A proposal for the definition of anatomical reference systems for the bones of the foot and ankle complex

This study proposes a new method for the definition of anatomical reference system (ARS) for the bones of foot and ankle based on morphological and functional criteria, meant for the 3D description of the foot posture. The method shows high inter- and intra-operator precision (<1° and <1mm), providing a 3D characterization of the foot arches, which agrees with standard planar measures. Clinically sound ARS are needed to fully exploit the recent advances in the 3D description of the foot posture made possible by weight-bearing CT.