Anderson D D, Brown T D, Yang K H, Radin E L
Department of Orthopaedic Surgery, University of Iowa, Iowa City 52242.
J Biomech Eng. 1990 May;112(2):119-28. doi: 10.1115/1.2891162.
A dynamic nonlinear finite element model was developed to study juxtarticular stresses in the splinted rabbit knee, an established laboratory model for creating osteoarthrosis due to impulsive loading. Plane strain finite element results were validated by comparison with corresponding experimental data. Parametric effects studied included the input tibial displacement speed, the local bone density distribution, and the modulus of cartilage and subchondral bone. While the computed resultant contact force magnitude was sensitive to a number of model parameters, the stress patterns, when normalized to a given resultant force magnitude, were not. Despite comparable force peaks, the finite element results showed approximately six-fold higher effective strain rate levels for a severely impulsive loading protocol known to induce rapid osteoarthrosis, versus those for a mildly impulsive loading protocol not usually associated with cartilage damage. A propensity for elevated shear in the deep cartilage layer near the contact periphery, observed in nearly all computed stress distributions, is consistent with previous experimental findings of fissuring at that level in the impulsively loaded rabbit knee.
建立了一个动态非线性有限元模型，以研究夹板固定兔膝关节的关节周围应力，这是一个用于因冲击载荷导致骨关节炎的成熟实验室模型。通过与相应实验数据进行比较，验证了平面应变有限元结果。研究的参数效应包括输入胫骨位移速度、局部骨密度分布以及软骨和软骨下骨的模量。虽然计算得到的合力大小对许多模型参数敏感，但当归一化为给定合力大小时，应力模式却并非如此。尽管力峰值相当，但有限元结果显示，与通常不会导致软骨损伤的轻度冲击载荷方案相比，已知会导致快速骨关节炎的严重冲击载荷方案的有效应变率水平高出约六倍。在几乎所有计算得到的应力分布中都观察到，接触周边附近深层软骨层存在剪切力升高的倾向，这与先前在冲击加载兔膝关节该水平出现裂隙的实验结果一致。
