Osteogenesis and degradation behavior of magnesium alloy plate in vivo

The magnesium alloy was fabricated into orthopedic plates, and used to repair tibial fractures of New Zealand white rabbits. The osteogenesis and degradation behavior of magnesium alloy plates were investigated in vivo. Methods: 38 rabbits were randomly divided into an experimental group using the magnesium alloy plate and control group using a titanium alloy plate. Tibial fractures in the experimental group and control group were fixed with magnesium alloy plates and titanium alloy plates, respectively. An X-ray of the fracture site was taken at 1, 2, 4, 8, and 16 weeks after surgery. The formation of callus and expression of bone morphogenetic protein (BMP-2) in each group were examined at 4, 8, and 16 weeks postoperatively. The degradation behavior of the magnesium alloy plate was observed using a scanning electron microscope with an energy dispersive spectroscopy system. Results: The results of X-ray showed that the fracture healed gradually and there was significant callus around the plate in the magnesium alloy plate group than that in the titanium alloy plate groups. The formation of callus and the expression of BMP-2 in the magnesium alloy plate group were more significant than that in the titanium plate group. The degradation behavior of the magnesium alloy plates deepened in vivo with the implantation time. Conclusion: The results demonstrated that the magnesium alloy plate implanted into the rabbit tibia could promote the formation of callus and result in osteogenesis in vivo. Meanwhile, the magnesium alloy plate was absorbed gradually in vivo.