The Severity of Preoperative Cervical Disc Degeneration Is an Important Risk Factor for Cervical Fusion Failure After Anterior Cervical Discectomy and Fusion

Background: The relation between preoperative cervical disc degeneration and cervical fusion after anterior cervical discectomy and fusion (ACDF) remains unclear. Methods: We reviewed patients who received ACDF from 2019 to 2021. The Pfirrmann grading system was applied to six cervical discs (C2–T1) based on preoperative magnetic resonance imaging. The total degeneration score of six cervical discs was calculated as D Score. A mean degeneration score of operative cervical discs (Mean Surgery D Score) was calculated by dividing the total degeneration score of operative cervical discs by the number of operative segments. Postoperative computed tomography (CT) scans were conducted to determine the result of cervical fusion. Univariate and multivariate logistic regressions were used to explore the risk factors for cervical fusion failure. The receiver operating characteristic (ROC) curves were drawn according to multivariate results. Results: There were 159 patients in the nonfusion group and 135 patients in the fusion group. Univariate logistic regression showed that age, smoking, hypertension, coronary heart disease (CHD), D Score, and Mean Surgery D Score were associated with fusion failure. Hemoglobin, total protein, and albumin were associated with higher fusion rates. D Score (odds ratio [OR]: 1.887, 95%CI: 1.448–2.458, p = 0.001) and Mean Surgery D Score (OR: 8.827, 95%CI: 1.989–39.163, p = 0.004) were independent risk factors of fusion failure. The areas under the ROC curve of D Score and Mean Surgery D Score were 0.904 and 0.875, respectively. Conclusions: Patients with a higher preoperative D Score (> 23.5) and Mean Surgery D Score (> 4.125) have a higher risk of fusion failure after ACDF.