| 摘要 |
The invention disclosed a multi-axial expandable pedicle screw and an expansion method by using the same. Structure of the screw comprising a hollow screw being spherical shaped end connecting with an adapting piece, which is universal joint structure; an inner wall of the adapting piece connecting a lock bolt through screw threads; the hollow screw with sharp shaped on another end having a bore inside formed hollow structure in its entirety; the bore having taper shaped tip; expansion gaps uniformly setting up two, or three or four or more anterior fins on the hollow screw along its axial direction upward, prolonging from its tip to the bore; the inner needle is disposed in the bore. The invention can reduce the pedicle screw loose and even occurrence ratio of pull-out and increase the stability and reliability and reduce the failure rate of spinal surgeries at the same time. It is also easy to operate, and degree of expansion is of controllable level.
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