RESUMO
PURPOSE: This study examined the effect of the stem design and method of fixation on biomechanical features around a stem tip in revision total knee arthroplasty using finite analysis. MATERIALS AND METHODS: A 3D Finite element model was reconstructed for a CT scan of the normal tibia from a 26 year old male and the CAD model of total knee arthroplasty revision was developed. The design change in the stem such as the length, diameter, slot, press fit and coefficient of friction was performed. The contact pressure, von-Meises stress around the stem and the micromotion were evaluated. RESULTS: A longer length and larger diameter press fit stem significantly increased the contact pressure and stress at the end of stem. The distal slot reduces the contact pressure and stress at the end of stem. Less displacement between the tibial component and bone was noted in the increased coefficient of friction. CONCLUSION: A stem with shorter length sufficient to engage proximal diaphysis, a closer diameter of the proximal canal and a minimal press fit can be used to reduce the contact pressure and stress if the patient's surgical anatomy such as bone loss and quality is tolerable in revision total knee arthroplasty.