不同材料矫形棒在青少年特发性脊柱侧凸矢状面重建中作用的有限元研究  

Role of different material orthopaedic rods in sagittal reconstruction in patients with adolescent idiopathic scoliosis: a finite element study

作　　者：范建平 赵检 陈自强 李明 FAN Jian-ping;ZHAO Jian;CHEN Zi-qiang;LI Ming(Department of Orthopaedics,Changhai Hospital,Navy Medical University,Shanghai 200433,China;Department of Orthopaedics,285 Hospital of Chinese PLA, Handan 056000,Hebei,China)

机构地区：[1]海军军医大学附属长海医院骨科,上海200433 [2]中国人民解放军第285医院,河北056000

出　　处：《脊柱外科杂志》2018年第6期358-362,共5页Journal of Spinal Surgery

基　　金：国家自然科学基金面上项目(81372012)

摘　　要：目的探讨不同材料、不同预弯弧度矫形棒在青少年特发性脊柱侧凸(AIS)矢状面重建中的作用。方法建立从T_1到骨盆的AIS非线性有限元仿真模型。在建立的有限元模型上进行模拟手术,分别设定矫形棒的属性为钛合金和钴铬合金,比较2种材料在28°预弯弧度时对矢状面重建的效果以及螺钉拔出应力的差异。进一步探讨当预弯弧度为40°时,钛合金棒对矢状面重建的影响。结果建立了完整的AIS仿真三维有限元模型,模型包括691 271个单元。其中实体单元、壳单元以及仿真单元计数分别为667 459、62 838和575。在28°预弯弧度下,钴铬合金比钛合金能够更好地矫正AIS矢状面后凸,但是钴铬棒组螺钉拔出应力显著增加。当预弯弧度为40°时,钛合金棒对矢状面后凸矫正效果显著优于预弯弧度为28°时,同时螺钉拔出应力显著增加。结论采用强度较大的钴铬合金棒及适当加大矫形棒预弯弧度有助于矢状面力线的恢复,但也会导致螺钉拔出应力增加。Objective To investigate the role of different materials and pre-curvature rods in sagittal reconstruction for adolescent idiopathic scoliosis(AIS).Methods Base on the CT images(from T1to pelvis)of a14-year-old female AIS patient,a nonlinear three-dimensional finite element model was established by software Mimics.The finite element model was used to simulate the operation.The orthodontic rods were set with titanium alloy and cobalt-chromium alloy.The effect of the sagittal reconstruction and the difference of screw pull-out stress between the 2 materials were compared at28°pre-bending curve.The effect of titanium alloy rods on the sagittal reconstruction was also discussed when the pre-bending curve was40°.Results A complete three-dimensional finite element model of AIS simulation was established,which consists of691271units.The number of entity units,shell units and imitated units was667459,62838and575respectively.Correction of sagittal kyphosis in AIS with cobalt-chromium alloy rod was better than titanium alloy rod at 28°pre-bending curve,but the pull-out stress of cobalt-chromium alloy rod increased significantly.When the pre-bending curve was40°,the correction effect of titanium alloy rod on sagittal kyphosis was significantly better than that of pre-bending curve being 28°,and the screw pull-out stress increased significantly.Conclusion It is helpful to restore the sagittal force line by using cobalt-chromium alloy rod with higher strength and increasing the pre-bending curve of the orthodontic rod properly,but it will also increase the pull-out stress of the screw.

关 键 词：青少年 脊柱侧凸 钛 铬合金 内固定器 生物力学 

分 类 号：R682.3[医药卫生—骨科学]