摘要
[目的]建立胸腰椎爆裂性骨折后路不同固定方式的尸体标本和三维有限元模型,比较不同固定方式的生物力学特点,优化手术方式选择。[方法]6具20∽40岁青壮年胸腰椎（T11∽L3）标本,压缩法制作L1椎体爆裂性骨折模型。平均分成3组,分别行后路长节段固定、常规短节段固定和伤椎短节段固定的手术固定方式,三维运动试验机检测标本在10 N·m力矩下前屈、后伸、侧屈和旋转4个方位的运动范围（ROM）,材料机评估标本在500 N压力下的轴向压缩刚度。另取1具尸体为正常胸腰椎模型,借助CT扫描和有限元软件,模拟L1节段爆裂性骨折生成三种不同手术固定方式的有限元模型,施加相应载荷,分析各模型的应力分布,比较并进一步验证力学分析结果。[结果]生物力学证明,后路长节段固定、短节段固定和伤椎短节段固定后的胸腰段爆裂性骨折模型的ROM值和轴向压缩刚度组间差异无统计学意义。三维有限元应力分布显示,常规短节段和经伤椎短节段固定在T12平面的应力显著小于后路长节段固定方式。[结论]三种手术固定方式均能达到T11∽L3节段的稳定,但后路常规短节段固定和经伤椎短节段固定更易于对伤椎的保护,经伤椎短节段固定具有更高的稳定性。
[Objective]To establish cadaver specimens and the three- dimensional finite element model of T11- L3 segment of thoracolumbar burst fracture,which were used for comparing the biomechanical properties of thoracolumbar burst fracture with different fixed surgical procedures. [Method]Six fresh frozen normal adult spine specimens were divided into three groups after introduction of incomplete burst fracture at the body of L1. Short- segment pedicle instrumentation（ SSPI）,long- segment posterior fixation and SSPI via injured vertebra were performed on spine specimens of three groups respectively. Flexion / extension,axial rotation and lateral bending（ ROM） were determined by three dimensional laser scanner with a load of 10 Nm. Axial compression value was detected using the machine MTS with a load of 500 Nm. Another normal adult spine specimens was chosen for establishing the three- dimensional finite element model of T11- L3 with three kind of posterior fixation using CT- machines and related software to investigate the stress distribution of internal fixation on matching load to test and verify the mechanical analytical results. [Result]Biomechanical data reveled that there was no significant difference in ROM and axial compression value among three kind of surgical fixation method. The stress on T12 with the SSPI and SSPI via injured vertebra was much less than long- segment posterior fixation. [Conclusion]Three surgical fixation method could provide the instant stability to T11- L3. However,SSPI and SSPI via injured vertebra could protect spine better. SSPI via injured vertebra might has a higher stability and reliability.
出处
《中国矫形外科杂志》
CAS
CSCD
北大核心
2015年第10期917-920,共4页
Orthopedic Journal of China
基金
上海市卫生局科研计划课题资助项目(编号:20114228)
关键词
胸腰椎爆裂性骨折
三维有限元
生物力学
伤椎短节段固定
thoracolumbar burst fracture three-dimensional finite element model biomechanics short-segment posterior via injured vertebra
