Computationally Efficient Finite Element Evaluation of Natural Patellofemoral Mechanics
Computationally Efficient Finite Element Evaluation of Natural Patellofemoral Mechanics
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DOI：
10.1115/1.4002854
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发表时间：
2010-12-01
影响因子：
1.7
通讯作者：
Rullkoetter, Paul J.
中科院分区：
文献类型：
--
作者：
Fitzpatrick, Clare K.;Baldwin, Mark A.;Rullkoetter, Paul J.
有限元方法已被应用于评估体内关节行为、新设备和手术技术，但通常只应用于小型或单一受试者队列。解剖学变异性需要使用许多特定于受试者的模型或概率方法，以便对人群的设备或程序进行充分评估。然而，一个完全可变形的有限元模型在计算上可能是昂贵的，禁止大型多主体或概率分析。本研究的目的是开发一组特定受试者的髌股关节模型，并评估分析时间和准确性与完全可变形和刚体关节软骨表征之间的权衡。在模拟的深弯曲循环中，使用8个受试者的有限元模型来调整压力-过闭关系。髌骨运动学和接触力学进行了评估，并在完全变形和刚体分析之间进行了比较。另外8名受试者被用来确定刚体压力-过闭关系作为独立于受试者的参数的有效性。在调整组和测试组的变形分析和刚性分析之间，预测的运动学和接触力学有很好的一致性。在整个屈曲过程中，两组的运动学均方根差异均小于0.5度和0.2毫米。在接触面积、峰值和平均接触压力方面，调音组的平均差异分别为5.4%、9.6%和3.8%，试验组的平均差异为6.9%、13.1%和6.4%，两组之间无显著差异。与变形分析相比，刚体分析的计算时间减少了95%。从髌股分析得出的调整压力-过闭合关系也应用于8名受试者的胫股关节软骨。在胫股关节的刚性和可变形分析中，接触面积、峰值和平均接触压力的差异分别为8.3%、11.2%和5.7%。由于统计、概率和优化技术可能需要数百到数千次分析，因此可行的平台对于组件评估或临床应用至关重要。本研究中描述的计算效率高的刚体平台可以与统计和概率方法相结合，在了解特定受试者或群体的体内关节力学方面具有潜在的临床应用。(DOI: 10.1115/1.4002854)
Finite element methods have been applied to evaluate in vivo joint behavior, new devices, and surgical techniques but have typically been applied to a small or single subject cohort. Anatomic variability necessitates the use of many subject-specific models or probabilistic methods in order to adequately evaluate a device or procedure for a population. However, a fully deformable finite element model can be computationally expensive, prohibiting large multisubject or probabilistic analyses. The aim of this study was to develop a group of subject-specific models of the patellofemoral joint and evaluate trade-offs in analysis time and accuracy with fully deformable and rigid body articular cartilage representations. Finite element models of eight subjects were used to tune a pressure-overclosure relationship during a simulated deep flexion cycle. Patellofemoral kinematics and contact mechanics were evaluated and compared between a fully deformable and a rigid body analysis. Additional eight subjects were used to determine the validity of the rigid body pressure-overclosure relationship as a subject-independent parameter. There was good agreement in predicted kinematics and contact mechanics between deformable and rigid analyses for both the tuned and test groups. Root mean square differences in kinematics were less than 0.5 deg and 0.2 mm for both groups throughout flexion. Differences in contact area and peak and average contact pressures averaged 5.4%, 9.6%, and 3.8%, respectively, for the tuned group and 6.9%, 13.1%, and 6.4%, respectively, for the test group, with no significant differences between the two groups. There was a 95% reduction in computational time with the rigid body analysis as compared with the deformable analysis. The tuned pressure-overclosure relationship derived from the patellofemoral analysis was also applied to tibiofemoral (TF) articular cartilage in a group of eight subjects. Differences in contact area and peak and average contact pressures averaged 8.3%, 11.2%, and 5.7% between rigid and deformable analyses in the tibiofemoral joint. As statistical, probabilistic, and optimization techniques can require hundreds to thousands of analyses, a viable platform is crucial to component evaluation or clinical applications. The computationally efficient rigid body platform described in this study may be integrated with statistical and probabilistic methods and has potential clinical application in understanding in vivo joint mechanics on a subject-specific or population basis. [DOI: 10.1115/1.4002854]