Zant Nikolaus P, Wong Charles K Y, Tong Jie
Department of Mechanical and Design Engineering, University of Portsmouth, Anglesea Road, Anglesea Building, Portsmouth PO1 3DJ, UK.
Int J Fatigue. 2007 Jul;29(7):1245-1252. doi: 10.1016/j.ijfatigue.2006.10.013.
Although the role of fatigue failure in aseptic loosening of cemented total hip replacements has been extensively studied in femoral components, studies of fatigue failure in cement mantle of acetabular replacements have yet to be reported, despite that the long-term failure rate in the latter is about three times that of femoral components. Part of the reason may be that a complex pelvic bone structure does not land itself readily for a 2D representation as that of a femur.In this work, a simple multilayer model has been developed to reproduce the stress distributions in the cement mantle of an acetabular replacement from a plane strain finite element pelvic bone model. The experimental multilayer model was subjected to cyclic loading up to peak hip contact force during normal walking. Radial fatigue cracks were observed in the vicinity of the maximum tangential and compressive stresses, as predicted by the FE models. Typical fatigue striations were also observed on the fracture surfaces post cyclic testing. The results were examined in the context of retrieval studies, 3D FE analysis and in vitro experimental results using full-sized hemi-pelvic bone models.
尽管疲劳失效在骨水泥型全髋关节置换术股骨部件无菌性松动中的作用已得到广泛研究，但髋臼置换术骨水泥壳疲劳失效的研究尚未见报道，尽管后者的长期故障率约为股骨部件的三倍。部分原因可能是复杂的骨盆骨结构不像股骨那样容易进行二维呈现。在这项工作中，已开发出一个简单的多层模型，以从平面应变有限元骨盆骨模型再现髋臼置换术骨水泥壳中的应力分布。对实验多层模型施加循环载荷，直至正常行走时的峰值髋关节接触力。如有限元模型所预测，在最大切向和压缩应力附近观察到径向疲劳裂纹。在循环测试后的断口表面也观察到典型的疲劳条纹。结合翻修研究、三维有限元分析以及使用全尺寸半骨盆骨模型的体外实验结果对这些结果进行了研究。
