Table 1.

Osteoarthritis Research Society International (OARSI) score.

Grade	Osteoarthritic Damage
Grade 0	Normal cartilage
Grade 1	Threshold in cartilage for OA without loss of cartilage
Grade 2	Discontinuity of the superficial layer
Grade 3	Erosion of the matrix cracks by extending cartilage to <25% of the articular surface
Grade 4	Erosion of the matrix cracks by extending cartilage to <25–50% of the articular surface
Grade 5	Erosion of the matrix cracks by extending cartilage to <50–75% of the articular surface
Grade 6	Erosion of the matrix cracks by extending cartilage to <75% of the articular surface