Menu

4. Pediatrics MCQs

Practice Set 244 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 4861

Topic: Pediatric Lower Extremity

In the Ponseti method for the management of idiopathic clubfoot, what is the correct sequence of deformity correction?

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

Correct Answer & Explanation

. Cavus, Adductus, Varus, Equinus

Explanation

The sequence of correction in the Ponseti method is Cavus, Adductus, Varus, and finally Equinus (CAVE). Elevating the first ray corrects the cavus and unlocks the midfoot for further corrective casting.

Question 4862

Topic: Pediatric Upper Extremity & Spine

A 14-year-old girl is diagnosed with adolescent idiopathic scoliosis (AIS). Her Lenke classification is 1AN. Which of the following best describes the structural characteristics of her curve?

. Main thoracic curve is structural, proximal thoracic and thoracolumbar/lumbar are non-structural.
. Double major curve with a structural main thoracic and structural thoracolumbar/lumbar curve.
. Triple major curve with structural proximal thoracic, main thoracic, and thoracolumbar curves.
. Main thoracic curve is structural with a positive sagittal modifier (kyphosis > 40 degrees).
. Thoracolumbar/lumbar curve is structural, main thoracic is non-structural.

Correct Answer & Explanation

. Main thoracic curve is structural, proximal thoracic and thoracolumbar/lumbar are non-structural.

Explanation

Lenke 1 curves are main thoracic structural curves with non-structural proximal thoracic and thoracolumbar curves. The "A" modifier indicates the lumbar apex falls between the pedicles, and "N" designates normal thoracic kyphosis.

Question 4863

Topic: Pediatric Hip

An 18-month-old girl with Developmental Dysplasia of the Hip (DDH) is planned for a Salter innominate osteotomy. Which of the following is an absolute prerequisite for performing this procedure?

. Age greater than 4 years
. Preoperative skeletal traction
. A concentrically reduced hip
. A significantly dysplastic opposite hip
. Femoral head ossification center must be absent

Correct Answer & Explanation

. Age greater than 4 years

Explanation

A Salter osteotomy is a redirectional pelvic osteotomy that hinges through the symphysis pubis. A concentric reduction of the hip joint is an absolute prerequisite for the procedure to provide adequate anterolateral coverage.

Question 4864

Topic: 4. Pediatrics
A 14-year-old boy presents with right knee pain following a twisting injury. Radiographs reveal a Salter-Harris III fracture of the anterolateral aspect of the distal tibia epiphysis. Which ligament's pull is primarily responsible for this avulsion fracture?
. Anterior talofibular ligament
. Calcaneofibular ligament
. Anterior inferior tibiofibular ligament
. Posterior inferior tibiofibular ligament
. Deltoid ligament

Correct Answer & Explanation

. Anterior inferior tibiofibular ligament

Explanation

This is a Tillaux fracture, caused by avulsion of the anterolateral distal tibial epiphysis due to pull from the anterior inferior tibiofibular ligament (AITFL). It occurs in adolescents because the lateral physis is the last portion to close.

Question 4865

Topic: Pediatric Upper Extremity & Spine

A newborn is noted to have a missing thumb and severe radial deviation of the wrist. Radiographs confirm radial clubhand. Which of the following screening tests is most appropriate to rule out a potentially fatal associated condition?

. Renal ultrasound
. Chromosomal breakage analysis with diepoxybutane
. Echocardiogram
. Spinal MRI
. Thyroid function tests

Correct Answer & Explanation

. Renal ultrasound

Explanation

Radial clubhand is strongly associated with Fanconi anemia, a life-threatening aplastic anemia syndrome. It is screened via chromosomal breakage analysis using clastogenic agents like diepoxybutane (DEB).

Question 4866

Topic: 4. Pediatrics

A 5-year-old boy presents with bilateral genu varum. Standing radiographs show proximal tibial metaphyseal beaking, and the metaphyseal-diaphyseal angle is 18 degrees. Which of the following is the most appropriate management?

. Observation and reassurance
. KAFO bracing during daytime only
. Proximal tibial valgus osteotomy
. Guided growth with tension band plating
. Epiphysiodesis of the lateral proximal tibia

Correct Answer & Explanation

. Observation and reassurance

Explanation

This patient has late-onset infantile Blount's disease with a metaphyseal-diaphyseal angle > 16 degrees, making spontaneous resolution highly unlikely. Surgical intervention with a proximal tibial valgus osteotomy is indicated for severe or progressive cases in children over 4 years old.

Question 4867

Topic: 4. Pediatrics

A child with cerebral palsy is evaluated for hip subluxation. The Reimers Migration Index (MI) is measured on an AP pelvis radiograph. At what minimum MI percentage is prophylactic surgical intervention (e.g., adductor tenotomy) typically recommended?

. 10%
. 20%
. 33%
. 50%
. 75%

Correct Answer & Explanation

. 10%

Explanation

A Reimers Migration Index exceeding 30-33% indicates significant, progressive hip subluxation in cerebral palsy. Soft tissue releases, such as adductor longus and iliopsoas tenotomies, are typically recommended at this threshold to prevent complete dislocation.

Question 4868

Topic: 4. Pediatrics

A 9-year-old boy presents with a progressive leg length discrepancy. He has a history of an isolated lateral distal femoral physeal arrest after trauma. If left untreated, which of the following deformities will develop?

. Genu varum and shortening
. Genu valgum and shortening
. Genu recurvatum and shortening
. Genu valgum and overgrowth
. Flexion contracture and lengthening

Correct Answer & Explanation

. Genu varum and shortening

Explanation

Premature arrest of the lateral distal femoral physis allows the medial side to continue growing unchecked. This asymmetric growth pushes the knee into a varus alignment, combined with overall limb shortening.

Question 4869

Topic: 4. Pediatrics

Which of the following genetic mutations is responsible for Achondroplasia, the most common form of disproportionate short-stature dwarfism?

. COL1A1
. COMP
. FGFR3
. RUNX2
. SHOX

Correct Answer & Explanation

. COL1A1

Explanation

Achondroplasia is caused by an activating mutation in the Fibroblast Growth Factor Receptor 3 (FGFR3) gene. This overactivity profoundly inhibits chondrocyte proliferation within the proliferative zone of the physis.

Question 4870

Topic: Pediatric Upper Extremity & Spine

A 7-year-old boy sustains a completely displaced extension-type supracondylar humerus fracture. Upon examination, he is unable to flex the interphalangeal joint of his thumb or the distal interphalangeal joint of his index finger. Which nerve is most likely injured?

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

Correct Answer & Explanation

. Radial nerve

Explanation

The Anterior Interosseous Nerve (AIN) is the most frequently injured nerve in extension-type supracondylar fractures. Clinically, AIN palsy presents as the inability to form an 'OK' sign due to weakness of the flexor pollicis longus and flexor digitorum profundus to the index finger.

Question 4871

Topic: Pediatric Hip

A 14-year-old obese male presents with left groin pain and an altered gait. Radiographs reveal a slipped capital femoral epiphysis (SCFE). Which of the following is the most significant clinical predictor for the development of subsequent avascular necrosis (AVN)?

. Magnitude of the slip angle
. Duration of symptoms prior to presentation
. Patient's body mass index (BMI)
. Inability to ambulate with or without crutches
. Contralateral hip involvement

Correct Answer & Explanation

. Magnitude of the slip angle

Explanation

The inability to bear weight defines an unstable SCFE according to the Loder classification. Instability is the paramount risk factor for developing AVN, carrying a risk of up to 50% compared to near 0% in stable slips.

Question 4872

Topic: 4. Pediatrics

A 6-month-old infant is diagnosed with congenital fibular hemimelia. Which of the following associated clinical findings is most universally expected with this deficiency?

. Polydactyly of the foot
. Medial bowing of the tibia
. Absence of the anterior cruciate ligament
. Coxa vara
. Posterior medial bowing of the tibia

Correct Answer & Explanation

. Polydactyly of the foot

Explanation

Fibular hemimelia is frequently associated with a spectrum of lower limb anomalies, most notably the absence or severe hypoplasia of the anterior cruciate ligament (ACL). Other hallmark associations include anterolateral tibial bowing and absent lateral rays of the foot.

Question 4873

Topic: Pediatric Hip

A 4-week-old female infant is evaluated for developmental dysplasia of the hip (DDH). Ultrasound shows an alpha angle of 45 degrees and a beta angle of 65 degrees. According to the Graf classification, what is the appropriate management?

. Reassurance and repeat ultrasound in 4 weeks
. Pavlik harness application
. Rigid abduction orthosis
. Closed reduction and spica cast
. Open reduction and capsulorrhaphy

Correct Answer & Explanation

. Reassurance and repeat ultrasound in 4 weeks

Explanation

An alpha angle of 45 degrees indicates a Graf type IIc or worse (dysplastic hip). The standard of care for a dysplastic but reducible hip in an infant under 6 months is treatment with a Pavlik harness.

Question 4874

Topic: Pediatric Hip

A 14-year-old male with a BMI of 35 presents with acute-on-chronic left knee pain and an inability to bear weight. Radiographs show a severe left slipped capital femoral epiphysis (SCFE). He undergoes urgent in situ pinning. Which of the following is the most significant preventable risk factor for developing chondrolysis in this patient?

. The severity of the slip at presentation
. Acute presentation of the slip
. Unrecognized pin penetration into the joint
. The patient's obesity
. Delay in surgical intervention

Correct Answer & Explanation

. The severity of the slip at presentation

Explanation

Unrecognized hardware penetration into the joint space is the most significant preventable risk factor for chondrolysis following in situ pinning of a SCFE. Intraoperative fluoroscopy with approach-withdrawal views is essential to confirm extra-articular pin placement.

Question 4875

Topic: Pediatric Lower Extremity

A 6-month-old boy with idiopathic clubfoot was successfully treated with the Ponseti method. After serial casting and a percutaneous Achilles tenotomy, his foot is fully corrected. What is the most common cause of relapse in this patient over the next few years?

. Failure to perform a prophylactic tibialis anterior transfer
. Non-compliance with the foot abduction orthosis
. Under-correction of the cavus deformity initially
. Early transition to regular supportive shoes
. An underlying undiagnosed neurological condition

Correct Answer & Explanation

. Failure to perform a prophylactic tibialis anterior transfer

Explanation

The most common cause of clubfoot relapse following successful correction with the Ponseti method is non-compliance with the foot abduction brace. The brace must be worn full-time initially, then at night until age 3 to 4 years.

Question 4876

Topic: Pediatric Lower Extremity

An 8-year-old girl is evaluated for severe in-toeing. On examination, she has 80 degrees of internal hip rotation and 10 degrees of external hip rotation bilaterally. The thigh-foot angle is neutral. What is the most likely diagnosis and its expected natural history?

. Internal tibial torsion; typically resolves by age 10
. Femoral anteversion; usually improves spontaneously by age 10-12
. Metatarsus adductus; requires serial casting for correction
. Femoral anteversion; requires derotational osteotomy before puberty
. Internal tibial torsion; highly associated with early-onset osteoarthritis

Correct Answer & Explanation

. Internal tibial torsion; typically resolves by age 10

Explanation

Increased internal hip rotation and decreased external rotation indicate increased femoral anteversion. This condition typically peaks around age 5-6 and spontaneously resolves or compensates by age 10-12 without surgical intervention.

Question 4877

Topic: 4. Pediatrics

A 10-year-old boy with spastic diplegic cerebral palsy is evaluated for bilateral hip subluxation. His Reimers migration percentage is 50% bilaterally, and he experiences pain with seating. What is the most appropriate surgical intervention?

. Bilateral adductor and iliopsoas tenotomies alone
. Bilateral varus derotational femoral osteotomies (VDRO) with pelvic osteotomies
. Proximal femoral resections (Girdlestone procedure)
. Bilateral total hip arthroplasties
. Observation with optimized seating until skeletal maturity

Correct Answer & Explanation

. Bilateral adductor and iliopsoas tenotomies alone

Explanation

In a child with cerebral palsy and a Reimers migration percentage > 40-50%, soft tissue releases alone are insufficient. Bony reconstruction with VDRO and a pelvic osteotomy is required to restore joint congruency and stability.

Question 4878

Topic: 4. Pediatrics
A 13-year-old boy sustains a Salter-Harris type III fracture of the anterolateral distal tibia. Which of the following best explains the specific fracture pattern seen in this Tillaux fracture?
. The distal tibial physis closes asymmetrically from medial to lateral
. The distal tibial physis closes asymmetrically from lateral to medial
. The fracture is an avulsion by the anterior talofibular ligament
. The fracture is primarily a result of a hyperflexion injury
. The anterior inferior tibiofibular ligament pulls off the medial malleolus

Correct Answer & Explanation

. The distal tibial physis closes asymmetrically from lateral to medial

Explanation

A Tillaux fracture occurs due to the asymmetric closure of the distal tibial physis, which closes first centrally, then medially, and finally laterally. An external rotation force causes the anterior inferior tibiofibular ligament to avulse the unfused anterolateral epiphysis.

Question 4879

Topic: Pediatric Hip
A 7-year-old boy presents with a painless limp. Radiographs reveal fragmentation of the left capital femoral epiphysis. Physical exam shows a loss of hip internal rotation and abduction. What is the primary overarching goal of treatment for this condition?
. Immediate surgical pinning to prevent further epiphyseal slip
. Containment of the femoral head within the acetabulum
. Eradication of occult infection with intravenous antibiotics
. Percutaneous lengthening of the Achilles tendon to improve gait
. Strict complete non-weight bearing for 2 years

Correct Answer & Explanation

. Containment of the femoral head within the acetabulum

Explanation

In Legg-Calvรฉ-Perthes disease, the primary goal of treatment is containment of the inflamed, plastic femoral head within the acetabulum. This maintains a spherical head shape during the remodeling phase and minimizes future joint incongruity.

Question 4880

Topic: Pediatric Lower Extremity

A neonate is diagnosed with bilateral clubfeet. The parents ask about the specific sequence of deformity correction using the Ponseti method. What is the correct order of correction?

. Cavus, Adductus, Varus, Equinus (CAVE)
. Equinus, Varus, Adductus, Cavus (EVAC)
. Varus, Cavus, Equinus, Adductus (VCEA)
. Adductus, Varus, Equinus, Cavus (AVEC)
. Cavus, Equinus, Varus, Adductus (CEVA)

Correct Answer & Explanation

. Cavus, Adductus, Varus, Equinus (CAVE)

Explanation

The Ponseti method corrects clubfoot deformities in a very specific sequence: Cavus (by supinating the forefoot), Adductus, Varus, and finally Equinus (CAVE). Equinus is usually corrected last, often requiring a percutaneous Achilles tenotomy.

Test Yourself

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

On this Page