Acupuncture for Myofascial Pain Syndrome: A Network Meta-Analysis of 33 Randomized Controlled Trials.

BACKGROUND Acupuncture techniques are commonly used as initial treatments for myofascial pain syndrome. OBJECTIVE This study aimed to assess and compare the efficacy and safety of different techniques of acupuncture for myofascial pain syndrome. STUDY DESIGN Network meta-analysis. SETTING All selected studies were randomized controlled trials (RCTs). METHODS The Cochrane Central Register of Controlled Trials, PubMed, Web of Science, EMBASE, and Chinese Biomedical Literature Database were searched from their inceptions to February 2016. Only full texts of RCTs comparing acupuncture therapies with any other therapies or placebo-sham acupuncture were included. Two reviewers independently assessed eligibility and extracted data. The primary outcomes included pain intensity, PPT, and adverse events. Secondary outcome was physical function. RESULTS Thirty-three trials with 1,692 patients were included. Patients were allocated to 22 kinds of interventions, of which dry needling and manual acupuncture was the most frequently investigated intervention. Compared with placebo-sham acupuncture, scraping combined with warming acupuncture and moxibustion was found to be more effective for decreasing pain intensity (standardized mean difference (SMD) = -3.6, 95% confidence interval (CI) ranging from -5.2 to -2.1); miniscalpel-needle was more effective for increasing the PPT (SMD = 2.2, 95% CI ranging from 1.2 to 3.1); trigger points injection with bupivacaine was associated with the highest risk of adverse event (odds ratio = 557.2, 95% CI ranging from 3.6 to 86867.3); and only EA showed a significant difference in the ROM (SMD = -4.4, 95% CI ranging from -7.5 to -1.3). LIMITATIONS Lack of clarity concerning treatment periods, repetitive RCTs, and other valuable outcome measurements. The potential bias might affect the judgment of efficacy and safety. CONCLUSIONS The existing evidence suggests that most acupuncture therapies, including acupuncture combined with other therapies, are effective in decreasing pain and in improving physical function, but additional investigation on the safety of these therapies is required.Key words: Myofascial pain syndrome, acupuncture, anesthesia, efficacy, safety, network meta-analysis, systematic review, randomized controlled trials.