Table 2 OA score; semi-quantitative method
Grade (key feature) | Stage % Involvement (surface, area, volume) | Â | ||
|---|---|---|---|---|
| Â | Stage 1 < 10% | Stage 2 10-25% | Stage 3 25-50% | Stage 4 > 50% |
Grade 1(surface intact) | 1 | 2 | 3 | 4 |
Grade 2 (surface discontinuity) | 2 | 4 | 6 | 8 |
Grade 3 (vertical fissures, clefts) | 3 | 6 | 9 | 12 |
Grade 4 (erosion) | 4 | 8 | 12 | 16 |
Grade 5(denudation) | 5 | 10 | 15 | 20 |
Grade 6(deformation) | 6 | 12 | 18 | 24 |