Osteoarthritis, also known as degenerative joint disease,
occurs when the cushiony cartilage between two bones becomes worn down, and
the bones begin to rub against each other in the joint (the
area where two bones come together). This often leads to pain, swelling, a
decrease in motion at the joint, stiffness, or the formation of bone
spurs (tiny growths of new bone). While osteoarthritis can occur at
almost any joint, osteoarthritis of the knee is the most common type. More
than 10 million Americans have osteoarthritis of the knee. Most people affected
are older than 45 years.
The February 26, 2003, issue of JAMA includes
an article about osteoarthritis of the knee.
There may be a genetic (inherited) tendency to develop osteoarthritis.
Joint injuries and overweight also increase osteoarthritis risk.
During a physical examination of the knee joint, your doctor may be
able to see that movement of the knee is restricted. Your doctor can diagnose
osteoarthritis of the knee by taking an x-ray. The x-ray will show that the
space between the bones of the upper and lower leg is smaller than it should
Osteoarthritis begins when the joint cartilage starts to become worn
down. This decreases the ability of the cartilage to work as a shock-absorber
to reduce the impact of stress on the joints. The remaining cartilage wears
down faster, and eventually, the cartilage in some spots may disappear altogether,
leaving the bones to grind against one another. It is at this stage that bone
spurs may form.
Regular exercise is one of the best treatments for osteoarthritis.
See your doctor for advice.
Although there are currently no drugs that treat osteoarthritis
directly, pain relievers are often prescribed to help ease some of the pain
and stiffness associated with osteoarthritis.
Cortisone shots can help decrease inflammation in the joint.
Although most people with osteoarthritis will not need surgery,
surgery is a possibility for those with severely damaged joints who have trouble
walking. Surgery may involve joint replacement in which the rough worn surfaces
of the joint are replaced with smooth-surfaced metal and plastic pieces.
Sources: National Institute of Arthritis and Musculoskeletal and Skin
Diseases, The Arthritis Society
National Institute of Arthritis and Musculoskeletal and Skin Diseases 877/220-4267
The Arthritis Society 800/321-1433 www.arthritis.ca
To find this and previous JAMA Patient Pages, go to the
Patient Page Index on JAMA’s Web site at www.jama.com. They
are available in English and Spanish. A Patient Page on arthritis was published
in the November 24, 1999, issue.
The JAMA Patient Page is a public service of JAMA
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Osteoarthritis of the Knee. JAMA. 2003;289(8):1068. doi:JPG0226