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4. Pediatrics MCQs

Practice Set 250 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 4981

Topic: Pediatric Hip

A 4-month-old infant is treated with a Pavlik harness for Developmental Dysplasia of the Hip (DDH). The mother notes that the child is no longer actively extending the knee on the treated side. What is the most likely cause?

. Sciatic nerve palsy from excessive flexion
. Obturator nerve palsy from excessive abduction
. Femoral nerve palsy from hyperflexion
. Ischemic necrosis of the femoral head
. Harness slippage causing knee subluxation

Correct Answer & Explanation

. Sciatic nerve palsy from excessive flexion

Explanation

Femoral nerve palsy is a known complication of the Pavlik harness, typically caused by excessive hip flexion pressing the nerve against the inguinal ligament. The harness must be removed or adjusted immediately to allow nerve recovery.

Question 4982

Topic: Pediatric Hip

A 12-year-old boy presents with a stable Slipped Capital Femoral Epiphysis (SCFE) of the left hip. Which of the following is an established indication for prophylactic pinning of the asymptomatic contralateral hip?

. Age greater than 14 years
. African American ethnicity
. Presence of an underlying endocrine disorder
. Body mass index (BMI) > 95th percentile
. Radiographic evidence of closure of the triradiate cartilage

Correct Answer & Explanation

. Age greater than 14 years

Explanation

Prophylactic pinning of the contralateral hip in SCFE is highly recommended for patients with endocrine disorders (e.g., hypothyroidism) or those presenting at a very young age (<10 years), as they have a significantly higher risk of bilateral involvement.

Question 4983

Topic: Pediatric Hip

A 12-year-old boy with renal osteodystrophy presents with a limp and hip pain. Radiographs confirm a unilateral slipped capital femoral epiphysis (SCFE). Which of the following is the most appropriate management regarding the contralateral hip?

. Observation with clinical follow-up
. Prophylactic in situ pinning
. Spica cast immobilization
. Bilateral proximal femoral osteotomies
. Observation with serial MRI

Correct Answer & Explanation

. Observation with clinical follow-up

Explanation

Prophylactic pinning of the contralateral hip is highly recommended in patients with endocrine or metabolic disorders (e.g., renal osteodystrophy, hypothyroidism) due to the high risk of bilateral SCFE. Routine prophylactic pinning in idiopathic cases remains controversial.

Question 4984

Topic: Pediatric Hip

A 2-year-old girl is diagnosed with developmental dysplasia of the hip (DDH) after presenting with a painless limp. Which of the following is the most appropriate definitive management?

. Application of a Pavlik harness
. Closed reduction and spica casting
. Open reduction with possible pelvic or femoral osteotomy
. Observation until age 4, then corrective osteotomy
. Botulinum toxin injection into the adductors

Correct Answer & Explanation

. Application of a Pavlik harness

Explanation

In children aged 18 months to 3 years with late-diagnosed DDH, open reduction is usually required, often supplemented with a pelvic osteotomy (e.g., Salter) or femoral shortening osteotomy. The Pavlik harness is indicated for infants under 6 months.

Question 4985

Topic: Pediatric Hip

A 12-year-old obese male presents with acute left groin pain and inability to bear weight after a minor fall. Radiographs demonstrate a slipped capital femoral epiphysis (SCFE). He is classified as having an unstable SCFE. What is the most common severe complication associated with this specific classification?

. Chondrolysis
. Femoroacetabular impingement
. Avascular necrosis (AVN)
. Premature physeal closure
. Osteoarthritis

Correct Answer & Explanation

. Chondrolysis

Explanation

By definition, an unstable SCFE is one in which the patient cannot bear weight even with crutches. This instability significantly increases the risk of disrupting the epiphyseal blood supply, leading to avascular necrosis rates as high as 50%.

Question 4986

Topic: Pediatric Upper Extremity & Spine
A 6-year-old boy falls off monkey bars and sustains an extension-type Gartland III supracondylar humerus fracture. On evaluation in the ER, his hand is pink but the radial pulse is absent. The patient is taken emergently to the OR for closed reduction and percutaneous pinning. Post-operatively, the limb remains well-perfused (pink) with brisk capillary refill, but the radial pulse remains non-palpable. What is the most appropriate next step in management?
. Immediate open exploration of the brachial artery
. CT Angiography of the upper extremity
. Observation and hospital admission for close monitoring
. Immediate removal of the pins and re-reduction of the fracture
. Prophylactic forearm fasciotomy

Correct Answer & Explanation

. Observation and hospital admission for close monitoring

Explanation

A 'pink, pulseless' hand following reduction of a supracondylar humerus fracture is a well-recognized clinical scenario. Provided that the hand is definitively warm, pink, and has capillary refill < 2 seconds, collateral circulation is deemed adequate. The recommended management is observation and close monitoring for 24-48 hours. Open exploration is indicated only for a 'white, pulseless' hand or if signs of ischemia develop.

Question 4987

Topic: Pediatric Upper Extremity & Spine

A 35-year-old male with a severe traumatic brain injury develops massive heterotopic ossification (HO) around his right elbow following a supracondylar humerus fracture, resulting in complete ankylosis. What is the optimal criteria and timing for surgical excision of the heterotopic bone to maximize range of motion and minimize the risk of recurrence?

. Excision at 6 weeks post-injury, prior to complete maturation
. Excision at 3 months, regardless of radiographic appearance
. Excision when there is radiographic evidence of mature trabeculae, normal serum alkaline phosphatase, and neurological stability
. Immediate excision upon initial detection of fluffy calcifications on X-ray
. Excision is contraindicated in patients with TBI due to a 100% recurrence rate

Correct Answer & Explanation

. Excision at 6 weeks post-injury, prior to complete maturation

Explanation

Surgical excision of heterotopic ossification (HO) is technically demanding and carries a risk of recurrence. The classic criteria for safe excision include 1) neurologic recovery or stability, 2) normal serum alkaline phosphatase levels, and 3) radiographic evidence of mature bone with a clear trabecular pattern and sharp cortical margins. Historically, waiting 12-18 months was recommended, but modern literature suggests earlier excision (typically around 6 months) is safe as long as the bone appears radiographically mature and the patient is neurologically stable. Postoperative prophylaxis with radiation or indomethacin is critical.

Question 4988

Topic: 4. Pediatrics

A 14-year-old elite baseball pitcher complains of lateral shoulder pain during the late cocking phase of throwing. Radiographs demonstrate widening and irregularity of the proximal humeral physis. What is the most appropriate initial management for this condition?

. Corticosteroid injection into the subacromial space
. Arthroscopic labral repair
. Immediate cessation of throwing for 3 months
. Open reduction and internal fixation of the physis
. Physical therapy emphasizing vigorous internal rotation stretching

Correct Answer & Explanation

. Corticosteroid injection into the subacromial space

Explanation

Little Leaguer's shoulder represents an epiphysiolysis of the proximal humerus due to repetitive rotational stress. The primary treatment is absolute rest from throwing for typically 3 months until radiographic resolution.

Question 4989

Topic: Pediatric Upper Extremity & Spine

A 12-year-old baseball pitcher presents with chronic medial elbow pain. Radiographs demonstrate widening and fragmentation of the medial epicondyle apophysis. Which specific biomechanical force is the primary driver of this condition, commonly known as "Little League Elbow"?

. Valgus overload during the acceleration phase of throwing
. Varus overload during the deceleration phase of throwing
. Axial compression during the cocking phase
. Direct impact to the medial epicondyle
. Hyperextension during follow-through

Correct Answer & Explanation

. Valgus overload during the acceleration phase of throwing

Explanation

"Little League Elbow" represents a medial epicondyle apophysitis caused by repetitive valgus stress during the late cocking and early acceleration phases of pitching. This creates immense tension on the medial structures, causing microtrauma to the open apophysis.

Question 4990

Topic: Pediatric Hip

A 13-year-old overweight boy presents with a limp and vague knee pain. Upon physical examination, passive flexion of the affected hip results in obligate external rotation and abduction. What is this sign called, and what is the most likely diagnosis?

. Galeazzi sign; Developmental Dysplasia of the Hip
. Drehmann sign; Slipped Capital Femoral Epiphysis
. Trendelenburg sign; Legg-Calve-Perthes disease
. Stinchfield test; Femoroacetabular Impingement
. Ober test; Iliotibial Band Syndrome

Correct Answer & Explanation

. Galeazzi sign; Developmental Dysplasia of the Hip

Explanation

The Drehmann sign is the obligate external rotation and abduction of the hip during passive flexion, classically seen in Slipped Capital Femoral Epiphysis (SCFE) due to the altered biomechanics from the posterior and inferior slip of the proximal femoral epiphysis.

Question 4991

Topic: Pediatric Hip

A newborn female undergoes screening for Developmental Dysplasia of the Hip (DDH). The examiner adducts the hip while applying posterior force, resulting in a palpable clunk as the hip dislocates. Which test was performed, and what does it establish?

. Ortolani maneuver; confirms the hip is dislocated but reducible
. Ortolani maneuver; confirms the hip is dislocatable
. Barlow maneuver; confirms the hip is dislocated but reducible
. Barlow maneuver; confirms the hip is dislocatable
. Galeazzi test; confirms apparent leg length discrepancy

Correct Answer & Explanation

. Ortolani maneuver; confirms the hip is dislocated but reducible

Explanation

The Barlow maneuver attempts to dislocate a reduced hip by adduction and posterior pressure (assessing if it is 'dislocatable'). The Ortolani maneuver reduces an already dislocated hip by abduction and anterior pressure (assessing if it is 'reducible').

Question 4992

Topic: Pediatric Hip

A 13-year-old obese male presents with a slipped capital femoral epiphysis (SCFE) of the left hip. He undergoes in situ percutaneous pinning. According to the modified Oxford bone age score, which of the following is the strongest indication for prophylactic pinning of the asymptomatic right hip?

. Modified Oxford score of 26
. Chronological age greater than 14 years
. Modified Oxford score of 16
. Presence of knee pain rather than hip pain
. Male gender

Correct Answer & Explanation

. Modified Oxford score of 26

Explanation

The modified Oxford bone age score assesses skeletal maturity based on the pelvis and proximal femur. A score of 16 (the lowest score) indicates open triradiate cartilage and significant remaining growth potential. This strongly correlates with a high risk of developing a contralateral SCFE, making it a primary indication for prophylactic pinning.

Question 4993

Topic: Pediatric Hip

A 4-month-old female is diagnosed with Developmental Dysplasia of the Hip (DDH). She is currently being treated in a Pavlik harness. During a follow-up ultrasound, the alpha angle is measured. What does the alpha angle represent, and what is considered a normal value indicating a mature hip?

. The depth of the bony acetabular roof; normal is >60 degrees
. The coverage provided by the cartilaginous labrum; normal is <55 degrees
. The anterior inclination of the acetabulum; normal is >50 degrees
. The depth of the bony acetabular roof; normal is <43 degrees
. The amount of femoral head uncoverage; normal is >60 degrees

Correct Answer & Explanation

. The depth of the bony acetabular roof; normal is >60 degrees

Explanation

On a coronal infant hip ultrasound using the Graf method, the alpha angle measures the concavity and depth of the bony acetabular roof relative to the straight ilium. An alpha angle of greater than 60 degrees is considered normal (Type I hip). The beta angle relates to the cartilaginous roof.

Question 4994

Topic: Pediatric Upper Extremity & Spine

A 14-year-old girl with Adolescent Idiopathic Scoliosis (AIS) undergoes posterior spinal fusion. Postoperatively, the surgeon evaluates the correction using the Lenke classification criteria. According to the Lenke classification, which of the following determines if a proximal thoracic curve is considered 'structural'?

. A Cobb angle > 25 degrees on side-bending radiographs
. Apical vertebral rotation of grade II or higher on standing AP radiograph
. A Cobb angle > 10 degrees on side-bending radiographs
. Thoracic kyphosis (T2-T5) of > +20 degrees
. Presence of a rib hump > 15 degrees on forward bending test

Correct Answer & Explanation

. A Cobb angle > 25 degrees on side-bending radiographs

Explanation

In the Lenke classification for AIS, a minor curve is defined as 'structural' if it fails to correct to <25 degrees on voluntary side-bending radiographs. For the proximal and main thoracic regions, a regional kyphosis of > +20 degrees also defines the curve as structural.

Question 4995

Topic: Pediatric Hip

A 21-year-old collegiate wrestler suffers an anterior shoulder dislocation. An MRI arthrogram reveals an avulsion of the anterior labrum along with the anterior band of the inferior glenohumeral ligament (IGHL). The labrum remains attached to the intact periosteum, which is stripped medially down the glenoid neck. What is the eponym for this specific lesion?

. Bankart lesion
. ALPSA lesion
. Perthes lesion
. GLAD lesion
. HAGL lesion

Correct Answer & Explanation

. Bankart lesion

Explanation

A Perthes lesion is an avulsion of the anterior labrum and IGHL where the medial scapular periosteum remains intact but is stripped off the bone. Because it is non-displaced, it can heal in its anatomic position but remains patulous, often leading to a false-negative MRI if the joint is not adequately distended. An ALPSA involves medial displacement and 'rolling up' of the labrum.

Question 4996

Topic: Pediatric Lower Extremity

During the Ponseti method for the correction of idiopathic clubfoot (talipes equinovarus), the deformities are systematically corrected through a series of specific casts. What is the correct sequence of deformity correction using this technique?

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

Correct Answer & Explanation

. Cavus, Adductus, Varus, Equinus

Explanation

The mnemonic for the Ponseti method correction sequence is CAVE: Cavus (corrected first by elevating the first ray to align the forefoot with the hindfoot), Adductus, Varus, and finally Equinus (which often requires a percutaneous Achilles tenotomy to fully correct once the talonavicular joint is reduced).

Question 4997

Topic: 4. Pediatrics

In evaluating a child with cerebral palsy who exhibits a crouch gait, the examiner places the patient prone and rapidly flexes the knee. The examiner observes spontaneous, involuntary flexion of the ipsilateral hip. This positive Ely's test indicates spasticity or contracture of which muscle?

. Iliopsoas
. Hamstrings
. Rectus femoris
. Tensor fasciae latae
. Sartorius

Correct Answer & Explanation

. Iliopsoas

Explanation

Ely's test assesses for rectus femoris spasticity or contracture. Because the rectus femoris crosses both the hip and the knee joints (acting as a hip flexor and knee extensor), flexing the knee pulls on the tight muscle, causing a compensatory, involuntary flexion of the hip.

Question 4998

Topic: Pediatric Hip

During a newborn examination, the pediatrician flexes the infant's hips and knees to 90 degrees. The examiner then gently abducts the hips while applying an anteriorly directed force on the greater trochanters. A palpable "clunk" is felt. What does this positive test indicate?

. Reduction of a dislocated hip
. Dislocation of a reduced hip
. Normal developing hip variant
. Femoral head epiphyseal slip
. Acetabular dysplasia without instability

Correct Answer & Explanation

. Reduction of a dislocated hip

Explanation

The Ortolani maneuver is an active reduction test for developmental dysplasia of the hip (DDH). The palpable clunk occurs as the subluxated or dislocated femoral head slips over the posterior acetabular rim and reduces into the acetabulum.

Question 4999

Topic: Pediatric Hip

An obese 13-year-old boy presents with right knee pain and a limp. During the physical examination of the hip in the supine position, the hip passively goes into obligatory external rotation as it is flexed. What is the most likely diagnosis based on this physical finding?

. Legg-Calve-Perthes disease
. Slipped capital femoral epiphysis
. Developmental dysplasia of the hip
. Transient synovitis
. Septic arthritis

Correct Answer & Explanation

. Legg-Calve-Perthes disease

Explanation

The Drehmann sign is the obligatory external rotation of the hip during passive flexion. This is a hallmark physical examination finding for Slipped Capital Femoral Epiphysis (SCFE) due to the altered geometry of the displaced proximal femur.

Question 5000

Topic: Pediatric Hip

A 12-year-old boy presents with an acute-on-chronic left slipped capital femoral epiphysis (SCFE). Which of the following is considered a definitive indication for prophylactic in situ pinning of the contralateral, currently asymptomatic right hip?

. Male gender
. Obesity with a BMI > 95th percentile
. Hypothyroidism
. Age greater than 14 years at presentation
. African-American descent

Correct Answer & Explanation

. Male gender

Explanation

Endocrine disorders, such as hypothyroidism or renal osteodystrophy, are established indications for prophylactic pinning of the contralateral hip in patients presenting with a unilateral SCFE due to the significantly higher risk of bilateral involvement. The other options are risk factors for SCFE but do not serve as absolute indications for prophylactic contralateral pinning.

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