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JAMA Patient Page
February 26, 2003

Osteoarthritis of the Knee

JAMA. 2003;289(8):1068. doi:10.1001/jama.289.8.1068

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 be.


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.

For more information

Inform yourself

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.

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Sources: National Institute of Arthritis and Musculoskeletal and Skin Diseases, The Arthritis Society