Osteoarthritis (OA), also known as degenerative arthritis, is the most common of the arthritides and is a progressive joint disease. Described commonly as a "wear and tear" process, OA is caused by mild inflammation in the joint secondary to abnormal degradation of the articular cartilage that covers the bones forming the joint. As the articular cartilage wears away, the bone it covers is exposed and becomes a participant in joint movement, increasing friction. This process also involves decreasing the synovial fluid in the joint that normally lubricates its moving parts. This decrease can occur through consumption of the fluid over time and/or through slowly diminishing its production in the joint space by the synovial membrane. The combination of these two progressive events leads to pain in the joint. In response to the pain, the joint gets used less and atrophy of the muscles and ligaments associated with the joint occurs. These secondary effects cause further dysfunction in addition to the pain and stiffness that comes with cartilage erosion.
Currently, OA is the number one cause cited for joint replacement today in the United States. Short-term complications include deep vein thrombosis, blood loss, scarring and infection. Long-term complications include late infection, wearing down or loosening of the components. As materials and techniques improve, arthroplasty will continue to improve as a viable option for OA and other joint diseases.
Tuetken, Rebecca S. Osteoarthritis. In Turek's Orthopaedics, 6th ed. Eds. Stuart L Weinstein, Joseph A Buckwalter. 154-162. (Lippincott Williams & Wilkins, 2005).http://orthoinfo.aaos.org/topic.cfm?topic=a00227http://www.emedicine.com/orthoped/TOPIC384.HTMhttp://www.nlm.nih.gov/medlineplus/ency/article/000423.htm