Characteristics of population groups evaluated
| Group | Severity of radiographic osteoarthritis (OA) | Type of meniscal tear | Corresponding symptoms |
| (A) | Any (K-L 0–4) | Any | Pain |
| (B) | Without OA (K-L 0–1) | Any | Pain |
| (C) | Without OA (K-L 0–1) | Unstable (author definition) | Meniscal (author definition) |
K-L, Kellgren-Lawrence grade.