Robertson William J, Mattern Christopher J, Hur John, Su Edwin P, Pellicci Paul M
Hospital for Special Surgery, New York, New York 10021, USA.
J Arthroplasty. 2009 Feb;24(2):322.e5-11. doi: 10.1016/j.arth.2008.01.002. Epub 2008 Dec 9.
Unlike traditional bipolar constrained liners, the Osteonics Omnifit constrained acetabular insert is a tripolar device, consisting of an inner bipolar bearing articulating within an outer, true liner. Every reported failure of the Omnifit tripolar implant has been by failure at the shell-bone interface (Type I failure), failure at the shell-liner interface (Type II failure), or failure of the locking mechanism resulting in dislocation of the bipolar-liner interface (Type III failure). In this report we present two cases of failure of the Omnifit tripolar at the bipolar-femoral head interface. To our knowledge, these are the first reported cases of failure at the bipolar-femoral head interface (Type IV failure). In addition, we described the first successful closed reduction of a Type IV failure.
与传统的双极受限内衬不同，奥斯特尼克斯全适型受限髋臼内衬是一种三极装置，由一个在外部真正内衬内活动的内部双极轴承组成。每例已报道的全适型三极植入物失败均为在髋臼杯与骨界面处失败（I型失败）、在髋臼杯与内衬界面处失败（II型失败），或锁定机制失效导致双极内衬界面脱位（III型失败）。在本报告中，我们展示了两例全适型三极装置在双极股骨头界面处失败的病例。据我们所知，这些是首次报道的双极股骨头界面处失败（IV型失败）的病例。此外，我们描述了首例成功闭合复位IV型失败的病例。
