Ralph Mobbs, a neurosurgeon at the Prince of Wales Hospital in Sydney, made medical history in late 2015 when he successfully replaced two vertebrae with perfect 3D printed replicas of the patient's top two vertebrae made out of titanium. The patient, in his 60s, suffered from Chordoma, a particularly nasty form of cancer that had formed on his top two vertebrae and threatened to cinch off his spinal cord as it grew. That would have left him a quadriplegic.
http://www.engadget.com/2016/02/25/doctors-implant-3d-printed-vertebrae-in-worlds-first-surgery/
http://www.engadget.com/2016/02/25/doctors-implant-3d-printed-vertebrae-in-worlds-first-surgery/