Improving personalized medical implant design: An innovative and automated method leveraging implicit modeling

Abstract

Advancements in manufacturing technologies have made the design and surgical applications of personalized implants increasingly popular and widespread. This study presents a fast, parametric, and automatic workflow for creating customized implants to be used in the surgical treatment of humerus bone traumas. The workflow operates on various humerus fractures, such as “Butterfly Fragment” fractures, taking into account patient-specific bone geometries and areas where screws will be applied. The workflow is carried out using implicit modelling and nTopology software. Initially, a replica of the “Butterfly Fragment” fracture is created for the study, and the damaged bone tissue is removed. Subsequently, a filler structure connecting the two main fragments is obtained using a porous structure. The workflow continues with the identification of areas where screws will be applied around the bone trauma and the selection of the surface where the implant will be created. Using selected points on the surface mesh and single-dimensional beams guided by these points, the external geometry and screw holes of the implant are shaped. The workflow is completed by offsetting certain structures created in intermediate steps and applying surface treatments to obtain the final shape and thickness of the implant, which is compatible with the bone structure. At the end of the process, the workflow is converted into a single function block, which can be shared for use by an implant designer. This enables the widespread application of personalized implant designs. The workflow accelerates the design process of the implant, providing implicit data suitable for production using additive manufacturing. This study offers a preparatory process for the rapid design and production of customized implants for patients. Future research may include comparisons of CAD design and implicit modelling methods, time studies, process modifications, optimizations, and investigations related to additive manufacturing printers. This study contributes to shortening the time until the application of surgical treatment methods by accelerating the design and production process of customized implants.