Innovative fracture-controlled safety device for osseo-integration-based prosthetic limbs

The present study plays a crucial role in enhancing the safety and perceived quality of life for users of bone-anchored prostheses. It focuses on developing an innovative protective component using various metallic materials to identify and mitigate potential risks during use, thereby reducing the likelihood of sudden fracture and maintaining the system's structural integrity. The protective element is manufactured from Ti6Al4V alloy, while the safety pin is made from ductile cast iron. This combination allows controlled fracture of the protective element without complete separation of the prosthesis, thereby reducing the risk of falls. To optimise the numerical analysis, a 3D model of the prosthesis and its protective component was created using SolidWorks software. Loading conditions were simulated to reflect two critical phases of the gait cycle: heel strike and toe-off. The analysis revealed that the highest stress occurred during the toe-off phase, reaching 248 MPa, with a safety factor of 1.6, demonstrating the design's ability to prevent sudden failure. Tensile testing showed that ductile cast iron is a suitable material for the safety component. Although Ti6Al4V alloy surpasses it in tensile strength, ductile cast iron's lower strength ensures a controlled and less catastrophic failure under excessive loading. Numerical results confirmed a high safety factor for the protective system, indicating improved reliability and mechanical load resistance. This study presents a novel approach aimed at improving the safety of bone-anchored prostheses by minimising injury risks due to mechanical overload, ultimately enhancing user comfort and confidence.