Predictors of Venous Thromboembolism Following Geriatric Distal Femur Fracture Fixation: Are These Patients at Higher Risk Compared With Hip Fracture Patients?

Introduction: Venous thromboembolism (VTE) following injury and subsequent fixation of a distal femur fracture (DFFx) is associated with considerable morbidity. However, the incidence of VTE, associated factors, and the relative risk compared with hip fracture (HFx) fixation remains poorly characterized.

Methods: Retrospective cohort study using the PearlDiver M165 database to identify geriatric patients who underwent DFFx and HFx fixation. Clinical risk factors of VTE within 90 days of DFFx and the risk modification associated with enoxaparin (Lovenox) and direct oral anticoagulants (DOACs) relative to aspirin/nonprescription agents were characterized. To determine the odds of VTE following fixation of DFFx relative to HFx, a matched comparison based on age, sex, and Elixhauser Comorbidity Index was done.

Results: Of 24,358 DFFx patients, 1684 (6.9%) developed VTE. Independent risk factors included a prior VTE (odds ratio [OR] 28.76), displaced DFFx morphologies (condylar [OR 5.44], and supracondylar without intracondylar extension [OR 3.96] and with extension [OR 3.75]), active cancer (OR 2.11), coagulopathy disorder (OR 1.15), and younger age (OR 1.03) (P < 0.05 for all). Lovenox and DOAC were both associated with reduced odds of VTE (OR 0.40 and OR 0.61, respectively) (P < 0.05 for both). Relative to HFx patients, DFFx patients demonstrated heightened odds of VTE (OR 1.25) (P < 0.001).

Discussion: This study identified a relatively high rate of VTE, 6.9% within 90 days, following surgical management of DFFx and heightened odds of VTE relative to HFx patients. Various factors demonstrated a notable association with increased odds of VTE, although both Lovenox and DOACs may be effective therapeutic options for risk mitigation.