Preoperative Modic changes are related to axial symptoms after anterior cervical discectomy and fusion

BACKGROUND: The objective of this study was to compare the clinical and radiological outcomes between patients with or without axial symptoms (AS) and investigate the risk factors associated with AS by multivariate regression analysis in anterior cervical discectomy and fusion (ACDF). MATERIALS AND METHODS: The records of 117 patients who underwent ACDF were reviewed for clinical and radiological outcomes. These outcomes were evaluated before and after surgery and at the last follow-up. Preoperative Modic changes (MCs) adjacent to the treated disc were identified. Risk factors for AS were detected through logistic regression analysis. RESULTS: The patients were divided into two groups: one with AS (AS group, n=35) and the other without (NAS group, n=82). Visual Analog Scale values after the operation (P=0.013) and at final follow-up (P<0.001) and preoperative segmental angle (P=0.031) were significantly different between the two groups. There were no significant differences with respect to other clinical and radiographic outcomes between the two groups (P>0.05). Logistic regression analysis revealed that preoperative segmental kyphosis (OR =2.912, P=0.035) and MCs (odds ratio =3.268, P=0.015) were the risk factors for the occurrence of AS. CONCLUSION: AS do not correlate with recovery of neural function in patients treated by ACDF. In addition, preoperative segmental kyphosis and MCs at the fusion segment were found to affect the incidence of AS after ACDF.