脊柱内固定椎弓根螺钉置入后生物力学的稳定性

背景：椎弓根螺钉内固定系统由于具有牢固的三维固定效果、良好的生物力学稳定性以及较好的复位和矫正畸形作用,被广泛用于脊柱外科,但椎弓根螺钉系统松动、折断及螺钉拔出等并发症仍是导致内固定手术失败的主要原因. 目的：分析脊柱内固定植入物椎弓根钉的生物力学及稳定性探索. 方法：应用计算机检索万方、维普和PubMed数据库中1999年1月至2011年12月关于椎弓根钉植入后生物力学评价相关的文章,以“椎弓根钉,脊柱,内固定,稳定性,生物相容性”为关键词进行检索.选择脊柱内固定植入物生物力学及评价相关的文献,同一领域文献则选择近期发表或发表在权威杂志文章.初检得到260篇文献,根据纳入标准选择40篇文章进行综合分析. 结果与结论：要提高椎弓根螺钉系统对脊柱固定的稳定性,可通过改进内固定材料、设计和操作技术以分散固定界面应力,但对螺钉的改进受椎弓根和椎体大小的限制,如何从内固定系统装置上来增强固定效果,有待进一步研究.作者认为椎弓根螺钉植入后的稳定性评价应该结合动物实验和临床研究,包括椎弓根螺钉材质、置入位置、角度、固定装置等因素,还应该针对患者个体化因素进行,即对椎弓根螺钉置入遵循个体化原则,对每一个不同的椎弓根施以不同的置钉入点、方向及螺钉.

Biomechanical stability of pedicle screw in spine internal fixation

BACKGROUND：Pedicle screw fixation system with a solid three-dimensional fixed effect, good biomechanical stability and good reset and correct deformities role, has been widely used in spine surgery. But, pedicle screws loose, broken and screw pul out and other complications are major causes of the failure of fixation within the lead. OBJECTIVE：To analyze the biomechanics of spinal fixation implant pedicle screw and to explore the stability. METHODS：A computer-based search was performed on CNKI database and PubMed database from January 1999 to December 2011 for the related articles about biomechanical evaluation of pedicle screw implantation. The key words were“pedicle screw, spine, fixation, stability, biocompatibility”. The articles on the biomechanical evaluation of pedicle screw implantation were selected, and for the articles in the same field, those published recently or in the authorized journals were selected. There were 260 articles after the initial survey. Then, according to the inclusion criteria, 40 articles were included for the aggregate analysis. RESULTS AND CONCLUSION：We can improve fixation materials, design and operate techniques to diversify the fixed interface stress, thus improve the stability of pedicle screw spinal fixation. But, with the size limitation of the pedicle and vertebral body, how to enhance the fixation effect from the fixation system instal ations needs further study. The authors suggest that evaluation of the stability of pedicle screws should be combined with animal experiments and clinical studies, including pedicle screw material, placement position, angle, fixtures and other factors, and the individual factors in patients should also be considered, that is fol ow the individual principle during pedicle screw placement. Every pedicles should be imposed with different enter-point, directions and screws.