Effects of elastic modulus differences between titanium alloys and bone on bone formation during early stage of healing

Abstract

Nowadays, titanium alloys are being used as orthopedic implant devices due to their low elastic moduli which can suppress stress shielding phenomenon during long-term implantation. In the present study, the effects of elastic modulus differences between titanium alloys and bone on bone formation during early stage of healing were investigated. Ti-6Al-4V ELI (Ti-64:110 GPa) and Ti-29Nb-13Ta-4.6Zr (TNTZ:60 GPa) were used as materials for implant plates, and then were fixed on rabbit窶冱 femur after artificial half-circular defect was made. After 3 weeks, the rabbits were euthanized, and cross-sections of the femurs were evaluated by scanning electron microscopy, hematoxylin-eosin (HE), and Vickers hardness test. This study found that both implant plates resulted in similar amounts of new bone formation, but more mature bone was formed when using the TNTZ implant plate. Further, smaller but harder callus was formed when using the TNTZ implant plate, compared to using the Ti-64 implant plate.