Evaluation of patient-specific cranial implant design using finite elemental analysis

BACKGROUND Various studies have investigated the load-bearing capacity of patient-specific cranial implants. However, little attention has been given to the evaluation of the design of ceramic-titanium (CeTi) implants. METHODS A biomechanical evaluation of 3 patient-specific cranial implants was performed using finite element analysis. RESULTS The results of the analyses allowed the identification of the implant regions as well as the magnitudes of the maximum stresses on, and displacements along, these regions after traumatic impact. The analyses also showed that polyether ether ketone cranial implants offer inferior brain and neurocranial protection due to their high flexibility and local peak stresses at the bone-screw interface. In contrast, CeTi implants were able to evenly distribute the stresses along the interface and thus reduced the risk of neurocranial fracture. The scaffold structure at the border of these implants reduced stress shielding and enhanced bone ingrowth. Moreover, brain injuries were less likely to occur, as the CeTi implant exhibits limited deflection. CONCLUSIONS From the finite element analyses, CeTi cranial implants appear less likely to induce calvarial fractures with a better potential to protect the brain under impact loads.