Venous thromboembolism prophylaxis with low molecular weight heparin versus unfractionated heparin for patients undergoing operative treatment of closed femoral shaft fractures.

Background: The objective of this study was to compare inpatient mortality rates for patients with operatively treated closed femoral shaft fractures (AO/OTA 32 A-C) who received venous thromboembolism (VTE) prophylaxis with either low molecular weight heparin (LMWH) or unfractionated heparin. Methods: This was a retrospective cohort study of a national database of patients presenting to Level I through IV trauma centers in the United States. All patients ≥18 years of age who sustained an operatively treated closed femoral shaft fracture were included. The primary outcome of inpatient mortality was compared between two groups: those who received LMWH or unfractionated heparin for VTE prophylaxis. Secondary outcomes were complications including VTE and bleeding events. Groups were compared using a multivariate regression model. Results: There were 2058 patients included in the study. Patients who received VTE prophylaxis with LMWH had lower odds of inpatient mortality compared to patients who received VTE prophylaxis with unfractionated heparin (OR 0.19; 95% CI 0.05 to 0.68, p = 0.011). Conclusions: VTE prophylaxis with LMWH is associated with lower inpatient mortality compared to VTE prophylaxis with unfractionated heparin for patients undergoing operative treatment of closed femoral shaft fractures. To our knowledge this is the first study to report these associations for a specific subset of orthopedic trauma patients.