The Impact of Preoperative Myelopathy on Postoperative Outcomes among Anterior Cervical Discectomy and Fusion Procedures in the Nonelderly Adult Population: A Propensity-Score Matched Study

STUDY DESIGN: Retrospective cohort study. PURPOSE: Anterior cervical discectomy and fusion (ACDF) is a common surgical intervention for patients diagnosed with cervical degenerative diseases with or without myelopathy. A thorough understanding of outcomes in patients with and without myelopathy undergoing ACDF is required because of the widespread utilization of ACDF for these indications. OVERVIEW OF LITERATURE: Non-ACDF approaches achieved inferior outcomes in certain myelopathic cases. Studies have compared patient outcomes across procedures, but few have compared outcomes concerning myelopathic versus nonmyelopathic cohorts. METHODS: The MarketScan database was queried from 2007 to 2016 to identify adult patients who were ≤65 years old, and underwent ACDF using the international classification of diseases 9th version and current procedural terminology codes. Nearest neighbor propensity-score matching was employed to balance patient demographics and operative characteristics between myelopathic and nonmyelopathic cohorts. RESULTS: Of 107,480 patients who met the inclusion criteria, 29,152 (27.1%) were diagnosed with myelopathy. At baseline, the median age of patients with myelopathy was higher (52 years vs. 50 years, p<0.001), and they had a higher comorbidity burden (mean Charlson comorbidity index, 1.92 vs. 1.58; p<0.001) than patients without myelopathy. Patients with myelopathy were more likely to undergo surgical revision at 2 years (odds ratio [OR], 1.63; 95% confidence interval [CI], 1.54–1.73) or are readmitted within 90 days (OR, 1.27; 95% CI, 1.20–1.34). After patient cohorts were matched, patients with myelopathy remained at elevated risk for reoperation at 2 years (OR, 1.55; 95% CI, 1.44–1.67) and postoperative dysphagia (2.78% vs. 1.68%, p<0.001) compared to patients without myelopathy. CONCLUSIONS: We found inferior postoperative outcomes at baseline for patients with myelopathy undergoing ACDF compared to patients without myelopathy. Patients with myelopathy remained at significantly greater risk for reoperation and readmission after balancing potential confounding variables across cohorts, and these differences in outcomes were largely driven by patients with myelopathy undergoing 1–2 level fusions.