Onset Time of Nerve Block: A Comparison of Two Injection Locations in Patients Having Lower Leg/ Foot Surgery

The purpose of this study is to compare injecting local anesthetic (numbing medication) in different patterns around a major nerve in the leg. Patients who undergo surgery to the lower leg and/or foot are usually offered the option of a nerve block to help with pain control after surgery. A nerve block involves injecting local anesthetic (numbing medicine) by a nerve or nerves that provide sensation to the area where surgery will be performed. The local anesthetic (numbing medication) numbs up the area where the surgery is performed and helps decrease the amount of pain felt after surgery. The local anesthetic (numbing medication) can be injected in various patterns by a nerve, such as in one spot by a nerve or completely surrounding a nerve. The local anesthetic will be either injected around the sciatic nerve or will injected in a way that will split the sciatic nerve into the two component nerves that make it up, the tibial and sciatic, and surrounds each nerve. The hypothesis is that subjects in the group that local anesthetic is injected in a pattern that separates the sciatic nerve into the two component nerves may have a faster onset time of regional anesthesia and block success than subjects in the group that have the local anesthetic injected at around the nerve.