Osteoarthritis (OA), the syndrome of joint pain and dysfunction caused by joint degeneration, affects more people than any other joint disease. In most instances joint degeneration develops in the absence of an identifiable cause, but increasing age, excessive joint loading, and joint abnormalities and insults increase the risk of OA. Articular surface contact stress that causes tissue damage and compromises that ability of chondrocytes to maintain and restore the tissue has an important role in the development of joint degeneration Current methods of attempting to restore an articular surface in osteoarthritic joints include penetrating subchondral bone, altering joint loading, osteotomies and insertion of soft tissue grafts. Dramatic advances in the prevention and treatment of OA are likely to stem from better understanding of the role of mechanical forces in the initiation and progression of joint degeneration.