Cannabis use as a negative predictor of complications following total shoulder arthroplasty

Background: Total shoulder arthroplasty (TSA) is increasingly performed to improve shoulder function, driven by demographic shifts and advances in surgical techniques. Simultaneously, cannabis use amongst adults is rising due to increased legalization and expanding medical indications. Studies report varying effects of cannabis use on postoperative outcomes after total knee arthroplasty, hip arthroplasty, and spine surgery, but data on its impact following TSA remain limited. Given the increasing demand for TSA and rising prevalence of cannabis use in the U.S., it is important to understand how cannabis use impacts postoperative complications following TSA. The purpose of this study was to analyze the relationship between cannabis use and adverse postoperative outcomes following TSA. Methods: The TriNetX national database was queried for records of patients who underwent TSA between January 1st, 2010, and December 31st, 2024. Patient cohorts and outcomes were defined using International Classification for Disease, 10th edition diagnosis codes and Current Procedural Terminology codes. After 1:1 propensity score matching, the cannabis user and noncannabis user cohorts were analyzed for differences in major outcomes 90 days and 2 years following the procedure. Results: A total of 75,574 patients were identified in TriNetX who underwent TSA from 2010 to 2024. Of these, 2,043 had concomitant cannabis use and 73,531 had no prior record of cannabis use. After 1:1 propensity score matching based on demographics and comorbidities, 2,042 patients in each cohort were directly compared for postoperative outcomes. Compared to noncannabis users, patients who used cannabis had a higher risk for chronic obstructive pulmonary disease exacerbation (odds ratio [OR] 2.07, 95% confidence interval [CI] 1.28-3.35; P = .003), acute kidney failure (OR 1.56, 95% CI 1.10-2.21; P = .012), and pneumonia (OR 1.85, 95% CI 1.17-2.92; P = .007) within 90 days of the procedure. Compared to patients who did not use cannabis, those who did had a higher risk for prosthesis loosening (OR 1.79, 95% CI 1.06-3.03; P = .028), opioid dependence or abuse (OR 2.01, 95% CI 1.15-3.53; P = .013), and infection and inflammatory reaction due to prosthesis (OR 1.55, 95% CI 1.01-2.19; P = .012) within 2 years. Conclusion: Preoperative cannabis use was associated with several postoperative complications 90 days and 2 years following TSA. In the setting of increasing TSA utilization, preoperative patient counseling on cannabis cessation before TSA may be beneficial for postoperative outcomes.