Waldenstrom’s staging of Legg-Calve-Perthe disease

Initial stageincreased head-socket distance, subchondral plate thinning, dense epiphysis
Fragmentation stagesubchondral fracture, inhomogeneous dense epiphysis which is porous, metaphyseal cysts
Reparative stagenormal bone in areas of resorption, removal of sclerotic bone. epiphysis is more homogeneous
Growth stagere-ossification. normal femoral shape is approached
Definitive stagefinal shape determined with joint congruency or incongruency