Effects of Using the Posterior or Anterior Approaches to the Lumbar Plexus on the Minimum Effective Anesthetic Concentration (MEAC) of Mepivacaine Required to Block the Femoral Nerve: A Prospective, Randomized, Up-and-Down Study

Using a posterior psoas compartment approach to the lumbar plexus does not increase the minimum effective anesthetic concentration of mepivacaine required to block the femoral nerve as compared with the anterior 3-in-1 approach, and provides better quality of intraoperative anesthesia due to the more reliable block of the lateral femoral cutaneous and obturator nerves.