Patent ID: 6827719
Filing Date: 2004-12-07
Classification: A61B

Abstract:
A screw and coupling element assembly for use with an orthopedic rod implantation apparatus, comprising:a screw that has a head and a shaft that extends from the head; a coupling element that has a seat within which the head can be seated such that the shaft protrudes from the coupling element; and a locking element that can be mated with the coupling element and that thereafter can be selectively moved through a plurality of positions including an unlocked position and a locked position; wherein when the locking element is in the unlocked position, the locking element presents a rod-receiving channel, the rod-receiving channel is defined by substantially parallel walls, and the head is movable in the seat such that the shaft can be directed in a plurality of angles relative to the coupling element; and wherein when the locking element is in the locked position, a rod disposed within the rod-receiving channel is fixed relative to the coupling element, the head is immovable in the seat such that the shaft is fixed at an angle relative to the coupling element, and the walls are compressed toward one another such that the rod is compressed within the channel and thereby fixed relative to the coupling element; and wherein the head has a distal portion defined by a compression surface, the locking element has a permissive surface that is presented to the compression surface when the locking element is in the unlocked position, and when presented with the permissive surface, the compression surface is unhindered such that the head is movable in the seat; and wherein the locking element has a confrontational surface that is presented to the compression surface when the locking element is in the locked position, and the confrontational surface is defined by a recess that has a recessed surface corresponding to the compression surface; and wherein when the locking element is in the locked position, the locking element is compressed within the coupling element, a proximal portion of the head is compressed toward a bore in the coupling element and the head is immovable in the seat, and the compression surface seats in the recess and thereby is biased against retreat from the recess.