Effectiveness of acupuncture/dry needling for myofascial trigger point pain

Background: Myofascial trigger points (MTrPs) are widely accepted by clinicians and researchers as a primary source of pain. Needling is one common treatment, with dry needling as effective as injection. What is not clear is whether or not needling of any kind is superior to placebo. Objectives: To update a systematic literature review and meta-analysis (undertaken in 2007) investigating the effectiveness of direct MTrPs needling compared with placebo, and to discuss the variation in needling approaches adopted by randomized controlled trials (RCTs) investigating acupuncture/dry needling for MTrP pain. Methods: An electronic database search of RCTs published since the original review and a critical review of the literature. Results: Three RCTs of direct MTrP needling were identified as eligible for review. One concluded that needling was superior to standard care; two adopted a placebo control and were added to our original meta-analysis of four studies. Combining six studies (n= 183), needling was found to be statistically superior to placebo [weighted mean difference=516.67 (95% CI: 3.23-30.11)]; however, marked statistical heterogeneity was observed (I-2 = 582.6%). Conclusion: There is limited evidence that direct MTrP dry needling has an overall treatment effect when compared with standard care. While the results of the meta-analysis indicate that direct needling is superior to placebo, the results should be interpreted with caution due to the marked heterogeneity observed in this model. There remains a need for large-scale, adequately powered, high-quality placebo-controlled trials to provide a more trustworthy result.