Table 1 International Cartilage Repair Society (ICRS) evaluation form

I. Surface

 Smooth/continuous

3

 Discontinuities/irregularities

0

II. Matrix

 Hyaline

3

 Mixture: hyaline/fibrocartilage

2

 Fibrocartilage

1

 Fibrous tissue

0

III. Cell distribution

 Columnar

3

 Mixed/columnar-clusters

2

 Clusters

1

 Individual cells/disorganized

0

IV. Cell population viability

 Predominantly viable

3

 Partially viable

1

 <10 % viable

0

V. Subchondral bone

 Normal

3

 Increased remodeling

2

 Bone necrosis/granulation tissue

1

 Detached/fracture/callus at base

0

VI. Cartilage mineralization (calcified cartilage)

 Normal

3

 Abnormal/inappropriate location

0