LUMBAR PLEXUS BLOCK OR SELECTIVE LUMBAR PLEXUS BRANCH BLOCKS FOR HAMSTRING ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

Background: Although the femoral and obturator nerves are branches of the lumbar plexus, the success rate of blocking both nerves simultaneously using a lumbar plexus block (LPB) is relatively low. The purpose of this study was to compare the success rate of two peripheral nerve block techniques; combined selective obturator and femoral nerve blocks versus a posterior LPB. Methods: Sixty ASA physical status I patients undergoing hamstring ACL reconstruction were randomly allocated into two equal groups. In Group 1, 30 patients received obturator and femoral nerve blocks. In Group 2, 30 patients received a posterior LPB. Both groups received a sciatic nerve block. Neuro-stimulation technique was used to localize all nerves. The success rates and onsets of the obturator and femoral nerve blocks, the time required to localize the obturator nerve and any complication were recorded. Result: In Group 1, obturator and femoral nerves were blocked successfully in all patients (100%), versus 80% in Group 2 (P 0.05). Onsets of obturator motor block, femoral sensory and motor blocks were more rapid in Group 1 (4.25 ±3.44, 4.53 ±3.25 and 6.47±4.05 min respectively) than in Group 2 (7.27 ±3.99, 9.74 ±6.27and U.71±6.34 min respectively) (P 0.01).The localization time for the obturator nerve was 51.33 ±39.11 sec. Two patients in Group 2 (6.6%) had epidural extension. One patient in each group (3.3%) had urinary retention. Conclusion: Combined selective obturator and femoral nerve block is a successful and safe alternative to posterior lumbar plexus block for hamstring anterior cruciate ligament reconstruction surgery.