An osteo-implant including two end portions, at least one middle structure, and a plurality of connection portions is provided. The middle structure is disposed between the two end portions and includes a plurality of middle portions. The middle portions are connected to the two end portions through the connection portions. When the two end portions are moved relatively along an axial direction of the osteo-implant, the two end portions drive the middle portions to push with each other and have displacements along a radial direction of the osteo-implant through the connection portions, such that an outer diameter of the osteo-implant is increased by the middle portions.
