Legg-Calve-Perthes Disease

  • Etiology: idiopathic avascular necrosis of immature capital femoral epiphysis
  • Imaging: early see microfracture / subarticular lucency = crescent sign, later see fragmentation of femoral head / subchondral cysts / coxa magna or coxa plana = enlarged or flat femoral head + femoral neck shortening
  • Radiograph: course of disease divided into 4 stages
    — Stage 1 – condensation
    — Stage 2 – resorptive-fragmentation
    — Stage 3 – re-ossification-healing
    — Stage 4 – residual-healed
  • Bone scan: changes present 4-6 weeks before radiographic changes
  • MRI: decreased signal intensity, decreased height, fragmentation
  • Complications: early osteoarthritis
  • Clinical: seen in ~ 4-8 year old while slipped capital femoral epiphysis is seen in 13 year old, bilateral in 10-20% and if bilateral usually affected sucessively, not simultaneously

Radiology Cases of Legg-Calve-Perthes-Disease

Radiograph of Legg-Calve-Perthes disease and slipped capital femoral epiphysis
AP (above) and frogleg (below) radiographs of the pelvis shows the right femoral head to be flat and enlarged with femoral neck shortening. The left femoral epiphysis is slipped posteromedially.