Method for translating 3D bone defects into personalized implants made by Additive Manufacturing

Abstract 3D printing technology penetrates into the medical field at an accelerated pace. Although there is still a long way to go towards organ printing, and despite existing ethical and technical changes, 3D printing can form three-dimensional support structures in a revolutionary and controllable way. 3D printing has penetrated into areas such as tissue and regenerative engineering. In clinical interventions, 3D printing, as a new prosthesis manufacturing technique, applies mainly to orthopaedics and dentistry. In this paper, the authors propose a method for translating 3D bone defects into personalized implants, to be further produced by AM (additive manufacturing) techniques, based on CT (computed tomography) imaging. The method consists of delimiting bone defect areas in computed tomography, isolation of defects, and the construction of a virtual implant model that is saved in the .stl format for 3D printing. If the bone defect is located in a symmetrical area in respect to a central plane, which is correct from the anatomical and medical point of view, the mirror image will be used as a virtual model for the implant. This ensures a very good imitation of the implant with the healthy area. If the bone defect area is singular, reconstruction is done with so-called “reconstruction pieces” made with CAD (computer-aided design) software and assembled in the 3D Slicer software so as to repair defects in the problematic area. The robustness and efficiency of the proposed method is demonstrated through numerical experiments and compared to experimental results for validation purposes.