Measurement and Characterization of Wear in Shoulder Replacements

根据国家关节登记处的数据，英国每年大约有7000人接受初级肩关节置换手术，而大约700人接受修复手术。主要手术包括由于骨关节炎或袖带撕裂性关节病等多种原因导致的肩关节置换。肩关节置换术有三种类型：全肩关节置换术、反向肩关节置换术和部分肩关节置换术。最常见的主要手术是反向全肩关节置换术，占手术总数的51%。其次是标准极性全肩关节置换术，30%的手术（NJR）。目前，重量法被用于量化UHMWPE组件的磨损，用于体外模拟器测试，以开发新的植入物。由于缺乏可用的方法，有关检索分析的工作有限。此外，由于与髋关节置换术相比，肩关节置换术的手术次数较少，收回的假体数量也较少，因此缺乏评估肩关节置换术性能的深入研究。该项目将专注于开发磨损测量方法，可用于分析无预磨损数据的回收植入物。将开发的方法与重量法进行比较，以验证准确性和评估重复性。该方法将允许更好地了解磨损过程，并将使磨损区域可视化，体积量化以及表面变化。将使用一系列坐标和表面测量仪器，从置换体的承载面和配合面收集数据，并开发定制分析程序，以解决肩部植入物的特定几何形状。

Around 7000 people undergo primary shoulder replacement surgery every year in the UK whilst around 700 undergo revision surgery according to the National Joint Registry. The primary surgery involves replacement of the shoulder joint due to a number of causes such as osteoarthritis or cuff tear arthropathy. There are three types of shoulder replacements: total, reverse and partial shoulder replacement. The most frequently performed primary procedure was the reverse polarity total shoulder replacement, carried out in 51% of procedures. This was followed by the standard polarity total shoulder replacement, carried out in 30% of procedures (NJR).Currently gravimetric methods are used to quantify wear in the UHMWPE component for in vitro simulator testing to develop new implants. Due to a lack of available methods limited work has been performed regarding retrieval analysis. Also due to the lower number of surgeries performed and lower number of retrieved implants when compared to hip replacements there is a lack of in depth retrieval studies evaluating the performance of shoulder implants. This project will focus on developing wear measurement methods that can be used for analysis of retrieved implants where no pre wear data is available. The developed methods will be compared with gravimetric methods to verify the accuracy and evaluate repeatability. The methods will allow for a better understanding of the wear process and will enable the visualization of the wear area, quantification of volume as well as surface changes. A range of coordinate and surface measurement instruments will be used to gather data from the bearing surface and the mating surfaces of the replacement with bespoke analysis procedures being developed to address the particular geometry of the shoulder implant.