Enhanced pre-clinical experimental simulation of the natural knee

关节置换的磨损仍然是决定其可靠性和使用寿命的主要因素。对于膝关节，聚乙烯的磨损是决定寿命的关键因素，在更年轻、更活跃、寿命更长的患者中，失败率、骨溶解和松动率增加（瑞典联合登记处）。目前，临床前磨损的确定和预测是通过联合模拟器在有限的条件下进行的，这些条件没有考虑到患者临床条件的广泛变化。我们的分层方法增强可靠性（SAFER）方法考虑了手术交付的变化、运动学的变化、患者群体的变化和生物材料技术的退化，以及所有这些不同情况的组合。关于手术交付，最近已经转向运动学对齐，而不是更传统的机械轴对齐。尽管运动学对齐与更好的屈曲和临床结果相关[A]，但尚不清楚这对膝关节置换术磨损的影响。在如此广泛的分层条件下的测试不能仅通过实验模拟来实现，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，可以与实验方法相结合[B]。在这个博士项目中，这种独特的计算和实验相结合的方法将用于具体研究手术交付（如机械与运动对齐）对全膝关节置换术磨损性能的影响。该博士项目通过研究和开发在更广泛的手术和患者依赖条件下膝关节置换术磨损的计算和实验临床前测试方法，解决了“50年后50年活跃”的医疗保健挑战。目的：通过实验与计算相结合的方法，探讨手术对准对DePuy合成全膝关节置换术（TKR）磨损的影响。目的：-开发手术对准的实验模拟模型，并将其应用于DePuy Synthes TKR，以确定磨损-开发DePuy Synthes TKR的计算模型，将通过实验模拟进行验证。-通过实验和计算模拟相结合的方法来确定运动学和机械手术对准对磨损的影响。设施：实验模拟将在iMBE机械工程实验室进行。这个项目将推进我们的计算和实验临床前生物力学和生物摩擦学方法评估膝关节置换术。它将告诉我们手术方式的变化，运动学的变化，患者群体的变化以及生物材料技术的退化，以及所有这些不同条件对膝关节置换磨损的影响。这些先进的方法将与我们的行业合作伙伴DePuy Synthes一起应用于临床产品，并转化为国际标准。

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.