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Spine

Protective Effects of Metformin on Fusion Outcomes After PLIF/TLIF: A Multi-Year Database Study

Protective Effects of Metformin on Fusion Outcomes After PLIF/TLIF: A Multi-year Database Study

    Presenting Author(s)

  • Khaled M. Taghlabi, MD

    Clinical Research Fellow
    Houston Methodist Hospital
    Houston, Texas, United States

Introduction: Pseudarthrosis is the failure of bony union following arthrodesis.
Metformin has been associated with protective effects and degenerative disc disease in vivo, and increased bone fracture healing in vitro. The relationship between spine fusion outcomes and this medication has yet to be explored. Our objective was to investigate the effect of Metformin on single level lumbar fusion pseudarthrosis rates.

Methods: TriNetX, a national research network, was retrospectively queried to identify 39,512 PLIF/TLIF patients between 2012 and 2022. Of these patients, 4305 had a prescription for Metformin from 6 months before the surgery to 6 months after the surgery. 35,207 did not ever have a prescription for Metformin in their medical record. One-to-one propensity score matching for age, sex, race, comorbidities, including Diabetes,was conducted to balance cohorts. The incidence of pseudarthrosis was then assessed within the six-month, one-year, and two-year postoperative periods.

Results: After propensity score matching, there were 3593 patients in each cohort. Patients that took a GLP-1 agonist had lower odds of developing pseudarthrosis six months [odds ratio (OR): 0.753, 95% confidence interval (CI): (0.648,0.876)], one year [OR: 0.785, 95% CI: (0.68,0.908)], and two years (OR:0.766, 95% CI: (0.666,0.881)) following a PLIF/TLIF procedure. There was a significant risk difference in all three cohorts(p=0.0002, p=0.0011, p=0.0002, respectively).

Conclusion : Metformin use is associated with significantly reduced rates of pseudarthrosis following single-level lumbar fusion surgery, with approximately 23-25% lower odds observed across six-month, one-year, and two-year follow-up periods. These findings suggest that Metformin may have protective effects on bone healing after spinal fusion procedures. Further research is warranted to elucidate the underlying mechanisms and potential clinical applications of these results in spine surgery patients.