By Frances Alves

Osteoarthritis (OA), known as degenerative joint disease, is the most common of all arthritic conditions. This so-called "wear and tear" arthritis typically affects middle-aged and older adults. Weight-bearing joints are usually affected—the hips, the knees, and the spine, but also the finger joints.

Little is known about the exact cause of this type of arthritis. Although it is not inevitable like death and taxes, about 85 percent of Americans have some degree of OA by age 75. The most common risks are being overweight, having a family history of OA, and having a congenital defect (e.g., hip dysplasia). People who repeatedly injure their joints, such as runners who have spent 20 or so years pounding the pavement in pursuit of healthy bodies, may begin to develop OA in their knees as they move into their 40s.

OA is a condition that affects the cartilage ("gristle") in joints. In a healthy joint, the smooth, elastic cartilage that cushions the ends of our bones does not have its own blood supply. It receives oxygen and nutrients from the synovial fluid that surrounds and bathes the joints.

Over the years, cartilage can become thin, fray, split, and wear away completely. The ends of the bones at the joints then begin to grate on each other. This causes pain, stiffness, and limited joint movement. Unlike rheumatoid arthritis, there is little inflammation (i.e., swelling, redness) in the joints.

If you have arthritis, treatment you are using or considering should be aimed at relieving your pain, maintaining or improving your joint function, preventing disability, and improving your quality of life.

• Weight loss (if needed) and regular rest and sleep

• Heat and cold treatments (talk with your health practitioner)

• Regular (gentler) exercise, such as walking and swimming, water aerobics, and range-of motion exercise for affected joints (i.e., bending and moving joints as far as they will go normally without pain)

• Over-the-counter pain relievers. Acetaminophen is generally considered the first choice because it usually costs less and has fewer side effects than the anti-inflammatory pain relievers, such as ibuprofen and aspirin. Acetaminophen overdoses can be toxic to your liver, and alcohol enhances its toxic effects.

Ibuprofen should be avoided if you're allergic to aspirin or have asthma, heart failure, kidney problems or ulcers. Aspirin should be avoided if you have asthma, a history of ulcers, a bleeding disorder or if you're taking a blood thinner.

• Supportive devices to help you maintain your activities. These include canes, crutches, splints, walkers, and special shoes.

• Physical and occupational therapy for learning how to correctly use canes, walkers, and so on and when to use heat versus cold therapy

• Prescription pain relievers. The latest prescription drug for arthritis pain is a group of anti-inflammatories called COX-2 inhibitors, which includes the new drugs, celecoxib (Celebrex™) and rovecoxib (Vioxx™). These nonsteroidal anti-inflammatory drugs (NSAIDs) are easier on the stomach than aspirin or ibuprofen. The most commonly reported side effects for Vioxx™ are diarrhea, headache, insomnia, edema, and upper respiratory infection

Corticosteroids injected directly into painful joints (usually limited to one to three injections per affected joint) have been a long-standing treatment for arthritis. They may negatively effect other medical problems, and may lower your resistance to infections. Common side effects include increased appetite; indigestion; nervousness or restlessness; trouble in sleeping. There is also the possibility for more severe side effects.

• Skin creams. Capacian is rubbed into the skin over the affected joint. The main ingredient is an extract from hot peppers; it appears to relieve joint pain in some people.

• Surgery (almost always a last resort). This includes osteotomy (removing a wedge of bone from an affected knee or hip joint); total hip or knee replacement; small joint replacement in the hands; and the rarely used fusion for OA in neck, spine, hip, knee, and other joints.