Patent ID: 8911484

Claim:
A multi-axial expandable pedicle screw device, comprising: a hollow screw having a tip at an end and a spherical shaped end at another end, with a bore formed inside, the bore including an opening at the spherical shaped end of the hollow screw and a tapered tip at an intermediate location between the spherical shaped end and the tip of the hollow screw, the bore receiving an inner needle disposed therein; expansion gaps uniformly arranged on, and extending axially along the hollow screw, from the tip of the bore to the tip of the hollow screw; an adapting piece connected to the spherical shaped end of the hollow screw, the adapting piece being a universal joint having a cavity with an open pore; and a fixation rod mounted in the cavity above the inner needle in a manner to enable transmittance of a pressing force to the inner needle, wherein the inner needle disposed in the bore has a length that is greater than the length of the bore, the adapting piece, at the open pore, is adapted to receive a sealing lock bolt by way of a screw thread on an inner wall of the adapting piece and a coupler on the sealing lock bolt, and the screw device is configured such that the transmittance of a pressing force to the inner needle, from the fixation rod, will drive the inner needle into the bore to cause an expansion of the hollow screw.