Porous alloys for biomedical applications: From controllable fabrication and structural design to functional performance with a focus on titanium

To overcome limitations of traditional dense metallic implants, such as stress-shielding and poor osseointegration, porous alloys have emerged as promising biomaterials offering tunable mechanics and enhanced bio-integration. This review systematically analyzes advancements in their fabrication, focusing on three mainstream strategies: powder metallurgy, dealloying, and additive manufacturing. It examines the design of uniform, bimodal, and gradient pore structures and their critical influence on mechanical properties, corrosion/degradation, and biological responses. The discussion extends to performance modulation via alloy design, post-processing, and surface functionalization. Finally, it summarizes key challenges in fabrication and clinical translation, while outlining future trends toward computational design, hybrid manufacturing, and smart multifunctional implants, aiming to bridge controlled fabrication with performance optimization for next-generation biomedical materials.