Department of Biomechanics, Hospital for Special Surgery, New York, New York, USA.
Department of Foot and Ankle Surgery, Hospital for Special Surgery, New York, New York, USA.
J Orthop Res. 2021 Jan;39(1):103-111. doi: 10.1002/jor.24876. Epub 2020 Oct 20.
Finite element (FE) models to evaluate the burden placed on the interaction between total ankle arthroplasty (TAA) implants and the bone often rely on peak axial forces. However, the loading environment of the ankle is complex, and it is unclear whether peak axial forces represent a challenging scenario for the interaction between the implant and the bone. Our goal was to determine how the loads and the design of the fixation of the tibial component of TAA impact the interaction between the implant and the bone. To this end, we developed a framework that integrated robotic cadaveric simulations to determine the ankle kinematics, musculoskeletal models to determine the ankle joint loads, and FE models to evaluate the interaction between TAA and the bone. We compared the bone-implant micromotion and the risk of bone failure of three common fixation designs for the tibial component of TAA: spikes, a stem, and a keel. We found that the most critical conditions for the interaction between the implant and the bone were dependent on the specimen and the fixation design, but always involved submaximal forces and large moments. We also found that while the fixation design influenced the distribution and the peak value of bone-implant micromotion, the amount of bone at risk of failure was specimen dependent. To account for the most critical conditions for the interaction between the implant and the bone, our results support simulating multiple specimens under complex loading profiles that include multiaxial moments and span entire activity cycles.
有限元（FE）模型用于评估全踝关节置换（TAA）植入物与骨骼相互作用的负担，通常依赖于峰值轴向力。然而，踝关节的受力环境很复杂，目前尚不清楚峰值轴向力是否代表了植入物与骨骼相互作用的具有挑战性的情况。我们的目标是确定 TAA 胫骨组件的负载和固定设计如何影响植入物与骨骼之间的相互作用。为此，我们开发了一个框架，该框架集成了机器人尸体模拟以确定踝关节运动学，肌肉骨骼模型以确定踝关节的载荷，以及有限元模型以评估 TAA 与骨骼之间的相互作用。我们比较了三种常见的 TAA 胫骨组件固定设计（钉，柄和龙骨）的骨-植入物微动和骨失效风险。我们发现，植入物与骨骼相互作用的最关键条件取决于标本和固定设计，但始终涉及亚最大力和大扭矩。我们还发现，尽管固定设计会影响骨-植入物微动的分布和峰值，但有风险发生骨折的骨质量取决于标本。为了考虑到植入物与骨骼相互作用的最关键条件，我们的结果支持模拟多个标本在包括多轴力矩和跨越整个活动周期的复杂加载情况下的情况。
