Joints occur where bones meet, and they allow our bodies to be flexible. Lubricated tissue called cartilage lines the ends of bones and prevents friction during movement, and fibrous ligaments surrounding the joint give strength and support. Joints may be damaged by arthritis, injury, infection, or degeneration of bone, cartilage, and ligaments caused by aging or disease.
Joint disorders are a major cause of disability and immobility, but the treatment of long-term joint disorders has greatly improved during the past 25 years, partly due to the availability of safe, reliable artificial joints.
The first article describes the many types of arthritis, a general term for disease of one or more joints. This is followed by separate articles on the most common types, including osteoarthritis, rheumatoid arthritis, gout, and reactive arthritis. Septic arthritis, which in the past was a major cause of crippling joint disease, is now usually curable with antibiotics. Next in this section is a detailed look at lower back pain together with self-help measures that can be taken to prevent back pain from occurring. The section ends with articles on nonarthritic conditions such as bursitis, in which the fluid-filled cushions around the joints become swollen and inflamed.
There is a similar but distinct form of rheumatoid arthritis that can develop in children (see Juvenile chronic arthritis).
For more information on the structure and function of joints and ligaments, see How Bone Repairs itself.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.