Menu

4. Pediatrics MCQs

Practice Set 5 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 81

Topic: 4. Pediatrics

A 4-week-old infant presents with a right-sided neck mass and a head tilt to the right with the chin rotated to the left. The mass is firm, mobile, and located within the sternocleidomastoid muscle. Neurological examination is normal. What is the most appropriate initial management?

. Excision of the mass
. Cervical spine MRI
. Stretching exercises and observation
. Botulinum toxin injection
. Immediate bracing

Correct Answer & Explanation

. Stretching exercises and observation

Explanation

Congenital muscular torticollis typically presents with a sternocleidomastoid mass ('fibromatosis colli') and a characteristic head tilt. Initial management consists of gentle stretching and observation, which resolves the condition in over 90% of cases.

Question 82

Topic: Pediatric Upper Extremity & Spine

A 13-year-old male presents with adolescent idiopathic scoliosis. He has a 40-degree left thoracic curve. Neurological examination is completely normal. Why is a total spine MRI indicated for this patient?

. To measure the pedicle width for screws
. Left-sided thoracic curves have a higher incidence of neural axis abnormalities
. It is standard of care for all AIS patients
. To evaluate for pulmonary hypoplasia
. Males have a higher incidence of dural ectasia

Correct Answer & Explanation

. Left-sided thoracic curves have a higher incidence of neural axis abnormalities

Explanation

Atypical curve patterns, such as a left-sided thoracic curve in adolescent idiopathic scoliosis, carry a higher risk of underlying neural axis abnormalities (e.g., syringomyelia, Chiari malformation). MRI is indicated even with a completely normal neurological exam.

Question 83

Topic: Pediatric Upper Extremity & Spine

Six months ago, an 11-year-old premenarchal girl with adolescent idiopathic scoliosis had a right thoracic curve from T5 to T12 measuring 20°. Her physical examination was normal. She returned to the office and a standing posteroanterior radiograph demonstrates a 28° right thoracic curve from T5 to T12; she is Risser stage 0. A lateral radiograph shows a thoracic kyphosis of 10°. At this time, you recommend:

. Repeat radiograph in 6 months
. Thoracic flexibility exercises
. Full-time use of a thoracolumbosacral orthosis
. Electrical stimulation
. Posterior spinal fusion with instrumentation

Correct Answer & Explanation

. Full-time use of a thoracolumbosacral orthosis

Explanation

In skeletally immature patients with adolescent idiopathic scoliosis and curves approaching 30° with documented progression, bracing may be effective at preventing further progression of the curve. Risk of progression in adolescent idiopathic scoliosis is related to curve magnitude and remaining growth potential. The risk of further progression in this patient is 68%, and bracing is indicated. Electrical stimulation and physical therapy have not been shown to affect the natural history of scoliosis. Surgery may be indicated in patients with more severe curves. In the sagittal plane, hypokyphosis is usually present in adolescent idiopathic scoliosis.

Question 84

Topic: Pediatric Hip

A 12-year-old obese boy presents with right hip and knee pain for 3 months. A radiograph is shown

. He is diagnosed with a stable slipped capital femoral epiphysis (SCFE). Which of the following is the most appropriate initial management?

. In situ pinning with a single cannulated screw
. Closed reduction and spica casting
. Open reduction and internal fixation
. Proximal femoral osteotomy
. Observation and crutch use

Correct Answer & Explanation

. In situ pinning with a single cannulated screw

Explanation

The gold standard treatment for a stable SCFE is in situ pinning with a single central cannulated screw. Attempting closed reduction increases the risk of avascular necrosis.

Question 85

Topic: Pediatric Hip

A 4-week-old female infant is diagnosed with a dislocated but reducible left hip. Treatment with a Pavlik harness is initiated. Which of the following is an absolute contraindication to the continued use of a Pavlik harness?

. Alpha angle of 55 degrees on ultrasound
. Failure to obtain reduction after 3 to 4 weeks of use
. Bilateral hip dysplasia
. Presence of a positive Ortolani sign at initial presentation
. Age greater than 2 weeks at the start of treatment

Correct Answer & Explanation

. Failure to obtain reduction after 3 to 4 weeks of use

Explanation

Failure to achieve reduction within 3-4 weeks is an absolute contraindication to continued Pavlik harness use. Prolonged use of a harness on a dislocated hip causes "Pavlik harness disease" (posterior lip damage) and risks femoral nerve palsy.

Question 86

Topic: 4. Pediatrics

A 4-year-old girl is evaluated for severe bowing of the left leg. Radiographs reveal varus deformity at the proximal tibia with a metaphyseal-diaphyseal angle (Drennan's angle) of 18 degrees. What is the most appropriate treatment?

. Reassurance and annual follow-up
. KAFO bracing
. Proximal tibial valgus osteotomy
. Guided growth with a medial tension band plate
. High tibial osteotomy after physeal closure

Correct Answer & Explanation

. Proximal tibial valgus osteotomy

Explanation

For infantile Blount disease in a child over age 3 or with a metaphyseal-diaphyseal angle >16 degrees, surgical realignment (proximal tibial osteotomy) is indicated. Bracing is typically ineffective at this advanced stage and age.

Question 87

Topic: Pediatric Upper Extremity & Spine

A 6-year-old boy sustains a completely displaced, extension-type supracondylar humerus fracture. After closed reduction and percutaneous pinning with two lateral pins, you notice the anterior interosseous nerve (AIN) is non-functional. What is the most common physical finding of AIN palsy?

. Inability to extend the IP joint of the thumb
. Inability to flex the IP joint of the thumb and the DIP joint of the index finger
. Decreased sensation over the volar aspect of the index finger
. Inability to spread the fingers
. Wrist drop

Correct Answer & Explanation

. Inability to flex the IP joint of the thumb and the DIP joint of the index finger

Explanation

The AIN innervates the flexor pollicis longus (FPL) and flexor digitorum profundus (FDP) to the index finger. Palsy results in the inability to make an "OK" sign (flexion of thumb IP and index DIP joints).

Question 88

Topic: Pediatric Lower Extremity

When treating an idiopathic clubfoot using the Ponseti method, what is the correct sequence of deformity correction?

. Cavus, Adductus, Varus, Equinus
. Equinus, Varus, Adductus, Cavus
. Adductus, Cavus, Varus, Equinus
. Varus, Equinus, Cavus, Adductus
. Cavus, Varus, Adductus, Equinus

Correct Answer & Explanation

. Cavus, Varus, Adductus, Equinus

Explanation

The Ponseti method corrects deformities sequentially using the CAVE acronym: Cavus (by supinating forefoot), Adductus, Varus, and finally Equinus (usually requiring a percutaneous Achilles tenotomy).

Question 89

Topic: Pediatric Hip

An 18-month-old child presents with a painless limp and is found to have an untreated developmental dysplasia of the hip (DDH) on the right side. Which of the following is the most appropriate treatment?

. Pavlik harness
. Closed reduction and spica casting
. Open reduction, capsulorrhaphy, and likely pelvic/femoral osteotomy
. Observation until age 4
. Skeletal traction

Correct Answer & Explanation

. Open reduction, capsulorrhaphy, and likely pelvic/femoral osteotomy

Explanation

In children >18 months of age with DDH, open reduction is generally required due to adaptive soft tissue and bony changes. Concomitant pelvic and/or femoral osteotomies are frequently necessary to maintain reduction.

Question 90

Topic: 4. Pediatrics
Which of the following pediatric physis injuries has the highest risk of premature physeal closure and subsequent growth arrest?
. Salter-Harris I of the distal radius
. Salter-Harris II of the proximal humerus
. Salter-Harris III of the distal tibia
. Salter-Harris IV of the distal femur
. Salter-Harris I of the proximal femur

Correct Answer & Explanation

. Salter-Harris IV of the distal femur

Explanation

Salter-Harris IV fractures cross the epiphysis, physis, and metaphysis, intrinsically carrying a high risk of physeal bar formation. The distal femur physis is particularly prone to severe growth arrest after injury.

Question 91

Topic: 4. Pediatrics

A 2-year-old boy presents with anterolateral bowing of the tibia and a radiographic pseudarthrosis

. This condition is most strongly associated with which of the following systemic disorders?

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

Correct Answer & Explanation

. Neurofibromatosis type 1

Explanation

Anterolateral bowing of the tibia and congenital pseudarthrosis of the tibia (CPT) are highly associated with Neurofibromatosis type 1 (NF1). Up to 50% of patients with CPT have clinical or genetic findings of NF1.

Question 92

Topic: Pediatric Hip

Which of the following conditions is the strongest indication for prophylactic pinning of the contralateral asymptomatic hip in a patient presenting with a unilateral slipped capital femoral epiphysis (SCFE)?

. Obesity
. Renal osteodystrophy
. Male gender
. Age greater than 14 years
. Family history of SCFE

Correct Answer & Explanation

. Renal osteodystrophy

Explanation

Endocrine and metabolic disorders (such as renal osteodystrophy and hypothyroidism) significantly increase the risk of bilateral SCFE. Prophylactic pinning of the contralateral hip is highly recommended in these high-risk populations.

Question 93

Topic: Pediatric Lower Extremity

When correcting an idiopathic clubfoot deformity using the Ponseti method, what is the proper sequence of deformity correction?

. Cavus, Adduction, Varus, Equinus
. Equinus, Varus, Adduction, Cavus
. Cavus, Varus, Adduction, Equinus
. Adduction, Varus, Cavus, Equinus
. Varus, Cavus, Adduction, Equinus

Correct Answer & Explanation

. Cavus, Adduction, Varus, Equinus

Explanation

The acronym CAVE dictates the correct sequence of manipulation and casting: Cavus, Adduction, Varus, then Equinus. Equinus is the final deformity corrected, which typically requires a percutaneous Achilles tenotomy.

Question 94

Topic: Pediatric Upper Extremity & Spine

A 5-year-old boy sustains a completely displaced supracondylar humerus fracture. On examination, the hand is pink and well-perfused but the radial pulse is absent. What is the next best step in management?

. Immediate open vascular exploration
. Closed reduction and percutaneous pinning followed by reassessment
. CT angiography of the upper extremity
. Application of a long arm cast in 120 degrees of flexion
. Observation for 24 hours before intervention

Correct Answer & Explanation

. Closed reduction and percutaneous pinning followed by reassessment

Explanation

For a pulseless, pink, and well-perfused hand associated with a supracondylar fracture, the initial step is urgent closed reduction and pinning. If the hand remains pink and perfused post-reduction despite an absent pulse, close observation without immediate exploration is standard practice.

Question 95

Topic: Pediatric Hip

An infant with developmental dysplasia of the hip (DDH) is being treated with a Pavlik harness. During a follow-up visit, the infant is unable to actively extend the knee on the treated side. Which of the following harness adjustments was most likely flawed?

. Excessive abduction
. Insufficient abduction
. Excessive flexion
. Insufficient flexion
. Excessive external rotation

Correct Answer & Explanation

. Excessive flexion

Explanation

Excessive flexion in a Pavlik harness can compress the femoral nerve against the inguinal ligament, leading to a temporary femoral nerve palsy (manifesting as loss of active knee extension). Excessive abduction, conversely, increases the risk of avascular necrosis.

Question 96

Topic: 4. Pediatrics
A 13-year-old girl sustains an ankle injury. Radiographs reveal an avulsion fracture of the anterolateral distal tibial epiphysis. What is the typical pathomechanics of this fracture?
. Internal rotation causing failure of the PITFL
. External rotation causing failure of the AITFL
. Hyperplantarflexion causing anterior capsular avulsion
. Supination-adduction causing medial malleolar avulsion
. Direct axial load causing physeal impaction

Correct Answer & Explanation

. External rotation causing failure of the AITFL

Explanation

A juvenile Tillaux fracture is a Salter-Harris III injury of the anterolateral distal tibial epiphysis. It is caused by external rotation of the foot, which places tension on the anterior inferior tibiofibular ligament (AITFL), avulsing the bony attachment.

Question 97

Topic: Pediatric Hip

In Legg-Calve-Perthes disease, the Herring Lateral Pillar classification is most useful for predicting outcome. In a Group C classification, what percentage of the lateral pillar height is maintained?

. 100%
. Greater than 50%
. Less than 50%
. Exactly 75%
. 0%

Correct Answer & Explanation

. Less than 50%

Explanation

In the Herring Lateral Pillar classification, Group C is defined by the lateral pillar retaining less than 50% of its original height. This group carries the poorest prognosis for hip remodeling.

Question 98

Topic: 4. Pediatrics

A 2-year-old child presents with bilateral genu varum. A standing AP radiograph is obtained. Which radiographic parameter most strongly predicts the progression of infantile Blount disease rather than physiologic bowing?

. Tibiofemoral angle of 10 degrees varus
. Metaphyseal-diaphyseal angle greater than 16 degrees
. Physeal widening at the distal femur
. Medial femoral condyle hypoplasia
. Lateral tibial thrust during gait

Correct Answer & Explanation

. Metaphyseal-diaphyseal angle greater than 16 degrees

Explanation

A metaphyseal-diaphyseal angle (Drennan angle) greater than 16 degrees on an AP radiograph strongly suggests progression to infantile Blount disease. Angles less than 10 degrees are typically associated with physiologic bowing.

Question 99

Topic: 4. Pediatrics

Osteogenesis imperfecta (OI) is primarily caused by mutations affecting which of the following structural proteins?

. Type II collagen
. Type I collagen
. Fibroblast growth factor receptor 3
. Core binding factor alpha 1 (CBFA1)
. Cartilage oligomeric matrix protein (COMP)

Correct Answer & Explanation

. Type I collagen

Explanation

Osteogenesis imperfecta is most commonly caused by autosomal dominant mutations in the COL1A1 or COL1A2 genes. This results in qualitative or quantitative defects in Type I collagen, the predominant structural protein in bone.

Question 100

Topic: 4. Pediatrics

Congenital pseudarthrosis of the tibia (CPT) is most strongly associated with which of the following systemic conditions?

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

Correct Answer & Explanation

. Neurofibromatosis type 1

Explanation

Congenital pseudarthrosis of the tibia is heavily associated with Neurofibromatosis type 1 (NF1), occurring in about 50% of CPT cases. It presents as an anterolateral bow of the tibia that is highly prone to fracture and nonunion.

Test Yourself

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

On this Page