INTERGRANULAR CORROSION-FATIGUE FAILURE OF COBALT-ALLOY FEMORAL STEMS - A FAILURE ANALYSIS OF 2 IMPLANTS
INTERGRANULAR CORROSION-FATIGUE FAILURE OF COBALT-ALLOY FEMORAL STEMS - A FAILURE ANALYSIS OF 2 IMPLANTS
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DOI：
10.2106/00004623-199401000-00014
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发表时间：
1994-01-01
影响因子：
5.3
通讯作者：
ZERNICH, MR
中科院分区：
文献类型：
--
作者：
GILBERT, JL;BUCKLEY, CA;ZERNICH, MR
在股骨部件的颈部区域发生骨折后，分别在植入后85个月和70个月取出了两个具有钴合金股骨头和钴合金股骨柄的组配式髋关节植入物。两种植入物均在距股骨头和股骨柄之间的锥体连接处远端不到1 mm处（锥体外部）失效。使用扫描电子显微镜对种植体的断裂表面进行了研究，以确定失效过程的性质。断裂发生在微观结构的晶界处，似乎是三个因素的结果：晶界处的孔隙度;晶间腐蚀侵蚀，在头颈锥和自由表面处开始;以及股骨柄的循环疲劳载荷。自由表面的腐蚀攻击开始，在某种程度上，由表面晶粒的退出和由流体进入晶粒间区域。断面显示假体颈部广泛的晶间腐蚀侵蚀，位于股骨头-颈部锥形连接区域，并深入渗透到微观结构中。
Two modular hip implants with a cobalt-alloy head and a cobalt-alloy stem were retrieved after a fracture had occurred in the neck region of the femoral component, eighty-five and seventy months after implantation. Both implants failed less than one millimeter distal to the taper junction between the head and the stem (outside of the taper). The-fracture surfaces of the implant were investigated with the use of scanning electron microscopy, to determine the nature of the failure process. The fractures occurred at the grain boundaries of the microstructure and appeared to be the result of three factors: porosity at the grain boundaries; intergranular corrosive attack, initiated both at the head-neck taper and at the free surface; and cyclic fatigue-loading of the stem. The corrosive attack of the free surface was initiated, in part, by the egression of surface grains and by the ingression of fluid into the intergranular regions. Sectioned surfaces showed extensive intergranular corrosive attack in the prosthetic neck localized in the region of the head-neck taper junction and penetrating deeply into the microstructure.