Patients consenting to participate in the study will be randomized to receive an ACB performed with either a single bevel (conventional) or a fenestrated needle. The ACB will be placed in the preoperative holding area approximately 30 minutes before being transported to the operating room. During performance of the nerve block, the time to complete the nerve block, the number of attempts used to complete the nerve block, the incidence of blood vessel puncture and/or blood aspiration will be recorded for each case. All patients will also be assessed for sensory changes in the lower extremity as a metric for block efficacy.