Design, finite element analysis (FEA), and fabrication of custom titanium alloy cranial implant using electron beam melting additive manufacturing

Abstract

Skull defect reconstruction is one of the most difficult challenges faced by the surgeons because of the complex shape of the skull. Skull defects are dramati-cally increasing with the increase in road accidents, tumors, and wars, thereby increasing the demand for reconstruction of skull. It is difficult to manufac-ture standard implants for skull defects especially for large and complex de-fects, due to the complexity and the difference in anatomy of skulls. Design and fabrication of custom cranial implant is required in these cases. The con-ventional technologies face multiple challenges in fabricating lightweight custom cranial implants closer to that of bone in terms of weight; the differ-ence in the weight introduces stress-shielding effects onto the surrounding bone. In order to overcome this problem, several researches proposed lattice structure implants fabricated by additive manufacturing. However, lattice structure implants are difficult to remove later when some problems are encountered. This paper presents a methodology of design analysis and fabri-cation of solid lightweight custom cranial implant using additive manufactur-ing. A Case study is presented where, a custom cranial implant is designed and analysed using finite element analysis (FEA) and then fabricated using electron beam melting (EBM) additive manufacturing. The titanium alloy Ti6Al4V which is biocompatible and non-toxic is used as the implant materi-al. The functionality, fitting, and aesthetic of the proposed design are evaluat-ed. The results show the successful fabrication of thin custom cranial implant for skull defect reconstruction via EBM technology. The fabricated implant has sufficient strength, weight close to the weight of the removed bone por-tion while maintaining a good fit and aesthetics.