60 patients undergoing total knee arthroplasty were randomized into three groups assessing the efficacy of femoral nerve block (FNB) as an analgesia treatment. There were 2 groups randomized to receive FNB at a high or low dose and a third group which acted as a control. During the 72 hour post-operative assessment, there was a significant reduction in pain during the first 6 hours in the FNB groups. This result was accompanied by a reduction in total morphine consumption and an increase in patient satisfaction. There were no differences in functional outcomes between the three groups at 2 year follow-up.