摘要
[目的]采用非接触应变测量技术对颈椎前路钛板椎体钉系统(anterior screw plate system,AP)和颈椎前路人工椎体系统(anterior transpedicular screw-artificial vertebral body,AVB)的邻近节段进行了应变分析,以评估两种固定方法对邻近节段的力学影响。[方法]取8具新鲜成年男性C_2~C_7标本,剔除椎旁肌,去除颈椎前纵韧带及骨膜以暴露骨面,保留小关节囊、椎间盘及椎体节段。于标本前面喷涂散斑,并置于加载台上以1 N/m的力偶矩分别模拟前屈、后伸、左右侧弯、左右旋转六个方向运动。同时用标定后的非接触应变测量系统记录加载全过程图像。通过ARAMIS软件计算,可自动输出Von Mises应变云图。在软件中选择加载稳定后的云图,并统计该图C_3~C_4、C_6~C_7椎间盘应变均值,此为完整组。行C_5次全切,并分别安装AP、AVB,并按相同流程采集数据。[结果]同一运动状态下,AVB、AP组的上邻近节段应变均大于完整组,AP、AVB组的下邻近节段应变均小于完整组,但差异均无统计学意义(P>0.05);比较不同运动状态之间的邻近节段应变发现,前屈时邻近节段的应变显著大于其他运动状态(P<0.05),后伸时邻近节段应变则小于其他运动状态;同一组中上邻近节段的应变均大于下邻近节段,AP、AVB组存在显著统计学差异(P<0.05)。[结论]本实验获得了不同条件不同运动状态下,邻近节段椎间盘前面的应变云图。在装配固定器械后,上下节段间出现了应力分布不均的现象,提示可能与邻近节段退变有关。同AP相似,AVB也具有引起邻近节段退变的潜在可能。
[ Objective] A non -contact strain measurement technology was used to evaluate and compare the influences on surface strain at adjacent segment discs after fused by anterior transpedicular screw - artificial vertebral body （AVB） and ante- rior screw plate system （AP）. [ Method] Eight fresh -frozen cervical spines of adult males from C2 to C7 were required. Periost of paravcrtebral muscles and anterior longitudinal ligament were removed to expose the vertebra surface. Facet joint capsules, in- tervertebral discs and vertebrae were handled carefully. Specimens were treated with speckles, and then placed on loading plat- form with 1N/m to simulate six conditions,which were flection,extension,left/right lateral bending and left/fight rotation. The non- contact strain measurement system recorded the whole loading process. ARAMIS software automatically exported strain nephogram through software calculation. Then stable loading strain nephogram were chosen and the mean strain of C3 - C4 and C6 -C7 discs were recorded as the intact group. After corpectomy, Cs was installed anterior screw plate system （AP） and AVB. Data were collected following the same routine. [Result]The strain at upper adjacent segment in beth AP and AVB groups was larger than that of intact group and the strain at lower adjcent segment was smaller that that of intact group, whereas with no sig- nificant difference （ P 〉 0.05）. Comparison of the six conditions in same group showed that strain was significantly larger than any other conditions （P 〈 0. 05） in flection condition and extension was the smallest. Comparison between upper and lower adja- cent segments in same group showed that strain was larger in the upper segment than lowerk. Significant difference was found be- tween AP and AVB groups （P 〈 0.05 ）. [ Conclusion] This experiment got the strain nephogram under different conditions and^Lxations at adjacent segment discs. The maldistribution of stress was found between upper and lower adjacent segments after fusio
出处
《中国矫形外科杂志》
CAS
CSCD
北大核心
2015年第16期1498-1502,共5页
Orthopedic Journal of China
基金
国家自然科学基金资助项目(编号:31170903)
关键词
非接触应变测量
应变
邻近节段
前路椎弓根螺钉
non- contact strain measurement technology, strain, adjacent segment, anterior transpedicular
