Topology optimization for the control of load transfer at the bone-implant interface: a preliminary numerical study

International audience; The numerical approach of topological optimization allows determining the optimal distribution of the material in a given volume in the function of an objective. This approach has recently regained interest thanks to the development of additive manufacturing, which makes it possible to manufacture its resulting parts with complex geometries. In the biomedical field, this numerical approach can also improve the performance of medical devices. Most of the time, the objective of topological optimization is to maximize the stiffness of the considered part while reducing its mass or volume. For example, this criterion has been applied for the optmisation of craniofacial reconstruction prosthesis (Al-tamimi et al. 2017). Some studies have integrated biomechanical considerations in the form of geometrical constraints in taking into account anatomical areas to be avoided (Sutradhar et al. 2016).To our knowledge, no study considers the phenomenon of “stress-shielding” between the bone and the implant in its optimization process. In this work, the originality is the optimization approach which does not only consider the mechanical characteristics of the optimized part (such as its stiffness) but also the mechanical characteristics of the surrounding bone. Thus, it involves specifically taking into account the mechanical behavior of the surrounding bone to topologically optimize the geometry of the medical device and improve the load transfer between the bone and the implant. For that, a numerical simplified Finite Element (FE) model is developed in this paper with a simplified geometry to highlight the possibility of controlling the load transfer bone and implant.