Lessons learned from loosening of the McKee-Farrar metal-on-metal total hip replacement.
Lessons learned from loosening of the McKee-Farrar metal-on-metal total hip replacement.
复制标题
DOI：
10.1016/s0883-5403(99)90059-1
复制
发表时间：
1999-04
期刊：
影响因子：
--
通讯作者：
C. Zahiri;T. Schmalzried;T. Schmalzried;Edward Ebramzadeh;E. Szuszczewicz;David Salib;Carrie Kim;Harlan Amstutz
中科院分区：
文献类型：
--
作者：
C. Zahiri;T. Schmalzried;T. Schmalzried;Edward Ebramzadeh;E. Szuszczewicz;David Salib;Carrie Kim;Harlan Amstutz
对15个因无菌性松动(4个柄松动，9个杯状松动，2个假体松动)而失败的McKee-Farrar人工髋关节置换术的临床和X线资料进行了比较，时间为0.6~21年(平均8.3年)，与McKee-Farrar全髋关节置换术存活21~26年的15个髋关节进行了比较。与那些长期存活的髋关节相比，松动的髋关节在生物力学上处于劣势。X线片评估显示，在无菌股骨松动的翻修髋关节中，偏移量平均减少了1.4，而存活的髋关节平均增加了4.9 mm(P=0.04)。此外，在无菌松动矫正的髋关节中，旋转中心平均中移1.4 mm，而存活髋关节的旋转中心平均中移6.4 mm(P=.1)。不利的生物力学导致关节反作用力增加，这可能导致这些假体松动。与15个存活的假体中的7个相比，6个McKee-Farrar假体中有5个在内翻(P=.1)，因此在III和Vi区有水泥套缺陷。因此，在McKee-Farrar假体中，类似于金属对塑料支架的髋关节，弯曲的假体假体与内翻定位、水泥假体缺陷和松动有关。在这些情况下，金属对金属关节的磨损似乎不是失败的原因。用射线照相无法检测到磨损。在翻修手术中，没有迹象表明轴承过度磨损或假体周围组织大体金属染色。组织切片的显微镜分析显示，金属颗粒和聚甲基丙烯酸甲酯颗粒的大小和形状各不相同。这些颗粒的可变性表明，它们很可能是松动的结果，而不是由可能导致松动的轴承表面磨损产生的。虽然人们希望轴承耐磨性的改善将提高存活率，但McKee-Farrar全髋关节置换术的经验和分析表明了植入物设计、重建的生物力学和外科植入技术的作用的重要性。
Clinical and radiographic data for 15 McKee-Farrar hip replacements that had failed because of aseptic loosening (4 stem loosening, 9 cup loosening, and 2 loosening of both components) between 0.6 and 21 years (average, 8.3 years) were compared with 15 hips in which the McKee-Farrar total hip replacement has survived between 21 and 26 years. Hips that loosened were biomechanically disadvantaged compared with those that demonstrated long-term survival. Radiographic evaluation demonstrated that in hips that were revised for aseptic femoral loosening, the offset was decreased by a mean of 1.4, whereas it was increased by a mean of 4.9 mm in the surviving hips (P = .04). Further, in hips revised for aseptic loosening, the center of rotation was medialized by a mean of only 1.4 mm, whereas the center of rotation was medialized by a mean of 6.4 mm in the surviving hips (P = .1). Unfavorable biomechanics results in increased joint reaction forces that could contribute to loosening of these prostheses. Five of 6 McKee-Farrar stems revised for aseptic loosening compared with 7 of 15 surviving stems were in varus (P = .1) and, as a result, had cement mantle defects in zones III and VII. Thus, in the McKee-Farrar, similar to what has been seen in hips with metal-on-plastic bearings, curved stems are associated with varus positioning, cement mantle defects, and loosening. Wear of the metal-on-metal articulation does not appear to be the cause of failure in these cases. Wear could not be detected radiographically. At revision surgery, there was no indication of excessive bearing wear or gross metal staining of periprosthetic tissues. Microscopic analysis of tissue sections demonstrated both metal and polymethylmethacrylate particles of variable size and shape. The variability of the particles suggests that they are likely the result of loosening and that they were not generated by bearing surface wear that could cause loosening. Although it is hoped that improvements in the wear resistance of the bearing will increase survivorship, this experience and analysis of the McKee-Farrar total hip replacement illustrates the importance of the implant design, biomechanics of the reconstruction, and role of surgical implantation technique.