摘要
背景:腰椎间融合固定究竟采用单侧还是双侧椎弓根钉固定以及单枚还是双枚融合器置入融合存在较大争议。目的:建立L4～L5经椎间孔腰椎间4种不同融合固定方式的三维有限元模型,观察其稳定性。设计、时间及地点:4组三维模型的对比观察,于2008-04/07在南京航空航天大学材料动力学实验室完成。材料:于东南大学医学院中大医院CT室选取1名健康自愿者腰椎CT图像,男性,32岁,以64排螺旋CT机从腰4上缘到腰5下缘连续(L4～L5)进行横切扫描,得到层厚为1mm的连续断面图像。方法:对断层CT影像进行预处理后,利用建模软件UG4.0和有限元软件ANSYS10.0建立经椎间孔腰椎间不同融合固定方式的三维有限元模型。模型1:单枚融合器(矩形,斜向45°)+双侧椎弓根钉;模型2:单枚融合器(矩形,斜向45°)+单侧椎弓根钉;模型3:双枚融合器(圆形椎间融合器)+双侧椎弓根钉;模型4:双枚融合器(圆形椎间融合器)+单侧椎弓根钉。主要观察指标:每种模型的螺钉、融合器应力及模型位移变化。结果:4种模型中,螺钉和融合器应力在不同的运动状态下因内固定的单双侧和融合器的形状位置不同而有差异。使用单侧内固定者,在螺钉上的应力以及融合器上的应力较双侧固定者高,但差异无显著性意义(P>0.05)。在不同的运动状态下4种模型L4的位移差异无显著性意义(P>0.05)。结论:三维有限元分析结合临床实践,单侧椎弓根螺钉内固定加单枚融合器(矩形,斜向45°)置入融合是目前微创经椎间孔腰椎间融合固定的较好术式。
BACKGROUND： Transforaminal lumbar interbody fusion （TLIF） with unilateral or bilateral transpedicular screws fixation and with unilateral fusion cage or double cage is controversial.
OBJECTIVE： To develop a three-dimensional f＇mite element model of L4-5 undergoing TLIF with four different approaches and to evaluate lumbar stability.
DESIGN, TIME AND SETTING： Comparative observation of three-dimensional finite element model in four groups was performed at the Material and Power Engineering Laboratory, Nanjing University of Aeronautics and Astronautics from April to July 2008.
MATERIALS： The L4-5 segment transverse data were obtained from CT scans （at 1 mm width increments） of the lumbar spine of a 32-year-old man, form Department of CT, Zhongda Hospital of Southeast University.
METHODS： After these images were processed, the three-dimensional finite element model of the transforaminal lumbar interbody fusion （TLIF） using different approaches was established by UG4.0 and ANSYS 10.0. Model one： single cage （rectangle, slope 45°） plus bilateral vertebral pedicle screw fixation. Model two： single cage （rectangle, slope 45° ） plus unilateral vertebral pedicle screw fixation. Model three： double cage （cylindrical cage） plus bilateral vertebral pedicle screw fixation. Model four： double cage （cylindrical cage） plus unilateral vertebral pedicle screw fixation.
MAIN OUTCOME MEASURES： Stress of vertebral pedicle screw and fusion cage and model displacement.
RESULTS： The stress of screws and fusion cage was different in four different approaches. The stress on the screw and fusion cage of unilateral fixation was higher than the bilateral fixation, but there were no statistical differences （P 〉 0.05）. There were no significant differences in L4 displacement among four models under different conditions （P 〉 0.05）.
CONCLUSION： Three-dimensional finite element analysis and clinical practice show that TLIF with unilateral transpedicular screws fixation and unilateral fusion cage is a good method.
出处
《中国组织工程研究与临床康复》
CAS
CSCD
北大核心
2008年第39期7605-7610,共6页
Journal of Clinical Rehabilitative Tissue Engineering Research
