12. A bone screw comprising: an elongated shaft having a distal end and a proximal end; a post having a distal end and a proximal end; a ball joint which pivotally secures the distal end of the post to the proximal end of the elongated shaft such that the post can pivot relative to the elongated shaft; a tubular extension of the elongated shaft which extends over the ball joint and a distal portion of the post; a compliant member disposed between the post and the tubular extension of the elongated shaft which flexible aligns the post with the elongated shaft; and a screw thread which extends along said elongated shaft and a portion of said tubular extension, said screw thread extending more proximally than the ball joint such that, upon implantation, the elongated shaft and the portion of the tubular extension are adapted to be implanted in a bone and the ball joint is adapted to be positioned within the bone.
12. A bone screw comprising: an elongated shaft having a distal end and a proximal end; a post having a distal end and a proximal end; a ball joint which pivotally secures the distal end of the post to the proximal end of the elongated shaft such that the post can pivot relative to the elongated shaft; a tubular extension of the elongated shaft which extends over the ball joint and a distal portion of the post; a compliant member disposed between the post and the tubular extension of the elongated shaft which flexible aligns the post with the elongated shaft; and a screw thread which extends along said elongated shaft and a portion of said tubular extension, said screw thread extending more proximally than the ball joint such that, upon implantation, the elongated shaft and the portion of the tubular extension are adapted to be implanted in a bone and the ball joint is adapted to be positioned within the bone. 13. The bone screw of claim 12 , wherein the ball joint is adapted to be positioned in a location adjacent or below the surface of a bone, without obstruction of pivoting of the post.