Needle acupuncture for osteoarthritis of the knee. A systematic review and updated meta-analysis.

OBJECTIVE To evaluate the efficacy of treatment with acupuncture for knee osteoarthritis. METHODS We searched PUBMED, EMBASE, and the Cochrane Central Register of Controlled Trials databases from July to October 2011 for randomized controlled trials that compared needle acupuncture with sham acupuncture, standard care, or waiting list control groups in patients with knee osteoarthritis. Of the 490 potentially relevant articles, 14 RCTs involving 3,835 patients were included in the meta-analysis. Two authors independently extracted outcome data on short-term and long-term pain and functional measures. RESULTS Standardized mean differences and 95% confidence intervals were calculated using the mean differences in improvements from baseline and the associated standard deviations in patients assigned to acupuncture and those assigned to control groups according to measurement time points. Compared with sham acupuncture control treatment, acupuncture was significantly better at relieving pain (p=0.002) and restoring function (p=0.01) in the short-term period, and relieving pain (p=0.06) and restoring function (p=0.06) in the long-term. Compared with the standard care and waiting list control treatments, acupuncture was significantly better at relieving pain and restoring function. CONCLUSION Acupuncture provided significantly better relief from knee osteoarthritis pain and a larger improvement in function than sham acupuncture, standard care treatment, or waiting for further treatment.