ARTICULAR CONTACT IN A 3-DIMENSIONAL MODEL OF THE KNEE
ARTICULAR CONTACT IN A 3-DIMENSIONAL MODEL OF THE KNEE
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DOI：
10.1016/0021-9290(91)90019-j
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发表时间：
1991-01-01
影响因子：
2.4
通讯作者：
GROOTENBOER, HJ
中科院分区：
文献类型：
--
作者：
BLANKEVOORT, L;KUIPER, JH;GROOTENBOER, HJ
本研究旨在分析人体膝关节的三维数学模型中的关节接触。特别地，关节接触对被动运动特性的影响被评估与实验获得的关节运动学。为此，比较了两种基本不同的数学接触描述。一种描述是刚性接触，另一种描述是可变形接触。变形接触的描述是基于刚性基础上薄弹性层接触的简化理论。关节软骨被描述为线性弹性材料或非线性弹性材料。在膝关节的数学模型中引入了接触描述。韧带插入的位置和关节表面的几何形状是从关节标本中获得的，实验确定的运动学数据可用，并用作模型的输入。用非线性的碎屑线元来描述韧带。韧带和关节软骨的力学性能来源于文献资料。参数模型评估表明，相对于刚性关节接触，变形接触的加入在定性意义上没有改变运动特性，而且定量变化很小。弹性层弹性的变化表明，降低表面刚度导致韧带松弛，从而增加关节松弛，特别是轴向旋转。在中等载荷条件下，膝关节模型中线性与非线性变形接触的差异很小。该模型模拟的膝关节运动特性与实验结果吻合较好。结果表明，在模拟膝关节被动运动特性时，刚性基础上细线弹性层接触的简化描述是研究中等载荷条件下膝关节运动特性的有效方法。在膝关节模型中使用变形接触，可以模拟表面之间的几何一致性，而不是只假设点接触的刚性接触。
This study is aimed at the analysis of articular contact in a three-dimensional mathematical model of the human knee-joint. In particular the effect of articular contact on the passive motion characteristics is assessed in relation to experimentally obtained joint kinematics. Two basically different mathematical contact descriptions were compared for this purpose. One description was for rigid contact and one for deformable contact. The description of deformable contact is based on a simplified theory for contact of a thin elastic layer on a rigid foundation. The articular cartilage was described either as a linear elastic material or as a non-linear elastic material. The contact descriptions were introduced in a mathematical model of the knee. The locations of the ligament insertions and the geometry of the articular surfaces were obtained from a joint specimen of which experimentally determined kinematic data were available, and were used as input for the model. The ligaments were described by non-linear clastic line elements. The mechanical properties of the ligaments and the articular cartilage were derived from literature data. Parametric model evaluations showed that, relative to rigid articular contact, the incorporation of deformable contact did not alter the motion characteristics in a qualitative sense, and that the quantitative changes were small. Variation of the elasticity of the elastic layer revealed that decreasing the surface stiffness caused the ligaments to relax and, as a consequence, increased the joint laxity, particularly for axial rotation. The difference between the linear and the non-linear deformable contact in the knee model was very small for moderate loading conditions. The motion characteristics simulated with the knee model compared very well with the experiments. It is concluded that for simulation of the passive motion characteristics of the knee, the simplified description for contact of a thin linear elastic layer on a rigid foundation is a valid approach when aiming at the study of the motion characteristics for moderate loading conditions. With deformable contact in the knee model, geometric conformity between the surfaces can be modelled as opposed to rigid contact which assumed only point contact.