Table 1. Modified mankin histological grading system of articular cartilage.
| Surface | Score | Criteria |
|---|---|---|
| Toluidine blue staining | 0 | Normal |
| 1 | Slight loss in staining (superficial zone) | |
| 2 | Moderate decrease in staining (mid zone) | |
| 3 | Large decrease in staining (deep zone) | |
| 4 | No staining | |
| Cartilage integrity | 0 | Normal |
| 1 | Discontinuity at cartilage surface | |
| 2 | Cartilage surface damaging and vessel erosion | |
| 3 | Clefts at superficial zone | |
| 4 | Clefts extending to mid cartilage | |
| 5 | Clefts extending to deep zone | |
| 6 | Full-thickness cartilage defect | |
| Tidemark | 0 | Continuous |
| 1 | Discontinuity, crossed with blood vessels | |
| Arrangement of chondrocytes | 0 | Normal |
| 1 | Hypercellularity | |
| 2 | Cloning | |
| 3 | Hypocellularity | |
| Total | 0–14 |