Patent ID: 7201754

Claim:
An anchor device for installation in a borehole formed in a bone of a patient comprising: (a) an anchor body to be inserted in a borehole formed in a surface of a bone having expandable side walls in a tapered shape with a narrower proximal end thereof to face outwardly from the borehole and a wider distal end thereof to be inserted into the interior of the borehole, wherein said side walls have retention members formed on their external surfaces for inhibiting the anchor body from being retracted from the borehole when the side walls are expanded; (b) an expansion member positioned in an interior space defined within the side walls of the anchor body and movable from a disengaged position toward the distal end of the anchor body to an engaged position toward the proximal end of the anchor body, wherein when said expansion member is moved to the engaged position, it presses on the inside of the side walls of the anchor body to expand them outwardly in order to thereby engage the retention members with the borehole walls to inhibit retraction from the bone, and wherein said proximal end of the anchor body has a central aperture to allow insertion of a distal end of an elongated expansion tool into the interior space of the anchor body in order to grasp the expansion body in its disengaged position in the anchor body and pull the expansion member to the engaged position to thereby expand the side walls of the anchor body outwardly, wherein said expansion member is formed as a frustoconically shaped plug, and wherein said anchor body has a pair of guide ribs provided along the inner surfaces of the side walls for guiding the movement of the expansion member from the disengaged to the engaged position, and said expansion member has a pair of slot recesses formed in its side walls for sliding along the guide ribs of the anchor body.