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 24h, 48h, 72h 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 24h, 48h after surgery, but with no difference at 72h. 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 48h 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.

研究目的：回顾性分析分期双侧全膝关节置换术（staged bilateral total knee arthroplasty, TKA）中首次与第二次手术侧膝关节的术后早期疼痛情况，为镇痛策略的调整提供临床证据。
研究方法：选取2009年1月至2013年1月期间符合纳入标准的87例患者，对其临床资料进行回顾性分析。在分期全膝关节置换术中，采用视觉模拟评分法（Visual Analogue Scale, VAS）分别评估术后24h、48h、72h时，首次与第二次手术侧膝关节在静息状态及最大屈膝位的疼痛评分；同时对比不同间隔时间组（<6个月、6~12个月、>12个月）中，第二次与首次手术侧膝关节的疼痛评分差值（ΔVAS）。
研究结果：术后24h、48h时，第二次手术侧膝关节的VAS评分显著高于首次手术侧，但术后72h时两组评分无显著差异。间隔时间<6个月组的ΔVAS显著高于>6个月组，而6~12个月组与>12个月组的ΔVAS无显著差异。
研究结论：接受分期双侧全膝关节置换术的患者，其第二次手术侧膝关节在术后48h内的疼痛程度显著高于首次手术侧，该结果可为分期双侧全膝关节置换术第二次手术时强化镇痛方案提供临床依据。此外，在分期双侧全膝关节置换术后疼痛管理中，建议将两次手术的间隔时间延长至6个月以上，此举可减轻第二次手术侧的术后疼痛，提升患者满意度，并加快患者康复进程。