A randomized, controlled trial of comparison of a continuous femoral nerve block (CFNB) and continuous epidural infusion (CEI) using 0.2% ropivacaine for postoperative analgesia and knee rehabilitation after total knee arthroplasty (TKA)

BACKGROUND AND AIMS: Postoperative pain relief following total knee arthroplasty (TKA) is a major concern as it will help to achieve an effective functional outcome. The present study was conducted to compare continuous femoral nerve block (CFNB) and continuous epidural infusion (CEI) techniques using ropivacaine. MATERIAL AND METHODS: Forty patients were randomly allocated into group F and group E to receive 0.2% ropivacaine through femoral catheter or epidural catheter respectively. An infusion was started @6 ml/h post-operatively when VAS was ≥4. The dose was titrated to keep VAS <4 (with minimum rate 2 ml/h and maximum rate 10 ml/h). If VAS ≥4 occurred despite maximum rate of infusion, a rescue analgesic was given. Primary objectives were to compare visual analogue score (VAS), rehabilitation indices, and rescue analgesic requirement. Secondary objectives were to assess patient and surgeon's satisfaction score, motor blockade, and complications if any. RESULTS: The mean VAS score, rehabilitation goals, rescue analgesic requirement, and patient's and surgeon's mean satisfaction scores were comparable in both the groups. Motor blockade was not seen and though the number of side effects were more in group E, they did not achieve statistical or clinical significance. CONCLUSION: CFNB can be used as an alternative, effective postoperative analgesic technique for TKA.