Dr. Yazici is Attending Physician, Division of Rheumatology, Hospital for Special Surgery, Weill Medical College of Cornell University, New York, NY, and Dr. Ince is Assistant Professor of Internal Medicine, Division of Rheumatology, Saint Louis University School of Medicine, St. Louis, MO.

Osteoarthritis (OA) is the most common form of arthritis. If you live long enough, you'll probably get it. Arthritis is defined as the inflammation of one or more joints in the body, such as a knee, hip or elbow. There are a number of possible causes; sometimes, no clear cause is found. OA is as serious as it is common. Today, it is the second leading cause of long-term disability in the U.S. As the Baby Boom generation ages, OA will become even more widespread and more of a burden on the nation's health care system.

Who Gets OA?
While the percentage of people with OA varies from one group to another, no age group, community or category of people is immune. As you get older, you are more likely to suffer from OA. More than half of all people over 65 have OA symptoms in the knees. By age 75, virtually everyone suffers from OA-related knee problems.

We do not know exactly why the risk of getting OA increases with age. We do know that certain occupations that are hard on the knees or other joints, including those requiring kneeling, squatting and climbing stairs, carry an increased risk of OA. Many more women than men get the disease, especially women who have passed menopause. For some reason, African-Americans are more likely to develop knee OA than whites.

Those who are overweight are also more likely to develop OA, especially in the knees. While some explain this by pointing to the stress that extra weight puts on our weight-bearing joints, there may also be something else at work here. Studies show, for instance, that overweight people are also more likely to get OA in the hand, fingers and other non-weight-bearing joints.

As with knee OA, hip OA is more common in people whose jobs involve heavy lifting and other activities that stress joints. Unless carried to an extreme, amateur sports and recreational activities do not generally increase someone's likelihood of getting OA.

Finally, some people seem to have been born with a genetic predisposition for the disease.

What Are the Symptoms?
Joint pain is the most important symptom of OA, the one that causes people to seek treatment from a doctor. The pain of OA usually comes on gradually over a period of months or years. Typically, the pain gets worse when the affected joints are used and gets better with rest.

Morning stiffness is a common sign of OA and usually lasts less than 30 minutes. Longer-lasting morning stiffness sometimes, but not always, points to another type of arthritis called rheumatoid arthritis, or RA. OA sufferers commonly feel stiff after prolonged periods of rest; this stiffness usually goes away after a few minutes.

OA causes physical changes to the joints, including making them swollen or sore and reducing range of motion. It can also cause the growth of osteophytes, or bone spurs. Over time, these spurs can damage the joint by destroying cartilage and causing other problems.

What Is the Treatment?
For rheumatoid arthritis, doctors have a range of drugs that treat the underlying disease. Unfortunately, we do not have similar weapons against OA. The only way to treat OA is to try to relieve the pain and other symptoms. These treatments can be divided into three categories:
  • Education, physical therapy and exercise
  • Drugs
  • Surgery

Education, Physical Therapy, and Exercise
Learning more about OA and how it works can help OA sufferers better live with the disease and its treatments. Counseling can also help families and friends take better care of a loved one with OA. As for exercise, lifting weights, other muscle strengthening exercises and aerobic exercise programs can make a big difference. For instance, exercises that strengthen the quadriceps, the large muscle in front of the upper leg, provide relief for knee OA symptoms by transferring some of the weight-carrying burden from the joint to nearby muscles. Many OA sufferers are similarly helped by occupational therapy or weight loss.

Drug treatment for OA pain begins with ordinary, over-the-counter acetaminophen. OA sufferers normally begin with up to 3,000-4,000 mg/day.

Those who need something stronger move up to a nonsteroidal anti-inflammatory drug, also known as an NSAID. There are a number of different NSAIDs. all of which are about equally effective in relieving pain. The choice of which one to take is usually determined by personal considerations such as side effects, convenience and price.

Recently, NSAIDs have begun to be replaced by a new class of drugs called COX-2 inhibitors. These seem to be just as effective as NSAIDs but are easier on the stomach.

Sometimes, doctors will treat OA, particularly knee OA, by injecting the surrounding tissue with a steroid drug. Studies have shown that this often makes the joint feel better for anywhere from a week or two to six months. Because steroids have negative side effects, such as speeding up cartilage damage, they are rarely used more than three or four times in a year.

Other treatments include rubbing the skin around the joint with capsaicin or other creams and cold packs to reduce inflammation and pain.

More controversial or experimental drug treatments for OA include a process called , in which a substance called hyaluronic acid is injected into the knee or other joint; glucosamine sulfate, and magnets. The bottom line is that there is currently not enough scientific evidence to judge the overall effectiveness of these drugs and OA sufferers who are interested in them should talk to their doctor.

When drugs and the other treatments described above fail, it may be time to talk about surgery. There are a number of knee operations that can help certain OA sufferers, depending on their symptoms and degree of disability. Complete joint replacement, or total joint arthroplasty, is an increasingly popular choice that can make a huge difference in an OA sufferers' quality of life. Thanks to constant improvements in technology, this relatively safe operation is getting easier and safer all the time.

OA is a painful, poorly understood and potentially debilitating disease that most of us, unfortunately, have in our future. With the American population growing older and older, we can expect a staggering number of new cases of OA over the next few decades.

On the bright side, if you exercise and are otherwise physically active, you will be better able to live with OA. With continuing progress on the drug front and improved joint replacement surgery, there is every reason to expect that safer and more effective treatments will arrive with each passing year.