新型颈椎3D打印多孔椎间融合器的三维有限元分析

背景:颈椎前路椎间盘切除减压融合内固定已成为目前临床上常用的手术,但是传统融合器的上下弧度难以与上下终板保持完全一致,容易引起椎间融合器沉降等一系列相关并发症,作者所在课题组研究出与上下终板保持一致的新型颈椎3D打印多孔椎间融合器.目的:通过三维有限元分析法评价新型颈椎3D打印多孔椎间融合器的力学特点,为临床应用和进一...

Three-dimensional finite element analysis of a new three-dimensional printed porous fusion cage for cervical vertebra

BACKGROUND:Anterior cervical discectomy with fusion has become a common procedure in clinical practice.However,the upper and lower radian of the traditional fusion cage is difficult to be consistent with the upper and lower endplates,which is easy to cause a series of complications such as the settlement of the intervertebral fusion cage.Our research group developed a new three-dimensional(3D)printed porous fusion cage that is consistent with the upper and lower endplates.OBJECTIVE:The mechanical characteristics of the new 3D printed porous fusion cage were evaluated by 3D finite element analysis to provide theoretical basis for clinical application and further improvement.METHODS:A 3D finite element model of anterior cervical discectomy with fusion was established.Traditional cervical fusion cage and a new cervical 3D printed porous fusion cage were used for reconstruction.In addition,50 N preload and 1.0 N·m additional bending moment were applied under six working conditions of forward bending and backward stretching,left and right side bending,left and right rotation.The peak values of vertebral displacement and the peak values of Von-Mises stress on titanium plates,titanium nails,fusion cage,and upper and lower end plates were observed.RESULTS AND CONCLUSION:(1)Combined with the 3D finite element analysis,we found that the peak values of vertebral displacement and the peak values of Von-Mises stress on fusion cage,upper and lower end plates were significantly lower in the new cervical 3D printed porous fusion cage group than those of the traditional cage group under the six conditions of forward bending,back stretching,left and right side bending and left and right rotation.(2)As for titanium plates and titanium nails,except under the two working conditions of posterior extension and right rotation,the peak value in the new cervical 3D printed porous fusion cage group was larger than in the traditional cage group.Under the other four working conditions,stress peak values were smaller in the new cervical 3D printed porous fusion cage group than in the traditional cage group.(3)Therefore,compared with the traditional fusion cage,the application of the new 3D printed porous intervertebral fusion cage can avoid the stress concentration of upper and lower endplates,improve the stability of fixed segments,and reduce the sinking risk of internal plants to a certain extent.