Engh Charles A, Sychterz Christi J, Engh C Anderson
Anderson Orthopaedic Clinic, Alexandria, Virginia, USA.
Instr Course Lect. 2005;54:183-7.
Data from a series of four recent studies showed that conventional polyethylene liners sterilized by gamma irradiation in air and coupled with second-generation acetabular components outperformed first-generation components with consistent average wear behavior below 0.1 mm/yr. It was found that liners sterilized by gamma irradiation in air outperformed liners sterilized by gas plasma, indicating that cross-linking induced by gamma irradiation sterilization, even if the component is radiated in an oxygen environment, is essential for keeping wear rates low. No negative clinical effects were found on wear for conventional polyethylene sterilized by gamma irradiation in air with a shelf life up to 3 years (r2 = 0.04, P = 0.60). Finally, 16-year temporal wear patterns for gamma irradiation in air sterilized components demonstrated no significant changes in wear rates over time, indicating that gamma irradiation sterilized liners with short shelf lives will not likely experience late increases in wear because of continued in vivo oxidation of the polyethylene. From these studies it was determined that standardized radiographic methods, optimal radiographs, serial measurements, and minimum 4-year follow-up are essential for reliable wear data. More specifically, it was concluded that a conventional ultra-high molecular weight polyethylene liner gamma irradiation sterilized in air with a shelf life less than 3 years, coupled with a second-generation cup, performs well in vivo and is unlikely to experience late increases in wear. Because no comparable in vivo data will be available for new cross-linked polyethylene materials for several years, conventional gamma irradiated polyethylene can be considered the industry's current gold standard for wear performance comparisons.
最近四项系列研究的数据表明，在空气中经伽马射线辐照灭菌并与第二代髋臼组件配合使用的传统聚乙烯衬垫，其性能优于第一代组件，平均磨损行为一致，低于每年0.1毫米。研究发现，在空气中经伽马射线辐照灭菌的衬垫优于经气体等离子体灭菌的衬垫，这表明即使组件在氧气环境中进行辐照，伽马射线辐照灭菌所诱导的交联对于保持低磨损率至关重要。对于在空气中经伽马射线辐照灭菌、保质期长达3年的传统聚乙烯，未发现磨损方面的负面临床影响（r2 = 0.04，P = 0.60）。最后，对在空气中经伽马射线辐照灭菌组件的16年时间磨损模式研究表明，磨损率随时间没有显著变化，这表明保质期短的伽马射线辐照灭菌衬垫不太可能因聚乙烯在体内持续氧化而出现后期磨损增加的情况。从这些研究中可以确定，标准化的放射学方法、最佳的X光片、系列测量以及至少4年的随访对于获得可靠的磨损数据至关重要。更具体地说，得出的结论是，在空气中经伽马射线辐照灭菌、保质期小于3年的传统超高分子量聚乙烯衬垫，与第二代髋臼杯配合使用时，在体内表现良好，不太可能出现后期磨损增加的情况。由于在未来几年内新的交联聚乙烯材料将无法获得可比的体内数据，因此传统的伽马射线辐照聚乙烯可被视为该行业目前磨损性能比较的黄金标准。
