Use of Postoperative TENS and Continuous Passive Motion Following Total Knee Replacement

This randomized study analyzed the effectiveness of postoperative transcutaneous electrical nerve stimulation (TENS) used continuously for the first three postoperative days following total knee replacement (TKR) for 1) pain relief, 2) knee flexion arc, 3) narcotic dosage, and 4) hospital stay. Group 1 (N = 18) received sensory threshold TENS and group 2 (N = 18) received subthreshold TENS. Both groups also used continuous passive motion during their hospitalization as did patients from group 3 (control, N = 12) that did not receive TENS. Pain decrease from postoperative day 1-3 was 50% for group 1 patients and 38% for group 2 patients, as measured by the visual analog scale. Wilcoxon Rank Sum did not show a significant difference (p > 0.05) for pain relief or hospital stay for these two groups. Analysis of variance failed to show significant differences (p > 0.05) for knee flexion arc or narcotic dosage for the three groups. Although not statistically significant, an observed decrease in pain may be the only indication for postoperative TENS after TKR. J Orthop Sports Phys Ther 1990;11(12):599-604.