For the purpose of firmly fusing a low-cost osteosynthetic implant having high osteoconductivity with a bone in a short period of time after implanting without having to perform treatment to restore surface hydrophilicity, a osteosynthetic implant is provided with a substrate that is formed of magnesium or a magnesium alloy and a porous anodic oxide coating that is formed on a surface of the substrate, wherein the anodic oxide coating has an outer surface that, due to the sizes and distribution of pores that are formed when generating the anodic oxide coating by means of anodic oxidation treatment, structurally prevents water from entering the pores while maintaining the hydrophilicity thereof.
