Strontium‐loaded 3D intramedullary nail titanium implant for critical‐sized femoral defect in rabbits

The treatment of critical‐sized bone defects has long been a major problem for surgeons. In this study, an intramedullary nail shaped three‐dimensional (3D)‐printed porous titanium implant that is capable of releasing strontium ions was developed through a simple and cost‐effective surface modification technique. The feasibility of this implant as a stand‐alone solution was evaluated using a rabbit's segmental diaphyseal as a defect model. The strontium‐loaded implant exhibited a favorable environment for cell adhesion, and mechanical properties that were commensurate with those of a rabbit's cortical bone. Radiographic, biomechanical, and histological analyses revealed a significantly higher amount of bone ingrowth and superior bone‐bonding strength in the strontium‐loaded implant when compared to an untreated porous titanium implant. Furthermore, one‐year histological observations revealed that the strontium‐loaded implant preserved the native‐like diaphyseal bone structure without failure. These findings suggest that strontium‐releasing 3D‐printed titanium implants have the clinical potential to induce the early and efficient repair of critical‐sized, load‐bearing bone defects.