Mechanical assessment of lower-limb prosthetic sockets after printing-path optimization

A conventional way to design and manufacture prosthetic sockets is labor-intensive and time-consuming, as such products are tailored to individual users. Achieving the desired and comfortable fit relies on a prosthetist's expertise and a patient's feedback. To digitalize this process, computer aided design (CAD) methods have been used recently to design the prosthetic socket while novel manufacturing methods such as Additive Manufacturing (AM) have been employed to increase time efficiency. Mechanical performance of products manufactured with this approach is still not fully understood. In this study, above-knee prosthetic sockets were printed with a material-extrusion 3D printing technique using various printing paths with an increased inter-layer contact area. Compliance of AM PLA prosthetic sockets to safety regulations, as described in the BS EN ISO 10328:2006, was achieved, while at the same time the conventional path sockets were outperformed. Understanding the material behavior at the inter-layer bond is a step towards reduced manufacturing times and increased mechanical performance.