Appendix: Table 1.
Description of the articular cartilage degeneration grading classifications used for each study.
| Author | Grade | Description | Defect Size |
|---|---|---|---|
|
| |||
| Bachman (MRI) | 0 | Normal intrinsic signal | |
| I | Focal intrinsic signal and normal surface contour | ||
| II | Fibrillation or erosion | <50% cartilage | |
| III | Fibrillation or erosion | >50% cartilage | |
| IV | Full thickness defect with denudation of bone | ||
|
| |||
| Ficat (MRI) | I | Closed chondromalacia, surface intact, softening | |
| II | Surface irregularities, superficial ulcerations | ||
| III | Ulceration with exposure of subchondral bone | ||
|
| |||
| Gluckert (Arthroscopy) | 0 | Smooth surface, no soft areas on probing | |
| I | Slight fibrillation | ||
| II | Moderate fibrillation | <50% depth | |
| III | Deep fibrillation, down to subchondral bone | >50% depth | |
| IV | Complete loss of cartilage, exposure of subchondral bone | ||
|
| |||
| Gluckert (Modification for MRI by Irie) | 0 | Continuous, smooth surface, homogenous signal | |
| I | Continuous, smooth, slight inhomogeneity | ||
| II | Surface irregularity | <50% thickness | |
| III | Marked surface irregularity, inhomogeneity | >50% thickness | |
| IV | Complete loss of cartilage layer | ||
| V | Inhomogeneity of subchondral bone | ||
|
| |||
| Noyes (Arthroscopy) | I | Intact cartilage | |
| IA | Softening | <1 cm | |
| IB | Softening with deformation | 1.5 cm | |
| II | Fibrillation/fissuring | ||
| IIA | Fibrillation/fissuring | <1/2 thickness | |
| IIB | Fibrillation/fissuring | >1/2 thickness | |
| III | Exposure of subchondral bone | ||
| IIIA | Exposure of subchondral bone, intact | ||
| IIIB | Exposure of subchondral bone, bony excavation | ||
|
| |||
| Outerbridge (Arthroscopy) | I | Softening and swelling | |
| II | Fragmentation/fissuring | <1/2 inch | |
| III | Fragmentation/fissuring | >1/2 inch | |
| IV | Erosion with exposed subchondral bone | ||
|
| |||
| Shahriaree (Arthroscopy) | I | Softening | |
| II | Blisterlike swelling | ||
| III | Surface irregularity, areas of thinning | ||
| IV | Ulceration, exposure of subchondral bone | ||
|
| |||
| Recht (MRI) | 0 | Intact cartilage surface | |
| 2A | Cartilage defect | <1/2 thickness | |
| 2B | Cartilage defect (not full thickness) | >1/2 thickness | |
| 3A | Exposed bone with normal bone contour | ||
| 3B | Exposed bone with cavitation or erosion | ||
|
| |||
| Vallotton (MRI) | 0 | Normal cartilage | |
| I | Surface intact, hypo or hyper signal | ||
| II | Mild surface irregularity | <50% thickness | |
| III | Severe surface irregularity, up to 100% thickness | >50% thickness | |
| IV | Bone reaction | 100% thickness | |