- 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
