Taylor M, Abel E W
School of Biomedical Engineering, University of Dundee, Scotland.
Proc Inst Mech Eng H. 1993;207(4):255-61. doi: 10.1243/PIME_PROC_1993_207_304_02.
The difficulty of achieving good distal contact between a cementless hip endoprosthesis and the femur is well established. This finite element study investigates the effect on the stress distribution within the femur due to varying lengths of distal gap. Three-dimensional anatomical models of two different sized femurs were generated, based upon computer tomograph scans of two cadaveric specimens. A further six models were derived from each original model, with distal gaps varying from 10 to 60 mm in length. The resulting stress distributions within these were compared to the uniform contact models. The extent to which femoral geometry was an influencing factor on the stress distribution within the bone was also studied. Lack of distal contact with the prosthesis was found not to affect the proximal stress distribution within the femur, for distal gap lengths of up to 60 mm. In the region of no distal contact, the stress within the femur was at normal physiological levels associated with the applied loading and boundary conditions. The femoral geometry was found to have little influence on the stress distribution within the cortical bone. Although localized variations were noted, both femurs exhibited the same general stress distribution pattern.
非骨水泥型髋关节假体与股骨之间实现良好的远端接触存在困难，这一点已得到充分证实。这项有限元研究调查了不同长度的远端间隙对股骨内应力分布的影响。基于对两个尸体标本的计算机断层扫描，生成了两种不同尺寸股骨的三维解剖模型。从每个原始模型又衍生出另外六个模型，远端间隙长度从10毫米到60毫米不等。将这些模型内的应力分布结果与均匀接触模型进行了比较。还研究了股骨几何形状对骨内应力分布的影响程度。研究发现，对于长达60毫米的远端间隙长度，假体与远端缺乏接触不会影响股骨内的近端应力分布。在无远端接触的区域，股骨内的应力处于与施加的载荷和边界条件相关的正常生理水平。研究发现股骨几何形状对皮质骨内的应力分布影响很小。尽管注意到局部差异，但两根股骨均呈现出相同的总体应力分布模式。
