Lumbar spine fusion surgery and stroke: a national cohort study.

ABSTRACT

PURPOSE: To investigate the incidence and risk of stroke after lumbar spinal fusion surgery. METHOD: Study subjects were identified from a nationwide cohort of 1 million people from 2000 to 2005 and were divided into the lumbar spinal fusion group (n = 2,015), who received posterior lumbar spinal fusion surgery, and the comparison group (n = 16,120) composed of age-, sex-, and propensity score-matched control subjects. The matching process was intended to adjust for demographics, comorbidities, and other immeasurable covariates to minimize selection bias. All subjects were followed up for 3 years for stroke, including hemorrhagic and ischemic strokes. Kaplan-Meier and Cox regression analyses were performed. RESULTS: The overall incidence rate of stroke in the cohort was 9.99 per 1,000 person-year. The lumbar spinal fusion group was less likely to have any stroke (adjusted hazard ratio (HR) = 0.83, p = 0.293), hemorrhagic stroke (adjusted HR = 0.74, p = 0.739) and ischemic stroke (adjusted HR = 0.81, p = 0.250) than the comparison group, but without significance. CONCLUSIONS: Three years post-operatively, patients who received lumbar spinal fusion had stroke incidence rates similar to those without surgery. Posterior lumbar spinal fusion surgery is not associated with increased risks for any kind of stroke.