Addition of femoral nerve block to epidural infusion for pain control post total knee arthroplasty: Does it make a difference?

Introduction: Effective postoperative analgesia is a major factor in functional outcome after total knee arthroplasty (TKA). To reduce postoperative pain arecovery, peripheral nerve blocks, such as the femoral nerve block (FNB) have been used as an adjunct to the analgesic regime. We assessed whether the addition of a FNB to continuous epidural analgesia (CEA) would improve pain control after TKA. Materials and Methods: A prospective, randomised, controlled study was conducted on 58 pa� tients undergoing TKA and randomised into two groups. The CEA+FNB Group received a singleshot FNB of 30 ml 0.5% bupivacaine using a nerve stimulator technique. The CEA Group acted as a control group and did not receive FNB. Patients in both groups then received combined spinalepidural anaes� thesia for the surgery. Postoperative epidural inf usion with 0.1% bupivacaine and 2 µg/ml of fentanyl, at 6 ml/hr was continued up to 48 hours postoperat ively. Visual analogue scale (VAS) scores, motor blockade, requirement of rescue analgesia and patient satisfaction were recorded. Results: VAS scores were not significantly different between the CEA+FNB and CEA groups during rest (3 vs. 2) and flexion (5 vs. 6) on postoperative day�1 and during rest (1 vs. 2) and flexion (4 vs. 4) on postoperative day� 2. There was no significant difference in rescue analgesia required, the volume of epidural infusion, motor blockade or patient satisfaction between both groups. Conclusion: We concluded that the addition of FNB to epidural infusion did not improve analgesia after TKA.