Clinical Study of the Serial Changes of Fixed Segmental Height and Cobb Angle in Anterior Cervical Fusion.

Cho, Do Sang; Song, Jun Hyeok; Kim, Eun Young; Kim, Myung Hyun; Park, Hyang Kwon; Kim, Sung Hak; Park, Dong Been; Shin, Kyu Man

Original Article

Journal of Korean Neurosurgical Society 1998;27(9): 1210-1215.

Do Sang Cho, Jun Hyeok Song, Eun Young Kim, Myung Hyun Kim, Hyang Kwon Park, Sung Hak Kim, Dong Been Park, Kyu Man Shin

Department of Neurosurgery, College of Medicine, Ewha Women's University, Seoul, Korea.

ABSTRACT

The authors investigated the serial changes of height and Cobb angle in the fused segments in the anterior cervical fusion. Patients who underwent anterior cervical fusion and fixation were investigated from September 1993 to August 1997. Total of 52 cases who met the following entry criteria were included in this study: (a) no history of prior cervical spine surgery or concomittent posterior fusion, (b) an anatomic radiculopathy or myelopathy that correlated with a radiographic study at the corresponding level, and(c) the clinical follow-up period of at least ten months. The radiographic data were obtained retrospectively from routine clinical radiographs, which included neutral radiographs preoperatively, immediate-postoperatively, and at 4-6 months postoperatively. The heights of the fixed segment were increased significantly after the operation(p<0.05 on Oneway ANOVA on ranks), and then decreased to preoperative value at last follow-up. The lordotic angles were increased after the operation and maintained throughout the study period(p<0.05 on Oneway ANOVA). In conclusion, on the contrary to the general belief that plate fixation can prevent the decrease in the segmental height, we found that the gain of height lasted only temporarily. Despiter this, postoperatively increased lordotic curve was maintained through the study period in spite of height loss. Therefore, we think that the lordosis of the cervical spine may reflects most of functional status of the whole cervical spine rather than height gain of the fused segment.

Key Words: Height; Cobb angle; Cervical fusion; Fixation