国人解剖型后踝锁定接骨板的研发和有限元分析

Development of an anatomic posterior malleolar locking plate for Chinese people:a finite element analysis

目的研发新型解剖型后踝锁定接骨板,并通过有限元分析其力学稳定性。方法收集100例健康志愿者胫腓骨和踝关节螺旋CT数据,测量国人后踝解剖学参数,结合相关计算机辅助技术设计制作新型国人解剖型后踝锁定接骨板,进行体外匹配性验证。通过建立有限元模型,对比分析该新型接骨板与3.5 mm皮质骨螺钉及1/3管型接骨板经力学加载后后踝骨折面的相对位移、最大Von Mises应力及置入物Von Mises应力峰值及分布。结果利用胫腓骨和踝关节螺旋CT数及相关计算机辅助技术设计生产的新型解剖型后踝锁定接骨板与胫骨后踝匹配良好,解剖贴服。影像解剖学测量显示,后踝宽度四分位数Q_(1)、Q_(2)、Q_(3)分别为19.4、26.6、35.0 mm,相应踝关节CT三维重建模型对应小、中、大3种型号后踝基础接骨板。有限元分析显示:在不同加载方案下,新型国人解剖型后踝锁定接骨板固定后踝骨折时,骨折面Von Mises应力较3.5 mm皮质骨螺钉和1/3管型接骨板更低,内置物最大Von Mises应力较3.5 mm皮质骨螺钉和1/3管型接骨板更低,但不同固定方式间骨折面位移未见明显差异。结论新型国人解剖型后踝锁定接骨板与后踝匹配良好,力学强度高、稳定性好,可实现后踝骨折坚强固定。

ObjectiveTo explore the biomechanical stability of a self-developed anatomic posterior malleolar locking plate for Chinese people using finite element analysis.MethodsThe tibiofibular+ankle spiral CT data were collected from 100 healthy Chinese volunteers to measure the anatomic parameters of the posterior malleolus of Chinese people.After a novel type of anatomic posterior malleolar locking plate for Chinese people was designed and produced using relevant computer techniques,in vitro matching verification was performed.A finite element model was established to compare the relative displacement and maximum Von Mises stress of the posterior malleolus fracture,and the peak Von Mises stress of the implant among the self-designed novel anatomic posterior malleolar locking plate,a 3.5 mm cortical bone screw and a 1/3 tubular plate.ResultsThe novel anatomic posterior malleolar locking plate produced using the tibiofibular+ankle spiral CT data and relevant computer techniques fitted anatomically well with the tibial posterior malleolus.According to imaging anatomic measurement,the width quartiles of the posterior malleolus(Q_(1),Q_(2),Q_(3))were 19.4,26.6,and 35.0 mm.The 3D CT reconstruction models of the ankle joint corresponded to the small,medium,and large types of basic posterior malleolus plates.Compared with a 3.5 mm cortical bone screw and a 1/3 tubular plate,the novel anatomic posterior malleolar locking plate for Chinese people led to lower Von Mises stress on the fracture surface and lower maximum Von Mises stress on the screw and plate when used to fix the posterior malleolar fracture in all loading schemes.However,different loading schemes led to no significant difference in the displacement of the fracture surface between different fixation methods.ConclusionSince the self-developed novel anatomic posterior malleolar locking plate fits well with the posterior malleolus of the Chinese people,it results in high biomechanical strength and good stability to achieve strong fixation of the posterior malleolar fractures.