Evaluating the Lack of Association Between Preoperative Hormone Replacement Therapy and Increased Venous Thromboembolism After Arthroscopic Orthopedic Surgery

Background: Hormone replacement therapy (HRT) has been associated with increased venous thromboembolism (VTE) risk in select patient populations, raising concern regarding its perioperative safety in orthopedic surgery. However, the impact of preoperative HRT use on postoperative complications following common arthroscopic procedures remains poorly characterized. Methods: The TriNetX Research Network was queried to identify adults aged 40-75 who underwent arthroscopy of the shoulder, elbow, hip, knee, or ankle. Patients with documented HRT use within three months prior to surgery were propensity-matched 1:1 to controls with no HRT use any time before or within three months of surgery. Exclusions included prior VTE events, coagulation disorders, active neoplasm, and kidney failure. Propensity matching accounted for age, sex, body mass index (BMI) (>30), diabetes, hypertension, hyperlipidemia, tobacco use, cardiovascular comorbidities, autoimmune disease, and procedure type. The primary outcome was 90-day VTE, defined as deep vein thrombosis (DVT) or pulmonary embolism (PE); secondary outcomes included hospital readmission, surgical site infection, and hemarthrosis. Results: After propensity score matching, each cohort included 3,868 patients. Ninety-day VTE occurred in 0.7% of HRT patients vs. 1.0% of controls (risk ratio, 0.68; 95% confidence interval, 0.42-1.10; p = 0.14). DVT (0.6% vs. 0.9%, p = 0.15), PE (0.3% vs. 0.3%; p = 1.00), readmission (p = 1.00), infection (p = 0.54), and hemarthrosis (p = 1.00) rates were also similar between the groups. Conclusion: In this large, multicenter, propensity-matched cohort, preoperative HRT was not associated with a statistically significant increase in 90-day VTE or other postoperative complications following arthroscopic surgery. These findings should be interpreted as reassuring but hypothesis-generating evidence rather than definitive guidance regarding perioperative HRT management.