Table 1.
Histological grading scale modified from that of Wakitani et al. [6]
| Grade | Description |
|---|---|
| A. Cell morphology | |
| 4 | Hyaline cartilage |
| 3 | Mostly hyaline cartilage |
| 2 | Mostly fibrocartilage |
| 1 | Mostly non-cartilage |
| 0 | Non-cartilage only |
| B. Matrix staining (metachromasia) | |
| 3 | Normal (compared with host) |
| 2 | Slightly reduced |
| 1 | Significantly reduced |
| 0 | No staining |
| C. Surface regularitya | |
| 3 | Smooth (>3/4) |
| 2 | Moderate (1/2 to <3/4) |
| 1 | Irregular (1/4 to <1/2) |
| 0 | Severely (<1/4) |
| D. Thickness of cartilageb | |
| 2 | >2/3 |
| 1 | 1/3 to 2/3 |
| 0 | <1/3 |
| E. Integration of donor to host adjacent cartilage | |
| 2 | Both edges integrated |
| 1 | One edge integrated |
| 0 | Neither edge integrated |
| F. Thickness of subchondral bonec | |
| 4 | >100% |
| 3 | 75–100% |
| 2 | 50–75% |
| 1 | 25–50% |
| 0 | <25% |
aTotal smooth area of the repaired cartilage compared with that of the entire area of the cartilage defect
bMean thickness of the repaired cartilage compared with that of the adjacent normal cartilage
cMean thickness of the repaired subchondral bone compared with that of the surrounding subchondral bone