Table 1.
Modified Mankin score used for histological analysis
| I. Structure | Grade |
| Normal | 0 |
| Superficial layer disrupted | 1 |
| Superficial layer absent | 2 |
| Irregular surface | 3 |
| Fissures into the middle zone | 4 |
| Slight disorganization | 5 |
| Fissure into the deep zone | 6 |
| Chaotic disorganization | 7 |
| II. Cellular abnormalities | |
| Normal | 0 |
| Hypocellularity | 1 |
| Large clones | 2 |
| III. Matrix staining | |
| Normal | 0 |
| Staining reduced in middle layer | 1 |
| Staining reduced in territorial matrix of middle and deep layer | 2 |
| Staining present in interterritorial matrix and reduced in the territorial matrix | 3 |
| Staining reduced in both territorial and interterritorial matrices | 4 |
| Maximum score | 13 |