Taper degradation in Total Hip Replacements (THR) has been identified as a clinical concern, and the degradation occurring at these interfaces has received increased interest in recent years. Wear and corrosion products produced at the taper junction are associated with adverse local tissue responses, leading to early failure and revision surgery. Retrieval and in-vitro studies have found that variations in taper design affect degradation. However, there is a lack of consistent understanding within the literature of what makes a good taper interface. Previous studies assessed different design variations using their global parameters assuming a perfect cone such as: taper length, cone angle and diameters. This study assessed geometrical variations of as-manufactured head and stem tapers and any local deviations from their geometry. The purpose of this study was to provide a greater insight into possible engagement, a key performance influencing parameter predicted by Morse taper connection theory. This was achieved by taking measurements of twelve different commercially available male tapers and six female tapers using a coordinate measurement machine (CMM). The results suggested that engagement is specific to a particular head-stem couple. This is subject to both their micro-scale deviations, superimposed on their macro-scale differences. Differences in cone angles between female and male tapers from the same manufacturer was found to create a predominately proximal contact. However, distally mismatched couples are present in some metal-on-metal head-stem couples. On a local scale, different deviation patterns were observed from the geometry which appeared to be linked to the manufacturing process. Future work will look at using this measurement methodology to fully characterise an optimal modular taper junction for a THR prosthesis.

全髋关节置换术 (THR) 中的锥度退化已被确定为临床问题，近年来，这些界面处发生的退化越来越受到关注。在锥形连接处产生的磨损和腐蚀产物与不利的局部组织反应有关，导致早期失败和修复手术。检索和体外研究发现锥形设计的变化会影响降解。然而，文献中对什么是好的锥形接口缺乏一致的理解。先前的研究使用它们的全局参数来评估不同的设计变化，假设一个完美的锥体，例如：锥度长度、锥角和直径。该研究评估了制造的头部和阀杆锥度的几何变化以及与其几何形状的任何局部偏差。本研究的目的是更深入地了解可能的接合，这是莫尔斯锥度连接理论预测的关键性能影响参数。这是通过使用坐标测量机 (CMM) 测量十二种不同的市售公锥和六个母锥来实现的。结果表明，订婚是特定于特定头干夫妇的。这取决于它们的微观尺度偏差，叠加在它们的宏观尺度差异上。发现来自同一制造商的母锥和公锥之间的锥角差异会产生主要的近端接触。然而，在一些金属对金属头杆对中存在远端不匹配的对。在局部范围内，从似乎与制造过程相关的几何形状中观察到不同的偏差模式。未来的工作将着眼于使用这种测量方法来全面表征 THR 假体的最佳模块化锥形连接。