Effect of Geometrical Designs on Mechanics of Unicompartmental Knee Arthroplasty (UKA): A Finite Element Study

Abstract

— Unicompartmental knee arthroplasty (UKA) is a surgical method used to treat osteoarthritis in one portion of the knee, most often the medial compartment. UKA supporters argued that the procedure more closely replicates natural knee kinematics, results in reduced perioperative morbidity and intraoperative blood loss, and allows for quicker mobility and rehabilitation than traditional bicondylar knee arthroplasty. The goal of this study is to look at the impact of implant design on the mechanics of unicompartmental knee arthroplasty (UKA). 3D models of the UKA implant were modified from three different design of off-the-shelf total knee arthroplasty (TKA) implants. Then, finite element analysis was performed to investigate the influence of implant geometrical design on stress distribution and deformation in polyethylene (PE) inserts. This study revealed that the implant design significantly affects the stress distribution and deformation of tibial insert and varies with the joint angle. Keywords—Deformation, polyethylene (PE) insert, stress distribution, Unicompartmental knee arthroplasty