Osteoarthritis Health Article

OSTEOARTHRITIS

Osteoarthritis, which is also called degenerative arthritis or degenerative joint disease, is primarily a disease that results from the breakdown and loss of cartilage in joints (e.g., knees, hips, wrists). Cartilage, a connective tissue that covers the surfaces of articular joints, is essential for proper joint function because it allows the ends of bones to slide over one another smoothly. Osteoarthritis results from both mechanical (e.g., trauma to joints) and biological (metabolic) events that interfere with the maintenance of healthy cartilage. Eventually, cartilage may be lost, causing the bones in the joint to rub together, and bony spurs may form.

SIGNS, SYMPTOMS, AND DIAGNOSIS

Osteoarthritis is characterized by joint pain, tenderness, swelling, and limitation in joint movement. The joints most often affected are the joints of the fingers, the base of the thumb, the hips, the knees, the neck (cervical spine), and the lower back (lumbar spine). Unlike some types of arthritis that affect multiple organ systems, any inflammation associated with osteoarthritis is limited to the joints. Pain after joint use that subsides with resting the joint is a classical sign of osteoarthritis. As osteoarthritis worsens, pain may occur at rest or at night. Health care providers diagnose osteoarthritis based on a history of joint symptoms, physical examination, and radiographic (X-ray) changes. X-ray changes may include joint-space narrowing, changes in the bones, and the presence of bony spurs.

In addition to the physical symptoms, osteoarthritis also impacts psychological, social, and economic well-being. Psychological effects include stress, depression, anger, feelings of helplessness, and anxiety. The social impacts may include decreased community involvement and lack of understanding by family, friends, and coworkers. The economic status of people with arthritis and their families is also affected. The financial burden of health care and days lost from work may seriously impact the financial well-being of persons with arthritis and their families.

Age is a major demographic risk factor for the development of osteoarthritis. Although aging does not cause osteoarthritis, the prevalence of osteoarthritis increases with age. Almost half of people over the age of sixty-five have arthritis—mostly osteoarthritis. Osteoarthritis is also more common among women than among men. In addition to age, risk factors for osteoarthritis include joint injury and being overweight (especially for knee and hip osteoarthritis). Reduction of weight has been shown to reduce the risk of symptomatic osteoarthritis in overweight people.

THE BURDEN OF OSTEOARTHRITIS

Osteoarthritis is the most common form of the more than one hundred conditions that are considered arthritis and other rheumatic conditions. In 1998, these conditions affected 43 million Americans, and they are among the most common chronic diseases. Arthritis is also a leading cause of disability—it limits activities for 7 million Americans. The costs of arthritis are enormous. In 1992, the costs of medical treatment and lost wages were estimated at $65 billion. The cost of osteoarthritis alone may currently exceed $15.5 billion.

Osteoarthritis affects as many people as all of the other types of arthritis combined. Almost 22 million Americans have osteoarthritis—almost one of every twelve people in the United States. Prevalence estimates of osteoarthritis will differ by how the data are collected or how the diagnosis is made. For example, people who have pain due to osteoarthritis may not show X-ray changes, and those with X-ray changes consistent with osteoarthritis may not have symptoms. The prevalence of osteoarthritis is high and will get even higher as the number of older Americans increases. In 2020, an estimated 60 million Americans will have arthritis—osteoarthritis alone is likely to affect over 30 million people. Osteoarthritis is a major cause of disability. Sixty to 80 percent of people with osteoarthritis are limited in their activities because of the disease.