基于三柱结构分型股骨头坏死的有限元研究

3D finite element analysis on femoral head necrosis based on three-column classification

[目的]本研究基于三柱结构中日友好医院(CJFH)分型对股骨头进行三维有限元分析,研究不同坏死体积的股骨头受力情况,为临床保髋治疗提供理论依据。[方法]选取正常25岁男性青年髋关节CT片股骨头有限元模型,按CJFH分型中的每一型建立占股骨头总体积5%,15%,30%,50%的坏死体积模型,划分网格后进行力学分析。[结果]根据股骨头位移云图及数据,坏死组织的位移偏大,位移峰值均处在负重区的坏死组织上,不同坏死体积坏死带的力学分布可以发现,在坏死体积<15%的情况下,压力最高峰值未达到塌陷压力,当坏死体积达到30%时,L2型及L3型塌陷风险极高,L3型以有超过50%坏死区域应力大于塌陷应力。[结论]坏死组织体积越大,位移越大,越容易塌陷,当涉及外侧柱的坏死体积达30%时,塌陷概率大大增加。

[Objective]By three-dimensional finite element analysis on femoral head necrosis based on the classification of China-Japan Friendship Hospital(CJFH)by three-column structure,to explore the force on femoral head with different necrotic volumes,so as to provide theoretical basis for clinical hip preservation.[Methods]The CT scanning data obtained from a healthy 25 young men were treated by using Mimics,Geomagic studio software to create a preliminary 3D finite element hip model.And then models of each type of femoral head necrosis based on CJFH classification by three-column structure were mimicked with 5%,15%,30%and 50%of necrosis.Mechanical analysis was carried out after grid division.[Results]Accord ing to the cloud picture of the models,the strength and displacement focused on the necrotic tissue under weight-bearing area.In term of force distribution on different necrosis volume,the maximal pressure force did not reach the collapsing force in 30%necrosis,however,the collapsing risk was extremely high in type L2 and L3.By contrast,the pressure force in 50%necrosis of the type L3 surpassed the failure force.[Conclusion]The greater necrosis,the greater displacement,and the greater chance to collapse are proved in the 3D finite element analysis.As the necrosis involves the lateral column with more than 30%dimen sion,the femoral head is at very high risk of breakdown.