Legg–Calvé–Perthes Disease

Basics

Description

  • Idiopathic avascular necrosis of the femoral head in children 4–12 yr
  • Genetics:
    • Increased frequency with factor V Leiden and anticardiolipin antibodies
    • Usually sporadic but small percentage associated with type 2 collagen COL2A1 gene mutations

Pediatric Considerations

Exclusively a pediatric disease

Etiology

  • Idiopathic avascular necrosis from interruption of blood supply to the femoral head from ischemia/occlusion, followed by reossification, deformity, and mechanically weakened bone
  • May be multifactorial
  • Risk factors include secondhand exposure to tobacco smoke, wood smoke, low birth weight, birth length <50 cm, delayed skeletal maturity, trauma, coagulation disorders
  • Repetitive trauma from high impact activities has also been suggested as a risk factor
  • Gradual progression through 4 stages of disease:
    • Initial (necrosis) stage: Interruption of vascular supply causing necrosis, intermittent synovitis, increased joint space seen on x-ray
    • Fragmentation: Femoral head becomes soft and deforms causing loss of motion. Resorption occur, causing radiodense bone islets on x-ray
    • Reossification: Bone islets reabsorbed, irregular bone tissue formed
    • Healing or residual damage: Necrotic bone replaced by new bone in femoral head, may have some residual deformity
  • Most commonly occurs between ages 3 and 12, peak ages between 5 and 8; male > female, 4:1; Caucasians
  • Typically unilateral, but bilateral in 10–15% of cases
  • Associated with short stature, delayed and disproportionate growth

There's more to see -- the rest of this topic is available only to subscribers.