Device for dynamic stabilization of bones or bone fragments

Abstract

A device for dynamic stabilization of bones or bone fragments comprising at least one anchor member for attachment to vertebrae having an opening configured to receive a longitudinal member; and the longitudinal member being viscoelastically deformable and having a predetermined bending resilience.

1 . A device for dynamic stabilization of bones or bone fragments comprising:
 at least one anchor member for attachment to vertebrae having an opening configured to receive a longitudinal member; and   the longitudinal member being viscoelastically deformable and having a predetermined bending resilience comprising
 a plastic rod comprising biocompatible plastics material in which metal armoring comprising biocompatible metal is embedded. 
   
     
     
         2 . The device of  claim 1 , wherein the longitudinal member has a peripheral surface and the metal armoring has a round or flat profile which extends to the peripheral surface of the longitudinal member. 
     
     
         3 . The device of  claim 1 , wherein the metal armoring is formed by a flat profile defined by W-shaped elements alternately rotated about 180° and connected together. 
     
     
         4 . The device of  claim 3 , wherein the W-shaped elements extend to the peripheral surface of the longitudinal member. 
     
     
         5 . The device of  claim 3 , wherein the W-shaped elements comprise central members which are widened at their extremity to form support surfaces, whereby the support surfaces are flush with the peripheral surface of the longitudinal member. 
     
     
         6 . The device of  claim 3 , wherein the W-shaped elements have connecting members comprising outer surfaces, whereby the outer surfaces are rounded off in the direction transverse to the longitudinal extent of the longitudinal member such that they are integrated into and flush with the peripheral surface of the longitudinal member. 
     
     
         7 . The device of  claim 1 , wherein the metal armoring comprises at least one metal rod that extends parallel to the longitudinal direction of the longitudinal member. 
     
     
         8 . The device of  claim 7 , wherein the at least one metal rod is fixed at their ends through a star-shaped disc or cap. 
     
     
         9 . The device of  claim 7 , wherein the longitudinal member has a peripheral surface and further comprises disc-shaped supporting elements which extend to the peripheral surface of the longitudinal member. 
     
     
         10 . The device of  claim 1 , wherein the metal armoring comprises at least one central metal rod, which extends parallel to the longitudinal direction of the longitudinal member and on which metal sleeves are mounted, the metal sleeves arranged uniformly around the periphery of the longitudinal member. 
     
     
         11 . The device of  claim 10 , wherein the metal sleeves comprise longitudinal elements extending from the sleeve and separated by longitudinal recesses. 
     
     
         12 . The device of  claim 11 , wherein the longitudinal elements are connected to one another by a central star-like connecting element. 
     
     
         13 . The device of  claim 12 , wherein the connecting element comprises a central longitudinal hole such that at least one central metal rod is received therein. 
     
     
         14 . The device of  claim 10 , wherein the external diameter of the metal sleeves corresponds to the external diameter of the longitudinal member. 
     
     
         15 . A device for dynamic stabilization of bones or bone fragments comprising:
 at least one anchor member for attachment to vertebrae having an opening configured to receive a longitudinal member;   the longitudinal member being viscoelastically deformable and having a predetermined bending resilience, the longitudinal member having a peripheral surface and comprises   a biocompatible plastics material, and a metal armoring at least partially embedded within the biocompatible plastics material, the metal armoring comprises at least three metal rods extending parallel to the longitudinal member.   
     
     
         16 . The device of  claim 15 , wherein the at least three metal rods consist of two ends opposite one another such that one end of the at least three metal rods is attached to an end-face end cap and the other end of the at least three metal rods is embedded in biocompatible plastics material. 
     
     
         17 . The device of  claim 15 , wherein the ends of the metal rods which are embedded in biocompatible plastics material have enlarged portions. 
     
     
         18 . A device for dynamic stabilization of bones or bone fragments comprising:
 First and second anchor members for attachment to first and second vertebrae having an opening configured to receive a portion of a longitudinal member; and   the longitudinal member being viscoelastically deformable and having a predetermined bending resilience, the longitudinal member comprising
 a biocompatible plastic rod and a metal band helically wound around the plastic rod, the metal band embedded in the plastic rod such that the metal band forms with the plastic rod a continuously smooth surface, the metal band including a plurality of interruptions which are filled with a biocompatible plastic material. 
   
     
     
         19 . The device of  claim 18 , wherein the metal band comprises titanium or titanium alloy. 
     
     
         20 . The device of  claim 19 , wherein the biocompatible plastics material comprises polycarbonate-urethane, polyether-urethane, silicone-urethane copolymer, or a mixture thereof.