Functional Neurological Disorder is Associated with Postoperative Complications After ACDF: A Retrospective Propensity-Matched Analysis.

INTRODUCTION: Psychiatric comorbidities are associated with worse postoperative outcomes after cervical spine surgery, yet the impact of Functional Neurological Disorder (FND), a neuropsychiatric condition characterized by involuntary neurologic symptoms, has not been investigated. The objective of this study was to evaluate the association between FND and perioperative and long-term complications following anterior cervical discectomy and fusion (ACDF). METHODS: The TriNetX United States Collaborative Network was used to examine adults (≥18 years) undergoing primary ACDF between 2004 and 2023. Patients were stratified into cohorts based on the presence or absence of FND prior to surgery. Patient demographics and comorbidities were 1:1 propensity score matched. The primary outcomes were complications within 90-days and 2 years after ACDF. RESULTS: 89,338 patients underwent ACDF, and 502 (0.56%) had FND. After 1:1 matching, 501 FND and 501 control patients were analyzed. Within 90 days, FND was associated with higher odds of dysphagia (OR 2.05, 95% CI 1.37-3.07, p < 0.001), surgical site infection (SSI) (OR 2.84, 95% CI 1.34-5.86, p = 0.004), ED utilization (OR 1.92, 95% CI 1.38-2.67, p < 0.001), and hospitalization (OR 1.82, 95% CI 1.21-2.28, p = 0.001). At 2 years, FND patients had greater odds of pseudoarthrosis (OR 1.49, 95% CI 1.05-2.11, p = 0.026) and opioid use disorder (OR 2.36, 95% CI 1.11-5.01, p = 0.021). CONCLUSION: FND was associated with increased perioperative and long-term complications following ACDF, including dysphagia, SSI, pseudoarthrosis, and opioid use disorder. Preoperative identification of FND may enable targeted perioperative management and multidisciplinary follow-up to mitigate risk in this complex population. STUDY DESIGN: Retrospective cohort study.