RESUMO
<p><b>OBJECTIVE</b>To evaluate the clinical effectiveness of pulsed electromagnetic field therapy in the treatment of knee osteoarthritis.</p><p><b>METHODS</b>Based on the principles and methods of Cochrane systematic reviews, the authors searched the Cochrane Library (2012, 2 issue), PubMed (1966 to February, 2012), EMBASE (1974 to February, 2012), Chinese Biomedicine Database (1978 to February, 2012), China Journal Full-text Database (1979 to February, 2012), VIP database (1989 to February, 2012), as well as search engine Google Scholar. Randomized controlled trials (RCTs) of pulsed electromagnetic field therapy to treat knee osteoarthritis were included. The authors assessed the quality of the included trials according to the Cochrane Handbook for Systematic Reviews of Interventions Version. The Cochrane Collaboration's software RevMan 5.1 was used for meta-analysis.</p><p><b>RESULTS</b>Five RCTs totaling 331 patients were included. The results showed that compared with placebo control treatment, pulsed electromagnetic field therapy had little clinical benefit in relieving the pain of knee osteoarthritis [WMD=0.12, 95%CI (-0.46,0.69)], reducing morning stiffness time [WMD=0.08, 95%CI (-0.05, 0.21)] and improving the knee function [WMD=-1.16, 95%CI (-4.36, 2.05)]. There were no significant differences between the two groups.</p><p><b>CONCLUSION</b>The effects of Pulsed electromagnetic field therapy for treating knee osteoarthritis need more powerful trails to be confirmed. The above conclusions still need more high-quality randomized controlled trails to be verified owing to the limitations of the number and the quality of systematic review included studies.</p>