Patent ID: 8133262
Filing Date: 2012-03-13
Classification: A61B

Abstract:
1. A bone anchor assembly for engagement to a connection element comprising: a receiver member having an opening at the proximal end for receiving the connection element and a bore at the distal end, the receiver member having a seat portion having a groove provided within the distal end, between the opening and the bore, and being accessible from the bore; a bone-engaging shank having a generally spherically shaped head at a proximal end, the head sized to fit within the bore of the receiver member and having a generally hemispherically shaped distal surface; a retaining member interposed between the head of the shank and the bore at the distal end of the receiver member, the retaining member having an outer surface shaped to fit and positioned within the seat portion of the receiver member and a proximal inner surface shaped to accommodate the head of the bone-engaging shank, the distal surface of the head of the shank engaging the proximal inner surface of the retaining member to thereby retain the head within the receiver member; and a locking member shaped to fit and positioned within the groove of the seat portion to thereby lock the retaining member within the seat portion of the receiver member.