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4. Pediatrics MCQs

Practice Set 162 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 3221

Topic: Pediatric Upper Extremity & Spine
A 6-year-old girl sustains a Gartland type III supracondylar humerus fracture. On emergency department presentation, she has a 'pink, pulseless' hand with a normal neurologic examination. Capillary refill is less than 2 seconds. What is the most appropriate initial management?
. Immediate open vascular exploration and bypass
. Prompt closed reduction and percutaneous pinning followed by vascular reassessment
. CT angiography of the upper extremity prior to any intervention
. Application of a warm blanket and elevation for 24 hours
. Immediate fasciotomy of the forearm to prevent compartment syndrome

Correct Answer & Explanation

. Prompt closed reduction and percutaneous pinning followed by vascular reassessment

Explanation

For a 'pink, pulseless' hand in a displaced pediatric supracondylar humerus fracture, the initial step is prompt closed reduction and percutaneous pinning. Vascular exploration is indicated only if the hand becomes poorly perfused (white/cool) after reduction.

Question 3222

Topic: Pediatric Hip

A 6-week-old female infant is diagnosed with a dislocated left hip that is reducible on Ortolani maneuver. A Pavlik harness is initiated. At the 4-week follow-up, ultrasound reveals the left hip remains persistently dislocated in the harness. What is the most appropriate next step in management?

. Continue the Pavlik harness for an additional 4 weeks
. Discontinue the Pavlik harness and transition to a rigid abduction orthosis
. Proceed immediately with an open reduction and capsulorrhaphy
. Perform a femoral derotational osteotomy
. Administer botulinum toxin to the adductor longus

Correct Answer & Explanation

. Discontinue the Pavlik harness and transition to a rigid abduction orthosis

Explanation

If a dislocated hip fails to reduce after 3 to 4 weeks in a Pavlik harness, it must be discontinued to prevent "Pavlik harness disease" (erosion of the posterior acetabulum). Transitioning to a rigid abduction orthosis (e.g., Ilfeld brace) or proceeding with closed reduction and spica casting are the standard next steps.

Question 3223

Topic: Pediatric Upper Extremity & Spine

A 6-year-old boy falls from the monkey bars and sustains a completely displaced posteromedial supracondylar humerus fracture. On examination, the hand is pink and warm, but the radial pulse is absent. After closed reduction and percutaneous pinning, the hand remains pink and warm, and the radial pulse remains nonpalpable. What is the most appropriate next step?

. Urgent open exploration of the brachial artery
. Immediate angiography of the upper extremity
. Observation and hospital admission for neurovascular checks
. Administration of intravenous heparin
. Immediate removal of the pins and transition to open reduction

Correct Answer & Explanation

. Observation and hospital admission for neurovascular checks

Explanation

In a "pink, pulseless" hand following adequate reduction and stabilization of a supracondylar humerus fracture, collateral circulation is sufficient for distal perfusion. Close observation is recommended, as the pulse typically returns within several days without the need for urgent arterial exploration.

Question 3224

Topic: Pediatric Lower Extremity

In the Ponseti method for the nonoperative treatment of idiopathic clubfoot, which of the following represents the correct sequence of deformity correction?

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

Correct Answer & Explanation

. Cavus, Adductus, Varus, Equinus

Explanation

The correct sequence of correction in the Ponseti method is Cavus, Adductus, Varus, and finally Equinus (acronym CAVE). The cavus is corrected first by supinating the forefoot to align it with the hindfoot.

Question 3225

Topic: Pediatric Hip

A 13-year-old obese boy presents with acute-on-chronic right groin pain and an inability to bear weight after a minor trip. Radiographs show a severe slipped capital femoral epiphysis (SCFE). Which of the following factors represents the most significant risk for the development of avascular necrosis (AVN) in this patient?

. The severity of the epiphyseal slip angle
. The patient's elevated body mass index (BMI)
. The clinical inability to bear weight
. The chronicity of the antecedent groin pain
. A 24-hour delay in surgical fixation

Correct Answer & Explanation

. The clinical inability to bear weight

Explanation

The inability to bear weight defines an unstable SCFE according to the Loder classification. Unstable slips have a dramatically higher risk of developing avascular necrosis (up to 47%) compared to stable slips, regardless of the slip angle severity.

Question 3226

Topic: 4. Pediatrics

A 7-year-old girl with spastic quadriplegic cerebral palsy (GMFCS level IV) presents for routine surveillance. An anteroposterior pelvis radiograph demonstrates a Reimers migration percentage of 45% in the left hip, with intact joint cartilage. What is the most appropriate management?

. Observation with repeat radiographs in 1 year
. Adductor and iliopsoas tenotomies alone
. Varus derotational osteotomy of the proximal femur with a pelvic osteotomy
. Botulinum toxin injection into the hip adductors
. Proximal femoral resection (Castle procedure)

Correct Answer & Explanation

. Varus derotational osteotomy of the proximal femur with a pelvic osteotomy

Explanation

For a migration percentage between 40% and 50% in a child with cerebral palsy, bony reconstructive surgery (VDRO and pelvic osteotomy) is indicated to prevent frank dislocation. Soft-tissue releases alone are insufficient at this degree of subluxation.

Question 3227

Topic: Pediatric Hip
A 7-year-old boy is diagnosed with Legg-Calvé-Perthes disease. Radiographs reveal greater than 50% loss of height in the lateral portion of the capital femoral epiphysis. According to the Herring lateral pillar classification, which group does this represent, and what is the typical prognosis?
. Group A; excellent prognosis
. Group B; fair prognosis
. Group B/C border; variable prognosis
. Group C; poor prognosis
. Group C; excellent prognosis

Correct Answer & Explanation

. Group C; poor prognosis

Explanation

Herring Group C is defined by >50% collapse of the lateral pillar height. Patients in Group C generally have poor outcomes, and surgical containment often does not significantly alter the natural history of the severe disease.

Question 3228

Topic: 4. Pediatrics

An 18-month-old boy presents with an anterolateral bow of the right tibia. Radiographs demonstrate a sclerotic medullary canal with a pending fracture. This condition is most strongly associated with a genetic mutation affecting the production of which of the following?

. Type I collagen
. Fibroblast growth factor receptor 3 (FGFR3)
. Neurofibromin
. Cartilage oligomeric matrix protein (COMP)
. Core binding factor alpha 1 (CBFA1)

Correct Answer & Explanation

. Neurofibromin

Explanation

Anterolateral bowing of the tibia is highly associated with congenital pseudarthrosis of the tibia (CPT) and Neurofibromatosis type 1 (NF1). NF1 is an autosomal dominant disorder caused by a mutation in the NF1 gene, which encodes the tumor-suppressor protein neurofibromin.

Question 3229

Topic: 4. Pediatrics
A 3-year-old girl is evaluated for severe bilateral genu varum. Standing radiographs reveal a metaphyseal-diaphyseal angle (Drennan's angle) of 18 degrees and early fragmentation of the medial proximal tibial metaphysis. What is the most appropriate initial management for this condition?
. Observation and reassurance for physiologic bowing
. High-dose Vitamin D and calcium supplementation
. Knee-ankle-foot orthoses (KAFOs)
. Proximal tibial valgus osteotomy
. Guided growth via lateral tension band plating

Correct Answer & Explanation

. Knee-ankle-foot orthoses (KAFOs)

Explanation

The metaphyseal-diaphyseal angle >16 degrees and medial metaphyseal fragmentation indicate infantile Blount's disease. For children under or around age 3 with early Langenskiöld stages, a trial of KAFOs during weight-bearing is the recommended initial management.

Question 3230

Topic: 4. Pediatrics

A 6-month-old infant is brought to the clinic for swelling and decreased spontaneous movement of the right leg. Radiographs reveal a displaced spiral fracture of the right femoral shaft. The parents deny any history of trauma. Which of the following is the most crucial next step in management?

. Application of a Pavlik harness and discharge with outpatient follow-up
. Immediate closed reduction and single-leg spica casting
. Open reduction and flexible intramedullary nailing
. Complete skeletal survey and consultation with the child protection team
. Dual-energy X-ray absorptiometry (DEXA) scan for bone mineral density

Correct Answer & Explanation

. Complete skeletal survey and consultation with the child protection team

Explanation

A diaphyseal femur fracture in a non-ambulatory infant is highly suspicious for non-accidental trauma (NAT). A complete skeletal survey and child protective services evaluation are mandatory to ensure the child's safety before definitive orthopedic treatment.

Question 3231

Topic: Pediatric Hip

A 12-year-old boy with obesity presents with a stable slipped capital femoral epiphysis (SCFE). He undergoes in situ single-screw fixation. Which of the following is the most significant predictor of avascular necrosis (AVN) in this patient?

. Severity of the slip
. Patient age at presentation
. Instability of the slip prior to surgery
. Number of screws used for fixation
. Concurrent prophylactic fixation of the contralateral hip

Correct Answer & Explanation

. Instability of the slip prior to surgery

Explanation

The most significant risk factor for AVN in SCFE is the stability of the slip at presentation. Unstable SCFEs (inability to bear weight) have an AVN rate of up to 47%, compared to nearly 0% in stable SCFEs.

Question 3232

Topic: 4. Pediatrics
A 4-year-old boy treated successfully for idiopathic clubfoot with the Ponseti method during infancy presents with a relapsed dynamic supination deformity during the swing phase of gait. His ankle dorsiflexes to 15 degrees past neutral. What is the most appropriate management?
. Repeat percutaneous Achilles tenotomy
. Split anterior tibial tendon transfer (SPLATT)
. Complete anterior tibial tendon transfer to the lateral cuneiform
. Posteromedial release
. Lateral column lengthening

Correct Answer & Explanation

. Complete anterior tibial tendon transfer to the lateral cuneiform

Explanation

Dynamic supination in a previously treated clubfoot is best managed with a complete anterior tibial tendon transfer to the lateral cuneiform (often without Achilles lengthening if dorsiflexion is >10 degrees). SPLATT is generally reserved for spastic conditions like cerebral palsy.

Question 3233

Topic: Pediatric Upper Extremity & Spine
A 6-year-old girl sustains a Gartland type III extension-type supracondylar humerus fracture. On examination, she has a pulseless but pink, well-perfused hand. After closed reduction and percutaneous pinning, the hand remains pink and warm, but the radial pulse remains unpalpable. What is the most appropriate next step?
. Immediate vascular exploration
. Observe and admit for 24-48 hours
. Perform a sympathetic block
. Remove the pins and re-reduce the fracture
. Obtain an emergent CT angiogram

Correct Answer & Explanation

. Observe and admit for 24-48 hours

Explanation

A pulseless, pink, well-perfused hand after anatomical reduction and pinning of a supracondylar humerus fracture can be observed. Collateral circulation is adequate, and the radial pulse often returns within a few days due to relief of vasospasm.

Question 3234

Topic: Pediatric Hip

A 6-week-old female infant with a completely dislocated, irreducible left hip (developmental dysplasia of the hip) has been treated in a Pavlik harness for 4 weeks. Ultrasound shows no improvement, and the hip remains dislocated. What is the most appropriate next step?

. Continue the Pavlik harness for 4 more weeks
. Transition to a rigid abduction orthosis
. Perform closed reduction and spica casting
. Perform open reduction and spica casting
. Perform a Dega pelvic osteotomy

Correct Answer & Explanation

. Transition to a rigid abduction orthosis

Explanation

If a Pavlik harness fails to reduce a dislocated hip after 3 to 4 weeks, it should be discontinued to prevent Pavlik harness disease (posterior acetabular wear). The next step is a trial of a rigid abduction orthosis (e.g., Ilfeld or von Rosen splint) or closed reduction and spica casting.

Question 3235

Topic: 4. Pediatrics
A 13-year-old boy sustains an ankle injury. Radiographs show a fracture that appears as a Salter-Harris type III on the AP view and a Salter-Harris type IV on the lateral view. Which of the following best describes the typical sequence of distal tibial physeal closure that explains this fracture pattern?
. Central, anteromedial, posteromedial, lateral
. Central, posteromedial, anteromedial, lateral
. Lateral, central, anteromedial, posteromedial
. Anteromedial, central, lateral, posteromedial
. Posteromedial, anteromedial, central, lateral

Correct Answer & Explanation

. Central, posteromedial, anteromedial, lateral

Explanation

The distal tibial physis closes in a characteristic sequence: central, then posteromedial, then anteromedial, and finally lateral. This sequence creates a structurally vulnerable lateral physis, leading to transitional fractures like triplane and Tillaux fractures.

Question 3236

Topic: Pediatric Hip
An 8-year-old boy is diagnosed with Legg-Calve-Perthes disease. According to the lateral pillar (Herring) classification, his radiograph demonstrates >50% loss of height in the lateral third of the capital femoral epiphysis. Which of the following describes his classification and prognosis?
. Lateral Pillar A; good prognosis without surgery
. Lateral Pillar B; surgical containment yields superior outcomes
. Lateral Pillar C; surgical containment yields superior outcomes
. Lateral Pillar B; outcomes are poor regardless of treatment
. Lateral Pillar C; outcomes are poor regardless of treatment

Correct Answer & Explanation

. Lateral Pillar C; outcomes are poor regardless of treatment

Explanation

A lateral pillar height loss of >50% corresponds to Herring Lateral Pillar Group C. In children >8 years old, Group C hips have historically poor outcomes (stiff, non-spherical) regardless of conservative or surgical containment efforts.

Question 3237

Topic: Pediatric Hip

A 13-year-old obese male presents with acute-on-chronic slipped capital femoral epiphysis (SCFE) and undergoes urgent in situ pinning. Which of the following factors is most strongly associated with the development of avascular necrosis (AVN) in this patient?

. The number of pins used for fixation
. Timing of surgery greater than 24 hours from onset
. Instability of the slip
. Severity of the slip angle on the lateral radiograph
. Concurrent prophylactic pinning of the contralateral hip

Correct Answer & Explanation

. Instability of the slip

Explanation

The stability of the slip (the patient's ability to bear weight) is the most critical prognostic factor for AVN in SCFE. Unstable slips have a significantly higher rate of AVN compared to stable slips.

Question 3238

Topic: Pediatric Hip

A 4-week-old female is placed in a Pavlik harness for developmental dysplasia of the hip (DDH). Two weeks later, the parents report she has stopped kicking her leg on the affected side. Exam reveals decreased quadriceps activity. What is the most appropriate next step in management?

. Increase hip abduction by adjusting the posterior straps
. Decrease hip flexion by loosening anterior straps or temporarily removing the harness
. Proceed to urgent closed reduction and spica casting
. Order a stat MRI of the lumbar spine
. Perform an ultrasound to evaluate for septic arthritis

Correct Answer & Explanation

. Decrease hip flexion by loosening anterior straps or temporarily removing the harness

Explanation

Femoral nerve palsy in a Pavlik harness is typically caused by excessive hip flexion. Management involves decreasing flexion by loosening the anterior straps or temporarily removing the harness until quadriceps function returns.

Question 3239

Topic: Pediatric Lower Extremity

In the treatment of idiopathic congenital talipes equinovarus (clubfoot) using the Ponseti method, what is the correct sequence of deformity correction?

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

Correct Answer & Explanation

. Cavus, Varus, Adductus, Equinus

Explanation

The Ponseti method corrects clubfoot deformities in a specific sequence: Cavus, Adductus, Varus, and finally Equinus (CAVE). The equinus is typically corrected last, often requiring a percutaneous Achilles tenotomy.

Question 3240

Topic: Pediatric Upper Extremity & Spine
A 6-year-old boy sustains a Gartland type III extension supracondylar humerus fracture. On examination, the hand is pink and warm, but the radial pulse is not palpable. What is the most appropriate initial management?
. Immediate open vascular exploration
. Closed reduction and percutaneous pinning followed by vascular reassessment
. Computed tomography angiography (CTA) to localize the arterial injury
. Open reduction and internal fixation via an anterior approach
. Administration of intravenous heparin and observation

Correct Answer & Explanation

. Closed reduction and percutaneous pinning followed by vascular reassessment

Explanation

For a pink, pulseless hand associated with a supracondylar humerus fracture, the initial treatment is urgent closed reduction and percutaneous pinning. Vascular exploration is reserved for a persistently white, pulseless hand post-reduction.

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