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4. Pediatrics MCQs

Practice Set 184 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 3661

Topic: Pediatric Hip
A 7-year-old boy is diagnosed with early-stage Legg-Calvé-Perthes disease. He has a limp and restricted hip abduction. Which of the following factors at the time of presentation is considered the most significant indicator of a poor long-term prognosis?
. Male sex
. Age greater than 8 years
. Loss of internal rotation
. Catterall group II classification
. Slight widening of the medial joint space

Correct Answer & Explanation

. Age greater than 8 years

Explanation

Age at onset is the single most important prognostic factor in Legg-Calvé-Perthes disease. Patients older than 8 years at the onset of symptoms generally have a worse prognosis due to having less remaining growth for femoral head remodeling.

Question 3662

Topic: Pediatric Lower Extremity

A 4-year-old child with a history of idiopathic clubfoot treated successfully with the Ponseti method presents with a dynamic supination deformity during the swing phase of gait. Passive range of motion of the ankle and foot is full. What is the most appropriate management?

. Repeat manipulation and serial casting
. Full tibialis anterior tendon transfer to the lateral cuneiform
. Split tibialis anterior tendon transfer
. Extensor hallucis longus transfer to the first metatarsal head
. Tibialis posterior tendon lengthening

Correct Answer & Explanation

. Full tibialis anterior tendon transfer to the lateral cuneiform

Explanation

Dynamic supination in a relapsed clubfoot, without fixed deformity, is best managed with a full tibialis anterior tendon transfer to the lateral cuneiform. This converts the deforming supinating force into a corrective dorsiflexion force.

Question 3663

Topic: Pediatric Hip

A 6-month-old girl with Developmental Dysplasia of the Hip (DDH) undergoes closed reduction and spica casting. Which of the following intraoperative positioning parameters is most strongly associated with an increased risk of avascular necrosis (AVN) of the femoral head?

. Flexion of 100 degrees
. Abduction of 60 degrees
. Internal rotation of 10 degrees
. Extension of 10 degrees
. External rotation of 15 degrees

Correct Answer & Explanation

. Abduction of 60 degrees

Explanation

Excessive abduction (greater than 60 degrees) in a spica cast places the medial circumflex femoral artery under tension, significantly increasing the risk of avascular necrosis. The "human position" emphasizes safe limits of abduction to prevent this complication.

Question 3664

Topic: Pediatric Hip

A 13-year-old obese boy presents with sudden severe right hip pain and inability to bear weight after a minor fall. Radiographs confirm an unstable slipped capital femoral epiphysis (SCFE). What is the primary proposed benefit of performing an urgent capsulotomy and gentle reduction prior to pinning?

. Reduces the risk of chondrolysis
. Reduces the risk of avascular necrosis
. Prevents contralateral slip
. Enhances limb length equalization
. Prevents future femoroacetabular impingement

Correct Answer & Explanation

. Reduces the risk of avascular necrosis

Explanation

In unstable SCFE, urgent decompression via capsulotomy and gentle reduction decreases intracapsular pressure and restores capsular blood flow. This intervention is thought to lower the historically high risk of avascular necrosis in unstable slips.

Question 3665

Topic: Pediatric Hip
A 7-year-old boy is diagnosed with Legg-Calvé-Perthes disease. Radiographs show radiolucency and fragmentation. The lateral pillar of the femoral head maintains 40% of its original height. According to the Herring Lateral Pillar Classification, what is the grade and expected outcome without surgical containment?
. Group A, good outcome
. Group B, moderate outcome
. Group B/C, poor outcome
. Group C, poor outcome
. Group C, moderate outcome

Correct Answer & Explanation

. Group C, poor outcome

Explanation

Herring Group C is defined as less than 50% maintenance of the lateral pillar height. These patients generally have a poor natural history and a higher risk of developing a non-spherical femoral head.

Question 3666

Topic: 4. Pediatrics
A 3-year-old boy presents with progressive bilateral genu varum. Standing radiographs reveal metaphyseal-diaphyseal angles of 18 degrees bilaterally, with prominent medial metaphyseal beaking. What is the most appropriate initial management?
. Reassurance and annual follow-up
. Vitamin D and calcium supplementation
. Knee-ankle-foot orthoses (KAFOs)
. Guided growth with tension band plates
. Proximal tibial corrective osteotomies

Correct Answer & Explanation

. Knee-ankle-foot orthoses (KAFOs)

Explanation

A metaphyseal-diaphyseal angle greater than 16 degrees strongly suggests infantile Blount disease. In a child under 3 to 4 years old with early Langenskiöld stages, bracing with KAFOs is the appropriate initial treatment.

Question 3667

Topic: 4. Pediatrics

A 5-year-old girl with spastic quadriplegic cerebral palsy (GMFCS Level V) is evaluated for hip surveillance. Her migration percentage (MP) on an AP pelvis radiograph is 45%. Clinically, she has 20 degrees of hip abduction bilaterally. What is the most appropriate management?

. Continued radiographic surveillance every 6 months
. Botulinum toxin injections to the adductors
. Adductor tenotomies and obturator neurectomies
. Bilateral varus derotational osteotomies (VDRO) with pelvic osteotomies
. Total hip arthroplasty

Correct Answer & Explanation

. Bilateral varus derotational osteotomies (VDRO) with pelvic osteotomies

Explanation

In non-ambulatory children with CP, a migration percentage >40% with restricted abduction indicates significant hip subluxation that will not resolve with soft tissue releases alone. Bony reconstruction with VDRO and often a pelvic osteotomy is required.

Question 3668

Topic: Pediatric Upper Extremity & Spine
A 6-year-old boy sustains a completely displaced (Gartland Type III) posteromedial supracondylar humerus fracture. On examination, the hand is pink and warm, but the radial pulse is absent. After anatomical closed reduction and percutaneous pinning, the hand remains pink and the pulse remains absent. What is the next best step?
. Immediate open exploration of the brachial artery
. Immediate CT angiography
. Observation and admission for close neurovascular monitoring
. Removal of pins and open reduction
. Administration of intravenous heparin

Correct Answer & Explanation

. Observation and admission for close neurovascular monitoring

Explanation

A "pulseless, pink" hand after a well-reduced supracondylar fracture usually indicates adequate collateral circulation. Current guidelines recommend close observation over immediate vascular exploration, provided the limb remains well-perfused.

Question 3669

Topic: Pediatric Upper Extremity & Spine

A 12-year-old premenarcheal girl with a Risser stage of 0 presents with a right thoracic adolescent idiopathic scoliosis (AIS). Her curve measures 30 degrees. Which of the following represents the most appropriate management?

. Observation with radiographs in 6 months
. Immediate posterior spinal fusion
. Full-time Thoracolumbosacral Orthosis (TLSO) bracing
. Nighttime bending brace only
. Vertebral body tethering

Correct Answer & Explanation

. Full-time Thoracolumbosacral Orthosis (TLSO) bracing

Explanation

In an immature patient (Risser 0, premenarcheal) with an AIS curve between 25 and 40 degrees, full-time TLSO bracing is indicated to halt progression. Observation is inappropriate given her high risk for rapid curve worsening.

Question 3670

Topic: Pediatric Hip

A 12-year-old boy is diagnosed with a unilateral stable slipped capital femoral epiphysis (SCFE). Which of the following factors most strongly supports the decision for prophylactic pinning of the contralateral hip?

. Male gender
. Obesity (BMI >95th percentile)
. Open triradiate cartilage
. Symptom duration greater than 3 months
. Slip angle of 30 degrees on the affected side

Correct Answer & Explanation

. Open triradiate cartilage

Explanation

An open triradiate cartilage indicates significant remaining skeletal growth, making it one of the strongest predictive risk factors for a subsequent contralateral slip. Prophylactic pinning is highly recommended in these high-risk patients.

Question 3671

Topic: Pediatric Hip

Which of the following is considered the most common extra-articular block to closed reduction in developmental dysplasia of the hip?

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

Correct Answer & Explanation

. Iliopsoas tendon

Explanation

The iliopsoas tendon is the most common extra-articular block to closed reduction in DDH, often causing an hourglass constriction of the capsule. The pulvinar, ligamentum teres, inverted limbus, and transverse acetabular ligament are intra-articular blocks.

Question 3672

Topic: Pediatric Hip

Which of the following factors at presentation is most strongly predictive of developing avascular necrosis following a slipped capital femoral epiphysis (SCFE)?

. Degree of slip angle
. Patient weight
. Instability defined as the inability to bear weight
. Age at presentation
. Bilateral involvement

Correct Answer & Explanation

. Instability defined as the inability to bear weight

Explanation

The inability to bear weight (instability) is the strongest predictor of avascular necrosis in SCFE. Unstable SCFE has an AVN rate approaching 50 percent, compared to almost zero for stable SCFE.

Question 3673

Topic: Pediatric Lower Extremity

An infant with idiopathic clubfoot is being treated via the Ponseti casting method. The foot has been successfully abducted to 60 degrees, but dorsiflexion is limited to neutral. What is the most appropriate next step in management?

. Change the cast and continue abduction to 70 degrees
. Perform a percutaneous Achilles tenotomy
. Perform a tibialis anterior tendon transfer
. Perform a comprehensive posteromedial release
. Apply a dynamic ankle-foot orthosis

Correct Answer & Explanation

. Perform a percutaneous Achilles tenotomy

Explanation

Once abduction reaches 60 degrees and the heel is in valgus, residual equinus should be corrected with a percutaneous Achilles tenotomy. This is required in roughly 80 to 90 percent of idiopathic clubfeet treated with the Ponseti method.

Question 3674

Topic: Pediatric Hip

An 8-year-old boy presents with lateral pillar B/C border Legg-Calve-Perthes disease. According to current evidence-based guidelines, what is the most appropriate management?

. Observation alone with non-weight bearing
. Application of bilateral Petrie casts
. Proximal femoral varus osteotomy or pelvic osteotomy
. Core decompression of the femoral head
. Articulated hip distraction external fixation

Correct Answer & Explanation

. Proximal femoral varus osteotomy or pelvic osteotomy

Explanation

Surgical containment, such as a proximal femoral varus osteotomy or pelvic osteotomy, is indicated for children over 8 years of age with lateral pillar B or B/C border Perthes disease. It provides better spherical outcomes than non-operative management in this age group.

Question 3675

Topic: Pediatric Upper Extremity & Spine
A 6-year-old girl sustains a displaced Gartland III supracondylar humerus fracture. On examination, the radial pulse is absent, but the hand is warm, pink, and has capillary refill under 2 seconds. What is the most appropriate initial management?
. Immediate open exploration of the brachial artery
. Observation and splinting in 90 degrees of flexion
. CT angiogram of the upper extremity
. Urgent closed reduction and percutaneous pinning
. Immediate administration of intravenous heparin

Correct Answer & Explanation

. Urgent closed reduction and percutaneous pinning

Explanation

A pulseless, pink hand indicates adequate collateral circulation. The most appropriate initial step is urgent closed reduction and percutaneous pinning, which frequently restores the palpable pulse.

Question 3676

Topic: 4. Pediatrics

A 7-year-old non-ambulatory child with spastic quadriplegic cerebral palsy has a Reimers migration index of 45 percent. Radiographs demonstrate significant coxa valga and acetabular dysplasia. What is the most appropriate surgical intervention?

. Adductor and psoas tenotomy alone
. Intrathecal baclofen pump insertion
. Selective dorsal rhizotomy
. Total hip arthroplasty
. Varus derotational osteotomy (VDRO) with pelvic osteotomy

Correct Answer & Explanation

. Varus derotational osteotomy (VDRO) with pelvic osteotomy

Explanation

In a child with CP and a migration percentage greater than 40 percent combined with bony dysplasia, soft tissue release alone is insufficient. Bony reconstruction with a VDRO and a volume-reducing pelvic osteotomy is required.

Question 3677

Topic: Pediatric Hip

A 13-year-old boy develops severe hip pain and progressive loss of motion six months after undergoing in situ single screw fixation for a stable SCFE. Radiographs show significant joint space narrowing. What is the most likely etiology of this complication?

. Unrecognized avascular necrosis
. Deep surgical site infection
. Prominent hardware penetrating the joint
. Concurrent untreated hypothyroidism
. Autoimmune inflammatory arthropathy

Correct Answer & Explanation

. Prominent hardware penetrating the joint

Explanation

Chondrolysis in the setting of treated SCFE is most commonly caused by unrecognized penetration of the hardware into the joint space. It presents with pain, stiffness, and radiographic joint space narrowing.

Question 3678

Topic: 4. Pediatrics

Which of the following radiographic findings is recognized as one of Catterall's head-at-risk signs in Legg-Calve-Perthes disease?

. Medial subluxation of the femoral head
. Narrowing of the teardrop distance
. Gage sign
. Central acetabular osteophyte
. Acetabular retroversion

Correct Answer & Explanation

. Gage sign

Explanation

Catterall's head-at-risk signs include Gage sign (a V-shaped lucency in the lateral epiphysis/metaphysis), lateral subluxation, lateral epiphyseal calcification, horizontal physis, and metaphyseal cysts.

Question 3679

Topic: Pediatric Upper Extremity & Spine

A 14-year-old premenarchal girl (Risser 0) presents with adolescent idiopathic scoliosis. Standing radiographs demonstrate a right thoracic curve of 35 degrees. What is the recommended treatment?

. Observation with clinical follow-up in 1 year
. Physical therapy focusing on the Schroth method alone
. TLSO bracing for 16 to 23 hours a day
. Posterior spinal fusion with pedicle screws
. Anterior vertebral body tethering

Correct Answer & Explanation

. TLSO bracing for 16 to 23 hours a day

Explanation

In a growing child (Risser 0-2) with an adolescent idiopathic scoliosis curve measuring between 25 and 45 degrees, TLSO bracing for a minimum of 16-18 hours daily is the standard of care to prevent progression.

Question 3680

Topic: Pediatric Hip

A 4-month-old infant with developmental dysplasia of the hip has been treated with a Pavlik harness. At the 4-week follow-up, an ultrasound demonstrates that the hip remains dislocated. What is the primary risk of continuing the Pavlik harness in this patient for an additional 3 weeks?

. Avascular necrosis of the femoral head
. Femoral nerve palsy
. Posterior acetabular rim damage
. Acetabular dysplasia
. Superior subluxation of the femoral head

Correct Answer & Explanation

. Posterior acetabular rim damage

Explanation

Continuing a Pavlik harness in an unreduced hip beyond 3 to 4 weeks can cause severe pressure on the posterior acetabulum. This leads to "Pavlik harness disease," which degrades the acetabulum and makes subsequent closed reduction much more difficult.

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