Fig. 3. Effect of interscalene perineural ropivacaine infusion on the time to reach three discharge criteria (adequate analgesia, independence from intravenous opioids, and the ability to tolerate at least 50% of passive shoulder motion targets during physical therapy) after total shoulder arthroplasty. Data are expressed in a Kaplan-Meier plot for patients randomly assigned to the ropivacaine group (perineural ropivacaine from surgery through postoperative day 4) or the placebo group (perineural ropivacaine from surgery through 06:00 postoperative day 1 followed by perineural normal saline through postoperative day 4).