3D printing This is a first in Switzerland: a surgical technique using 3D printing is notably employed in orthopaedics to implant an ankle prosthesis. This is a complex operation. To position the prosthetic implant, the surgeon must make cuts into the bone with extreme precision. The method used at HUG consists in creating a three-dimensional reproduction of the bones in advance, based on scans of the joint to be operated, in order to simulate the ideal location of the prosthesis. Positioning guides are then printed in 3D and subsequently used during the surgery. These pieces are unique and produced with millimetre accuracy. As each phase of the procedure is planned, the operating time is shortened, as is the duration of the anaesthesia. Recovery is faster.