Research Progress on Application of Additive Manufacturing Titanium Alloys in Orthopedics

Titanium alloy is one of the most well-established metallic materials for clinical orthopedic implants, owing to its characteristics such as high specific strength, low elastic modulus, and favorable biocompatibility. However, traditional subtractive manufacturing processes are inherently limited in their capacity for patient-specific customization, a challenge that has been effectively addressed by the emergence of additive manufacturing (AM) technologies. This review systematically summarizes recent research progress in titanium alloys in terms of elastic modulus regulation, porous structure design, enhanced biological activity and improved corrosion resistance. The comparative advantages and limitations of selective laser melting (SLM) and electron beam melting (EBM) are critically evaluated in terms of fabrication precision, mechanical performance, and biological responses. Furthermore, typical clinical applications of additively manufactured titanium alloys, including hip arthroplasty, interbody fusion cages, and mandibular reconstruction, are examined through representative case studies. Through cross-scale mechanical adaptation, the effective elastic modulus of titanium alloys can be adjusted to approximate that of cortical or cancellous bone. The biocompatibility and corrosion resistance of titanium alloy implants can be synergistically enhanced via compositional optimization, hierarchical porous architectures, functional surface coatings, and integrated drug-eluting delivery systems. Moreover, By means of phase transition regulation, pore structure optimization, surface functionalization and thermal cycle redesign, the classical trade-off among high strength, low modulus, high bioactivity can be locally circumvented, thereby enabling concurrent improvements in mechanical properties and osseointegration ability in the same system. Collectively, by virtue of surface bioactivation and precision structural reconstruction, additively manufactured titanium alloys are driving a paradigm shift in orthopedic implants from standardized mass production toward individualized, function-adaptive designs.