Formation of New Bone with Preferentially Oriented Biological Apatite Crystals Using a Novel Cylindrical Implant Containing Anisotropic Open Pores Fabricated by the Electron Beam Melting (EBM) Method

Abstract

New cylindrical bone implants containing elongated pores interconnected as open pores were fabricated by an electron beam melting (EBM) method using Ti–6mass%Al–4mass%V ELI powder (mean particle diameter, 65 μm). New bone formation in the elongated pores of the implant and preferential arrangement of biological apatite c-axis were confirmed along the long bone axis by microbeam X-ray diffraction. Bone mass and preferential degree of biological apatite c-axis, which were considered a bone quality parameter, decreased with the distance from the edge of the implant along the longitudinal bone axis because of a stress-shielding effect. Although clear interconnections between new bones appeared through the implant with elongated pores parallel to the bone axis, the defective portion was not covered with new bone in the absence of the new implant.