|
Filling of the defect relative to surface of normal adjacent cartilage |
111%–125% | 1 |
91%–110% | 0 |
76%–90% | 1 |
51%–75% | 2 |
26%–50% | 3 |
<25% | 4 |
Integration of repair tissue with surrounding articular cartilage |
Normal continuity and integration | 0 |
Decreased cellularity | 1 |
Gap or lack of continuity on one side | 2 |
Gap or lack of continuity on two sides | 3 |
Matrix staining with safranin O/fast green | |
Normal | 0 |
Slightly reduced | 1 |
Moderately reduced | 2 |
Substantially reduced | 3 |
None | 4 |
Cellular morphology (choose first between a, b, c, and d) | |
(a) Normal | 0 |
(b) Mostly round cells with the morphology of chondrocytes |
>75% of tissue with columns in radial zone | 0 |
25%–75% of tissue with columns in radial zone | 1 |
<25% of tissue with columns in radial zone (disorganized) | 2 |
(c) 50% round cells with the morphology of chondrocytes | |
>75% of tissue with columns in radial zone | 2 |
25%–75% of tissue with columns in radial zone | 3 |
<25% of tissue with columns in radial zone (disorganized) | 4 |
(d) Mostly spindle-shaped (fibroblast-like) cells | 5 |
Architecture within entire defect (not including margins) |
Normal | 0 |
1–3 small voids | 1 |
1–3 large voids | 2 |
>3 large voids | 3 |
Clefts or fibrillations | 4 |
Architecture of surface |
Normal | 0 |
Slight fibrillation or irregularity | 1 |
Moderate fibrillation or irregularity | 2 |
Severe fibrillation or disruption | 3 |
Percentage of new subchondral bone |
90%–100% | 0 |
75%–89% | 1 |
50%–74% | 2 |
25%–49% | 3 |
<25% | 4 |
Formation of tidemark |
Complete | 0 |
75%–99% | 1 |
50%–74% | 2 |
25%–49% | 3 |
<25% | 4 |
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