A review on powder-bed fusion additive manufacturing for metallic fixation implants

The World Health Organization predicted that by 2020 trauma cases are going to be the main reason of death. Internal fixations “bone fixation plates” currently used to treat bone fractures present significant drawbacks that decrease the healthcare quality and increase its costs. Biocompatible metallic materials such as titanium and its alloys (e.g., Ti-6Al-4V) and 316L stainless steel are used for internal fixations. Current internal fixation drawbacks are: it requires pre-shaping to anatomically fit the patient (personalisation); a second surgery required to remove the implant with the possibility of bone refracture; if the implant remains in the body, metal toxicity/carcinogenic effects may occur; stress shielding possibility may increase due to the mechanical properties mismatch between the metallic implant and the native bone. This review presents an insight to address the mentioned limitations through additive manufacturing, and in particularly metallic powder bed fusion techniques. Different and successful cases aiming to personalise internal fixation implants and to minimise stress shielding are presented. On the other hand, for the metallic implant second surgery requirement and its possibly long-term toxicity, extensive ongoing research on different biodegradable materials are considered. Research future and challenges are also discussed.