Commonly affecting the hands, spine, knees and hips, osteoarthritis affects the smooth cartilage lining of the joint. You may also see osteoarthritis referred to as OA.
Healthy cartilage is smooth and tough and allows joints to move freely against each other, however, once damaged, it becomes thinner and rougher making moving the affected joint more difficult than usual. Once the cartilage starts to thin and become rough, this causes the tendons and ligaments, that also support joints to move, to work harder. This can cause swelling, pain and the formation of osteophytes.
Osteophytes are bony growths that the body creates on the affected joint to try and repair the damage made. Sometimes, the growths can rub against other tissues that surround the joint and may become visible on the surface of the skin.
In some cases, a large amount of cartilage loss can cause the joint to alter shape, forcing the bones out of their normal position.