Indications: Didactical use of 3D printing, surgical didactical use, surgical planning, patient information, custom-made prosthesis, spacer and template, external prosthesis, cast

Recently developed 3D technologies give some relevant advantages in complex orthopedic surgery: a more accurate preoperative evaluation of the margins of tumor resection and of the relationship with noble structures or pelvic organs, and a new instrument to simulate surgery with colleagues and to explain the surgical procedure to the patient. 3D technologies permit to design and realize patient-specific cutting guides, to simulate surgical navigation over a previous planning and intraoperatively navigate the tumor resection or a corrective osteotomy, or to guide the implantation of a custom-made prosthesis. 3D printing of custom-made implants for the reconstruction is the more advanced feature of these technologies. Theoretically any anatomical site could be reconstructed with 3D custom implants, but the pelvis is the most frequently replaced because of its anatomic peculiarity, the duration of surgery, and the difficulty to obtain stable and long-lasting reconstructions. 3D customizing is an innovative and expanding field in orthopedic surgery and orthopediconcology, and especially in pelvic surgery. Preoperative study, resection, intraoperative navigation and custom-made implants are nowadays viable options for selected orthopedic conditions.