Osteoarthritis

Definition

Osteoarthritis (OA) is the most common joint disorder.

Alternative Names

Causes

Most of the time, the cause of OA is unknown. It is mainly related to aging, but metabolic, genetic, chemical, and mechanical factors can also lead to OA.

The symptoms of osteoarthritis usually appear in middle age and almost everyone has them by age 70. Before age 55, the condition occurs equally in both sexes. However, after 55 it is more common in women.

The disease causes the cushioning (cartilage) between the bone joints to wear away, leading to pain and stiffness. As the disease gets worse, the cartilage disappears and the bone rubs on bone. Bony spurs usually form around the joint.

OA can be primary or secondary.

Primary OA occurs without any type of injury or obvious cause.

Secondary OA is osteoarthritis due to another disease or condition. The most common causes of secondary OA are metabolic conditions, such as acromegaly, problems with anatomy (for example, being bow-legged), injury, or inflammatory disorders such as septic arthritis.

References

Harris ED, Budd RC, Genovese MC, Firestein GS, Sargent JS, Sledge CB, Kelley's Textbook of Rheumatology, 7th ed. St. Louis, MO; W.B. Saunders; 2005.

US Food and Drug Administration. FDA Announces Series of Changes to the Class of Marketed Non-Steroidal Anti-Inflammatory Drugs (NSAIDs). Rockville, MD: National Press Office; April 7, 2005. Press Release P05-16.

US Food and Drug Administration. FDA Issues Public Health Advisory Recommending Limited Use of Cox-2 Inhibitors. Rockville, MD: National Press Office; December 23, 2004. Talk Paper T04-61.