Table II.

Smillie staged the osteochondrosis into five stages¹³

Smillie staging
Fissure type fractures in an ischaemic epiphysis. Altered articular contour of the dorsal and central part of the head Altered articular contour with widening and subchondral cystic changes. Presence of loose bodies. Complete metatarsal head flattening and a deforming arthrosis.