106 patients undergoing either conventional or reverse total shoulder arthroplasty due to osteoarthritis or cuff tear arthropathy were randomized to postoperative analgesia via liposomal bupivacaine injection or interscalene brachial plexus blockade (ISBPB). The results from this study indicated that postoperative morphine equivalent units were similar between treatments; however, liposomal bupivacaine required significantly more intraoperative narcotics. Pain scores were significantly lower in the ISBPB group at 0 and 8 hours; however, significant difference between groups was lost at 16 hours, and by 24 hours postoperatively, pains were significantly lower in the liposomal bupivacaine group, indicative of rebound pain in the ISBPB group.