ABSTRACT: Background: This systematic review and meta-analysis aimed to evaluate the effect of neuromuscular electrical stimulation (NMES) on quadriceps muscle strength, pain, and function outcomes following total knee arthroplasty (TKA). Methods: PubMed/Medline, Embase, Web of Science, CENTRAL, Scopus, PsycINFO, PEDro, CINAHL, CNKI, and Wanfang were systematically searched for randomized controlled trials (RCTs) from their inception to 18 June 2021. Results: Nine RCTs that involving 691 patients were included in the meta-analysis. Our pooled analysis showed that NMES improved quadriceps muscle strength after TKA within 1 months [standardized mean difference (SMD): 0.81; 95% CI: 0.51-1.11], 1-2 months (SMD: 0.55; 95% CI: 0.13-0.97), 3-4 months (SMD: 0.42; 95% CI: 0.18-0.66), and 12-13 months (SMD: 0.46; 95% CI: 0.18-0.74), pain between 1 and 2 months [mean difference (MD): -0.62; 95% CI: -1.04 to -0.19], pain between 3 and 6 months (MD: -0.44; 95% CI: -0.74 to -0.14) Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) between 3 and 4 months (MD: -0.43; 95% CI: -0.82 to -0.05), timed up and go test (TUG) within 1 month (MD: -2.23; 95% CI: -3.40 to -1.07), 3 minutes walk test between 3 and 6 months (MD: 28.35; 95% CI: 14.55-42.15), and SF-36 MCS between 3 and 6 months after TKA (MD: 4.20, 95% CI: 2.41-5.98). Conclusion: As a supplementary treatment after TKA, postoperative NMES could improve the short-term to long-term quadriceps muscle strength, mid-term pain, and mid-term function following TKA. However, many outcomes failed to achieve statistically meaningful changes and minimal clinically important difference (MCID), thus the clinical benefits remained to be confirmed. Level of Evidence: Therapeutic level I. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42021265609.
