<b>Comparing the effects of transcutaneous electrical nerve stimulation and microcurrent electrical stimulation after total knee arthroplasty</b>

[Purpose] To compare the effects of transcutaneous electrical nerve stimulation and microcurrent electrical stimulation on pain relief and knee function following total knee arthroplasty．[Participants and Methods] This was a prospective, single-center, 3-group parallel study. Thirty-five patients scheduled for total knee arthroplasty were divided into the transcutaneous electrical nerve stimulation, microcurrent electrical stimulation, and control groups. Interventions began on postoperative day three and continued for two weeks. Pain intensity during walking, maximum walking speed, timed up-and-go test, and isometric knee extension strength were evaluated before and 2 and 4 weeks after surgery. Statistical analyses were performed using a mixed-effects model for repeated measures with split-plot analysis and preoperative pain catastrophizing score as a covariate.[Results] Two weeks after surgery, pain during walking was lower in the transcutaneous electrical nerve stimulation group than in the other groups, and maximum walking speed was faster than in the microcurrent electrical stimulation group. Timed up-and-go and isometric knee extension strength improvements were observed over time 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 stimulation did not show significant benefits compared to the control.

【研究目的】比较经皮神经电刺激（transcutaneous electrical nerve stimulation）与微电流电刺激（microcurrent electrical stimulation）对全膝关节置换术（total knee arthroplasty）后疼痛缓解及膝关节功能的影响。
【研究对象与方法】本研究为一项前瞻性、单中心、三组平行对照研究。纳入35例拟行全膝关节置换术的患者，分为经皮神经电刺激组、微电流电刺激组及对照组。干预于术后第3日启动，持续2周。分别于术前、术后2周及4周评估患者步行时疼痛强度、最大步行速度、计时起立行走测试（timed up-and-go test）成绩及等长膝关节伸肌力量。统计分析采用重复测量混合效应模型（mixed-effects model for repeated measures）结合裂区分析（split-plot analysis），并以术前疼痛灾难化评分（pain catastrophizing score）作为协变量。
【研究结果】术后2周时，经皮神经电刺激组患者步行时疼痛程度低于其余两组，且最大步行速度快于微电流电刺激组。计时起立行走测试成绩与等长膝关节伸肌力量随时间均有所改善，但组间差异无统计学意义。
【研究结论】全膝关节置换术后早期，经皮神经电刺激可有效缓解疼痛并改善步行速度，而微电流电刺激与对照组相比未展现出显著获益。