Computational Simulation of Dynamic Motion for Knees with Patellar Instability to Compare MPFL Reconstruction to Tibial Tuberosity Medialization as a Function of Knee Anatomy

项目摘要/摘要 复发性髌骨不稳患者最常用的两种稳定方法是 重建内侧髌股韧带(MPFL)和胫骨粗隆内化。MPFL 重建术越来越受欢迎，这在很大程度上是由于胫骨结节的技术要求 与截骨术中的骨愈合有关的重新调整和关注。重度滑车发育不良病例 和/或明显偏侧的胫骨结节，根据当前标准张力的MPFL移植物 可能不能提供足够的抵抗力来限制导致持续不稳定的外侧髌骨追踪。 移植物张力增加会使内侧髌股软骨超载。建议的研究是基于 假设MPFL重建有效地限制外侧髌骨跟踪不良的能力降低为 滑车发育不良和胫骨粗隆外侧位置增加。计算动态仿真 将进行膝关节功能检查，以建立胫骨结节中性化的解剖学标准 比MPFL重建术更有可能在不超负荷的情况下限制髌骨跟踪不良 软骨。第一个特别的目标是计算复制外侧的膝盖骨错位和施加的压力。 对于正在接受治疗的髌骨不稳定患者，在功能过程中对软骨的影响。膝关节多体动力学模型 代表正在接受治疗的复发性髌骨不稳定的患者将基于从 核磁共振扫描。该建模技术将骨骼和软骨表面视为刚体，采用Hertzian方法 接触决定接触力并引导关节运动。将使用离散元素分析技术 描述基于软骨表面重叠的接触压力模式。模特们将单独 通过将输出与体内数据进行比较进行了验证。体内数据的来源将是计算性的 基于提供成像数据的患者进行的运动重建活体功能 用于模型开发。第二个具体目标将是通过计算来表征 个体化手术对膝关节功能的影响。MPFL重建与胫骨粗隆 将模拟每种手术参数不同的介入化。实际的外科手术程序 对患者进行模拟，并与活体结果进行横向跟踪的影响比较 以验证手术程序的代表性。第三个具体目标将是比较外科手术 作为髌股解剖功能的选项。髌骨轨迹和压力的变化应用于 我们将对MPFL重建和结节中性化的软骨进行比较。此外，技术 为了在参数上改变滑车发育不良和结节，将在模型内建立偏侧化。 模拟将在改变解剖结构的同时进行，以设置每个手术方案可以限制的范围 在不增加接触压力的情况下，膝盖骨错位。建模系统将在未来可用 研究涉及其他手术选择和与髌骨不稳定相关的解剖参数。

Project Summary/Abstract The two most common stabilization procedures for patients with recurrent patellar instability are reconstruction of the medial patellofemoral ligament (MPFL) and medialization of the tibial tuberosity. MPFL reconstruction has been growing in popularity, due in large part to the technical demands of tibial tuberosity realignment and concerns related to bone healing across the osteotomy. In cases of severe trochlear dysplasia and/or a dramatically lateralized tibial tuberosity, an MPFL graft tensioned according to current standards may not provide sufficient resistance to limit lateral patellar tracking that causes continued instability. Increasing graft tension could overload medial patellofemoral cartilage. The proposed study is based on the hypothesis that the ability of MPFL reconstruction to effectively limit lateral patellar maltracking decreases as trochlear dysplasia and the lateral position of the tibial tuberosity increase. Computational dynamic simulation of knee function will be performed to establish anatomical standards for which tibial tuberosity medialization is more likely than MPFL reconstruction to limit patellar maltracking without overloading patellofemoral cartilage. The first specific aim is to computationally replicate lateral patellar maltracking and pressure applied to cartilage during function for patients being treated for patellar instability. Multibody dynamics knee models representing patients being treated for recurrent patellar instability will be based on 3D reconstructions from MRI scans. The modeling technique treats the bones and cartilage surfaces as rigid bodies with Hertzian contact determining contact forces and guiding joint motion. Discrete element analysis techniques will be used to characterize contact pressure patterns based on overlap of cartilage surfaces. Models will be individually validated by comparing output to in vivo data. The source of the in vivo data will be computational reconstruction of in vivo function based on motions performed by the patients who provide the imaging data for model development. The second specific aim will be to computationally characterize the influence of surgical stabilization on knee function for individual patients. MPFL reconstruction and tibial tuberosity medialization, each with variations in surgical parameters, will be simulated. The actual surgical procedures performed on the patients will be simulated, with the influence on lateral tracking compared to in vivo results to validate the representation of the surgical procedures. The third specific aim will be to compare surgical options as a function of patellofemoral anatomy. Variations in patellar tracking and pressure applied to cartilage will be compared between MPFL reconstruction and tuberosity medialization. In addition, techniques to parametrically alter trochlear dysplasia and tuberosity lateralization within the models will be developed. Simulations will be performed while varying anatomy to set ranges over which each surgical option can limit patellar maltracking without elevating contact pressures. The modeling system will be available for future studies addressing additional surgical options and anatomical parameters related to patellar instability.