人工髋关节金属柄折断与槽口的关系

人工髋关节金属柄的折断必伴随股骨干折断问题出现，缩短金属柄的使用寿命。为此，必须分析槽口是不是柄折断的真正原因，按照文献揭示，烧结的多孔层置入体孔隙在柄表面产生槽口使柄折断为主要的原因是不正确的，因为钎缝不是裂口。把孔隙尖部当成槽口，经扩展成裂纹，使柄折断的结论是错误的。有研究认为槽口是孔隙的尖部可能扩展成裂纹，但槽口与柄折断无关。烧结温度下，柄表面层生成晶界缝隙，在受力区扩展成裂纹，导致柄折断。槽口并不存在，也无理论根据，又无病例佐证。柄折断是由烧结引起的。烧结粘连多孔层置入体使柄折断是由于烧结温度太高，形成晶界缝隙，适逢柄最大受力区扩展成裂纹所致。

The Notch and the Metal Handle Broken

A broken metal handle accompanied by femoral trunk fracture, which would shorten service life of handles. Therefore, it is necessary to judge whether the notch is the main reason for handle broken. Some literatures thought that the pores of sintered porous coated anatomic (PCA) porous layer produce the notch on the handle surface and the notches lead to the handle broken being incorrect. The Apex of the pore is taken for the bottom of the notch, expanding into a crack, and it should also not grow to the base-alloy, accordingly, the above conclusion is wrong. Some reports pointed out the notch, apex of the pore, will expand into the crack, but it is not associated with the broken handle. Under the sintering temperature, the grain boundary apertures be generated on the base metal surface, the aperture is expanded into the crack, which leads to handle broken in the forced area. However, neither theoretical basis, nor a case of corroboration, can prove exist of notch. Actually, the broken handle is caused by the sintering technology. The high temperature of sintering joining results in grain boundary aperture, when encounter the largest forced area and expand into crack, it will break the handle.