CAE model of Total Knee Replacement with knee joint at standing position

Total Knee Replacement (TKR) is a permanent solution for arthritis in the knee joint; the infected knee is replaced with biocompatible components of TKR. After this surgery the patient can resume everyday activities with normal functioning of the knee.

Total Knee Replacement has three components- femoral component, bearing, and tibial component. These components are fixed to Femur and Tibia with a strong cement (Kanyal, 2020).

Finite element analysis or CAE analysis can be used to simulate the dynamics of TKR with knee joint. The CAE model of a posterior-stabilized, fixed bearing total knee prosthesis, PFC Sigma (De Puy, Johnson & Johnson, Leeds, UK) assembled along with Femur and Tibia bones is presented here.

Kanyal(2021) developed a CAD model for TKR components with knee joint which could be used to further develop a finite element model of the TRK components with knee joint, however, an already meshed CAE model is presented here representing the same CAD as Kanyal(2021) developed which will help to save time and effort; brick or hex meshing (meshing a solid with brick elements or hex elements) takes considerable time and effort. The bearing component is the most critical component in a TKR as it is prone to wear and therefore failure. Godest et al (2002), and Zelle et al (2009) also used hex elements to mesh bearing component in CAE analysis. Meshing of Femur bone, Tibia bone, and Femoral component is done with three noded tria elements, however the Tibial component is meshed with hex elements.
The meshing of TKR components, Femur and Tibia bones is executed in Hypermesh 13 (Altair Engineering, Inc., Troy, MI, USA). The CAE meshed model(cae.hm) can be opened in Hypermesh 13 (Altair Engineering, Inc., Troy, MI, USA) for further model development like defining material properties, section properties, contact definitions etc. , then it can be exported to a CAE solver as .inp file for analysis and post processing. All dimensions are in mm.

全膝关节置换术（TKR）是膝关节关节炎的永久性解决方案；感染膝关节被生物相容性的TKR组件所替代。手术之后，患者能够恢复日常活动，并实现膝关节的正常功能。
全膝关节置换术包含三个组件——股骨组件、关节面和胫骨组件。这些组件通过强固的粘合剂（Kanyal, 2020）固定于股骨和胫骨上。
有限元分析或计算机辅助工程分析可用于模拟膝关节的TKR动力学。在此，我们展示了由De Puy, Johnson & Johnson（英国利兹）制造的、后稳定型、固定关节面的全膝关节假体PFC Sigma（PFC Sigma）的CAE模型，该模型与股骨和胫骨骨骼组装在一起。
Kanyal（2021）开发了一个适用于TKR组件及其膝关节的CAD模型，该模型可用于进一步开发TKR组件及其膝关节的有限元模型。然而，此处展示了一个已网格化的CAE模型，代表了Kanyal（2021）开发的相同CAD，这将有助于节省时间和精力；砖形或六边形网格化（使用砖形或六边形元素对实体进行网格化）需要相当的时间和精力。在TKR中，关节面组件是最关键的组件，因为它容易磨损，因此也容易失效。Godest等人（2002年）和Zelle等人（2009年）也在CAE分析中使用了六边形元素对关节面组件进行网格化。股骨、胫骨和股骨组件的网格化采用三个节点的三角形元素进行，然而胫骨组件采用六边形元素进行网格化。
TKR组件、股骨和胫骨的网格化在Hypermesh 13（Altair Engineering, Inc.，美国密歇根州特洛伊）中执行。CAE网格化模型（cae.hm）可在Hypermesh 13（Altair Engineering, Inc.，美国密歇根州特洛伊）中打开，以进行进一步模型开发，如定义材料属性、截面属性、接触定义等，然后可以将其导出为.inp文件以进行分析和后处理。所有尺寸均以毫米为单位。