BONE REMODELING ADJACENT TO INTRAMEDULLARY STEMS - AN OPTIMAL STRUCTURES APPROACH

The internal parameters in bone remodelling theories often are not cle arly related to the bony structure which results from the simulations in which they are implemented. For a restricted class of bone remodell ing theories, we have previously found a connection between overall st ructural optimization and the parameters within a continuum-level remo delling rule. In this study, we assess whether a simplified analytical formula based on structural optimization can predict the behaviour of a large-scale finite element bone remodelling simulation. The analyti cal formula predicts when bone will remain around an intramedullary im plant. The predictions of the formula are borne out in the numerical r esults. This leads to a physical interpretation of one of the two para meters in the remodelling rule used. The results also show some charac teristics which are clinically relevant. This study extends earlier re sults due to Huiskes for internal remodelling around intramedullary im plants by using a different, numerically stable remodelling algorithm based on optimization. The study also shows a direct practical applica tion of the optimizing remodelling theory the authors have developed p reviously.