Research on the fabrication and circulation performance of personalized femurs based on additive manufacturing

Personalized porous femoral implants require internal pore architectures that support fluid transport and are suitable for additive manufacturing. Primitive, gyroid, and diamond TPMS scaffolds with porosities of 55%, 60%, 65%, 70%, and 75% were constructed and evaluated by computational fluid dynamics. Velocity distribution, wall shear stress, pressure drop, and permeability were compared to screen suitable scaffold architecture. The results showed that both pore geometry and porosity affected fluid transport performance. As porosity increased from 55% to 75%, permeability increased by 206.82%, 177.12%, and 184.05% for the primitive, gyroid, and diamond structures, respectively. The primitive structure showed a more uniform velocity distribution, lower average wall shear stress, and higher permeability than the other two structures. Based on the simulation results, a personalized porous femoral implant was reconstructed from CT images and fabricated by selective laser melting using 316L stainless steel. Surface observation confirmed the continuity of interconnected pore channels. These results provide a preliminary basis for fluid-performance-driven design of personalized porous femoral implants.