Background:The Stopping Opioids after Surgery (SOS) score was developed to identify patients at risk for sustained opioid use following surgery. The SOS score has not been specifically validated for patients in a general orthopaedic context. Our primary objective was to validate the SOS score within this context.Methods:In this retrospective cohort study, we considered a broad array of representative orthopaedic procedures performed between January 1, 2018, and March 31, 2022. These procedures included rotator cuff repair, lumbar discectomy, lumbar fusion, total knee and total hip arthroplasty, open reduction and internal fixation (ORIF) of ankle fracture, ORIF of distal radial fracture, and anterior cruciate ligament reconstruction. The performance of the SOS score was evaluated by calculating the c-statistic, receiver operating characteristic curve, and the observed rates of sustained prescription opioid use (defined as uninterrupted prescriptions of opioids for ≥90 days) following surgery. For our sensitivity analysis, we compared these metrics among various time epochs related to the COVID-19 pandemic.Results:A total of 26,114 patients were included, of whom 51.6% were female and 78.1% were White. The median age was 63 years. The observed prevalence of sustained opioid use was 1.3% (95% confidence interval [CI], 1.2% to 1.5%) in the low-risk group (SOS score of <30), 7.4% (95% CI, 6.9% to 8.0%) in the medium-risk group (SOS score of 30 to 60), and 20.8% (95% CI, 17.7% to 24.2%) in the high-risk group (SOS score of >60). The performance of the SOS score in the overall group was strong, with a c-statistic of 0.82. The performance of the SOS score showed no evidence of worsening over time. The c-statistic was 0.79 before the COVID-19 pandemic and ranged from 0.77 to 0.80 throughout the waves of the pandemic.Conclusions:We validated the use of the SOS score for sustained prescription opioid use following a diverse array of orthopaedic procedures across subspecialties. This tool is easy to implement for the purpose of prospectively identifying patients in musculoskeletal service lines who are at higher risk for sustained opioid use, thereby enabling the future implementation of upstream interventions and modifications to avert opioid abuse and to combat the opioid epidemic.Level of Evidence:Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.