Effect of cervical curvature reduction after ACCF on adjacent segmental lesions

Abstract Objective: To investigate the relationship of adjacent segment degeneration (RASP) and the variation of cervical curvature and vertebral height after Anterior Cervical Corpectomy and Fusion (ACCF). Methods: A retrospective analysis of 80 patients with cervical spondylotic myelopathy (CSM) who had been followed up for at least 1 year after ACCF. The patients were divided into RASP group and no RASP group according to whether the RASP occured after surgery. On the standing cervical lateral radiograph of all patients before and after surgery at the short-term and final follow-up, the C2-7 Cobb angle of the cervical vertebrae, the Cobb angle of the surgical segment and the height of the fusion segment for the anterior and posterior segments of the vertebral body were measured. The difference between the two groups of patients before and after surgery was calculated, as well as its correlation with the occurrence of RASP. Result: there were 37 patients in the RASP group and 43 patients in the no-RASP group. In RASP group, the short-term average curvature of cervical vertebra was significantly reduced after surgery. However, there was no significant difference in no RASP group. The height of the anterior and posterior fusion segments in two groups was significantly higher than that before surgery, however, which was significantly lower during the final follow-up than that in the short-term after surgery. Cox regression analysis showed that only the variation of postoperative C2-7Cobb angle was associated with RASP. Conclusion: The reduction of cervical curvature after ACF may be related to postoperative RASP. Maintaining good cervical curvature after operation may be expected to reduce the occurrence of RASP after ACF.