Updated systematic review and meta-analysis of acupuncture for chronic knee pain

Objective To assess the effectiveness and safety of acupuncture for the treatment of chronic knee pain (CKP). Methods We searched the MEDLINE, EMBASE, Cochrane CENTERAL, CINAHL and four Chinese medical databases from their inception to June 2017. We included randomised controlled trials of acupuncture as the sole treatment or as an adjunctive treatment for CKP. The primary outcome was pain intensity measured by visual analogue scale (VAS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale and 11-point numeric rating scale. Secondary outcome measurements included the 36-Item Short Form Health Survey and adverse events. The quality of all included studies was evaluated using the Cochrane risk-of-bias criteria and the STRICTA (Standards for Reporting Interventions in Controlled Trials of Acupuncture) checklist. Results Nineteen trials were included in this systematic review. Of these, data from 17 studies were available for analysis. Regarding the effectiveness of acupuncture alone or combined with other treatment, the results of the meta-analysis showed that acupuncture was associated with significantly reduced CKP at 12 weeks on WOMAC pain subscale (mean difference (MD) -1.12, 95%confidence interval (CI) -1.98 to -0.26, I-2=62%, 3 trials, 608 participants) and VAS (MD -10.56, 95%CI -17.69 to -3.44, I-2=0%, 2 trials, 145 patients). As for safety, no difference was found between the acupuncture and control groups (risk ratio 1.08, 95%CI 0.54 to 2.17, I-2=29%). Conclusion From this systematic review, we conclude that acupuncture may be effective at relieving CKP 12 weeks after acupuncture administration, based on the current evidence and our protocol. However, given the heterogeneity and methodological limitations of the included trials, we are currently unable to draw any strong conclusions regarding the effectiveness of acupuncture for chronic knee pain. In addition, we found that acupuncture appears to have a satisfactory safety profile, although further studies with larger numbers of participants are needed to confirm the safety of this technique. Strengths Systematic review without language restrictions. Limitations Only a few high-quality and consistent trials could be included in this review.