Biomechanical analysis of an enhanced 3D-printed hip prosthesis socket for reducing stress concentrations and improving gait performance

Abstract

The prosthetic socket serves as a critical interface between the human body and the prosthesis; however, conventional sockets are associated with a skin breakdown risk exceeding 60%. To address this issue, we conducted a biomechanical analysis of the limb-socket interface aiming to enhance both comfort and functional performance. Medical imaging scans of three hip disarticulation amputees were combined with reverse engineering techniques and finite element analysis to reconstruct a 3D model of the residual limb and socket, enabling stress distribution assessment. A novel socket design was proposed, leveraging computer-aided digital modeling and 3D printing to replace conventional manual fabrication, thereby enhancing fit, comfort, and manufacturing precision. The novel socket reduced stress concentrations at the limb-socket interface by 16.97% overall, with nearly a 25% reduction observed at the bottom of the residual limb. Experimental pressure distribution measurements exhibited a high degree of consistency with finite element analysis simulations ( $\overline{R^2}$  = 0.991). Furthermore, the socket significantly improved gait symmetry in prosthesis users. The inverse design methodology based on digital modeling, coupled with biomechanical analysis, offers an effective strategy for optimizing the structural design and fabrication process of hip prosthetic sockets.