Understanding the Impact of Low-Density Lipoprotein Levels and Lipid-Lowering Agents on Rates of Pseudarthrosis After Anterior Cervical Discectomy and Fusion

Introduction: Anterior cervical discectomy and fusion (ACDF) is a common procedure for treating cervical degenerative diseases or injuries causing neck pain, myelopathy, and radiculopathy. Pseudarthrosis after multi-level ACDF can result in persistent symptoms and may require revision surgery. The pseudarthrosis rate can be as high as 20% for single-level ACDF and 50% for multi-level ACDF. Known risk factors include age, diabetes, and smoking. However, the link between LDL levels and pseudarthrosis in ACDF has not been studied.

Methods: A retrospective cohort study was conducted using TriNetX, a healthcare database with over 100 million patients. Pseudarthrosis rates at 6 months, 1 year, and 2 years post ACDF were compared between patients with LDL levels above 142 mg/dL and below 66 mg/dL within 1 year before surgery. LDL thresholds represent one standard deviation above and below the mean LDL data in TriNetX. Pseudarthrosis rates at six months, 1 year and 2 years were compared between patients taking or not taking statins, fish oil, ezetimibe, or niacin 6 months before surgery. LDL levels for patients taking or not taking a lipid-lowering agent were collected at all three time points. Propensity score matching in a 1:1 ratio was performed based on age, sex, race, body mass index, osteoporosis, diabetes, tobacco use, malnutrition, metabolic syndrome, and chronic use of steroids. P< 0.01 was considered significant.

Results: In multi-level ACDF, patients with LDL levels above 142 mg/dL had significantly higher pseudarthrosis rates at all time points compared to those below 66 mg/dL. Patients not taking statins also had higher pseudarthrosis rates. No significant associations were found in single-level ACDF. Statin users had lower LDL levels at all time points for both single- and multi-level ACDF. Fish oil users showed lower pseudarthrosis rates in multi-level ACDF, though LDL levels were not significantly different. Fish oil, ezetimibe, and niacin had no significant impact on pseudarthrosis rates or LDL levels in single-level ACDF.

Conclusion : Low LDL levels and the use of statins or fish oil reduce pseudarthrosis rates after multi-level, but not single-level, ACDF. These findings can inform pre-operative planning, patient optimization, and risk stratification to improve outcomes and reduce revision surgery.