Joint dislocation is a critical problem of total hip replacement. We have newly proposed an artificial hip joint with a structure that prevents dislocation. The proposed joint has a simple form with a femoral head partially covered with an acetabular cup. In the present study, the effects of inset heights and slit configurations of the cup on the pull-out forces of the joint were evaluated using finite element analysis. Joint models with different inset heights and those with or without a slit in the cup were used for the analyses to estimate the pull-out forces of the joint. In the case without the slit, the maximum pull-out force of the joint with 1.0 and 1.5 mm of the inset height was approximately 12 and 40 N, respectively. In the case of 1.0-mm inset height, the maximum force of the joint with and without the slit was approximately 9 and 12 N, respectively. These results reveal that the maximum force is markedly changed by the inset height and is moderately affected by the slit. Thus, we can gain insights into a strategy to optimally design an artificial joint in which dislocation does not occur easily.

关节脱位是全髋关节置换的关键问题。我们最近提出了一种具有防止脱位的结构的人工髋关节。提出的关节具有简单的形式，其股骨头部分覆盖有髋臼杯。在本研究中，使用有限元分析评估了杯的插入高度和狭缝形状对接头拔出力的影响。使用具有不同插入高度的关节模型以及杯中有或没有缝的关节模型进行分析，以估计关节的拔出力。在没有缝隙的情况下，插入高度为1.0和1.5毫米的关节的最大拉力分别约为12 N和40N。在插入高度为1.0毫米的情况下，带有和不带有缝隙的接头的最大力约为9和12 N，分别。这些结果表明，最大力明显受到插入高度的影响，并且受缝隙的影响中等。因此，我们可以深入了解优化不易发生脱位的人工关节的策略。