Additive Manufacturing of Titanium Alloys for Orthopedic Applications: A Materials Science Viewpoint

Titanium-based orthopedic implants are increasingly being fabricated using additive manufacturing (AM) processes such as selective laser melting (SLM), direct laser deposition (DLD), and electron beam melting (EBM). These techniques have the potential to not only produce implants with properties comparable to conventionally manufactured implants, but also improve on standard implant models. These models can be customized for individual patients using medical data, and design features, such as latticing, hierarchical scaffolds, or features to complement patient anatomy, can be added using AM to produce highly functional patient-anatomy-specific implants. Alloying prospects made possible through AM allow for the production of Ti-based parts with compositions designed to reduce modulus and stress shielding while improving bone fixation and formation. The design-to-process lead time can be drastically shortened using AM and associated post-processing, making possible the production of tailored implants for individual patients. This review examines the process and product characteristics of the three major metallic AM techniques and assesses the potential for these in the increased global uptake of AM in orthopedic implant fabrication.