Analgesia After Total Knee Arthroplasty: Continuous Femoral Nerve Block Versus Continuous Epidural Analgesia

Objective:To compare the effects of analgesia,side effects and range of knee movement by using continuous femoral nerve block and continuous epidural analgesia after total knee arthroplasty.Method:Forty patients scheduled for elective unilateral TKA in Department of Orthopaedics,Zhongshan Hospital from September 2006 to April 2008 were randomly divided into two groups.Postoperative analgesia was provided with continuous femoral nerve block in Group A,and continuous epidural analgesia in Group B.The intensity of pain was assessed by the patients using a visual analog scale(0=no pain;10=worst possible pain) 12,24,and 48 h after the operation.The range of knee movement and side effects such as nausea,vomiting,urinary retention,catheter-related problems,were recorded for each group.Result:36 patients were involved in the result analysis.2 patients in group A quitted the research in midway.①The VAS score:there were no significant differences in VAS scores between Group A and Group B:12(4.0vs3.3 [p=0.76]),24(3.4vs3.1[p=0.69]),48h(2.9vs2.4[p=0.79])after operation.②The range of knee movement(ROM) in each group after operation:there were no significant differences in ROM(93.9vs93.0[p=0.67]) between Group A and Group B 10 days after operation.③Side effects:Compared with Group A,urinary retention,nausea and vomiting were significantly more frequent in Group B(P＜0.05).Compared with Group B,catheter-related problems were significantly more frequent in Group A(P＜0.01). Conclusion:Continuous femoral nerve block provides effective pain relief after total knee arthroplasty.There were no significant differences in effects of analgesia or range of knee movement between continuous femoral nerve block and continuous epidural analgesia.After total knee arthroplasty, continuous femoral nerve block causes fewer side effects and more catheter-related problems than continuous epidural analgesia.