Effect of long and short segment fixation for degenerative scoliosis on spinal three-dimensional imbalance

Objective To compare the effect of long and short segment fixation for degenerative scoliosis on spinal 3-dimensional balance. Methods Thirty patients who underwent spinal surgery in our hospital from June 2005 to January 2012 were included in this retrospective study. They were divided into long segment fusion fixation group (n=18) and short segment fusion fixation group (n=12). The lumbar Cobb angle, lumbar lordosis(LL), pelvic tilt (PT), pelvic incidence (PI), sacral slope (SS), sagittal vertical axis(SVA)， central sacral vertical line distance (CSVL), nash-moe vertebral rotation grading, and Oswestry (ODI) score were compared between the two groups before and after operation. Results A significant difference was found between LL, PT, CSVL and ODI score before and after operation(P＜ 0.05). However, no significant difference was observed between Cobb angle, nashmoe grading and ODI score before and after operation (P＞ 0.05). Conclusion Long segment fusion fixation can reconstruct the spinal three-dimensional sequence. The purpose to reconstruct coronal surface is to achieve its whole balance. The orthopedic rate should not be excessively high for those with a good preoperative balance. The effect of long segment fusion fixation is better than that of short segment fusion fixation on scoliosis curvature and overall imbalance. Long segment fusion fixation should thus be selected for those with severe rotatory subluxation Cobb angle in order to minimize adjacent segment lesions.