Menu

4. Pediatrics MCQs

Practice Set 266 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 5301

Topic: 4. Pediatrics
Which type of Osteogenesis Imperfecta (OI) is considered the most severe form compatible with survival past the neonatal period, typically characterized by severe progressive deformity, extremely short stature, and dentinogenesis imperfecta?
. Type I
. Type II
. Type III
. Type IV
. Type V

Correct Answer & Explanation

. Type III

Explanation

According to the Sillence classification for OI: Type I is mild (blue sclera, normal height, rare deformity). Type II is perinatal lethal. Type III is the most severe non-lethal form, characterized by progressive deformity, very short stature, dentinogenesis imperfecta, and normal to grayish sclerae. Type IV is intermediate in severity.

Question 5302

Topic: Pediatric Hip

An 8-year-old boy with Legg-Calve-Perthes disease is evaluated.

Radiographs obtained during the fragmentation phase demonstrate that only 40% of the lateral pillar of the femoral head has maintained its normal radiolucent height. According to the Herring Lateral Pillar Classification, what is the assigned grade, and what is the expected prognosis?

. Group B; excellent prognosis with conservative care
. Group B; fair prognosis, requires surgical containment
. Group C; poor prognosis regardless of treatment modality
. Group C; excellent prognosis with timely femoral varus osteotomy
. Group B/C; excellent prognosis with bracing

Correct Answer & Explanation

. Group C; poor prognosis regardless of treatment modality

Explanation

Herring Lateral Pillar Group C indicates that less than 50% of the lateral pillar height is maintained during the fragmentation phase. These hips have a poor prognosis for spherical congruency (often developing Stulberg IV or V outcomes) and generally perform poorly regardless of the chosen treatment modality, especially in children older than 8 years.

Question 5303

Topic: Pediatric Hip

A 12-year-old boy weighing 95 kg presents with a unilateral stable slipped capital femoral epiphysis (SCFE). Which of the following is the strongest indication for prophylactic in-situ pinning of the asymptomatic, normal contralateral hip?

. Patient age less than 13 years
. Male gender
. Initial slip angle of 40 degrees
. Presence of an underlying endocrinopathy
. Body mass index greater than the 95th percentile

Correct Answer & Explanation

. Presence of an underlying endocrinopathy

Explanation

While young age (boys <12, girls <10) and open triradiate cartilage increase the risk for contralateral SCFE, the strongest absolute indication for prophylactic pinning is an underlying endocrinopathy (e.g., hypothyroidism, growth hormone deficiency, renal osteodystrophy) or prior pelvic radiation therapy, as the risk of a contralateral slip approaches 50-100% in these populations.

Question 5304

Topic: Pediatric Upper Extremity & Spine
A newborn is noted to have severe bilateral radial deviation of the wrists, absent thumbs, and an absent radius on radiographs. An echocardiogram reveals an atrial septal defect (ASD). Which of the following syndromes is most likely?
. TAR syndrome (Thrombocytopenia-Absent Radius)
. Holt-Oram syndrome
. Fanconi anemia
. VACTERL association
. Cornélia de Lange syndrome

Correct Answer & Explanation

. Holt-Oram syndrome

Explanation

Holt-Oram syndrome is an autosomal dominant condition characterized by radial longitudinal deficiency (often bilateral with absent thumbs) and congenital heart defects, most commonly an ASD or VSD. TAR syndrome typically features an absent radius but importantly has present thumbs, distinguishing it from other causes of radial clubhand.

Question 5305

Topic: 4. Pediatrics

A 6-year-old child with spastic quadriplegic cerebral palsy (GMFCS Level V) undergoes routine hip surveillance.

The AP pelvic radiograph shows a Reimers Migration Percentage of 45% on the right hip. The hip is reducible, and there is no pain. Which of the following is the most appropriate management?

. Continued observation with annual radiographs
. Botulinum toxin injection to the adductor musculature
. Bilateral adductor and iliopsoas tenotomies
. Varus derotational osteotomy (VDRO) of the proximal femur with pelvic osteotomy
. Total hip arthroplasty

Correct Answer & Explanation

. Varus derotational osteotomy (VDRO) of the proximal femur with pelvic osteotomy

Explanation

In children with CP, a Reimers Migration Percentage (RMP) >40-50% indicates significant hip subluxation with bony dysplasia. While soft tissue releases are indicated for early subluxation (RMP 30-40%) in younger children, an RMP >40% typically requires bony reconstruction with a Varus Derotational Osteotomy (VDRO) and a pelvic osteotomy (e.g., Dega or San Diego) to prevent painful chronic dislocation.

Question 5306

Topic: 4. Pediatrics

A newborn is examined in the nursery and noted to have severe genu recurvatum with the tibia dislocated anteriorly on the femur. Which of the following conditions is most commonly associated with this presentation, and what is the primary initial treatment?

. Developmental dysplasia of the hip (DDH); serial casting in flexion
. Spina bifida; urgent open reduction
. Achondroplasia; Pavlik harness
. Larsen syndrome; observation
. Down syndrome; serial casting in extension

Correct Answer & Explanation

. Developmental dysplasia of the hip (DDH); serial casting in flexion

Explanation

Congenital dislocation of the knee (CDK) presents as a hyperextension deformity. It is strongly associated with developmental dysplasia of the hip (DDH) and clubfoot. Initial treatment for idiopathic CDK involves gentle manipulation and serial casting to gradually bring the knee into a flexed position.

Question 5307

Topic: Pediatric Upper Extremity & Spine

A 6-year-old boy falls on an outstretched hand and sustains an extension-type supracondylar humerus fracture. Upon neurologic examination, he is unable to flex the interphalangeal joint of his thumb and the distal interphalangeal joint of his index finger. Which of the following nerves is most likely injured?

. Radial nerve
. Ulnar nerve
. Anterior interosseous nerve
. Posterior interosseous nerve
. Musculocutaneous nerve

Correct Answer & Explanation

. Anterior interosseous nerve

Explanation

Anterior interosseous nerve (AIN) injury is the most common neurologic complication in extension-type supracondylar humerus fractures. It presents clinically as an inability to form the "OK" sign due to weakness of the flexor pollicis longus and flexor digitorum profundus.

Question 5308

Topic: Pediatric Hip

A 6-week-old female is being treated with a Pavlik harness for developmental dysplasia of the hip (DDH). At her one-week follow-up, the parents report she is not moving her right leg as much. Exam reveals decreased active knee extension on the affected side. What is the most appropriate next step in management?

. Continue the harness and re-evaluate in 1 week
. Adjust the anterior straps to increase hip flexion
. Adjust the posterior straps to decrease hip abduction
. Discontinue the harness temporarily and observe
. Immediately transition to a rigid hip spica cast

Correct Answer & Explanation

. Discontinue the harness temporarily and observe

Explanation

Transient femoral nerve palsy is a known complication of excessive hip flexion in a Pavlik harness, presenting as decreased active knee extension. The harness must be discontinued temporarily to allow for nerve recovery before resuming or altering treatment.

Question 5309

Topic: Pediatric Lower Extremity

A 3-year-old boy treated successfully with the Ponseti method for idiopathic clubfoot presents with an early relapse. He walks with a dynamic supination deformity of the foot during the swing phase of gait. Passive dorsiflexion is 15 degrees. After correcting any residual fixed deformities with a brief period of serial casting, what is the most appropriate surgical intervention?

. Fractional lengthening of the Achilles tendon
. Tibialis anterior tendon transfer to the lateral cuneiform
. Repeat percutaneous Achilles tenotomy
. Extensive posteromedial soft tissue release
. Lateral closing wedge calcaneal osteotomy

Correct Answer & Explanation

. Tibialis anterior tendon transfer to the lateral cuneiform

Explanation

Relapsed clubfoot presenting with dynamic supination in a child over 2.5 years of age is best treated with a tibialis anterior tendon transfer (TATT) to the lateral cuneiform. This eliminates the deforming supination force and balances the foot.

Question 5310

Topic: 4. Pediatrics
A 14-year-old boy presents with acute ankle pain after an external rotation injury. Radiographs demonstrate a Salter-Harris III fracture of the anterolateral aspect of the distal tibial epiphysis. Avulsion by which of the following structures is responsible for this fracture pattern?
. Anterior talofibular ligament
. Posterior inferior tibiofibular ligament
. Anterior inferior tibiofibular ligament
. Deltoid ligament
. Calcaneofibular ligament

Correct Answer & Explanation

. Anterior inferior tibiofibular ligament

Explanation

A juvenile Tillaux fracture is a Salter-Harris III fracture of the anterolateral distal tibia. It is caused by an avulsion force from the anterior inferior tibiofibular ligament (AITFL) during an external rotation injury as the physis begins to close asymmetrically.

Question 5311

Topic: 4. Pediatrics

A 5-year-old girl with spastic quadriplegic cerebral palsy is undergoing routine hip surveillance. Which of the following radiographic parameters is the most critical to monitor for predicting the risk of progressive hip subluxation and the need for reconstructive surgery?

. Acetabular index
. Center-edge angle of Wiberg
. Reimers migration percentage
. Neck-shaft angle
. Tonnis angle

Correct Answer & Explanation

. Reimers migration percentage

Explanation

Reimers migration percentage is the standard and most reliable radiographic measurement for monitoring hip displacement in children with cerebral palsy. A migration percentage exceeding 30% typically prompts consideration for soft tissue or bony reconstructive surgery.

Question 5312

Topic: Pediatric Upper Extremity & Spine

A 13-year-old premenarchal female presents for evaluation of a spinal deformity. Radiographs reveal a right thoracic curve with a Cobb angle of 32 degrees. Her Risser stage is 0. What is the most appropriate management?

. Observation with radiographs in 6 months
. Schroth physical therapy
. Thoracolumbosacral orthosis (TLSO) bracing
. Posterior spinal fusion
. Vertebral body tethering

Correct Answer & Explanation

. Thoracolumbosacral orthosis (TLSO) bracing

Explanation

TLSO bracing is indicated in skeletally immature patients (Risser 0-2, premenarchal) with adolescent idiopathic scoliosis who have a curve magnitude between 25 and 45 degrees. Bracing has been shown to significantly decrease the risk of curve progression to surgical magnitude.

Question 5313

Topic: Pediatric Hip

A 13-year-old obese boy with left hip pain after a minor fall is unable to bear weight, even with crutches. Radiographs confirm a severe slipped capital femoral epiphysis (SCFE). Compared to a patient with a stable SCFE, this patient is at significantly higher risk for which of the following complications?

. Chondrolysis
. Avascular necrosis (AVN)
. Femoroacetabular impingement
. Physeal arrest
. Premature osteoarthritis

Correct Answer & Explanation

. Avascular necrosis (AVN)

Explanation

An unstable SCFE is defined clinically by the inability to bear weight. It carries a markedly higher risk of avascular necrosis (AVN), reaching up to nearly 50%, due to the acute disruption of the epiphyseal blood supply.

Question 5314

Topic: 4. Pediatrics

A newborn is evaluated for a shortened right lower extremity and an absent lateral foot ray. Radiographs confirm fibular hemimelia. Which of the following is the most common associated ligamentous anomaly in the ipsilateral knee?

. Absent posterior cruciate ligament
. Absent anterior cruciate ligament
. Patellar duplication
. Congenital patellar dislocation
. Discoid lateral meniscus

Correct Answer & Explanation

. Absent anterior cruciate ligament

Explanation

Fibular hemimelia is a longitudinal limb deficiency characterized by a shortened tibia, absent fibula, and absent lateral rays. It is highly associated with knee instability, most commonly due to an absent or severely hypoplastic anterior cruciate ligament (ACL).

Question 5315

Topic: 4. Pediatrics
A neonate is born with blue sclerae, significant limb deformities, and multiple healing intrauterine fractures. The infant develops severe respiratory distress and succumbs to respiratory failure shortly after birth. According to the Sillence classification for Osteogenesis Imperfecta (OI), which type does this presentation represent?
. Type I
. Type II
. Type III
. Type IV
. Type V

Correct Answer & Explanation

. Type II

Explanation

Sillence Type II is the perinatal lethal form of Osteogenesis Imperfecta. It is characterized by severe bone fragility, multiple in utero fractures, profound deformities, and early death typically due to pulmonary hypoplasia and respiratory insufficiency.

Question 5316

Topic: 4. Pediatrics
A 2-year-old child weighing in the 99th percentile presents with bilateral severe genu varum. Radiographs reveal a sharp varus angulation at the proximal tibial metaphysis, consistent with Langenskiöld stage II infantile Blount's disease. What is the most appropriate initial management?
. Observation and parental reassurance
. Knee-ankle-foot orthosis (KAFO) bracing
. Proximal tibial valgus-producing osteotomy
. Guided growth via lateral hemiepiphysiodesis
. Medial physeal bar resection

Correct Answer & Explanation

. Knee-ankle-foot orthosis (KAFO) bracing

Explanation

Infantile Blount's disease in a child under 3 years of age with early Langenskiöld stages (I or II) is initially managed non-operatively with knee-ankle-foot orthoses (KAFOs). Surgery is reserved for older children or cases that fail bracing.

Question 5317

Topic: 4. Pediatrics

A 4-year-old girl is evaluated for anterolateral bowing of her left tibia that recently progressed to a fracture after a minor stumble. This specific condition is most strongly associated with which of the following genetic disorders?

. Marfan syndrome
. Ehlers-Danlos syndrome
. Neurofibromatosis type 1
. Osteogenesis Imperfecta
. Achondroplasia

Correct Answer & Explanation

. Neurofibromatosis type 1

Explanation

Congenital pseudarthrosis of the tibia presents with anterolateral bowing and typically fractures early in childhood. It is highly associated with Neurofibromatosis type 1 (NF-1), which is present in approximately 50% of these patients.

Question 5318

Topic: Pediatric Upper Extremity & Spine

A 6-year-old boy presents with a displaced extension-type supracondylar humerus fracture. His hand is pink and well-perfused, but he cannot flex the interphalangeal joint of his thumb or the distal interphalangeal joint of his index finger. Which of the following nerve structures is most likely injured?

. Ulnar nerve
. Radial nerve
. Anterior interosseous nerve
. Posterior interosseous nerve
. Musculocutaneous nerve

Correct Answer & Explanation

. Anterior interosseous nerve

Explanation

The anterior interosseous nerve (AIN) is the most commonly injured nerve in extension-type supracondylar humerus fractures. It innervates the flexor pollicis longus and the flexor digitorum profundus to the index and middle fingers.

Question 5319

Topic: 4. Pediatrics
A 3-year-old boy with a history of idiopathic clubfoot treated with the Ponseti method presents with a relapsed deformity. Examination reveals dynamic supination of the foot during the swing phase of gait. He has a plantigrade foot with passive correctability. Which of the following is the most appropriate surgical intervention?
. Achilles tendon lengthening
. Split anterior tibial tendon transfer (SPLATT)
. Tibialis anterior tendon transfer to the lateral cuneiform
. Posterior medial release
. Calcaneal osteotomy

Correct Answer & Explanation

. Tibialis anterior tendon transfer to the lateral cuneiform

Explanation

Dynamic supination in a relapsed Ponseti-treated clubfoot is best managed with a full tibialis anterior tendon transfer (TATT) to the lateral cuneiform. A SPLATT is typically reserved for spastic conditions like cerebral palsy.

Question 5320

Topic: Pediatric Hip

A 4-week-old female infant is undergoing treatment for developmental dysplasia of the hip (DDH) with a Pavlik harness. During a follow-up visit, the parents report she has stopped kicking her leg on the affected side. On examination, there is an absence of active knee extension, but ankle and toe movements are normal. 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 and re-evaluate in 1-2 weeks
. Immediately proceed to closed reduction and spica casting
. Switch to a rigid abduction orthosis

Correct Answer & Explanation

. Remove the harness and re-evaluate in 1-2 weeks

Explanation

The infant has developed a femoral nerve palsy, a known complication of hyperflexion in a Pavlik harness. The harness must be removed temporarily until nerve function recovers to prevent permanent injury or 'Pavlik disease'.

Test Yourself

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

On this Page