Knee Cartilage Grading Protocol

Macroscopic scores (1-4) are assigned to cartilage surfaces during tissue harvesting and recorded on the Gross Morphological Assessment Sheet (See Description). These scores use a modified Outerbridge classification grading system.

Score of 1 = normal, intact surface

Score of 2 = minimum fibrillation

Score of 3 = overt fibrillation, fissuring

Score of 4 = erosion

Each grid space on the assessment sheet is assigned a score, as seen above 1-4, for cartilage on the Patella, Trochlea, Medial Femoral Condyle, Lateral Femoral Condyle, Medial Tibial Plateau, and Lateral Tibial Plateau.

The individual grid scores for each knee are added together ( left and right knees are added up separately). Each sum will range from 48 to 192.

The total score for each knee will determine the grade category with normal (Grades 0 or I) or OA (Grades 3 or 4).

Knee Cartilage Grades 0-IV V:

Grade 0 = normal (total score of 48)

Grade I = minimal change (total score 49-72)

Grade II = mild change (total score 73-96)

Grade III = moderate change (total score 97-120)

Grade IV = severe change (total score 121+)