Classification of Avascular Necrosis of the Hip
Stages
- Normal hip with contralateral disease
- Normal radiographic appearance diagnosided on MRI or bone scan
- Radiographic changes with no collapse & spherical head
- Wedged shaped ↑ density, mottled osteoporosis, subchondral lucency / fracture, collapse, head no longer spherical
- Marked changes with secondary degeneration & collapse of subchondral bone
- Secondary acetabular degeneration
