1. A bone anchor assembly comprising: an anchor body with an anchor; an anchor head including a stirrup including a yoke extending from the anchor body and a shaft spanning the yoke; a saddle mounting element located about said shaft; a saddle adapted to hold a member; which saddle includes a port that is received about said saddle mounting element and a saddle capture opening adapted to receive the member; a lower compression element located in said saddle above said saddle mounting element and adapted to capture the member relative to said saddle capture opening; and a set screw that can be received in said saddle to lock the member against said lower compression element against said saddle mounting element.
16. The anchor assembly of claim 1 wherein said saddle mounting element is a cylinder mounted on said shaft.