Abstract: A cannular bolt that is used to inject a bone marrow paste into a vertebra, to stabilize vertebrae and has a body and a set screw. The body is screwed into the vertebra and has an outer end, an external thread, a coaxial channel and a crown bracket. The crown bracket is mounted around a shaft and is formed on the outer end of the body, and has two wings protruding from the outer end of the body, corresponding to each other and having an inner thread. The set screw is mounted in the bracket to fasten the shaft to the crown bracket. The crown bracket takes less space than the bracket of a conventional cannular bolt and is not easily obstructed by the spinous processes of vertebrae.