Osteoarthritis (OA)
This is the most common form of joint disease characterized by degenerative changes at the joint surfaces. OA can affect any joint and often those that weight-bear such as knees, hips and lumbar spine but can also affect the neck and hands. The typical changes that would be seen at the joint are thinning of the cartilage, the formation of osteophytes (bony spurs), thickening bone beneath the thinning cartilage and synovial thickening. In more severe cases the changes in the joint surfaces can lead to misalignment of the bones.
All these changes occur slowly over years although they can be accelerated by injury. The typical presentation includes pain at the joint, stiffness and swelling. The stiffness is usually worse in the morning which is typical when an inflammatory process is at play. This is because of reduced movement at night, the accumulation of fluid in the tissues and the release of pro-inflammatory cytokines in the early hours of the morning that increase the local inflammatory conditions. There also tends to be stiffness at the end of the day. The pain can vary and indeed some people have OA but very little pain and others have minor change sin the joints yet it hurts significantly. The understanding that pain is not an accurate indicator of tissue damage helps individuals understand how to manage themselves more effectively. Swelling is a further feature as the synovium produces more fluid at the joint. Surrounding tissues can also change, for example muscle wasting when the joint is not being used normally.
