MEASUREMENT AND ANALYSIS ON ELONGATION,DEFORMATION AND TENSILE CHARACTERISTIC OF THE CRUCIATELIGAMENT IN THE KNEE

本研究的目的是通过实验测量并从理论上分析前交叉韧带附着点在膝关节屈曲时发生三维运动时其整个表面的形状和应力分布的变化，以确定前交叉韧带整个区域的应力分布，进行实验以测量假韧带（具有极大拉伸的特殊橡胶板：600%）<max>。一个精心制作的仪器（膝关节运动模拟器），假韧带连接。两个附件都可以在多个方向上移动，并可以在多个轴上旋转，从而产生六个运动度以模拟膝关节运动。用立体摄影法测量了韧带上272个标记的三维位置，计算了拉格朗日方程的各分量， 关于我们 接下来，使用非压缩超弹性材料的有限元方法进行应力分析，以验证伪韧带（橡胶材料）的上述实验结果。介绍了一种特殊三角形单元的节点力与节点位移之间的非线性刚度关系。用Newton-Raphson方法求解了伪韧带的非线性有限元方程组，测量结果与理论计算结果吻合较好。特别注意纵向应变的分布作为膝关节屈曲角度的函数，并获得以下结果：在ACL的前侧，胫骨附着附近的区域在60 °屈曲时显著拉伸，并且几乎整个区域沿着纤维方向在90 °屈曲时拉伸。胫骨附件附近区域在屈曲120 °时明显拉伸。在后侧，股骨附着点附近区域的应变明显，但胫骨附着点附近的应变不明显。在这项研究中，由于应变分布变化，甚至沿着纤维方向变化，并且在骨附着区附近观察到大的应变梯度，因此获得了具有临床意义的结果。少

The objectives of this study are to experimentally measure and to theoretically analyze the change in shape and stress distribution over the entire surface of the ACL when its attachment sites are moved in the threedimensions associated with knee flexion.To determine stress distribution over the entire region in the ACL,experiments were carried out to measure the change in shape and strain distribution over the entire surface of a pseudo ligament (a special rubber plate with an extremely large stretch : 600%_<max>) when the attachment sites were moved in threedimensions. An elaborate instrument (knee motion simulator) was developed, to which the pseudo ligament was attached. Both of the attachments could be moved in several directions and could be rotated on several axs, resulting in six-degrees of motion to simulate knee motion. The three-dimensional positions of 272 markers on the ligament were measured by the Stereo-Photogramtric Method to compute the components of the Lagrangian st … More rain tensor for each element.Next, the stress analysis were carried out using the finite element method for a noncompressive hyper-elastic material to verify the above-mentioned experimental results for a pseudo ligament (rubber material). The non-linear stiffness relation between the node force and the node displacement for a special triangular element, was introduced. The Newton-Raphson method was used to solve the nonlinear equations associated with finite element representations of the pseudo ligament.Both the measurement and theoretical results were in good agreement. Special attention was paid for the distribution of longitudinal strain as a function of the knee flexion angle and the following results were obtained ; On the anterior side of the ACL,the region near the tibial bone attachment stretched noticeably at 60ﾟ of flexion, and almost the entire region along the fiber direction stretched at 90ﾟ of flexion. The region near the tibial bone attachment stretched noticeably at 120ﾟ of flexion. On the posterior side, the strain in the region near the femoral bone attachment was noticeable but not near the tibial bone attachment. ln this study, clinically significant results are obtained as strain distribution varied, even along the fiber direction, and large strain gradients were observed in the regions near the bone attachments. Less