Abstract： BACKGROUND: It is necessary to keep a good cervical curvature for improving nerve symptom in patients with cervical spondylotic myelopathy (CSM). It is verified that cervical anterior plate internal fixation implant is effective to restore the physiological curvature of cervical vertebra.OBJECTIVE: To assess the physiological lordosis of cervical vertebra in CSM patients after cervical anterior plate internal fixation implantation.DESIGN: Observational study.SETTING: First Affiliated Hospital of Nanchang University.PARTICIpANTS: Totally 72 CSM patients were enrolled at Department of Orthopaedics, First Affiliated Hospital,Nanchang University from February 2003 to January 2006, including 46 males and 26 females, aged 45-70 years,averagely 54 years, with the history of 2-6 years. Inclusive criteria included ①cervical spinal cord compression shown in MRI, and ②using autogenous iliac bone. The experiment was approved by Hospital Ethics Committee, and all patients signed the informed consent. Cervical anterior plate was Orion locking plate offered by Shufamo Company. There were single segmental discectomy group (n =32) and two-level segmental discectomy group (n =40) according to experimental requirement.METHODS: ①Anterior decompression plus autogenous iliac bone implant plus titanium plate internal fixation were utilized.The patients were in supine position; shoulder and back were blocked up; neck backward, and endotracheal tube was done under general anesthesia. Transverse or oblique incision was made at right anterior neck. Discectomy decompression was performed with Caspar vertebra ecarteur. Three-dimensional autogenous iliac bone was implanted in decompressed intervertebral space. Immediate stability was obtained after Orion locking titanium plate was fixed, with placement drainage, and then the incision was sutured. ②Postoperative daily activities were conducted with cervical gear, which was removed 8 weeks later. ③Lateral cervical vertebrae X-rays were taken before operation, immediately after operation, 6 and 12 months after operation. Lordosis of the fusion segment was measured with Cobb's angle, and lordosis of cervical vertebra was assessed with D value. These data were analysed by statistic software. ④Bone fusion of the patients was followed up for 12 months after operation. Vertebral fusion standards included no abnormity between two spinous processes of the fusion segment, no lucency between implant and vertebra, as well as bone trabecula across the interface between implant bone and vertebra. ⑤Biocompatibility between material and host was observed during follow-up.MAIN OUTCOME MEASURES: ①Changes of Cobb's angle and D value at different time points before and after operation,and ②Bone fusion and rejection were followed up.RESULTS: Totally 72 patients were involved in the result analysis. ①Cobb's angle was larger and D value was higher immediately after operation, 6 and 12 months after operation than those before operation in the single segmental discectomy group and the two-level segmental discectomy group (P＜0.05). ②Findings of 12-month follow-up showed that bone fusion appeared in all patients of the two groups. ③No significant rejection was found after titanium plate internal fixation implantation. It was found that material and host had a good biocompatibility.CONCLUSION: It is satisfactory to restore physiological lordosis of cervical spine by using cervical anterior plate internal fixation plus autogenous iliac bone for CSM.