Analysis Of The Related Factors Of The Adjacent Segment Degeneration After Operation Of Cervical Spondylosis

ObjectiveTo observe the preoperative and postoperative X-ray of the cervical spine for exploring factors that accelerate the degeneration of the adjacent segments.MethodBetween December 2007 and June 2009,264 cases of patients with cervical spondylosis were followed up through out-patient department for an average time of 78.2 months (range 36-156 months). And the surgical methods, segments operated on, preoperative and postoperative cervical alignment, and the alignment of fusion segments were analyzed respectively.102 patients underwent single-level fusion; 107 patients underwent two-level fusion; three-level procedure was done in 28 patients and posterior cervical laminoplasty in 27 patients. The cervical spine alignment (C2-7), the alignment of the fusion segments, the spinal canal diameter of adjacent segment, the disc space of contiguous segments, and their range of motion (ROM) were measured by computer software pre-and postoperatively. The chi square test and t-test were used to analyze differences in these parameters.ResultRadiologic degeneration of the adjacent segments was found in 43 patients (16%), of which 28 were male and 15 were female, single-level fusion in 10 cases (9.8%), two-level fusion in 25 patients (23.4%), three-level fusion in 8 patients (28.6%), none of posterior cervical laminoplasty patients after surgery. There was no statistically difference between the degeneration group and normal group in the number of segments fused (x2= 9.00, P＜0.025), and postoperative curvature of cervical spine and fusion segments become significantly smaller, which compared to the preoperative indications (x2= 44.83, P＜0.05).4 patients of failed conservative treatment were taken a secondary surgery.ConclusionThere was a statistically higher incidence of adjacent segment degeneration after anterior cervical fusion, which maybe caused by loss of lordosis and kyphotic change of the cervical spine both pre-and postoperatively, and there was no significant relation with the number of segments fused. Cervical laminoplasty rarely accelerates the adjacent segment degeneration.