Essential Requirements and Relevant Technologies for Load-Bearing 3D-Printed Transtibial Prosthetic Sockets and Their Components: State-of-the-Art Review.

Background: The manufacture of load-bearing prosthetic lower limb sockets is traditionally reliant on skilled technicians working with qualified clinicians to create bespoke solutions. While this approach is effective and, in some situations, necessary, the appeal of a sustainable, efficient, and digitalized production solution cannot be ignored. The focus of additive manufacturing (AM) is typically on low-weight-bearing prostheses, which can be misleading for clinics attempting to adopt AM solutions for clientele with weight-bearing or activity-level needs. Objective: This review aims to offer readers a way to approach AM for load-bearing requirements as opposed to non-load-bearing counterparts. The use cases of AM for the production of load-bearing transtibial prosthetic sockets and components are reviewed to highlight current trends, protocols, and standings. Methods: By reviewing publications from the past 25 years, this state-of-the-art review highlights the key requirements and technologies relevant for load-bearing transtibial prosthetic sockets specifically. Results: The most commonly used AM solutions for commercial use, such as selective laser sintering and binder jetting through Multi Jet Fusion, are outlined. As these solutions are most often paired with the structural testing standard International Organization for Standardization 10328, their relevance for evaluating the strength and durability of lower limb sockets is also discussed. Clinician and technician experiences of digitalized ways of working within the prosthetic industry for load-bearing applications are outlined. Conclusions: Observations of adoption barriers of AM solutions are brought to light, focusing on clinician and technician education, skill set, exposure to innovative technologies, and trust in the regulation of digital processes in a clinical and technical environment.