Computer-Aided Engineering Resources and FEM for Biodevices - Advanced Design and Manufacturing Technologies for Biomedical Devices - page 155

Fig. 8.13 FEM simulation of cardiac tissue heating during thermal ablation process for treating
mitral valve insufficiency and different aneurysms. Temperature results for t = 1 s, t = 5 s, t = 10 s,
and t = 15 s to assess and prepare the typical surgical treatment

8.5 Simulating the Interaction Between Prostheses

and Biological Tissues

8.5.1 Case Study: Interaction Between Artificial Prosthesis

and Hard Tissue

The prosthesis and femur already analyzed in Sects. 8.3.2 and 8.4.2 are now assem-
bled and analyzed together under static loading. It is relevant to carry out this kind
of studies, especially in the case of personalized prostheses, as in some cases, the
remaining bones or biological structures can extremely suffer, when the prostheses
are loaded. Also common is the stress-shielding phenomenon, based on the different
stiffness between prosthesis and bone, which promotes nonuniform loading of the
bone and resorption in the less-loaded parts (Ojeda Diaz et al. 2009 ).
Figure 8.14 shows the FEM model of the assembly, similar to previous ones, just
including a contact boundary condition between bone and prosthesis and a load of
1,200 N. Results from displacements and stresses are also included. It is relevant to
note that the contact between prosthesis and bone is not homogeneously loaded,
which can promote stress shielding, even though the maximum stress of 80 MPa in
the prosthesis and 30 MPa in the bone are, in principle, adequate.