High-intensity electroacupuncture is superior to low-intensity electroacupuncture for knee osteoarthritis: a meta-analysis of randomized controlled trials.

Background: Electroacupuncture (EA) has been demonstrated to be efficacious and safe in patients with knee osteoarthritis (KOA), yet the optimal current intensity for pain control in KOA remains unspecified. The present meta-analysis aimed to compare the effects of high-intensity and low-intensity EA in terms of pain relief and functional improvement in KOA.

Methods: A thorough and comprehensive literature search for randomized controlled trials (RCTs), all looking at the intensity of EA for KOA, was carried out in PubMed, EMBASE, Cochrane Library, China National Knowledge Infrastructure (CNKI), China Science Journal Citation Report (VIP) and Wanfang database, as well as ClinicalTrials.gov. All databases were searched from their inception until April 2022. Study quality was assessed using the Cochrane risk of bias (RoB)2 tool. Finally, a meta-analysis of all eligible RCTs was performed using Review Manager 5.3.

Results: Three studies with 472 individuals were included in the meta-analysis. The pain intensity reductions were significantly different between the high-intensity EA group and low-intensity EA group (mean difference (MD) = -0.22, 95% confidence interval (CI) = -0.26 to -0.18, p < 0.00001). There was no significant difference between the two groups in the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores (MD = -3.62, 95% CI = -12.22 to 4.98, p = 0.41). High-intensity EA significantly improved emotional scale (ES) scores compared to low-intensity EA (MD = -0.72, 95% CI = -0.76 to -0.67, p < 0.00001).

Conclusion: The findings of this systematic review and meta-analysis indicated that high-intensity EA provides superior pain relief and has a bigger impact on emotional scale scores in patients with KOA.