Weinans H, Huiskes R, Grootenboer H J
Biomechanics Section, University of Nijmegen, The Netherlands.
J Biomech. 1990;23(10):991-1000. doi: 10.1016/0021-9290(90)90314-s.
In the present study, the effects of a fibrous membrane between cement and bone in a femoral total hip replacement were investigated. The study involved the problem of modeling this fibrous membrane in finite-element analyses, and its global consequences for the load-transfer mechanism and its resulting stress patterns. A finite-element model was developed, suitable to describe nonlinear contact conditions in combination with nonlinear material properties of the fibrous membrane. The fibrous tissue layer was described as a highly compliant material with little resistance against tension and shear. The analysis showed that the load transfer mechanism from stem to bone changes drastically when such a membrane is present. These effects are predominantly caused by tensile loosening and slip at the interface, and are enhanced by the nonlinear membrane characteristics. Using parametric analysis, it was shown that these effects on the load-transfer mechanism cannot be described satisfactorily with linear elastic models. Most importantly, the fibrous tissue interposition causes excessive stress concentrations in bone and cement, and relatively high relative displacements between these materials.
在本研究中，对股骨全髋关节置换中骨水泥与骨之间纤维膜的影响进行了调查。该研究涉及在有限元分析中对这种纤维膜进行建模的问题，以及其对载荷传递机制及其产生的应力模式的整体影响。开发了一个有限元模型，适用于结合纤维膜的非线性材料特性来描述非线性接触条件。纤维组织层被描述为一种高度柔顺的材料，对拉伸和剪切的抵抗力很小。分析表明，当存在这样的膜时，从柄到骨的载荷传递机制会发生巨大变化。这些影响主要是由界面处的拉伸松动和滑动引起的，并因非线性膜特性而增强。通过参数分析表明，线性弹性模型无法令人满意地描述这些对载荷传递机制的影响。最重要的是，纤维组织的插入会在骨和骨水泥中导致过度的应力集中，以及这些材料之间相对较高的相对位移。
