Design and performance study of biomimetic bone scaffolds based on the fusion of triply periodic minimal surfaces

At present, the treatment of osteonecrosis of the femoral head (ONFH) with bone scaffolds has become a research hotspot. However, comparative studies on the performance of different fusion bone scaffolds are relatively scarce. This study adopted a method with a constant porosity of 70%. By adjusting the TPMS function equation, the three basic structures of D, G, and P were fused in pairs to form six fusion structures: D-G, G-D, D-P, P-D, G-P, and P-G. The simulations were performed using Ti6Al4V as the scaffold material, and through quasi-static compression experiments, we investigated the mechanical properties of these fused TPMS bone scaffolds. At the same time, we also used computational fluid dynamics (CFD) technology to study the effects of permeability, pressure, and flow rate on the fusion TPMS bone scaffolds. The results show that the fusion structure P-D has a low elastic modulus and a yield strength similar to that of natural bone tissue (153.6 MPa). The average wall shear stress of the P-D structure is 0.0037 Pa, the area suitable for cell growth accounts for as high as 98.9%, and it has the highest permeability (5.7245 × 10^{- 8}m²).The design of the fusion porous scaffold meets the implantation requirements of human bone tissue.