Table 1.
Stage | Criteria |
---|---|
0 | Normal or nondiagnostic radiograph, bone scan, MRI |
I | Normal radiographs; abnormal bone scan and/or MRI
|
II | Cystic and sclerotic changes in femoral head
|
III | Subchondral collapse (crescent sign) without flattening
|
IV | Flattening of femoral head
|
V | Joint narrowing or acetabular changes |
VI | Advanced degenerative changes |
Average femoral head and estimated acetabular involvement.