A Three-Dimensional Finite Element Analysis for the Stability of Tibial Plateau Prosthesis in Improved Unicompartmental Knee Arthroplasty

Background The primary treatment for end-stage unicompartmental knee osteoarthritis is unicompartmental knee arthroplasty. Reducing postoperative complications following unicompartmental knee arthroplasty has become a focal point of current research. Objective This study aimed to investigate the effects of stress magnitude and distribution on the tibial plateau prosthesis and tibial structure after conventional medial knee arthroplasty and modified surgery using finite element analysis. By comparing the two surgical methods, the advantages and feasibility of the modified surgery were evaluated. Method Models of unicompartmental knee arthroplasty with a fixed platform were constructed using Workbench 18.2 software, including models without fixed columns, models with fixed columns, and models with fixed columns and bone cement. To restore the normal physiological structure of the knee joint to a greater extent, the posterior inclination angle of the tibial fixation platform prosthesis was set to 5°. A vertical downward load of 1000 N was applied to the center of the tibial surface of the three models. The stress data of the tibial fixation platform prosthesis and the tibia under the prosthesis were observed and compared in each model. Result When there is a cement pile under the fixed platform column, the von Mises stress, first principal stress, and strain of the tibia are all lower than the other two cases. Therefore, the tibia with bone cement piles has less deformation and is more stable under stress compared to the other two structures of the tibia.