Effect of biodegradable magnesium-copper coatings on bone integration based on the porous structures in a rabbit model

Biodegradable magnesium (Mg)–copper (Cu) coatings are promising in orthopedic implants to enhance osteogenesis. The present study aimed to compare the osteogenic effect of Mg–Cu coating and non-coating implants using a rabbit model. Mg/Mg–Cu coating of porous Ti6Al4V alloys was performed by the arc ion plating method. Five porous implants (smooth, porous, Mg coated, Mg–0.1Cu coated, and Mg–0.7Cu coated) were implanted into the distal femurs of the rabbits. The rabbits were sacrificed after one and two months, respectively, and the distal femurs with the implants were analyzed via micro-computed tomography (CT), double fluorescent labeling, and hard tissue biopsy to evaluate their osteogenic effect. During the two months of observation, the Mg/Mg–Cu coatings exhibited no advantages when compared with the bare porous structures in terms of bone integration; however, the porous structures were more conducive for bone ingrowth than the smooth implants. The osteogenic application of Mg–Cu coated orthopedic implants is worth further investigation. Furthermore, due to its long-term antibacterial ability, the biodegradable Mg–Cu coatings are promising in orthopedic applications.