The most common cause of chronic knee pain and disability is Arthritis; of which Osteoarthritis, rheumatoid arthritis, and arthritis following injuries are the most common forms. Osteoarthritis usually occurs after the age of 50 and often in an individual with a family history of arthritis. The cartilage that cushions the bones of the knee softens and wears away. The bones then rub against one another causing knee pain and stiffness.
Rheumatoid Arthritis is a disease in which the synovial membrane becomes thickened and inflamed, producing too much synovial fluid, which over-fills the joint space. This chronic inflammation damages the cartilage and eventually causes cartilage loss, pain and stiffness. Post Traumatic Arthritis can follow a serious knee injury. A knee fracture or severe tears of the knee’s ligaments may damage the articular cartilage over time, causing knee pain and limiting knee function.