Time, Tumor, and Thrombosis: Drivers of 30-Day VTE After Femoral Fracture Surgery.

Background: Venous thromboembolism (VTE) remains a major source of morbidity after femoral fracture repair. We evaluated perioperative risk factors for 30-day deep vein thrombosis (DVT) and pulmonary embolism (PE) using a national clinical registry. Methods: We conducted a retrospective cohort study of adults undergoing femoral fracture repair in the American College of Surgeons National Surgical Quality Improvement Program. Outcomes were 30-day DVT and PE. Candidate predictors included demographics, comorbidities, functional status, preoperative laboratory values, American Society of Anesthesiologists (ASA) class, and operative time. Multivariable logistic regression models were fit separately for DVT and PE. Model performance was assessed with area under the receiver operating characteristic curve (AUC). Results: Disseminated cancer and longer operative time were independent predictors of postoperative DVT. Disseminated cancer conferred higher odds of DVT (adjusted odds ratio [aOR] 1.65, 95% CI 1.15-2.36, p=0.0065), and each additional operative minute increased DVT odds by 0.32% (aOR 1.0032, 95% CI 1.0017-1.0047, p<0.001), approximating 19% higher odds per 60 minutes. Body mass index (BMI) showed a borderline association (aOR 1.014 per kg/m², 95% CI 0.999-1.027, p=0.056), while age, sex, diabetes, smoking, functional status, preoperative creatinine, platelets, dialysis, heart failure, and preoperative INR were not significant. The DVT model demonstrated modest discrimination (AUC 0.57).For PE, disseminated cancer (aOR 2.77, 95% CI 1.92-4.00, p<0.001), longer operative time (aOR 1.0025 per minute, 95% CI 1.0006-1.0044, p=0.012), and higher BMI (aOR 1.018 per kg/m², 95% CI 1.002-1.035, p=0.031) were independent risk factors, whereas higher preoperative INR was protective (aOR 0.43 per unit, 95% CI 0.23-0.80, p=0.008). The PE model AUC was 0.61. Conclusions: Within 30 days of femoral fracture repair, disseminated cancer and prolonged operative time consistently increased VTE risk; BMI contributed modestly, and higher preoperative INR reduced PE risk. These findings support targeted prophylaxis and heightened surveillance in high-risk subgroups and highlight the need for enhanced, multifactorial prediction tools.