Combined posterior lumbar plexus–sciatic nerve block versus combined femoral–obturator–sciatic nerve block for ACL reconstruction

BACKGROUND: We compared the efficacy of combined posterior lumbar plexus–sciatic nerve block with that of combined femoral–obturator–sciatic nerve block as anesthesia for anterior cruciate ligament reconstruction surgery, because both block combinations have been recommended for lower limb arthroscopic and reconstructive surgery. METHODS: Forty-eight patients undergoing elective unilateral anterior cruciate ligament reconstruction under local anesthesia were randomized to undergo either combined posterior lumbar plexus–sciatic nerve block (Group 1), or combined femoral–obturator–sciatic nerve block (Group 2). Blocks were performed using nerve stimulation and bupivacaine 0.5% mixed with lignocaine 2%. Systolic and diastolic blood pressure, heart rate, and pulse oximetry were recorded. Quality of anesthesia, motor and sensory block, time to first analgesic use, sedation, and need for general anesthesia were recorded, along with verbal postoperative pain scores, and side effects. RESULTS: No patient in Group 1 and two patients in Group 2 needed general anesthesia. Complete sensory blockade was higher in Group 1 than in Group 2. However, complete motor blockade was similar in both groups. In Group 1, verbal pain scores were lower than in Group 2. Time to first analgesic was similar between the two groups. Total analgesic consumption was lower in Group 1. No significant differences were found for heart rate, pulse oximetry, or systolic and diastolic blood pressure between the groups, and no signs of toxicity were encountered. CONCLUSION: Combined posterior lumbar plexus–sciatic nerve block provided more comfortable intraoperative anesthesia and better postoperative analgesia than combined femoral–obturator–sciatic nerve block for anterior cruciate ligament reconstruction surgery.