膝关节有限元模型参数设置

Parameters of finite element model of the knee joint

背景:随着膝关节相关研究的深入,关于膝关节有限元模型建立时参数选用的准确性及适用性仍存在一定的争议,亟待研究。目的:综合膝关节有限元模型的文献,为模型构建和分析提供更合理的参数设置,并提升其适用性。方法:针对9组国内近5年膝关节有限元模型文献中骨性与非骨性组织的模型假设、材料赋值、网格划分以及载荷施加4个方面进行对比,结合外文文献及国外研究,验证其合理性。结果与结论:(1)模型假设:骨骼设刚体,韧带设超弹性,半月板设横向各向同性,软骨设单相各向同性线弹性;(2)材料赋值:骨骼无需赋值,韧带赋剪切模量,半月板区分轴向、径向和圆周方向赋值,软骨赋弹性模量;(3)网格划分:骨骼用壳单元,非骨性组织用8节点六面体或二阶四面体单元;(4)载荷施加:在股骨参考点施加1倍体质量轴向载荷;(5)通过对比得到的参数设置能让膝关节有限元模型的适用性更强,为之后进一步研究提供更加准确的模拟结果。

BACKGROUND:With the deepening of knee joint related research,there are still some controversies about the accuracy and applicability of parameter selection when establishing the knee joint finite element model,and it is urgent to study.OBJECTIVE:To synthesize the literature of knee joint finite element model,provide more reasonable parameter settings for model construction and analysis,and improve its applicability.METHODS:The four aspects of model assumptions,material assignment,meshing and load application of osseous and non-osseous tissues in nine sets of domestic knee finite element model documents in the past five years were compared,and foreign literature and foreign research were combined to verify its rationality.RESULTS AND CONCLUSION:(1)Model assumptions:Bones are set to rigid body;ligaments are set to be superelasticity;meniscus is set to be laterally isotropic;cartilage is set to be single-phase isotropic linear elasticity.(2)Material assignment:Bones do not need to be assigned;ligaments are assigned shear modulus;meniscus are assigned values in axial,radial and circumferential directions;cartilage is assigned elastic modulus.(3)Meshing:Shell elements for bones;8-node hexahedral or second-order tetrahedral elements for non-bone tissues.(4)Load application:Axial load of twice the body weight is applied at the femoral reference point.(5)The parameter settings obtained by comparison can make the finite element model of the knee joint more applicable and provide more accurate simulation results for further research.