Higher stress load in the lateral compartment after over-corrected UKA compared with HTO: a 3d-finite-element analysis

Abstract

Abstract Background The purpose of this study was to utilize a 3D finite-element(FE)model to analyze why there are differences in stress distribution in the knee joint between unicompartmental knee replacement༈UKA༉and high tibial osteotomy༈HTO༉ under the same force line. Methods The stress of the lateral meniscus, tibial plateau and inferior tibial plateau bone in healthy, OA, standard UKA, overcorrected UKA and HTO were assessed using FE models. In terms of stress load, standing is simulated by applying vertical static load, and then the stress distribution of knee joints in each group is compared. Results The results showed that the overcorrected UKA had significantly higher stresses in the lateral meniscus, lateral tibial plateau and below the plateau compared to the HTO. Also, the stress distribution in the knee joint after HTO is closer to that of a healthy knee due to the bridging effect of the lateral tibial Tomofix plate. Conclusion In general, when the lower limb force lines in UKA are corrected to the same level as in HTO, the stress distribution in the knee joint in HTO is close to physiological due to the bridging effect of the Tomofix plate. In contrast, the stresses on the lateral compartment of the UKA are significantly higher and more prone to lateral compartment OA.