38 patients with a history of chronic opioid use who were scheduled for primary total knee arthroplasty were randomized to periarticular injection analgesia containing either liposomal bupivacaine, or a standard drug mixture of ropivacaine, a non-steroidal anti-inflammatory drug (Toradol), and epinephrine. The purpose of this study was to evaluate if liposomal bupivacaine offered significantly lower narcotic consumption and pain scores over the first 2 days postoperatively. Results demonstrated no significant differences between groups in either outcome over the first 2 postoperative days.