一种新型高交联聚乙烯髋臼内衬的体外磨损性能测试

In vitro wear performance test of a new kind of highly cross-linked polyethylene acetabular liner

目的:分析一种含多酚的新型高交联聚乙烯(XLPE)髋臼内衬的磨损性能,为新型聚乙烯材料的研发和在人工髋关节置换术(THA)中的临床应用提供依据。方法:按照国际标准化组织(ISO)14242标准规定的方法,使用人工髋关节模拟试验机,按照人体步态生物力学运动参数,对新型XLPE髋臼内衬进行体外磨损试验。试验样品为4组髋关节假体,其中1组样品为对照组,其余3组样品分别为试验1组、试验2组和试验3组;每组样品均包含髋臼外杯、髋臼内衬和球头3个部件。4组样品均经过预浸泡、恒重、固定、磨损、清洗、称重等步骤,计算其髋臼内衬的磨损率。收集磨损500万次后的血清样本,按照ISO 17853标准规定的方法消解稀释血清,通过孔径1.2μm和0.1μm的滤膜过滤。使用扫描电子显微镜在滤膜上随机选取聚乙烯磨屑颗粒图像,分析磨屑的数量、大小和形状,评估其磨损性能。结果:新型XLPE髋臼内衬平均磨损率为(36.49±2.21)mg/million cycles;聚乙烯磨屑当量直径平均值为0.29μm,<0.6μm的磨屑颗粒占98.5%,磨屑的形态指数值<4的占比为99.5%。结论:含多酚的XLPE制成的髋臼内衬磨损率与普通超高分子量聚乙烯髋臼内衬相近,聚乙烯磨屑尺寸多数较小,形态以粒状为主,具有一定的耐磨损性能,其在THA中具有应用潜力。

Objective:To analyze wear performance of a new type of highly cross-linked polyethylene(XLPE)acetabular liner,so as to provide experimental basis for the research of new kind of polyethylene materials and clinical application of that in total hip arthroplasty(THA).Methods:Depended on the International Organization for Standardization(ISO)14242,the in vitro wear tests were performed for the new type of XLPE acetabular liner according to the biomechanical parameters of human gait by using a hip joint simulator.The samples were four groups of hip joint prostheses,of which three groups were test samples(group 1,group 2,group 3)and one group was control sample.Each group consists of an acetabular cup,an acetabular liner and a ball head.After four groups of samples underwent pre-soaking,constant weight,fixation,wear,cleaning and weigh,the wear rate of acetabular liner was calculated.The serum samples were collected after the wear times reached to 5 million.The serums were digested and diluted in accordance with ISO 17853,and were filtered through the filter membranes with the pore size of 1.2μm and 0.1μm.The scanning electron microscope was used to randomly select the images of the particles of abrasive dust on the filter membrane,and the amount,size and shape of wear debris were analyzed,and the wear resistance were assessed.Results:The average wear rate of the new type of XLPE acetabular liner was(36.49±2.21)mg/million cycles.The average value of equivalent diameter of polyethylene wear debris was 0.29μm,and the amount of the particles which diameter were less than 0.6μm accounted for 98.5%,and the shape index values of wear debris that were less than 4 accounted for 99.5%.Conclusion:The research results indicates that the acetabular liner made of the new type of XLPE that contains polyphenol has a similar wear rate with the common acetabular liner made of ultra-high molecular weight polyethylene(UHMWPE).The most of the sizes of polyethylene wear debris are smaller,and the main shapes of them are basically granular,which has a certain of the performance of wear resistance.It has application potential in THA.