The effects of femoral nerve blockade in conjunction with epidural analgesia after total knee arthroplasty.

Overview

Either epidural analgesia or femoral nerve blockade improves analgesia and rehabilitation after total knee arthroplasty. No study has evaluated the combination of femoral nerve blockade and epidural analgesia. In this prospective, randomized, blinded study we investigated combining femoral nerve blockade with epidural analgesia. Forty-one patients received a single-injection femoral nerve block with 0.375% bupivacaine and 5 microg/mL epinephrine; 39 patients served as controls. All patients received combined spinal-epidural anesthesia and patient-controlled epidural analgesia with 0.06% bupivacaine and 10 microg/mL hydromorphone. Average duration of epidural analgesia was 2 days. All patients received the same standardized physical therapy intervention. Median visual analog scale (VAS) scores with physical therapy were significantly lower for 2 days among patients who received a femoral nerve block versus controls: 3 versus 4 (day 1), 2.5 versus 4 (day 2); P < 0.05. Median VAS pain scores at rest were 0 in both groups on days 1 and 2. Flexion range of motion was improved on postoperative day 2 (70 degrees versus 63 degrees ; P < 0.05). No peripheral neuropathies occurred. We conclude that the addition of femoral nerve blockade to epidural analgesia significantly improved analgesia for the first 2 days after total knee arthroplasty.