三次元プリントカスタムインプラントの整形外科手術への応用

The goal of this protocol is to outline the clinical and technical workflow for the use of custom three-dimensional (3D) printed implants in orthopaedic surgery, particularly in cases of complex bone loss or deformity where standard implants are insufficient. While 3D printing has gained broad medical applications, its role in orthopaedics is especially transformative for patients with pathologies that lack conventional surgical solutions. This manuscript details the step-by-step process, from initial patient evaluation and decision-making to implant design, fabrication, and surgical implantation. Key considerations include patient selection, establishing clear expectations, and engaging in collaborative design with biomedical engineers to ensure optimal implant fit and functionality. The protocol emphasizes the critical role of high-resolution CT imaging, precise computer-aided design (CAD), and advanced manufacturing techniques such as powder bed fusion for metal implants. Post-processing steps, including heat treatment, electrical discharge machining, and surface finishing, are also discussed to highlight quality assurance in implant production. Despite promising early results and the potential for improved outcomes, the use of 3D printed implants remains limited due to elevated initial costs, lack of long-term outcome data, and the individualized nature of each case. Nevertheless, their application offers significant advantages in customization, surgical planning, and functional restoration, underscoring the need for continued research and refinement. This protocol serves as a guide for clinicians considering the integration of 3D printed custom implants into their orthopaedic practice, aiming to expand treatment possibilities for patients with complex reconstructive needs.