Computational and Experimental Analysis of Tibial Tuberosity Transfers

描述（由申请人提供）： 项目总结/摘要对于与外侧对线不良相关的持续髌股疼痛的患者，通常进行胫骨结节转移以改善髌股对线并减少施加于受损软骨区域的压力。尽管之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，但之前的研究都没有考虑髌股发育不良和软骨病变，这在持续疼痛的患者中很常见。拟议的研究将集中于表征软骨病变如何影响胫骨结节转移的有效性，以减少髌股压力，并开发计算方法，为未来的调查，占髌股发育不良和其他病变的位置。拟议研究的第一个具体目的是表征通过胫骨结节体外转移可以实现的减压，并表征外侧和内侧软骨病变如何影响转移的有效性。第二个目的是利用离散元分析和有限元分析，与软骨的多种表示，复制实验研究。第三个目的是比较计算和实验结果，以确定适当的计算建模技术（或技术）的建模有症状的膝盖。长期目标是开发工具来研究髌股疾病患者的各种手术和非手术治疗方法，并解释个体患者的病理学，以改善患者结局。第一个目标将通过模拟膝关节屈曲400、600和800时10个膝关节的等长膝关节伸展来实现。压力传感器将用于测量髌股压力分布，同时模拟胫骨结节的内侧化和前内侧化。在产生外侧和内侧软骨损伤后，将重复压力测量。第二个目标将通过创建每个膝关节的计算模型来解决，这些膝关节通过MRI图像进行实验测试。将髌股软骨表示为一层弹簧（离散元分析）时，将通过计算模拟实验测试。响应于所施加的载荷的压力分布将通过最小化弹簧内存储的势能来量化。还将使用有限元分析复制实验测试。将计算数据与实验数据进行比较，以验证一种或两种建模技术，用于未来的研究。将使用经验证的建模技术与症状性膝关节模型，以研究无法在体外轻松研究的治疗方法和病理条件。拟议的研究将提供软骨退化如何影响胫骨结节转移的有效性的初步评估，并提供工具来收集额外的数据，这些数据可供整形外科医生根据个体患者的软骨损伤和发育不良计划手术。 公共卫生相关性： 项目叙述手术通常用于治疗与对线不良和软骨受损相关的膝盖骨后疼痛。拟议的研究将利用实验测试和计算建模来表征为卸载受损软骨区域而执行的手术技术的有效性。减少施加在软骨上的压力可以减轻疼痛。

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.