Patent ID: 6981973
Filing Date: 2006-01-03
Classification: A61B

Abstract:
1. A low profile vertebral alignment/fixation assembly comprising: a screw comprising an elongated threaded shaft defining a screw axis with a substantially hemispherical head having a driver engaging recess disposed therein arranged at one end of the shaft and a tapered tip arranged at the other end of the shaft; a coupling element comprising a cylindrical body having an internal threading disposed on said upper surface and defining an axial bore through which said screw may be inserted, said bore having a narrowing inwardly curved lower surface defining a socket designed to engage the substantially hemispherical head of the screw such that the head of the screw is prevented from passing therethrough and such that the screw may be rotated therein to adjust the angle between the axis of the screw and the axis of the bore, said coupling element further comprising a pair of opposing upper channels formed in the top of said coupling element such that an elongated rod may be received therein and a pair of opposing lower channels formed in the bottom of said coupling element designed to allow the shaft of the screw to move therethrough, the lower channels being designed such that the angle between the axis of the screw and the axis of the coupling element can be adjusted to at least 90 degrees; and a securing nut, mateable with said internal threading and entirely within at least the radial boundaries of the axial bore of said coupling element, the nut having an engaging portion designed to engage the elongated rod, the engaging portion further comprising a plurality of engaging teeth designed to frictionally lock the rod within the upper channel of the coupling element.