Table 3.
Modified O’Driscoll Histological Scoring System.
| Feature | Score |
|---|---|
| I. Nature of the Repair Tissue | |
| Some Fibrocartilage, mostly nonchondrocytic cells | 0 |
| Mostly Fibrocartilage | 1 |
| Mixed Hyaline and Fibrocartilage | 2 |
| Mostly Hyaline Cartilage | 3 |
| Hyaline Cartilage | 4 |
| II. Surface Regularity | |
| Severe Disruption, Including Fibrillation | 0 |
| Fissures | 1 |
| Superficial Horizontal Lamination | 2 |
| Smooth and Intact | 3 |
| III. Structural Integrity (morphologic zone reconstitution) | |
| Severe Disintegration | 0 |
| Slight Disruption, Including Cysts | 1 |
| Normal | 2 |
| IV. Thickness | |
| 0% – 50% of Normal Cartilage | 0 |
| 50% – 100% of Normal Cartilage | 1 |
| 100% of Normal Adjacent Cartilage | 2 |
| V. Bonding to Adjacent Cartilage | |
| Not Bonded | 0 |
| Bonded at One End or Partially at Both Ends | 1 |
| Bonded at Both Ends of Graft | 2 |
| VI. Hypocellularity | |
| Moderate Hypocellularity | 0 |
| Slight Hypocellularity | 1 |
| Normal Cellularity | 2 |
| VII. Chondrocyte Clustering | |
| 25% – 100% of the Cells | 0 |
| < 25% of the Cells | 1 |
| No Clusters | 2 |
| VIII. Freedom from Degenerative Changes in Adjacent Cartilage | |
| Severe Hypocellularity, Poor or No Staining | 0 |
| Mild or Moderate Hypocellularity, Slight Staining | 1 |
| Normal Cellularity, Mild Clusters, Moderate Staining | 2 |
| Normal Cellularity, No Clusters, Normal Staining | 3 |
| IX. Reconstitution of Subchondral Bone | |
| No Subchondral Bone Reconstitution | 0 |
| Minimal Subchondral Bone Reconstitution | 1 |
| Reduced Subchondral Bone Reconstitution | 2 |
| Normal | 3 |
| X. Inflammatory Response in Subchondral Bone Region | |
| Severe | 0 |
| Moderate | 1 |
| None/Mild | 2 |
| XI. Safranin-O Staining | |
| None | 0 |
| Slight | 1 |
| Moderate | 2 |
| Normal | 3 |
| XII. Cumulative Histology Score (sum of above scores) | 0–28 |