The efficacy of transcutaneous electrical nerve stimulation as an adjunctive therapy for perioperative pain management after total knee arthroplasty: an umbrella review

Total knee arthroplasty (TKA) is a cornerstone intervention for end-stage knee pathologies, yet acute postoperative pain remains a critical barrier to rehabilitation. Transcutaneous electrical nerve stimulation (TENS), a non-pharmacological adjunct, has potential for pain mitigation, but its efficacy lacks robust evidence from umbrella reviews. This umbrella review systematically evaluated meta-analyses (MAs) published through September 2025 in PubMed/MEDLINE, Embase, the Cochrane Library, and Web of Science. Overlap among primary studies was assessed using the GROOVE tool, and evidence quality was graded via the AMSTAR 2 and GRADE frameworks. This umbrella review is registered on the Prospective Register of Systematic Reviews (PROSPERO) under accession no. CRD420251126630. Eleven MAs were included in this review. The results showed that TENS significantly reduced acute postoperative pain at 24 h (MD = − 0.42, 95% CI − 0.59, − 0.25, P < 0.00001, I 2 = 0%) and 72 h (MD = − 0.84, 95% CI − 1.17, − 0.52, P < 0.00001, I 2 = 0%), but no significant difference was observed at 2 weeks (MD = 0.97, 95% CI − 0.66, 2.60, P = 0.24, I 2 = 91%). Opioid consumption was lower in the TENS group (SMD = − 0.58, 95% CI − 1.06, − 0.11, P = 0.02, I 2 = 53%). Improvements were also seen in range of motion (SMD = 0.40, 95% CI 0.11, 0.68, P = 0.006, I 2 = 0%), Hospital for Special Surgery scores (MD = 4.18, 95% CI 2.91, 5.45, P < 0.00001, I 2 = 0%), and length of hospital stay (SMD = − 0.20, 95% CI − 0.38, − 0.03, P = 0.02, I 2 = 0%). TENS was associated with a reduced incidence of nausea and vomiting. TENS is an effective adjunct for acute pain management after TKA, reducing opioid use and improving early functional outcomes. Future research should aim to standardize TENS application protocols and evaluate long-term efficacy and safety.