Effect of Regional Nerve Block in Total Knee Arthroplasty

Purpose: The goal of this study is to evaluate the efficacy of femoral, obturator, and sciatic nerve regional blocks with using ropivacaine during total knee arthroplasty. Materials and Methods:As a prospective study, we performed total knee arthroplasty for 383 patients from Oct. 2004 to Feb. 2009.There was 139 cases of femoral and obturator nerve regional block, 123 cases of femoral, obturator, and sciatic nerve regional block, and 121 cases of lidocaine local anesthesia at the synovium and subcutaneous tissue during wound closure.All the femoral nerve block cases used a femoral catheter for an additional ropivacaine injection at 10 hours after surgery.The pain was examined using a visual analogue scale (VAS).The VAS scores were checked on the day of surgery and at post operative 24 hours, 48 hours and 6 days.The pain control effects among the 3 groups were compared with one-way ANOVA test and Scheffe`s multiple comparison test. Results:The mean postoperative VAS score on the day of surgery and at post operative 24 hours, 48 hours and 6 days in the femoral and obturator nerve block group, were 6.3, 5.6, 5.3, and 4.7, respectively.For the cases of femoral, obturator and sciatic nerve block, the VAS scores were 3.9, 4.3, 3.5 and 1.9, respectively, and the VAS scores in the lidocaine local anesthetic group were 7.1, 6.1, 5.8 and 5.2, respectively.There was a statistical significance in all three groups (p＜.0001), and the additional sciatic nerve block groups had significant effectiveness.Conclusion: Pain control with the ropivacaine regional nerve block is more effective than the lidocaine local anesthesia, and additional sciatic nerve block is a important factor for decreasing the postoperative pain after total knee arthroplasty.