一种新型人工膝关节胫骨衬垫的体外磨损分析

In vitro wear analysis of a new type of tibial liner for artificial knee joint

对添加十二烷基没食子酸酯的新型高交联聚乙烯材料(XLPE-DG)制造的膝关节胫骨衬垫进行体外磨损测试,研究其磨损质量损失(磨损量)、磨损率和磨损颗粒的特征(数量、大小和形状),分析其在不同磨损阶段的磨损性能,为国产医用聚乙烯材料的研发及临床应用提供数据支持。按照国际标准化组织(ISO)14243-1和14243-2标准方法,选取4件全膝关节置换假体为测试样品(3件试验组和1件对照组),试验中的润滑剂为小牛血清,利用膝关节模拟机对XLPE-DG衬垫进行循环磨损测试,分别计算100万次循环(1 Mc)、300万次循环(3 Mc)及500万次循环(5 Mc)磨损后的磨损量和磨损率,使用图像分析软件对扫描电镜获得的磨屑图像分析,分析磨屑的特征(数量、大小和形状)。通过5 Mc磨损测试后XLPE-DG衬垫的磨损量为(23.86±0.75)mg,磨损率为(4.39±0.75)mg/Mc,3~5 Mc阶段的磨损量与1~3 Mc阶段磨损量接近(8.79 mg vs 8.74 mg);磨屑颗粒数量随着磨损次数的增加而减少;5 Mc后XLPE-DG衬垫的磨屑颗粒等效圆面积直径(ECD)平均值为0.13μm(最小值0.04μm,最大值0.8μm),且(77.11±6.89)%的颗粒ECD平均值<0.2μm,ECD平均值随着磨损次数的增加而下降;5 Mc磨损后衬垫磨屑体态比(AR)平均值为2.8(最小1.0,最大9.9),其中77.9%的颗粒AR值<4,以圆形粒状颗粒为主。XLPE-DG衬垫表现出良好的耐磨损性能,在临床应用中能够减少发生假体周围炎症、骨溶解和假体松动的风险,具有良好的临床应用潜力。

In vitro wear tests were conducted on knee tibial liner manufactured from a new highly cross-linked polyethylene material(XLPE-DG)with dodecyl gallate.The characteristics(quantity,size and shape)of wear mass loss(wear volume),wear rate and wear particles were studied,and the wear performance in different wear stages was analyzed,so as to provide data support for the research and development and clinical application of domestic medical polyethylene materials.In accordance with the International Organization for Standardization(ISO)14243-1 and 14243-2 standard methods,4 total knee arthroplasty prostheses were selected as test samples(3 in the test group and 1 in the control group).The lubricant in the test was calf serum,and the XLPE-DG liner was tested for cyclic wear using a knee joint simulator.The wear volume and the wear rate after 1 million cycles(1 Mc),3 million cycles(3 Mc),and 5 million cycles(5 Mc)were calculated respectively.The abrasive debris images obtained by the scanning electron microscope(SEM)was analyzed by using image analysis software to analyze the characteristics of the debris of the wear debris(number,size and shape).After passing the 5 Mc wear test,the wear amount of XLPE-DG liner was(23.86±0.75)mg,with a corresponding wear rate of(4.39±0.75)mg/Mc and the wear amount during the 3–5 Mc stage was similar to that of the 1–3 Mc stage(8.79 mg vs.8.74 mg).The number of wear debris decreased with the increase of the number of wear times.The average value of the equivalent circular area diameter(ECD)of the wear debris of XLPE-DG liner after 5 Mc was 0.13μm(minimum value 0.04μm,maximum value 0.8μm),and the average ECD of 77.11%±6.89%particles was<0.2μm,the average value of ECD decreased with the increase of the number of wear times.The average value of the aspect ratio(AR)of the liner after 5 Mc wear was 2.8(minimum 1.0,maximum 9.9),of which 77.9%had an AR value of<4 and the particles are mainly round.The XLPE-DG liner demonstrated excellent wear resistance and can reduce the risk of periprosthetic inflammation,osteolysis,and prosthetic loosening in clinical applications,and have good clinical application potential.