Additive Manufacturing of Custom-made Cranial PEEK Implant and Postoperative Evaluation

Abstract

For cases where standard implant solutions are insufficient, additively produced patient-specific implants are developed. The steps to obtain a correct patient-specific implant require knowledge of medical and engineering sciences, thus doctor-engineer cooperation. This study aimed to create a personalized implant design using the fused layer modeling/manufacturing (FLM) additive manufacturing technique for bilateral cranial defect and implant fabrication. Medical image processing software is allowed to the design engineer to convert computed tomography of the patient into 3D models. For surgery planning, 3D anatomical models of the patient were printed using SLA technology. Adopting the design per the additive manufacturing rules, the implant design was made through medical-certified software. Determined technical requirements, such as the mechanical behavior of the material after application, the region's biological requirements, and the material's manufacturability with the selected AM technology, have been  key points for selection of the additive manufacturing technology-material combination. According to these, the implant was produced from polyetheretherketone (PEEK) material using FLM technology. As a recently emerging technique in the biomedical field, printing off-the-shelf, medical-grade PEEK material requires optimization of process parameters. Studies have been done and a comparative analysis has been made between digital and physical implant models. After implantation, clinical experience was reported, and radiological results were evaluated.