Berndt and Harty classification (Radiographic)31
| Stage | Description |
| I | Subchondral compression fracture |
| IIa | Chondral fracture (partial avulsion) |
| IIb | Subchondral cyst |
| III | Chondral fracture with separated segment (non-displaced) |
| IV | Chondral fracture with separated segment (displaced) |