Fig. (4) Representative images of MMP-13, Collagen X, and ANKH expression from the meniscus of nine OA patients undergoing total knee arthroplasty. Images on the top are from a Male patient with a Grade 3 meniscus whereas the bottom images are from a Female patient with a Grade 4 meniscus. Grading was conducted by the surgeon at the time of extraction. Images in the smaller box were taken with 4x objective and larger images are of the dashed outline box taken with the 10x objective.