Additively manufactured patient-specific transtibial prosthesis for enhanced biomechanical performance and comfort

Abstract

Affordable transtibial prosthetic solutions often lack optimal gait mechanics, thermal comfort, and structural customization. In contrast, advanced prosthetics provide improved performance but remain economically inaccessible for many users. This work presents the design and development of a patient-specific transtibial prosthesis fabricated using additive manufacturing techniques to improve comfort, adaptability, and biomechanical performance while maintaining affordability. A digital workflow is adopted where Computed Tomography (CT) scan data of the residual limb is used to design a customized prosthetic socket. The socket is fabricated using fused filament fabrication (FFF) with Polylactic Acid (PLA) and incorporates ventilation features to reduce perspiration and skin irritation. Structural reinforcement is introduced in the socket–pylon interface to address anisotropic strength characteristics of FFF components. A lightweight carbon fiber pylon replaces the conventional stainless-steel pylon to reduce overall prosthesis weight. The ankle–foot assembly consists of a hybrid PLA– Thermoplastic Polyurethane (TPU) structure with two degrees of freedom, including plantarflexion-dorsiflexion at an articulated ankle joint with a safe motion range and compliant bending at the toe region. Stiffness of the foot structure can be customized according to user requirements by modifying TPU printing parameters. The proposed design demonstrates the potential of additive manufacturing for developing patient-specific, affordable, lightweight, and biomechanically responsive transtibial prosthetic systems