Introduction This study aimed to compare the analgesic efficacy of different concentrations of ropivacaine used for the combination of ultrasound-guided adductor canal block (ACB) and infiltration between the popliteal artery and capsule of the posterior knee (IPACK) block in total knee arthroplasty (TKA).

Materials and Methods Before general anesthesia, 90 patients undergoing TKA were randomized to receive ACB + IPACK block with ropivacaine 0.2, 0.25, or 0.3% (defined as group A, B, and C, respectively). Primary outcome was the reported visual analog scale (VAS) pain scores at rest 30 minutes following arrival to the postanesthesia care unit (PACU). Secondary outcomes were postoperative VAS pain scores, postoperative morphine consumption, the time to first rescue analgesia, functional recovery of knee (including the range of motion and quadriceps strength), and postoperative complications.

Results Compared with group A, group B and group C had significantly lower VAS scores 30 minutes following arrival to the PACU (p < 0.001 and p < 0.001, respectively). These two groups also had significantly lower VAS pain scores at postoperative 2 hours (at rest: p = 0.037 and 0.002; during motion: p = 0.035 and 0.001, respectively) and 6 hour (at rest: p = 0.033 and 0.002; during motion: p < 0.001 and p < 0.001, respectively), lower postoperative morphine consumption (p = 0.001 and 0.002, respectively), longer time to first rescue analgesia (p = 0.010 and 0.009, respectively), and better range of knee motion on the day of surgery (p = 0.008 and 0.002, respectively). Group B and group C showed no significant differences in these outcomes between each other (p > 0.05). The three groups did not show a significant difference in postoperative quadriceps strength and complication rates (p > 0.05).

Conclusion Compared with ropivacaine 0.2%, ropivacaine 0.25 and 0.3% can provide early pain relief in the first 6 hours after surgery. Ropivacaine 0.25 and 0.3% may provide more clinical benefits for patients undergoing outpatient TKA.

本研究 旨在比较不同浓度罗哌卡因联合超声引导下收肌管阻滞（ACB）和腘动脉与后膝关节囊浸润（IPACK）阻滞在全膝关节置换术（TKA）中的镇痛效果。 ）。

材料和方法 全身麻醉前，90 例接受 TKA 的患者随机接受 ACB + IPACK 阻滞，其中罗哌卡因 0.2、0.25 或 0.3%（分别定义为 A、B 和 C 组）。主要结果是到达麻醉后监护室 (PACU) 后 30 分钟报告的视觉模拟量表 (VAS) 静息疼痛评分。次要结局为术后VAS疼痛评分、术后吗啡用量、首次救援镇痛时间、膝关节功能恢复（包括活动范围和股四头肌力量）以及术后并发症。

结果 与 A 组相比，B 组和 C 组到达 PACU 后 30 分钟的 VAS 评分显着较低（分别为p  < 0.001 和p  < 0.001）。这两组患者术后 2 小时（休息时：p  = 0.037 和 0.002；运动期间：p  = 0.035 和 0.001）和 6 小时（休息时：p  = 0.033 和 0.002；运动期间） VAS 疼痛评分也显着降低：分别为p  < 0.001 和p  < 0.001），术后吗啡消耗量较低（分别为p  = 0.001 和 0.002），首次救援镇痛时间更长（分别为p  = 0.010 和 0.009），膝关节活动范围更大手术当天（p 分别 = 0.008 和 0.002）。B 组和 C 组在这些结果之间没有显着差异 ( p  > 0.05)。三组术后股四头肌力量和并发症发生率差异无统计学意义（p  >0.05）。

结论 与0.2%罗哌卡因相比，0.25%和0.3%罗哌卡因可在术后6小时内早期缓解疼痛。0.25% 和 0.3% 罗哌卡因可能为接受门诊 TKA 的患者提供更多临床益处。