Table 1.

Osteoarthritis Research Society International (OARSI) score

Grade	Osteoarthritic damage
0	Normal
0.5	Loss of Safranin-O without structural changes
1	Small fibrillations without loss of cartilage
2	Vertical clefts down to the layer immediately below the superficial layer and some loss of surface lamina
3	Verical clefts/erosion to the calcified cartilage extending to < 25% of the articular surface
4	Verical clefts/erosion to the calcified cartilage extending to 25%-50% of the articular surface
5	Verical clefts/erosion to the calcified cartilage extending to 50%-75% of the articular surface
6	Verical clefts/erosion to the calcified cartilage extending to > 75% of the articular surface