NIH News Release
National Institute of Arthritis and
Musculoskeletal and Skin Diseases

Friday, January 5, 2001
Contact: Connie Raab,
Office of Communications
and Public Liaison, NIAMS
(301) 496-8190

Major Review Reveals That Osteoarthritis is a Complex Disease with New Solutions

A multidisciplinary group of scientists has declared that osteoarthritis (OA), the most common form of arthritis, is "surprisingly complex," but has outlined a number of new approaches to its understanding, prevention and treatment. Their report, a review by 28 researchers at 17 academic and government institutions, cites over 250 published articles and is presented in two parts in the Annals of Internal Medicine.

The effort was led by David T. Felson, M.D., M.P.H., of Boston University, and Reva C. Lawrence, M.P.H., of the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), a part of the National Institutes of Health (NIH).

The disease, says the review, can result from an inherited predisposition to OA combined with a joint injury. Regular runners have almost no additional risk of OA, but football and soccer players and baseball pitchers are at increased risk. A healthy lifestyle helps — exercise can lessen disability if OA has developed. Strengthening the thigh muscles reduces risk of OA of the knee, as can losing weight. For people who have the disease, a combination of treatment approaches, including new medications and patient education, is effective.

"I am delighted that we have been able to publish this comprehensive, two-part review arising from our 1999 conference 'Stepping Away from OA,' " says Stephen I. Katz, M.D., Ph.D., director of the NIAMS. "OA is a major public health problem, affecting some 20 million people in this country."

The review points out that in the United States about 6 percent of adults over 30 have OA of the knee and about 3 percent have OA of the hip. The disease is responsible for more trouble walking and stair climbing than any other disease, and it is the most common indication for total joint replacement of the hip and knee. Before age 50 the prevalence of OA in most joints is higher in men than women. After this age, more women are affected by OA of the hand, foot and knee. The occurrence of the disease increases with age, rising 2- to 10-fold in people from 30 to 65 years of age.

In osteoarthritis, there is focused, progressive loss of cartilage, the slippery material that cushions the ends of bones, along with changes in the bone below the cartilage leading to bony overgrowth. The tissue lining of the joint can become inflamed, the ligaments looser, and associated muscles weak, with resulting pain when the joint is used.

The review covers risk factors, such as being overweight and joint injury from specific sports, and treatments ranging from established and new medications, exercise, and patient education to surgery when other treatments do not work. It also discusses new areas of research, such as easily measured disease indicators known as biomarkers, as well as engineering of new cartilage. Specific findings are given on the attached backgrounder.

"This review shows that arthritis research is a vibrant area, yielding new means of preventing the disease and slowing its progression, as well as new and effective combinations of drug and behavioral treatments," says Dr. Katz, NIAMS director. "People with osteoarthritis and those at risk for the disease should be encouraged that there is much that they and their doctors can do about it."

The mission of the NIAMS is to support research into the causes, treatment and prevention of arthritis and musculoskeletal and skin diseases, the training of basic and clinical scientists to carry out this research and the dissemination of information on research progress in these diseases. For more information about NIAMS, call our information clearinghouse at 1-877-22-NIAMS or visit the NIAMS Web site at


The two-part review appears as:

The development of the review was coordinated and funded by the NIAMS and was based on a July 1999 conference at NIH initiated, organized and funded by the Institute. Conference cosponsors were the NIH Office of Disease Prevention, NIH National Center for Complementary and Alternative Medicine, NIH Office of Research on Women's Health, NIH Office of Behavioral and Social Sciences Research, NIH National Center for Medical Rehabilitation Research, National Institute of Child Health and Human Development, Centers for Disease Control and Prevention, Arthritis Foundation and American Academy of Orthopaedic Surgeons.

To interview Dr. Felson, contact Rebecca Sullivan, Boston University, at (617) 638-8491. For Ms. Lawrence, contact Connie Raab, NIAMS, at (301) 496-8190 or


Findings from the two-part NIAMS Annals of Internal Medicine article: "Osteoarthritis: New Insights"

Risk factors and disease prevention:

Serious joint injury can lead to osteoarthritis (OA), but more often the disease results from a combination of systemic and joint-related factors. OA is strongly genetically determined, with genetic factors accounting for about half of OA in the hands and hips and a smaller percentage of OA of the knees. However, several steps can be taken to prevent or delay onset of OA.


Once OA develops, certain factors put a patient at risk for disability. These include pain, depression, muscle weakness and poor aerobic capacity. Although the expert group said that OA cannot be cured, there are new medications available, and recent studies have shown the potential of treatments that range from new medications to complementary medicine, patient education approaches, exercise and surgery. These approaches are often combined.


Nondrug approaches, including exercise and patient education

Surgery (after nonsurgical treatments fail)