Genicular nerve block in people with total knee arthroplasty: A systematic review and meta-analysis

Abstract

Background: – No systematic review has assessed genicular nerve blocks (GNB) efficacy in total knee arthroplasty (TKA) widely. This study evaluated its effectiveness in patients undergoing TKA. Methods: – We conducted a Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)-guided systematic review and meta-analysis (PROSPERO CRD42024593742) of randomized controlled trials on GNB in TKA. Searches of PubMed, Embase, and Cochrane Library (July 2014–July 2024) included English-only studies. Risk of bias was assessed using Cochrane 2.0, and random-effects models were applied. No funding was received. Results: – This meta-analysis included 6 randomized controlled trials (335 patients; 169 GNB). Primary outcomes were pain scores (Visual Analog Scale), morphine use, and knee flexion. GNB significantly lowered pain at all time points: 4 hours (rest mean difference [MD]: –3.38, 95% confidence interval [CI]: –6.62 to –0.15, P = .04; activity MD: –3.91, 95% CI: –4.16 to –3.66, P < .00001), 8 hours (rest MD: –2.88, P = .01; activity MD: –3.58, P = .01), 12 hours (rest MD: –2.27, P = .004; activity MD: –2.33, P = .02), and 24 hours (rest MD: –1.40, P < .00001; activity MD: –2.42, P < .00001). However, GNB did not significantly affect knee flexion (MD: 19.86, 95% CI: –7.26 to 46.98, P = .15) or morphine use (SMD: 0.36, 95% CI: –2.22 to 2.93, P = .79). Subgroup analysis confirmed pain reduction with GNB alone or combined with other blocks at 12 and 24 hours: rest (MD: –1.10, P = .0001; MD: –2.85, P < .0001) and activity (MD: –1.30, P < .0001; MD: –4.00, P < .00001). Conclusion: – GNB reduces early postoperative pain after TKA without improving function or opioid use. Limitations include few trials, English-only data, short follow-up, and no complication assessment. Further research should confirm long-term efficacy and safety.