Analysis of Early Postoperative Pain in the First and Second Knee in Staged Bilateral Total Knee Arthroplasty: A Retrospective Controlled Study

OBJECTIVE A retrospective analysis of early postoperative pain in the first and second knee in staged bilateral total knee arthroplasty (TKA) to provide a clinical evidence for the change of analgesic strategy. METHODS From January 2009 to January 2013, 87 cases which meet the inclusion criterion were retrospectively reviewed. In stage TKA, the postoperative pain in the first and second knee at 24 h, 48 h, 72 h after operation were compared using the visual analogue scale (VAS) score in the rest and maximum knee flexion position. The difference in pain scores (ΔVAS) was also compared between the second and first knee at different time intervals (less than 6 months, 6-12 months, more than 12 months). RESULTS The VAS scores in the second knee were significantly higher than those in the first knee at 24 h, 48 h after surgery, but with no difference at 72 h. The ΔVAS in the group of less than 6 months was significantly higher than of those more than 6 months, and there was no difference in ΔVAS between group of 6-12 months and group of more than 12 months. CONCLUSIONS Patient receiving staged bilateral TKA experiences greater postoperative pain within 48 h after operation in the second knee than in the first knee, which can provide a clinical evidence to enhance the analgesic strategy in the second operation of the staged bilateral TKA. And for the management of postoperative pain in staged bilateral TKA, it's better to recommend that the interval between two operations should be more than 6 months, which may reduce the postoperative pain in the second knee, improve patient satisfaction, and speed up patient's rehabilitation process.