Patent ID: 7780706
Filing Date: 2010-08-24
Classification: A61B

Abstract:
1. A bone anchor assembly, comprising: a fixation element adapted to engage a bone, the fixation element having a shank portion and a head portion, the shank portion having an external thread form to engage bone, and the head portion adapted to articulate relative to a coupling element; an elongate axle; a coupling element having: (a) an internal bore extending along a longitudinal axis of the coupling element, the bore sized to mate with and articulate with the head portion of the fixation element, and (b) sidewalls comprising: wherein the axle extends through the cannulation to retain the head portion of the fixation element in the second channel and permit articulation of the fixation element between the opposing downward projections of the coupling element along the second plane and prevents articulation of the fixation element along the first plane; and a compression element engagable with the locking features of the opposing upright projections, the compression element adapted to move distally within the coupling element to transmit a compression force on a connecting rod positioned through the first channel toward the head portion of the fixation element.