Cruess Classification (necrosis femoral head)
A modification of the Ficat & Arlet Classification for osteonecrosis of the femoral head based on plain radiographs:
| Stage I |
No changes visible |
| Stage II |
Sclerosis and areas of osteopenia |
| Stage III |
Subchondral fracture (crescent sign) with minimal depression of the articular surface |
| Stage IV |
Collapse of joint surface and subchondral bone (fragmentation, loose bodies, secondary arthritis) |
| Stage V |
Degeneration involves the glenoid |
Reference
Cruess RL. Osteonecrosis of bone. Current concepts as to etiology and pathogenesis. Clin. Orthop. Relat. Res. 1986; 208: 30-9.
