Mechanism of magnesium alloy degradation and bone formation in vivo / 中国矫形外科杂志

ABSTRACT

[Objective]To study the mechanism of magnesium alloy degradation and bone formation at the bone-implant interface after implanting a magnesium alloy into rat femur.[Method]SD rats femur were filled with magnesium alloy stick.Nine weeks later,animals were killed and femur were retrieved.Systematic investigations on the surface morphology,composition,structure of bone-implant were performed by means of metallurgical microscope,scanning electron microscopy(SEM),and energy dispersive spectrum(EDS).Decalcified sections were prepared,and histologic examination was carried out.[Result]The bone response happened both on the surface of surrounding bone and the surface of magnesium alloy degradation layer while magnesium alloy degradating in rat femur.It was formed three layers at the interface of bone-implant the metal layer,the degradation layer,and the new bone layer.Discontinuity connective tissue could be seen on the new bone layer but no inflammatory cells were found.[Conclusion]The new bone response at the interface of bone-implant is consistent with normal bone tissue.Magnesium alloys have good characters of degradation ability,osteogenesis ability,and histocompatibility.And the rate of degradation is corresponding to the rate of new bone formation.