Estrogen hormonal therapy is not associated with increased risk of venous thrombosis in total hip arthroplasty or hemiarthroplasty for femoral neck fractures.

Objectives: To evaluate the impact of estrogen hormone therapy on venous thrombotic events for femoral neck fractures treated with either total hip arthroplasty (THA) or hemiarthroplasty (HA). Methods: Design: Retrospective cohort analysis. Setting: TriNetX Health Research Network. Patient Selection Criteria: Patients who sustained a femoral neck fracture (OTA/AO 31B) between 2005 and 2025 who were treated with either THA or HA were categorized into groups based on whether they were prescribed systemic estrogen hormone therapy (EHT) within 3 months before or after their fracture. Outcome Measures and Comparisons: The primary outcomes were deep vein thrombosis (DVT) or pulmonary embolism (PE) within 3 months after their fracture. A matched cohort was created after a 1:1 propensity match for demographics, diabetes, obesity, and tobacco use. Measures of association models were used to determine odds ratios. Results: A total of 39,631 patients with femoral neck fractures treated with either a THA or HA were identified. Of these, 330 (0.8%) patients with femoral neck fractures were prescribed estrogen within 3 months before or after their fracture. After a matched cohort comparison, there were no statistically significant differences in rates of PE (odds ratio [OR] = 1.31; 95% confidence interval [CI], 0.56-3.03; Conclusion: Systemic EHT was not associated with a significantly increased risk of DVT or PE after operatively treated femoral neck fractures with THA or HA. Level of Evidence: Level III, Prognostic.