Does Aspirin Use Influence Rates of Pseudoarthrosis After Anterior Cervical Discectomy and Fusion?

Study DesignRetrospective propensity-matched cohort study.ObjectivesAspirin's role in bone remodeling after spinal fusion is unclear. We evaluated the relationship between aspirin use and pseudoarthrosis after ACDF surgery.MethodsData was collected from TriNetX, a large research platform including 67 participating healthcare organizations, to identify single- and multi-level ACDF cohorts stratified by no aspirin, aspirin 81 mg and 325 mg daily use. The primary outcome was diagnosis of pseudoarthrosis. Propensity score matching (1:1 ratio) was performed for demographic/clinical variables, followed by risk analyses to determine odds of outcome at 6-months, 1-year, and 2-years. Reoperation rate (additional spinal fusion) was assessed for cohorts with significant results.ResultsThere were significantly lower pseudoarthrosis rates in the 81 mg aspirin group (n = 2504) for single-level ACDF at 6-months, 1-year, and 2-years, and a significantly lower reoperation rate at 2-years, compared to patients not taking aspirin. There were no differences in pseudoarthrosis for single-level ACDF with 325 mg dosing (n = 799) and for multi-level ACDF with 81 mg (n = 2287) or 325 mg (n = 678) dosing.ConclusionsPatients taking 81 mg aspirin had lower pseudoarthrosis rates at 6-months, 1-year, and 2-years and fewer reoperations at 2-years compared with single-level ACDF patients not taking aspirin. No significant associations between aspirin use and pseudoarthrosis were observed for 325 mg dosing or for multi-level ACDF. These results suggest the hypothesis that 81 mg or 325 mg aspirin does not increase the risk of pseudoarthrosis after ACDF. However, changes to clinical practice are not recommended until prospective clinical studies are completed.