Additive manufacturing of lower-limb prosthetic sockets: a scoping review with a focus on multi-material approaches.

Abstract

Purpose: Additive manufacturing (AM) is increasingly applied to lower-limb prosthetic sockets, offering faster production, lower cost, and improved customisation. Multi-material additive manufacturing (MMAM) enables rigid and flexible regions to be combined in one socket, potentially improving load distribution and user comfort. However, research on MMAM remains limited and distributed across engineering, biomechanical, and clinical research. Materials and Methods: A scoping review was conducted following PRISMA-ScR guidelines. Five databases (PubMed, Scopus, IEEE Xplore, Web of Science, and EBSCO) were searched for English-language publications from 2010 to 2024. Studies reporting AM in the fabrication of lower-limb prosthetic sockets were included. Data were extracted and synthesised using thematic categorisation. Results: Forty-six studies met the inclusion criteria. Five themes emerged: mechanical performance and structural enhancement (n=18), comfort and fit optimisation (n=11), AM parameter optimisation (n=8), comparisons with conventional sockets (n=7), and exploratory designs (n=2). Most research focused on mechanical reinforcement and parameter effects, while MMAM applications remained largely at the prototype stage. Conclusions: AM is a rapidly developing approach to lower-limb prosthetic socket fabrication. Evidence for MMAM remains preliminary, highlighting the need for standardised testing, reproducible workflows, and early clinical evaluation to support translation into rehabilitation practice.