Enhanced pre-clinical experimental simulation of the natural knee

关节置换物的磨损仍然是决定其可靠性和寿命的主要因素。在膝盖，聚乙烯的磨损是决定寿命的一个关键因素，寿命更长的年轻、更活跃的患者会增加衰竭、骨溶解和松动(瑞典联合登记处)。目前，磨损的临床前测定和预测是通过关节模拟器在有限的一组条件下进行的，这没有考虑到患者临床条件的广泛变化。我们的分层增强可靠性(SAFER)方法考虑了手术分娩的变化、运动学的变化、患者群体的变化和生物材料技术的退化，以及所有这些不同条件的组合。在手术分娩方面，最近出现了向运动学对齐的转变，而不是更传统的机械轴对齐。虽然运动学对齐与更好的屈曲和临床结果相关[A]，但这对膝关节假体磨损的影响尚不清楚。在如此广泛的分层条件下的测试不能仅使用实验模拟来实现，因为需要太多的实验模拟。因此，最近开发了一种新的计算建模方法，它可以与实验方法[B]相结合。在这个PHD项目中，这种独特的计算和实验相结合的方法将被用来专门研究手术分娩的变化(如机械对运动对齐)对全膝关节置换术磨损性能的影响。这一博士项目通过研究和开发在这一更广泛的外科和患者相关条件下膝关节置换物磨损的计算性和实验性临床前测试方法，来解决医疗保健方面的挑战“50年后50年活跃”。目的：通过实验和计算相结合的方法，研究Depuy Synths全膝关节置换术(TKR)手术路线对磨损的影响。目的：-开发手术对齐的实验模拟模型，并将其应用于DePuy Synths TKR以确定磨损。-开发DePuy Synths TKR的计算模型，该计算模型将与实验模拟进行验证。-通过实验和计算模拟相结合的方法来确定运动学和机械性手术对对齐的影响。便利：实验模拟将在IMBE机械工程实验室进行。该项目将推进我们用于评估膝关节置换的计算和实验临床前生物力学和生物摩擦学方法。它将告诉我们手术分娩的变化、运动学的变化、患者群体的变化和生物材料技术的退化，以及所有这些不同条件的组合对膝关节假体磨损的影响。这些先进的方法将与我们的行业合作伙伴DePuy Synths一起应用于临床产品，并转换为国际标准。

Wear of joint replacements remains a major factor determining their reliability and lifetime. In the knee, the wear of polyethylene is a key factor determining longevity, with increased failure, osteolysis and loosening in younger more active patients who live longer (Swedish Joint Registry). The pre-clinical determination and prediction of wear is currently undertaken experimentally by joint simulators under a limited set of conditions, which do not take into account the wide variation of clinical conditions in the patient. Our Stratified Approach For Enhanced Reliability (SAFER) approach takes into account variations in surgical delivery, variations in kinematics, variations in the patient population and degradation of the biomaterials technology, and indeed combinations of all these different conditions. With regards to surgical delivery there has recently been a shift towards kinematic alignment as opposed to more conventional mechanical axes alignment. Although kinematic alignment has been associated with better flexion and clinical outcome [A] there is no understanding of the implications of this on wear of the knee replacement.Testing under such a wide portfolio of stratified conditions cannot be achieved using experimental simulation alone, as too many experimental simulations are needed. Hence a new computational modelling approach has recently been developed, which can be combined with the experimental approach [B].In this PhD project this unique combined computational and experimental approach will be used to specifically investigate the influence of variations in surgical delivery (such as mechanical versus kinematic alignment) on the wear performance of total knee replacements. This PhD project addresses the healthcare challenge '50 active years after 50' through research and development of computational and experimental pre-clinical test methods of the wear of knee replacements under this wider set of surgical and patient dependent conditions. Aim:To investigate the influence of surgical alignment on wear of a DePuy Synthes Total Knee Replacement (TKR) through a combined experimental and computational approach. Objectives:- To develop an experimental simulation model of surgical alignment and apply it to a DePuy Synthes TKR to determine wear- To develop a computational model of the DePuy Synthes TKR, which will be validated against experimental simulation.- To determine the effects on wear of kinematic versus mechanical surgical alignment through the combined experimental & computational simulation approachFacilities:Experimental simulation will be carried out in the iMBE Mechanical Engineering laboratories.This project will advance our computational and experimental pre-clinical biomechanical and biotribological methods for the assessment of knee replacements. It will inform us as to what are the influence of variations in surgical delivery, variations in kinematics, variations in the patient population and degradation of the biomaterials technology, and indeed combinations of all these different conditions on the wear of knee replacements. These advanced methods will be applied to clinical products with our industry collaborator, DePuy Synthes, and translated into international standards.