A Streamlined Algorithmic Process for Creating Three-dimensional Printed Forearm Casts

Three-dimensional (3D) printing is a rapidly evolving field that has found its way into the medical field, providing unsurpassed contributions to the provision of patient-centered care. Its utilization lies in optimizing preoperative planning, the creation and customization of surgical guides and implants, and the designing of models that can be used to augment patient counseling and education. We integrate a simple yet effective method of scanning the forearm using an iPad device with Xkelet software to obtain a 3D printable stereolithography file, which is then incorporated to our suggested algorithmic model for designing a 3D cast, utilizing Rhinocerus design software and Grasshopper plugin. The algorithm implements a stepwise process of retopologizing the mesh, division of the cast model, creating the base surface, applying proper clearance and thickness to the mold, and creating a lightweight structure through the addition of ventilation holes to the surface with a joint connector between the two plates. In our experience, scanning and design of the patient-specific forearm cast using Xkelet and Rhinocerus, alongside implementing an algorithmic model through Grasshopper plugin has dramatically reduced the designing process from 2 to 3 hours to 4-10 minutes, further increasing the number of patient scans that can be sequenced in a short duration. In this article, we introduce a streamlined algorithmic process for the use of 3D scanning and processing software to create forearm casts that are tailored to the patients' dimensions. We emphasize the implementation of computer-aided design software for a quicker and more accurate design process.