Abstract：
Computational studies of total knee arthroplasty (TKA) often focus on either joint mechanics (kinematics and forces) or implant fixation mechanics. However, such disconnect between joint and fixation mechanics hinders our understanding of overall TKA biomechanical function by preventing identification of key relationships between these two levels of TKA mechanics. We developed a computational workflow to holistically assess TKA biomechanics by integrating musculoskeletal and finite element (FE) models. For our initial study using the workflow, we investigated how tibiofemoral contact mechanics affected the risk of failure due to debonding at the implant-cement interface using the four available subjects from the Grand Challenge Competitions to Predict In Vivo Knee Loads. We used a musculoskeletal model with a 12 degrees-of-freedom knee joint to simulate the stance phase of gait for each subject. The computed tibiofemoral joint forces at each node in contact were direct inputs to FE simulations of the same subjects. We found that the peak risk of failure did not coincide with the peak joint forces or the extreme tibiofemoral contact positions. Moreover, despite the consistency of joint forces across subjects, we observed important variability in the profile of the risk of failure during gait. Thus, by a combined evaluation of the joint and implant fixation mechanics of TKA, we could identify subject-specific effects of joint kinematics and forces on implant fixation that would otherwise have gone unnoticed. We intend to apply our workflow to evaluate the impact of implant alignment and design on TKA biomechanics.
摘要：
全膝关节置换术（TKA）的计算研究通常集中在关节力学（运动学和力）或植入物固定力学上。然而,关节和固定力学之间的这种脱节阻碍了我们对TKA整体生物力学功能的理解，因为我们无法识别这两个级别的TKA力学之间的关键关系。我们开发了一个计算工作流程，通过整合肌肉骨骼和有限元（FE）模型来全面评估TKA生物力学。对于我们使用工作流程的初始研究，我们研究了胫骨股接触力学如何影响植入物-水泥界面脱粘失败的风险，使用大型挑战赛中的四名受试者来预测体内膝关节负荷。我们使用具有12自由度膝关节的肌肉骨骼模型来模拟每个受试者的步态姿势阶段。在每个接触节点处计算出的胫骨股关节力直接输入到同一受试者的FE模拟中。我们发现，失败的峰值风险与关节力的峰值或极端的胫骨股接触位置并不一致。此外，尽管不同学科的联合力量是一致的，我们观察到步态过程中失败风险的重要变异性.因此，通过对TKA的关节和植入物固定力学的综合评估，我们可以确定关节运动学和力对植入物固定的受试者特定影响，否则这些影响不会被注意到。我们打算应用我们的工作流程来评估植入物对齐和设计对TKA生物力学的影响。
