Impact FEA simulation and analysis of custom-made cranial implants

Abstract

Cranioplasty is a surgical procedure used to repair cranial defects left behind after injury or previous surgeries. Postoperative results of cranioplasty have been drastically improved with the usage of custom made cranial implants, which can replicate the missing bone almost identical in shape. Materials used for these custom implants vary depending on the used technology. Additive manufactured implants are generally made with metal alloys powders. The present research conducts a Finite Element Analysis study in regard to modification of intracranial pressure conditions, in normal range between 7 mm Hg to 15 mm Hg, in four impact stress scenarios of fixed custom cranial implants. Two new cranial implant concepts are proposed by the authors, one with a sliding system and one with osteointegrating structures. Stress scenarios aim at evaluating implant behaviour in critical conditions such as a person falling from a certain height or an object being dropped, generating an impact point on the surface of the implant. Deformations, displacements and equivalent strain were analysed. Scenarios 1, 2 and 4 provided results within the limit values for Von Misses stress and equivalent strain for both cranial implant concepts and both considered materials, Ta and Ti6Al4V. ICP values are in limits for all four stress scenarios, due to the small values of the implants’ deformations.