Form follows function: a computational simulation exercise on bone shape forming and conservation

The present paper explores whether the shape of long bone shafts can be explained as a mere result of mechano-adapation. A computer simulation study was conducted in order to investigate adaptation processes of bone-like structures under load patterns comparable to those acting on the diaphysis of long bones. The aim of the study was to have a deeper look into the relationship between typical loading patterns and resulting bone shape and structure. The simulations are based on a mechanistic model approach for mechano-transduction and bone transformation. Results of the simulations are that axial torsion around the long axis is important for the evolvement and maintenance of tube-like structures. Of note such structures can form from a variety of starting geometries, provided that axial torsion is present. The selection of the set-point parameter for the regulation of load adapted bone transformation has an impact on the final structure as well. In conclusion, the present study confirms the mechanical environment's potential to generate shaft-like structures and demonstrates the respective boundary conditions.