Laboratory of Biomechanical Engineering (LEBm) of University Hospital, Department of Mechanical Engineering, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil.
J Arthroplasty. 2018 Mar;33(3):939-944. doi: 10.1016/j.arth.2017.10.032. Epub 2017 Nov 21.
Dimensional control and surface finish of the femoral head and acetabular liner are critical factors in the manufacturing process due to the risk of increased polyethylene wear, which is the primary cause of aseptic failure of a metal/polymer hip prosthesis. The aim of this study is to perform a dimensional and surface finish analysis to evaluate the reproduction and accuracy of the manufacturing processes of metal femoral heads and ultra high molecular weight polyethylene acetabular liners.
Four femoral heads and acetabular liners from 5 manufacturers were evaluated. The methods of evaluation followed the standards ISO 7206-2:2011 and ISO 21535:2010.
The diameter, sphericity, and roughness of the femoral heads from all the manufacturers were in accordance with the standard requirements. Only the sphericity showed a lack of repeatability among the manufacturers. The variability in sphericity was high among some manufacturers and low in others. The diameters of the acetabular liners of 2 manufacturers were not in accordance with the standard requirements. The repeatability of sphericity, thickness, and roughness of the acetabular liners were heterogeneous among the manufacturers, which means that some manufacturers need to improve quality control.
Our results showed a good dimensional and surface finish control of the manufacturing processes of the femoral heads. However, the same control was not shown during the manufacturing of the acetabular liners although all samples had a thickness and sphericity in accordance with the standard. A better quality control of the manufacturing process of ultra high molecular weight polyethylene acetabular liners should be made to improve the dimensional parameters of the acetabular liners and the tribological pair.
由于聚乙烯磨损增加的风险，股骨头和髋臼衬里的尺寸控制和表面光洁度是制造过程中的关键因素，这是金属/聚合物髋关节假体无菌失效的主要原因。本研究旨在进行尺寸和表面光洁度分析，以评估金属股骨头和超高分子量聚乙烯髋臼衬里制造工艺的再现性和准确性。
评估了来自 5 家制造商的 4 个股骨头和髋臼衬里。评估方法遵循 ISO 7206-2:2011 和 ISO 21535:2010 标准。
所有制造商的股骨头直径、球形度和粗糙度均符合标准要求。只有球形度显示出制造商之间缺乏可重复性。一些制造商的球形度变化性较高，而另一些制造商的球形度变化性较低。两家制造商的髋臼衬里直径不符合标准要求。髋臼衬里的球形度、厚度和粗糙度的重复性在制造商之间存在差异，这意味着一些制造商需要改进质量控制。
我们的结果显示，股骨头制造过程的尺寸和表面光洁度控制良好。然而，在制造髋臼衬里时，虽然所有样品的厚度和球形度均符合标准，但并未显示出相同的控制。应加强超高分子量聚乙烯髋臼衬里制造过程的质量控制，以改善髋臼衬里的尺寸参数和摩擦副。
