Dynamic spinal stabilization with rod-cord longitudinal connecting members

Abstract

A dynamic fixation medical implant having at least two bone anchors includes a longitudinal connecting member assembly having at least one transition portion and cooperating outer sleeve, both the transition portion and sleeve being disposed between the two bone anchors. In a first embodiment, the transition portion includes a rigid length or rod having apertures therein for tying or otherwise attaching the rigid length to a second rigid length or to a flexible cord. Slender ties or cords extend through a plurality of apertures in the rigid lengths or are threaded, tied or plaited to the larger flexible cord or cable. In a second embodiment, a transition portion includes slender ties of a cord that are imbedded in a molded plastic of a more rigid member. The outer sleeve may include compression grooves. The sleeve surrounds the transition portion and extends between the pair of bone anchors, the sleeve being compressible in a longitudinal direction between the bone anchors.

What is claimed and desired to be secured by Letters Patent is as follows: 
     
         1 . In a medical implant assembly having at least first and second bone anchors cooperating with a longitudinal connecting member, the improvement wherein the connecting member comprises:
 a) a first substantially solid connecting member portion attached to the first bone anchor; and   b) a transition portion disposed between the first and second bone anchors, the transition portion having at least one flexible tie attached to both the first connecting member portion and to a second discrete connecting member portion, the second connecting member portion being attached to the second bone anchor.