OA is the most common cause of joint discomfort, disability and limitation of activity especially in older people. OA is a chronic disease that affects the whole joint including bone, cartilage, ligaments and muscles. This degenerative joint disease usually affects the large weight-bearing joints of the lower extremities, including hip and knee.

OA can develop at any age but tends to be more common in people aged over 40 years or those who have had joint injuries. In Malaysia, OA of the knee is the most common form of OA affecting 10 to 20% of the elderly population, reaching about 30% for those over the age of 65.