Feasibility study on the acceleration and upscaling of bone ingrowth simulation

Abstract

Fixation of uncemented implants is known to be more problematic than cemented implants as the proces relies on the growth of bone into the porous implant surface. This bone growth determines the fixation of the implant and has been the subject of many investigations [1-6]. A literature survey [7] revealed that these models are either a highly detailed simulation of a small section of the interface between bone and implant or a more generalized simulation of a complete implant. This thesis is aimed at bridging the gap between the two. An investigation of the bone ingrowth model by Andreykiv [1] revealed possibilities of accelerating this simulation. Furthermore a feasibility study was performed to apply computational homogenization in order to upscale the results of the detailed microscopic model to a higher level. Investigation of the bone ingrowth model showed that it cannot be simplified. All elements of the model are essential in predicting the tissue growth within the system. A 65% gain in speed of the simulation was obtained by optimizing the code of the subroutines (written for MSC Marc). Furthermore the feasibility study on computational homogenization shows that the implementation in a commercial code leads to extremely long computing times. In light of these results it is concluded that homogenization is not the method to bridge the gap between the detailed microscopic simulations and the simulations of the complete implants. Recommendations are given on the continued research to use the results of the detailed simulation on a higher level.