Osteoarthritis, also called degenerative joint disease or wear-
and-tear arthritis, typically begins in late adulthood. The
joint's smooth covering of cartilage becomes thinned, damaged or
worn away entirely. This causes use-related pain and stiffness
in the joints, especially the hands, the knee and the hip. It is
important to recognize that osteoarthritis is not an inevitable
part of aging and occasionally occurs in young people. What
causes osteoarthritis? There are many potential causes of
osteoarthritis, but in most people the cause is not known.
Research suggests that cartilage may release abnormal enzymes in
osteoarthritis. Or some people may be born with defective
cartilage that eventually leads to cartilage breakdown, typical
of osteoarthritis. Osteoarthritis caused by other conditions,
called secondary osteoarthritis, may be a direct result of
trauma, bleeding into the joint, any cause of long-standing
joint inflammation (such as rheumatoid arthritis), joint
infection or certain metabolic disorders.