital scoliosis secondary to a fully segmented hemivertebra at T8. Which of the following screening tests must be routinely obtained to evaluate for associated conditions?

. Echocardiogram and renal ultrasound
. Pulmonary function tests
. MRI of the brain
. DEXA scan
. Genetic testing for FGFR3 mutation

Correct Answer & Explanation

. Echocardiogram and renal ultrasound

Explanation

Congenital scoliosis is highly associated with VACTERL anomalies, including congenital cardiac and renal defects. All patients must be screened with an echocardiogram, a renal ultrasound, and an MRI of the entire neuroaxis to rule out intraspinal anomalies.

Question 2894

Topic: 4. Pediatrics

On an anteroposterior pelvis radiograph of a 6-month-old infant being evaluated for DDH, the proximal femoral ossific nucleus is located in the upper outer quadrant formed by Hilgenreiner's and Perkin's lines. What does this radiographic finding indicate?

. Normal hip joint articulation
. Superior and lateral dislocation of the hip
. Inferior and medial subluxation of the hip
. Congenital coxa vara
. Slipped capital femoral epiphysis

Correct Answer & Explanation

. Normal hip joint articulation

Explanation

In a normal hip, the proximal femoral ossific nucleus should be located in the lower inner (inferomedial) quadrant formed by the intersection of Hilgenreiner's (horizontal) and Perkin's (vertical) lines. Location in the upper outer quadrant confirms a lateral and superior dislocation.

Question 2895

Topic: 4. Pediatrics

A 13-year-old boy complains of ankle pain after a twisting injury. Radiographs show a fracture of the distal tibia that appears as a Salter-Harris III on the AP view and a Salter-Harris II on the lateral view (Triplane fracture). What is the normal closure pattern of the distal tibial physis that predisposes adolescents to this injury?

. Lateral to medial
. Anterior to posterior
. Central to peripheral
. Central, then anteromedial, then posteromedial, then lateral
. Peripheral to central

Correct Answer & Explanation

. Lateral to medial

Explanation

The distal tibial physis closes asymmetrically in a specific pattern: central, anteromedial, posteromedial, and finally anterolateral. This asymmetric closure dictates the fracture pattern seen in transitional injuries like Tillaux and Triplane fractures.

Question 2896

Topic: Pediatric Hip

A 4-week-old boy is fitted with a Pavlik harness for an Ortolani-positive right hip. To ensure proper positioning and minimize neurovascular or ischemic complications, how should the harness straps be adjusted?

. Anterior straps flex hips to 120 degrees; posterior straps allow adduction to neutral
. Anterior straps flex hips to 90-100 degrees; posterior straps limit adduction to neutral
. Anterior straps flex hips to 60 degrees; posterior straps force abduction to 80 degrees
. Anterior straps flex hips to 90 degrees; posterior straps force abduction to 90 degrees
. Anterior straps flex hips to 120 degrees; posterior straps force abduction to 60 degrees

Correct Answer & Explanation

. Anterior straps flex hips to 120 degrees; posterior straps allow adduction to neutral

Explanation

The Pavlik harness should flex the hips to approximately 90-100 degrees to prevent femoral nerve palsy (caused by hyperflexion). The posterior straps should limit adduction to neutral to prevent redislocation while avoiding forced abduction, which causes avascular necrosis.

Question 2897

Topic: Pediatric Upper Extremity & Spine

A 13-year-old female with adolescent idiopathic scoliosis presents for routine evaluation. Radiographs reveal a 22-degree right thoracic curve. Evaluation of the iliac apophysis demonstrates ossification covering the anterior 75% of the iliac crest, but not yet reaching the posterior superior iliac spine (PSIS). What Risser stage does this represent?

. Risser 1
. Risser 2
. Risser 3
. Risser 4
. Risser 5

Correct Answer & Explanation

. Risser 1

Explanation

The Risser classification evaluates skeletal maturity based on the ossification of the iliac apophysis. Risser 3 corresponds to ossification covering 50% to 75% of the iliac crest. Risser 4 covers 75% to 100%, and Risser 5 indicates complete fusion to the ilium.

Question 2898

Topic: Pediatric Hip

A 4-month-old girl has been treated with a Pavlik harness for 4 weeks for an irreducible developmental dysplasia of the hip (DDH). Repeat ultrasound demonstrates a persistently dislocated left hip without significant improvement in the alpha angle. What is the most appropriate next step in management?

. Continue Pavlik harness for 4 more weeks
. Switch to a rigid abduction orthosis
. Closed reduction and spica casting under anesthesia
. Open reduction and femoral shortening osteotomy
. Observation until 1 year of age

Correct Answer & Explanation

. Continue Pavlik harness for 4 more weeks

Explanation

Prolonged use of a Pavlik harness in an irreducible hip beyond 3 to 4 weeks can cause 'Pavlik harness disease', damaging the posterior acetabulum. The appropriate next step is a closed reduction and spica casting under anesthesia.

Question 2899

Topic: Pediatric Upper Extremity & Spine

A 6-year-old boy sustains a completely displaced, extension-type supracondylar humerus fracture. On presentation, the hand is pink but the radial pulse is absent. After successful closed reduction and percutaneous pinning, the hand remains pink and capillary refill is brisk, but the radial pulse remains unpalpable. What is the most appropriate next step?

. Immediate vascular exploration
. Arteriography
. Remove pins and reposition the fracture
. Close clinical observation
. Sympathetic nerve block

Correct Answer & Explanation

. Immediate vascular exploration

Explanation

In a pulseless, pink hand following adequate reduction and pinning of a supracondylar fracture, the extremity has adequate collateral perfusion. Close clinical observation is recommended as the palpable pulse often returns gradually without surgical exploration.

Question 2900

Topic: Pediatric Hip

An 18-month-old girl is newly diagnosed with developmental dysplasia of the right hip (DDH). The hip is completely dislocated but reducible on examination. Which of the following is the most appropriate initial treatment?

. Pavlik harness
. Closed reduction and spica casting
. Open reduction and capsulorrhaphy
. Salter innominate osteotomy
. Observation until age 2

Correct Answer & Explanation

. Pavlik harness

Explanation

In a child older than 6 months of age who has begun to stand or walk, the Pavlik harness has an unacceptably high failure rate. Closed reduction and spica casting is the preferred initial treatment for typical DDH in children aged 6 to 18 months.

Test Yourself

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

On this Page