Engineering firm TWI worked with metal powder technology company Metalysis to create Hip Replacements using "metal additive layer manufacturing" which uses tantalum powder, a metal which is bio-inert, to form a lattice structure with consistent strength and density. The powder is formed into solid structures using "selective laser melting" to fuse the tiny metal particles together with heat and the whole process is cost-competitive according to company.

Source: http://eandt.theiet.org/news/2016/feb/3d-printed-hip-replacement.cfm