After the decision to proceed with shoulder replacement surgery, patients will be asked to participate in this randomized trial. Consent will be completed after explanation of each treatment group and the data to be collected. Patients will be randomized into one of the two treatment groups by simple randomization into one of two groups: Group 1 will receive interscalene nerve block and group 2 will receive liposomal bupivacaine for postoperative analgesia. Randomization will be stratified by site.
The surgeon at each site will be trained prior to enrollment on the correct way to perform Exparel injections intraoperatively. Patients in the interscalene nerve block group will be given a single shot block in the preoperative area by a fellowship-trained anesthesiologist.
The primary outcome is pain score on a visual analog scale (VAS) at 24 hours postoperatively. VAS pain scores range from 0 (no pain) to 10 (unbearable pain). Secondary outcomes are postoperative VAS pain scores at 6, 12, 18, 30, 36, 42, 48, 54, 60, 66, 72, 78, 84, 90, and 96 hours; VAS pain score at the first postoperative visit ; intraoperative opioid consumption; postoperative opioid consumption at days 1, 2, 3, and 4; total opioid consumption at day 1 (intraoperative + postoperative day 1); duration of stay in the post-anesthesia care unit (PACU); duration of hospital stay; and VAS score for satisfaction with pain control in the hospital and at home, assessed at participants' first postoperative visit. VAS satisfaction scores range from 0 (not satisfied) to 10 (completely satisfied).
