Dry Needling Versus Trigger Point Injection for Neck Pain Symptoms Associated with Myofascial Trigger Points: A Systematic Review and Meta-Analysis

Objective To examine the effects of dry needling against trigger point (TrP) injections (wet needling) applied to TrPs associated with neck pain. Methods Electronic databases were searched for randomized clinical trials in which dry needling was compared with TrP injections (wet needling) applied to neck muscles and in which outcomes on pain or pain-related disability were collected. Secondary outcomes consisted of pressure pain thresholds, cervical mobility, and psychological factors. The Cochrane Risk of Bias tool, the Physiotherapy Evidence Database score, and the Grading of Recommendations Assessment, Development, and Evaluation approach were used. Results Six trials were included. TrP injection reduced pain intensity (mean difference [MD ] –2.13, 95% confidence interval [CI] –3.22 to –1.03) with a large effect size (standardized mean difference [SMD] –1.46, 95% CI –2.27 to –0.65) as compared with dry needling. No differences between TrP injection and dry needling were found for pain-related disability (MD 0.9, 95% CI –3.09 to 4.89), pressure pain thresholds (MD 25.78 kPa, 95% CI –6.43 to 57.99 kPa), cervical lateral-flexion (MD 2.02°, 95% CI –0.19° to 4.24°), or depression (SMD –0.22, 95% CI –0.85 to 0.41). The risk of bias was low, but the heterogenicity and imprecision of results downgraded the evidence level. Conclusion Low evidence suggests a superior effect of TrP injection (wet needling) for decreasing pain of cervical muscle TrPs in the short term as compared with dry needling. No significant effects on other outcomes (very low-quality evidence) were observed. Level of Evidence Therapy, level 1a.