Optimizing permeability of microporous scaffolds through CFD simulation to enhance osseointegration

• Defined an optimal scaffold permeability window (6.99–8.82 × 10 −8 m 2 ) for osseointegration. • Integrated CFD simulations with in vivo validation in rabbit femur implants. • Demonstrated that intermediate permeability enhances bone ingrowth and cell adhesion. • Established permeability as a key design parameter for next-generation bone scaffolds. Osseointegration is critically governed by the microstructural topology of porous scaffolds, yet conventional scaffold design remains largely empirical, lacking predictive power regarding fluid transport and bone ingrowth. Here, we present a permeability-guided design paradigm integrating computational fluid dynamics (CFD), additive manufacturing, and in vivo validation. A library of Ti6Al4V scaffolds with varied topologies and permeability profiles was fabricated via selective laser melting (SLM), with permeability values quantified under unified CFD parameters. Rabbit distal femur implantation models revealed an optimal permeability window of 6.99 × 10 −8 to 8.82 × 10 −8 m 2 that maximized early-stage bone ingrowth and cell adhesion. Both excessively high and low permeability impaired osseointegration. Further flow field analysis indicated that moderate flow velocities and localized recirculation zones favored cellular attachment and nutrient perfusion. Our study defines an effective engineering window for scaffold permeability that supports early osseointegration, providing a robust framework for future topology optimization using active learning to enable predictive scaffold design