| Kellgren & Lawrence, grade | Operative treatment (n = 25) number (%) | Conservative treatment (n = 25) number (%) | Contralateral knees (n = 50) number (%) |
| 0 | 4 (16) | 8 (32) | 37 (74) |
| 1 | 9 (36) | 10 (40) | 11 (22) |
| 2 | 9 (36) | 4 (16) | 2 (4) |
| 3 | 3 (12) | 3 (12) | 0 (0) |
| 4 | 0 (0) | 0 (0) | 0 (0) |