Joint replacement is becoming an increasingly common procedure. In 2005, 534,000 total knee arthroplasties (TKA) were performed in the United States which is at a rate of 18.1 per 10,000 individuals, and the demand for primary TKA is projected to grow by 673% by 2030. Effective post-operative analgesia is an important component with regards to patient satisfaction and hospital stay. Regional anesthesia has been shown to decrease duration of surgery, need for transfusion, post-operative nausea and vomiting, and the incidence of thromboembolic disease in patients undergoing total knee or total hip replacement when compared with general anesthesia. Post-operatively, regional anesthesia has been shown to reduce pain scores and/or morphine consumption as well as opioid-related adverse effects.