Finite Element Modelling of Rheological Property of Curing PMMA Bone Cement. Part 1 - Effect of Prosthesis Insertion Velocity

PMMA (Polymethyl methacrylate) bone cement is currently the only material used for anchoring cemented arthroplasties to contiguous bones. The aim of this work is to model the flow of bone cement through porous cancellous bone to study the degree of penetration in total hip replacement using FIDAP simulation software. Two different viscosity models have been used (a) power law with constant consistency index and power law index less than 1 for pseudoplastic behaviour of Simplex P® and Zimmer bone cement; (b) FORTRAN subroutine for time dependent rheopectic behaviour of CMW3 and Zimmer bone cement. For each type of bone cement the effect of prosthesis insertion velocity have been investigated under four different values 5, 10, 15 and 20 mm/s. It has been observed that the depth of penetration increases with increasing prosthesis insertion velocity. On the other hand, the maximum pressure in bone cement decreases with increasing prosthesis insertion velocity. It has been observed that there is more penetration through cancellous bone for pseudoplastic behaviour than rheopectic behaviour of bone cement.