Characterization and biostability of HA/Ti6Al4V ACL anchor prepared by simple heat-treatment

Here, we report a simple heat-treatment process to prepare hydroxyapatite (HA)-coated Ti6Al4V anterior cruciate ligament (ACL) anchor that has good hard tissue compatibility and biostability. Heat treatment was carried out for 1.5 h at temperature range of 700-900 °C. Morphological characterization showed rougher surface and larger pore spaces as the heat treatment temperature was increased. The Ti6Al4V heat-treated at 800 °C had the highest diffused titanium phosphide formation, thus making it high in biocompatibility. For in vivo test, the most bone integration ability was obtained for heat-treatment at 800 and 900 °C. Furthermore, the HA/Ti6Al4V ACL anchor heat-treated at 800 °C had the highest amount of new bone formation. The present results suggest that an implant with complex shape like an ACL anchor could be prepared and used with an easy and low-cost technique by simple heat treatment surface modification method after dip-coating with HA.