19. An anchor assembly comprising: a anchor body with an anchor; an anchor head including a yoke extending from the anchor body and a shaft positioned across the yoke; a cylinder mounted on said shaft; a saddle including a cavity that is received about said cylinder wherein the saddle includes a mount adapted to secure the saddle to a spinal rod; and a fastener that can lock said cylinder against said shaft in order to position said saddle relative to said anchor body.
19. An anchor assembly comprising: a anchor body with an anchor; an anchor head including a yoke extending from the anchor body and a shaft positioned across the yoke; a cylinder mounted on said shaft; a saddle including a cavity that is received about said cylinder wherein the saddle includes a mount adapted to secure the saddle to a spinal rod; and a fastener that can lock said cylinder against said shaft in order to position said saddle relative to said anchor body. 23. The anchor assembly of claim 19 wherein said cylinder has one or more slots.