ImportanceIn arthroscopic knee and shoulder surgery, there is growing evidence that opioid-sparing protocols may reduce postoperative opioid consumption while adequately addressing patients’ pain. However, there are a lack of prospective, comparative trials evaluating their effectiveness.ObjectiveTo evaluate the effect of a multimodal, opioid-sparing approach to postoperative pain management compared with the current standard of care in patients undergoing arthroscopic shoulder or knee surgery.Design, Setting, and ParticipantsThis randomized clinical trial was performed at 3 clinical sites in Ontario, Canada, and enrolled 200 patients from March 2021 to March 2022 with final follow-up completed in April 2022. Adult patients undergoing outpatient arthroscopic shoulder or knee surgery were followed up for 6 weeks postoperatively.InterventionsThe opioid-sparing group (100 participants randomized) received a prescription of naproxen, acetaminophen (paracetamol), and pantoprazole; a limited rescue prescription of hydromorphone; and a patient educational infographic. The control group (100 participants randomized) received the current standard of care determined by the treating surgeon, which consisted of an opioid analgesic.Main Outcomes and MeasuresThe primary outcome was postoperative oral morphine equivalent (OME) consumption at 6 weeks after surgery. There were 5 secondary outcomes, including pain, patient satisfaction, opioid refills, quantity of OMEs prescribed at the time of hospital discharge, and adverse events at 6 weeks all reported at 6 weeks after surgery.ResultsAmong the 200 patients who were randomized (mean age, 43 years; 73 women [38%]), 193 patients (97%) completed the trial; 98 of whom were randomized to receive standard care and 95 the opioid-sparing protocol. Patients in the opioid-sparing protocol consumed significantly fewer opioids (median, 0 mg; IQR, 0-8.0 mg) than patients in the control group (median, 40.0 mg; IQR, 7.5-105.0; z = −6.55; P < .001). Of the 5 prespecified secondary end points, 4 showed no significant difference. The mean amount of OMEs prescribed was 341.2 mg (95% CI, 310.2-372.2) in the standard care group and 40.4 mg (95% CI, 39.6-41.2) in the opioid-sparing group (mean difference, 300.8 mg; 95% CI, 269.4-332.3; P < .001). There was no significant difference in adverse events at 6 weeks (2 events [2.1%] in the standard care group vs 3 events [3.2%] in the opioid-sparing group), but more patients reported medication-related adverse effects in the standard care group (32% vs 19%, P = .048).Conclusions and RelevanceAmong patients who underwent arthroscopic knee or shoulder surgery, a multimodal opioid-sparing postoperative pain management protocol, compared with standard opioid prescribing, significantly reduced postoperative opioid consumption over 6 weeks.Trial RegistrationClinicalTrials.gov Identifier: NCT04566250