Investigating the Relationship Between High Density Lipoprotein Cholesterol and Fusion Outcomes Following Single Level Lumbar Fusion: A Propensity Matched Analysis

Study DesignRetrospective cohort.ObjectivesAlthough dyslipidemia has been implicated in impaired bone healing, the role of high-density lipoprotein cholesterol (HDL-C) in spinal fusion outcomes remains poorly defined. Emerging evidence suggests that extremely elevated HDL-C levels may be associated with adverse osseous events. The objective of this study was to evaluate the association between HDL-C levels and rates of pseudoarthrosis and reoperation following single-level lumbar interbody fusion.MethodsThe TriNetX Research Network was queried for adult patients who underwent single level lumbar fusion during the 20-years period ended December 2, 2023. The high HDL-C cohort was designated by HDL-C ≥70.1 mg/dL, reflecting one standard deviation above the mean for all patients in the database. One standard deviation below the mean denoted the low HDL-C group (≤32.1 mg/dL). Propensity score matching was performed 1:1 according to demographics and comorbidities. Pseudoarthrosis diagnosis and reoperation were assessed at 6 months, 1 year, and 2 years postoperatively utilizing risk ratios (RR) and 95% confidence intervals (CI).ResultsAfter propensity matching, 1316 patient pairs were included. Patients with elevated HDL-C demonstrated significantly higher rates of pseudoarthrosis at 6 months, 1 year, and 2 years postoperatively. Early reoperation risk was also significantly increased in the high HDL-C cohort within 6 months, though differences were not sustained at later time points.ConclusionsElevated HDL-C was independently associated with increased risk of pseudoarthrosis following single-level lumbar fusion. These findings suggest that HDL-C may represent an underrecognized metabolic risk factor for impaired spinal fusion and warrants further investigation into underlying mechanisms and its possible utility in preoperative optimization programs.