Assessment of cortical thickening in total hip replacement patients

全髋关节置换术（THR）是一项成功的手术，但需要翻修的装置数量仍在不断增加。人口老龄化，越来越多的活跃和肥胖患者，都在增加对器械的需求：它们需要比以往更持久，承受更高的负荷。在翻修前的THR患者的x光片上经常观察到骨的变化（“远端皮质增厚”），但这些变化的特征很少，它们与种植体的选择或患者的结果有什么关系。本研究的目的是开发方法，使用自动图像处理方法客观地描述和量化远端皮层增厚，并评估它是否以及如何与随后的干松动相关。主要目标是：从x线证据发展表征和量化皮质增厚的方法。[2]通过与(a)临床专业人员使用的手工方法和(b)相同患者/尸体标本的3D CT/MRI成像进行比较，验证方法并定义其准确性。[3]将方法应用于由我们在贝尔法斯特马斯格雷夫公园医院的合作者提供的更大的数据集，以及通过我们的行业合作伙伴关系访问的其他来源，并评估随时间变化的进展及其与患者结果的关系。[4]扩展使用统计形状建模和有限元分析的分析方法，以检查不同股骨配合方案的生物力学效应，包括初级和翻修系统。这项工作符合EPSRC HealthTech关于优化治疗（基于证据的决策）和物理干预前沿（提高植入成功率）的重大挑战，以及EPSRC培训行业相关博士和增强未来数字技术的交付计划优先事项。它是与我们的行业合作伙伴共同开发的，并受到行业和临床需求的推动。这项工作将为骨重塑的基本机制提供新的证据，并量化其影响。它将为不同患者的手术器械选择建议提供证据，并可能提供更客观地监测高危病例的途径。

Total hip replacement (THR) is a successful operation but the number of devices requiring revision is continuing to rise. The aging population, growing cohorts of more active and more obese patients, are all increasing the demands on devices: they need to last for longer and withstand higher loads than ever before. Changes in the bone ('distal cortical thickening') are often observed on x-rays of THR patients prior to revision, but there has been little characterisation of these changes, how they relate to the choice of implant or to the outcomes for the patient. The aim of this study is to develop methods to characterise and quantify distal cortical thickening objectively using automated image-processing methods, and assess if and how it relates to subsequent stem loosening. The main objectives are: [1] To develop methods to characterise and quantify cortical thickening from x-ray evidence. [2] To validate the methods and define their accuracy by comparison with (a) manual methods used by clinical professionals, and (b) 3D CT/MRI imaging of the same patients/cadaveric specimens. [3] To apply the methods to larger datasets, provided by our collaborators at Musgrave Park Hospital, Belfast and other sources accessed through our industry partnership, and assess the progression of changes over time and the relationship to patient outcome. [4] To extend the methods of analysis using statistical shape modelling and finite element analysis to examine the biomechanical effects of different femoral fit scenarios, for both primary and revision stems.This work fits to EPSRC HealthTech Grand Challenges on Optimising Treatment (evidence based decision making) and Frontiers of Physical Intervention (improving success rates of implants), as well as EPSRC Delivery Plan priorities of training industry relevant PhDs and enhancing future digital technologies. It has been co-developed with our industry partner and is driven by both industry and clinical need. The work will provide new evidence of the underpinning mechanisms of bone remodelling and quantify its effects. It will provide evidence for surgical recommendations on device selection for different patients and may provide a route to monitor at-risk cases more objectively.