Acupuncture for Treating Knee Osteoarthritis

Summaries for Patients are a service provided by Annals to help patients better understand the complicated and often mystifying language of modern medicine.

Summaries for Patients are presented for informational purposes only. These summaries are not a substitute for advice from your own medical provider. If you have questions about this material, or need medical advice about your own health or situation, please contact your physician. The summaries may be reproduced for not-for-profit educational purposes only. Any other uses must be approved by the American College of Physicians.

The summary below is from the full report titled "Effectiveness of Acupuncture as Adjunctive Therapy in Osteoarthritis of the Knee. A Randomized, Controlled Trial." It is in the 21 December 2004 issue of Annals of Internal Medicine (volume 141, pages 901-910). The authors are B.M. Berman, L. Lao, P. Langenberg, W.L. Lee, A.M.K. Gilpin, and M.C. Hochberg.

What is the problem and what is known about it so far?

Knee osteoarthritis is a common condition in which changes in the knee joints lead to pain and difficulty walking. Treatment aims to relieve symptoms and maintain function. Treatments include drugs to decrease pain and inflammation; weight loss, if needed; physical therapy; and exercise. Unfortunately, these treatments do not always help, and some have side effects. Consequently, many people with knee osteoarthritis seek alternative treatments, such as acupuncture. Acupuncture is an ancient Chinese treatment that involves putting special needles into specific points of the body to treat medical conditions. Mainstream medicine is increasingly recognizing acupuncture as an effective treatment for some disorders. Past studies about acupuncture for osteoarthritis have been small and have had inconsistent results.

Why did the researchers do this particular study?

To find out whether acupuncture is an effective treatment for knee osteoarthritis.

Who was studied?

570 patients with osteoarthritis of the knee proven by x-ray.

How was the study done?

The researchers assigned patients to receive either 23 sessions of acupuncture or sham acupuncture over 26 weeks (twice a week during the first 8 weeks then down to once a month by the 14th week), or arthritis education. Sham acupuncture involved using a special device to place fake needles on the 9 areas of the body where the patients who received true acupuncture got real needles. The fake needles did not pierce the skin, but they created a needle-like feeling, and the device that held the needles in place made it look like they had been inserted. The arthritis education program involved 12 group sessions during which a patient education specialist discussed strategies for dealing with osteoarthritis. All patients in the study could continue to use other osteoarthritis treatments prescribed by their doctors. The researchers then compared changes in patients' pain and function after 8 and 26 weeks in the 3 groups.

What did the researchers find?

After 8 weeks, patients in the acupuncture group had greater improvement in function, but not pain, compared with patients in the sham acupuncture group. Among patients who remained in the study, those in the acupuncture group had greater improvements in both pain and function after 26 weeks compared with the other groups.

What were the limitations of the study?

By week 26, 25% of participants from each acupuncture group dropped out; this introduces some uncertainty in the results at 26 weeks. Less intensive acupuncture treatment might not be enough to produce the same results. This study tells us how acupuncture adds to other treatments for knee osteoarthritis since patients in all 3 groups could use other treatments during the study. It does not tell us whether acupuncture works better than other therapies.

What are the implications of the study?

An extended course of acupuncture seems to offer some improvements in pain and function for patients with knee osteoarthritis compared with sham acupuncture or education.