为了研究内翻对人工膝关节接触压力的影响,建立了符合国人解剖特征的人工膝关节三维有限元模型,进行了不同运动和载荷作用下,对线一致与内翻5°时人工膝关节接触压力分布的有限元分析,并进行了对比分析。结果表明,对线一致时,国产人工膝关节接触压力值适中,接触区域均匀、对称,可以满足要求;而内翻5°时,接触压力峰值急剧增大,接触区域主要出现在各组件的内侧且明显减小,容易出现应力集中的情形。因此,在临床置换手术中应极力避免内翻5°以上这种对线不齐状态的出现。
In order to investigate the effect of varus malalignment on the contact pressure distribution of Chinese artificial knee joint, a 3-D finite element model of artificial knee joint was established, which meets the anatomic characteristics of Chinese people. Finite element analysis and comparisons of contact conditions were conducted with normal and 5 degrees varus aligned cases in different motions and loads. The results show that, the peak contact pressure in normally aligned domestic artificial knee joint is moderate, contact region is homogeneous and symmetrical, and such type of knee joint can meet the clinical requirements; while with varus malalignment at 5 degrees, the peak value of the contact pressure is increased sharply, contact zones are mainly appeared on the medial side of every component with obviously reduced contact areas, and the phenomenon of stress concentration can be easily generated in this situation. So in the operation of clinical replacement, the abnormally aligned state of varus alignment with more than 5 degrees should be avoided. This paper has certain reference significance to better understand the effects of the daily activities on the contact pressure distribution of every component for artificial knee joint, to improve the designing level of Chinese artificial knee joint for better serving Chinese people as soon as possible.