Investigating the relationship between low-density lipoprotein cholesterol and lumbar spinal fusion outcomes amongst statin users: a propensity score-matched analysis.

Abstract

Recent evidence suggests that elevated low-density lipoprotein cholesterol (LDL-C) is associated with an increased risk of nonunion following spinal fusion. However, these studies may be confounded by discrepant rates of statin use that exert their own pleotropic effects on bone metabolism. The aim of this study was to evaluate the association between preoperative LDL-C levels and nonunion among statin-exposed patients undergoing single-level lumbar fusion. The TriNetX Research Network was queried for adult patients who underwent single-level lumbar fusion between September 17, 2003, and September 17, 2023. Patients with a statin prescription within 6 months before or after surgery were identified. In this subset, high and low LDL-C were defined as 1 standard deviation above and below the mean, respectively. A secondary analysis compared patients with and without perioperative statin use. Propensity score matching was performed 1:1 based on demographics and comorbidities. Diagnosis of nonunion was assessed at 6 months, 1 year, and 2 years using risk ratios with 95% confidence intervals. The primary analysis included 849 matched pairs. No differences in risk of nonunion between statin users with high and low LDL-C were observed. Conversely, statin use was associated with a significantly reduced risk of nonunion at all time intervals assessed (all p < 0.001). Among statin-exposed patients undergoing single-level lumbar fusion, LDL-C levels were not associated with nonunion; however, perioperative statin use was independently associated with reduced nonunion risk. These findings suggest that previously reported associations between elevated LDL-C and pseudarthrosis may be partially confounded by differences in statin utilization rather than LDL-C levels themselves.