Pedicle screws and methods of using the same

Abstract

Pedicle screws that can include a pedicle screw body, housing, plurality of clamps, rod, and set screw are disclosed herein. The clamps may be positioned side by side inside the lower portion of the housing. When the rod and set screw are provided in the housing, the set screw applies a force on the rod and the rod engages the plurality of clamps, causing the clamps to frictionally engage a head of the pedicle screw between the clamps.

What is claimed is: 
     
         1 . A pedicle screw comprising:
 a threaded screw body having a proximal end and a distal end, the proximal end comprising an enlarged head;   a housing having an upper portion with an upper opening and a lower portion with a lower opening extending along a first axis of the housing, the upper portion being internally threaded and the lower portion having a curved internal surface, and a third opening and a fourth opening along a second axis transverse to the first axis adapted to receive an elongated rod;   one or more clamps positioned adjacent the lower portion of the housing and having an upper portion with a cylindrical outer surface and a lower portion with a curved outer surface, the curved outer surface of the lower portion adapted to engage the curved internal surface of the lower portion of the housing, the upper portion of the one or more clamps adapted to contact the elongated rod, and an inner surface of the lower portion of the one or more clamps adapted to engage the enlarged head, wherein a radius of curvature of the curved outer surface of the lower portion of the one or more clamps is different from a radius of curvature of the curved internal surface of the lower portion of the housing; and   a set screw configured to be received within the internally threaded first portion of the housing, wherein the set screw when engaged in the first portion applies a force onto the rod when received in the housing, the rod engaging the one or more clamps to frictionally engage the enlarged head against the inner surface of the one or more clamps.