Orthopedic implant(hip/knee/spine) titanium alloy nano bioactive coatings use nano-HA(20-80nm) via EPD/electrospinning/MAO with multi-ion doping(Sr2+/Mg2+/Zn2+/CO32-/SiO44-) mimicking natural bone matrix. 2026 Bioactive Materials(Vol.55): multi-ion doped HA nanorod arrays promote M2 macrophage polarization and vascularized osseointegration,even detached particles retain anti-inflammatory activity preventing aseptic loosening(~5-15%/15yr). 2025 Chemical Engineering Journal: HA-Zn/CuTA coating,pH-responsive Cu2+ release(antibacterial:71.67% E.coli,98.54% S.aureus)+sustained Zn2+ release(osteogenesis+immune modulation). 2025 Int.J.Pharmaceutics(Aug): anodized Ti+EPD nano-HA loaded alendronate+gentamicin,92-94% sustained drug release,100% cell viability 72h. ISO 13779-3:2018(HA adhesion>15MPa),ASTM F1609,ISO 10993 series. Global orthopedic implant market ~$53B(2025),cementless risen from ~35%(2015) to ~55%(2025).