Influences of the temporal nature of the applied load and the tibial baseplate material on the stress distribution in a three‐dimensional model of the human knee joint containing a prosthetic replacement

Abstract

The finite element analysis method was used to determine the stresses in all sections of a three‐dimensional model of the proximal section of the human knee joint into which was cemented two parts of a total knee joint replacement (the tibial tray and the tibial baseplate), fully constrained at its distal end, and subjected to a total compressive joint force of 2 kN acting on points corresponding to the condyles. When the mean values of these stresses were computed for all sections of the model, two important trends were seen. First, when the load was applied dynamically, the stresses were between 1 and 20% different than when it acted quasi‐statically. Second, regardless of how the load was applied, the stresses when the tibial baseplate was considered fabricated from ultra‐high‐molecular‐weight polyethylene ranged from about 40% lower to about 320% higher compared to when Ti–13Nb–13Zr alloy was used. The significance of these findings as well as the limitations of the study are discussed.