Comparison of the effects of transcutaneous electrical nerve stimulation and microcurrent electrical neuromuscular stimulation after total knee arthroplasty

[Purpose] This study aimed to compare the effects of transcutaneous electrical nerve stimulation and microcurrent electrical neuromuscular stimulation on pain relief and knee function following total knee arthroplasty. [Participants and Methods] This was a prospective, single-center, three-group parallel study. Thirty-five patients scheduled for total knee arthroplasty were divided into transcutaneous electrical nerve stimulation, microcurrent electrical neuromuscular stimulation, and control groups. Interventions began on postoperative day 3 and continued for two weeks. Pain intensity during walking, maximum walking speed, timed up-and-go test, and isometric knee extension strength were assessed preoperatively, and two and four weeks postoperatively. [Results] Two weeks postoperatively, pain during walking was lower in the transcutaneous electrical nerve stimulation group than in other groups, and maximum walking speed was significantly faster in the transcutaneous electrical nerve stimulation group than in the microcurrent electrical neuromuscular stimulation group but not in the control group. Timed up-and-go and isometric knee extension strength improvements were observed gradually but were not significantly different between the groups. [Conclusion] Transcutaneous electrical nerve stimulation effectively relieved pain and improved walking speed early after total knee arthroplasty, whereas microcurrent electrical neuromuscular stimulation did not show significant benefits compared to the control.