Implant

An implant for repairing an intervertebral annulus fibrosus, comprising:

• a body having a first end portion, a second end portion, and a middle portion disposed between the first end portion and the second end portion;
• a limiting portion comprising a first solid structure and being located at the first end portion;
• and
• a filling portion comprising an elastic structure and a porous structure in the elastic structure, and being located between the middle portion and the second end portion, wherein the elastic structure comprises:
• a first region adjacent to the first end portion and having a first porosity;
• a second region adjacent to the second end portion and having a second porosity;
• and
• a third region disposed between the first region and the second region and having a third porosity,
• wherein the third porosity of the third region is greater than the first porosity of the first region,
• wherein a ratio of the first solid structure to the elastic structure is in a range of from 1:1 to 1:8;
• and
• wherein a diameter of the first end portion of the body is greater than a diameter of the middle portion, and a diameter of the second end portion is greater than the diameter of the middle portion.