Osteo-implant

An osteo-implant, comprising:

• two end portions;
• at least one middle structure, disposed between the two end portions and comprising a plurality of middle portions;
• and
• a plurality of connection portions, the plurality of middle portions being connected to the two end portions through the plurality of connection portions, wherein the two end portions drive the plurality of middle portions to push with each other and have displacements along a radial direction of the osteo-implant through the plurality of connection portions when the two end portions are moved relatively along an axial direction of the osteo-implant such that an outer diameter of the osteo-implant is increased by the plurality of middle portions, wherein
• a rotation axis of each of the middle portions is parallel to the axial direction of the osteo-implant when the two end portions are moved relatively along the axial direction of the osteo-implant to drive each of the middle portions to rotate relatively to the end portions along the rotation axis.