Grade | Description |
0 | Normal |
1 | Cartilage with softening and swelling |
2 | Partial-thickness defect with fissures on the surface that do not reach subchondral bone or exceed 1.5 cm in diameter |
3 | Fissuring to the level of subchondral bone in an area with a diameter more than 1.5 cm |
4 | Exposed subchondral bone |