Increased protein levels of MMP-3 and tissue inhibitor of metalloproteinases 1 (TIMP-1), as well as elevated proteoglycan and type II collagen fragments have been observed in the synovial fluid of patients following an ACL or meniscal tear from day 1 up to 20 years post injury [16, 17], suggesting an unbalanced degrading process, that can significantly increase the risk of osteoarthritis. Here, TIMP1 is linked to osteoarthritis.