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Difficulty: Very hardPediatric Musculoskeletal Disorders

Match each pediatric patient's clinical presentation with the statement that best describes the precise underlying pathophysiologic mechanism of their condition.

  • A 12-year-old gymnast reports activity-related anterior knee pain. Examination reveals isolated point tenderness at the proximal attachment of the patellar tendon. The tibial tubercle is non-tender.Traction apophysitis of the inferior pole of the patella caused by repetitive microtrauma.
  • A 30-month-old boy above the 95th percentile for weight presents with progressive bilateral genu varum and a lateral thrust during the stance phase of gait. Radiographs display medial metaphyseal beaking.Growth suppression and disordered endochondral ossification due to excessive compressive forces on the medial proximal tibial physis.
  • A 15-year-old pitcher experiences chronic lateral elbow pain and mechanical catching. Examination reveals a 15-degree flexion contracture. Radiographs show a focal radiolucent subchondral defect in the capitellum.Localized ischemia leading to avascular necrosis of subchondral bone and potential separation of articular cartilage.
  • A 10-year-old soccer player has insidious posterior heel pain. Pain is reproduced by simultaneous medial and lateral compression of the heel base, while the Achilles tendon itself is non-tender.Repetitive traction microtrauma at the secondary ossification center of the calcaneal tuberosity.
  • A 13-year-old boy presents with months of dull, aching pain radiating to the anterior knee. Knee examination is normal. Passive flexion of the affected hip results in obligate external rotation of the thigh.Mechanical shear failure occurring directly through the hypertrophic zone of the capital femoral physis.

Answer

Properly mapped pairs align the unique anatomic and biomechanical clues in each clinical vignette to the exact localized pathophysiologic mechanism of the respective disorder.
Each clinical vignette provides highly specific anatomic and biomechanical clues that distinguish closely related pediatric musculoskeletal conditions. Identifying the exact site of tenderness (e.g., inferior patellar pole versus tibial tubercle), recognizing the biomechanics of the injury (e.g., lateral compression in throwing), or noting classic clinical signs (e.g., Drehmann sign in SCFE) allows for accurate mapping to the underlying pathophysiology.

Step-by-Step Solution

1
Analyze the gymnast's presentation of proximal patellar tendon pain with a non-tender tibial tubercle.
Identifies Sinding-Larsen-Johansson syndrome (inferior patellar pole apophysitis) rather than Osgood-Schlatter.
Precise anatomic localization is necessary to determine which apophysis is inflamed.
2
Evaluate the toddler with progressive bowing and medial metaphyseal beaking.
Diagnoses infantile Blount disease, a failure of medial proximal tibial endochondral ossification.
Differentiates pathologic bowing from benign physiologic genu varum based on radiographic findings and excessive weight.
3
Examine the pitcher's lateral elbow pain, flexion contracture, and radiolucent capitellar defect.
Identifies osteochondritis dissecans (OCD) of the capitellum (subchondral avascular necrosis).
Distinguishes lateral compressive injuries from medial tension injuries (Little Leaguer's elbow) in throwing athletes.
4
Assess the soccer player's heel pain elicited by the calcaneal squeeze test.
Diagnoses Sever disease (apophysitis of the calcaneal tuberosity).
The normal Achilles tendon rules out primary tendinopathy, isolating the pathology to the secondary ossification center.
5
Evaluate the adolescent with chronic knee pain and obligate external rotation during hip flexion.
Identifies Slipped Capital Femoral Epiphysis (SCFE), an epiphyseal shear failure.
Recognizes referred pain via the obturator nerve and uses the Drehmann sign to localize the true defect to the hip physis.

Key Concept

Differentiating atypical or closely related pediatric musculoskeletal disorders using highly specific clinical exam maneuvers, isolated anatomic sites of tenderness, and precise pathophysiologic mechanisms.
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Topics

Pediatric Musculoskeletal Disorders

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