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

项目总结/摘要 复发性髌骨不稳定患者最常见的两种稳定手术是 重建内侧髌股韧带（MPFL）和胫骨结节内侧化。MPFL 由于胫骨粗隆的技术要求，重建越来越受欢迎 与截骨术中骨愈合相关的重新排列和问题。在重度滋养层发育不良的病例中， 和/或胫骨结节明显偏侧，根据当前标准拉紧MPFL移植物 可能无法提供足够的阻力来限制导致持续不稳定的外侧髌骨轨迹。 增加移植物张力可使内侧髌股软骨超负荷。拟议的研究是基于 假设MPFL重建有效限制外侧髌骨轨迹不良的能力随着 胫骨粗隆发育不良和胫骨粗隆外侧位置增加。计算动态模拟 将进行膝关节功能的评估，以建立胫骨结节内移的解剖标准 比MPFL重建更可能限制髌骨轨迹不良，而不会使髌股关节过载 软骨第一个具体目标是通过计算复制外侧髌骨轨迹不良和施加的压力 髌骨不稳定患者的功能过程中的软骨。多体动力学膝关节模型 代表因复发性髌骨不稳定而接受治疗的患者将基于3D重建， 核磁共振扫描。建模技术将骨骼和软骨表面视为具有赫兹的刚体 接触决定接触力并引导关节运动。将使用离散元分析技术 以基于软骨表面的重叠来表征接触压力模式。模特们将分别 通过将输出与体内数据进行比较进行验证。体内数据的来源将是计算性的 基于由提供成像数据的患者执行的运动来重建体内功能 用于模型开发。第二个具体目标将是计算表征的影响， 手术稳定对个体患者膝关节功能的影响。MPFL重建和胫骨粗隆 将模拟内侧化，每个内侧化都具有手术参数的变化。真正的外科手术 将模拟对患者进行的手术，并将对横向跟踪的影响与体内结果进行比较 来验证外科手术的代表性。第三个具体目标将是比较手术 髌股解剖结构的功能选项。髌骨轨迹和压力的变化 将比较MPFL重建和结节内侧化之间的软骨。此外，技术 将开发参数化改变模型内的转子骨发育不良和结节偏侧化。 将在不同解剖结构的情况下进行模拟，以设定每种手术选项的限制范围 髌骨轨迹不良，但接触压力不升高。该建模系统将可用于未来 研究涉及与髌骨不稳定相关的其他手术选择和解剖参数。

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.