Researchers from Peninsula Medical School at the Universities of Exeter and Plymouth in the UK reviewed 13 studies and found 5 with more than 1300 patients and analysed the results.
Acupuncture was superior to sham acupuncture (pretend acupuncture) for both pain and function. The effects were also significant at long-term follow-up.
This systematic review of acupuncture for knee pain was published in journal Rheumatology (Oxford). 2007 Mar;46(3):384-90.