Relationship between reconstruction of the clivo -axial angle and curative effect in posterior approach surgery for the treatment of upper cervical spine anomaly instability

Abstract

Objective The aim of this study was to describe the clinical outcomes and improvement of clivo-axial angle (CAA) during the posterior approach surgery of upper cervical anomaly instability patients. Methods All of 32 patients with symptomatic upper cervical anomaly instability were followed up from 2004 Apr. to 2014 Aug. in which 1 patient was excluded because of reoperation. There were 10 patients with OS odontiodeum,5 with odontoid deformity, 4 with Klipple-Feil syndrome, 4 with atlantoaxial dislocation, 4 with atlantoaxial instability, 1 with rheumatoid arthritis, 1 with old odontoid fracture, 1 with OS odontoideum and foramen magnum stenosis, 1 with basilarinvagination and Klipple-Feil syndrome. They were all performed posterior reduction internal fixation and fusion, and then released spinal cord compression with the promotion of CAA. The patients were divided into two groups on the basis of decompression or not: nondecompression group 17 cases (male 8 cases, female 9 cases; age 13-65 years old, average 50.1 years old) and decompression group 14 cases (male 7 cases, female 7 cases; age 19-68 years old, average 49.6 years old). The CAA numbers were measured and compared. The clinic date was compared between preoperatively and postoperatively, which included Neck Disability Index and Nurick Classification System for Myelopathy. Results All patients were followed up, the follow-up time of non-decompression group was 0.7-10.7 years, average 2.9 years; the follow-up time of compression group was 0.3-5.5 years, average 2.9 years. Analysis of CAA, NDI and Nurick score were performed with t-test. The postoperative CAA, NDI and Nurick score improved significantly compared to preoperative ones. There was no difference between non-decompression group and decompression group. One patient felt nausea and vomited, one got soleal vein thrombosis, one had a swelling face and blurring vision and one had decompression syndrome after operation, all of these were improved using respectively therapy. No such serious complications as injury to vertebral artery, infection or internal fixation loosening occurred. Conclusion Neck ability and spinal cord function was significantly improved through increasing CAA for the upper cervical anomaly instability patients underwent posterior reduction internal fixation andfusion. Key words: Atlanto-axial joint; Atlanto-occipital joint; Joint instability; Spinal cord compression; Cranial fossa, posterior