Computational and Experimental Analysis of Tibial Tuberosity Transfers

描述(由申请人提供)： 项目摘要/摘要对于与外侧对齐不良相关的顽固性髌股关节疼痛的患者，通常采用胫骨粗隆移位术来改善髌股对位并减少施加在受损软骨区域的压力。尽管先前已经进行了几项研究来描述胫骨结节转移对髌股压力分布的影响，但没有一项研究考虑到持续疼痛的患者中常见的髌股结构不良和软骨损伤。这项拟议的研究将集中于确定软骨损伤如何影响胫骨结节移位以减少髌股压力的有效性，并为未来的研究开发计算方法，以解决髌股发育不良和其他病变位置。这项拟议研究的第一个具体目标是确定通过胫骨结节移位在体外可以达到的压力降低，以及外侧和内侧软骨损伤如何影响移位的效果。第二个目标是利用离散元分析和有限元分析，对软骨进行多重表示，以重复实验研究。第三个目的是比较计算结果和实验结果，以确定合适的计算建模技术(或多个技术)来模拟有症状的膝盖。长期目标是开发工具来研究为髌股关节疾病患者开出的各种手术和非手术治疗方法，并考虑到个别患者的病理，以改善患者的预后。第一个目标将通过模拟10个膝关节在屈膝400、600和800度时的等长伸展来实现。压力传感器将被用来测量在模拟胫骨结节的内侧和前内侧时的髌股压力分布。在造成外侧和内侧软骨损伤后，将重复进行压力测量。第二个目标将通过从核磁共振图像中创建实验测试的每个膝盖的计算模型来实现。实验测试将通过计算模拟，同时将髌股软骨表示为一层弹簧(离散元素分析)。响应外加载荷的压力分布将通过最小化储存在弹簧内的势能来量化。实验测试也将使用有限元分析进行重复。计算数据将与实验数据进行比较，以便为未来的研究验证一种或两种建模技术。经过验证的建模技术将用于有症状的膝盖模型，以研究在体外不容易研究的治疗方法和病理条件。这项拟议的研究将对软骨退化如何影响胫骨结节移植的有效性进行初步评估，并提供工具来收集额外的数据，骨科医生可以使用这些数据来根据个别患者的软骨损伤和发育不良来计划手术。 公共卫生相关性： 项目叙事手术通常是为了治疗膝关节后面与排列不良和软骨损伤有关的疼痛。这项拟议的研究将利用实验测试和计算建模来表征手术技术对卸载受损软骨区域的有效性。减少施加在软骨上的压力应该会减轻疼痛。

DESCRIPTION (provided by applicant): Project Summary/Abstract For patients with unrelenting patellofemoral pain related to lateral malalignment, tibial tuberosity transfers are commonly performed to improve patellofemoral alignment and reduce the pressure applied to areas of damaged cartilage. Although several studies have previously been performed to characterize the influence of tibial tuberosity transfers on the patellofemoral pressure distribution, none of the previous studies accounted for patellofemoral dysplasia and cartilage lesions, which are common for patients with unrelenting pain. The proposed study will focus on characterizing how cartilage lesions influence the effectiveness of tibial tuberosity transfers performed to reduce patellofemoral pressures and on developing computational methods for future investigations that account for patellofemoral dysplasia and additional lesion positions. The first specific aim of the proposed study is to characterize pressure reductions that can be achieved via tibial tuberosity transfers in vitro and characterize how lateral and medial cartilage lesions influence the effectiveness of the transfers. The second aim is to utilize both discrete element analysis and finite element analysis, with multiple representations for cartilage, to replicate the experimental studies. The third aim is to compare the computational and experimental results to identify the appropriate computational modeling technique (or techniques) for modeling symptomatic knees. The long term goal is to develop tools to investigate a variety of surgical and non-surgical treatment methods prescribed for patients with patellofemoral disorders, and account for the pathology of individual patients, in order to improve patient outcomes. The first aim will be addressed by simulating isometric knee extension for 10 knees at 400, 600 and 800 of knee flexion. Pressure sensors will be used to measure the patellofemoral pressure distribution while simulating medialization and anteromedialization of the tibial tuberosity. The pressure measurements will be repeated after creating lateral and medial cartilage lesions. The second aim will be addressed by creating computational models of each knee tested experimentally from MRI images. The experimental tests will be simulated computationally while representing the patellofemoral cartilage as a layer of springs (discrete element analysis). The pressure distribution in response to applied loads will be quantified by minimizing the potential energy stored within the springs. The experimental tests will also be replicated using finite element analysis. The computational data will be compared to the experimental data in order to validate one or both modeling techniques for future studies. Validated modeling techniques will be utilized with models of symptomatic knees to investigate treatment methods and pathological conditions that can not be easily studied in vitro. The proposed study will provide an initial assessment of how cartilage degradation influences the effectiveness of tibial tuberosity transfers and provide tools to collect additional data that can be used by orthopedic surgeons to plan procedures based on the cartilage damage and dysplasia noted for individual patients. PUBLIC HEALTH RELEVANCE: Project Narrative Surgery is commonly performed to treat pain behind the knee cap related to poor alignment and damaged cartilage. The proposed study will utilize experimental testing and computational modeling to characterize the effectiveness of surgical techniques performed to unload areas of damaged cartilage. Decreasing the pressure applied to the cartilage should reduce pain.