111 patients undergoing primary unilateral total knee arthroplasty were randomized to receive a periarticular injection of either liposomal bupivacaine or bupivacaine during surgery, as part of a multimodal analgesic protocol. The purpose of this study was to determine how liposomal bupivacaine compared to bupivacaine injection alone in terms of pain and narcotic use. The results indicated no difference in pain up to 3 days post-operatively between groups. As well, narcotic use, length of hospital stay, nausea, and range of motion, the latter of which was assessed up to 3 weeks postoperatively, were similar between groups.