Mobile dynamic system for treating spinal disorder

• US 6,554,831 B1
• Filed: 09/01/2000
• Issued: 04/29/2003
• Est. Priority Date: 09/01/2000
• Status: Expired due to Term

• Current Assignee: Hospital Sainte-Justine
• Original Assignee: Hospital Sainte-Justine
• Inventors: Dujovne, Ariel, Rivard, Charles-Hilaire
• Primary Examiner(s): Philogene, Pedro
• Application Number:
  US09/653,328
• Time in Patent Office: 970 Days
• Field of Search: 606/61, 606/59, 606/60, 606/72, 606/74, 606/103, 623/17.11, 623/17.15, 623/17.16, 403/59, 403/61, 403/13, 403/92
• US Class Current: 606/253
• CPC Class Codes: A61B 17/7035 Screws or hooks, wherein a rod-clamping part and a bone-anchoring part can pivot relative to each other
• CPC Class Codes: A61B 17/7037 wherein pivoting is blocked when the rod is clamped
• CPC Class Codes: A61B 17/7041 with single longitudinal rod offset laterally from single row of screws or hooks A61B17/7044 takes precedence
• CPC Class Codes: A61B 17/7049 Connectors, not bearing on the vertebrae, for linking longitudinal elements together A61B17/7055, A61B17/7053, A61B17/7019 take precedence
• CPC Class Codes: A61B 17/8665 Nuts
• CPC Class Codes: A61B 2090/037 with a frangible part, e.g. by reduced diameter

Abstract

A mobile dynamic implantable spinal apparatus comprising at least one fixed bracket secured on a correcting rod and at least one mobile carrier slidably mounted on the correcting rod. The fixed bracket and the mobile carrier each include a body and a pedicle screw or a transverse process hook articulated to the body. The distribution of the degrees of freedom between the carrier and the rod, and the pedicle screws or hooks and the carrier and the fixed bracket provide a non-rigid assembly which preserves some of the natural mobility of the vertebrae and disk, and the potential growth of the spinal column.

Claims

1. A mobile dynamic internal system for treating a disorder of a spinal column having a sagittal plane, comprising at least one implantable correcting rod for mounting on one side of a patient'"'"'s spinal column, at least one fixed bracket rigidly mounted to said correcting rod, and at least one mobile carrier slidably mounted to said correcting rod on a selected side of said fixed bracket, and first and second anchors respectively mounted to said mobile carrier and said fixed bracket for anchoring said correcting rod to the spinal column, wherein, once said mobile dynamic internal system has been implanted, said first and second anchors still respectively have limited freedom of movement relative to said mobile carrier and said fixed bracket, thereby allowing said mobile carrier to slide along said correcting rod in response to movements of the spinal column.

2. A mobile dynamic internal system as defined in claim 1, wherein said mobile carrier is also mounted to said correcting rod for limited pivotal movement with respect thereto in a plane parallel to the sagittal plane of the spinal column.

3. A mobile dynamic internal system as defined in claim 2, wherein said mobile carrier includes a body defining a pair of opposed oblong holes disposed in registry and communicating with a socket formed within said body, a roller retained captive in said socket, said roller being free to rotate about a longitudinal axis thereof within said socket and defining a transversal through bore for slidably receiving said correcting rod therethrough, said transversal through bore being adapted to be placed in registry with said oblong holes for allowing said roller to be engaged on said correcting rod, and wherein pivotal movements of said body relative to said rod are limited by spinal mobility.

4. A mobile dynamic internal system as defined in claim 1, wherein said first anchor has three degrees of freedom relative to said mobile carrier.

5. A mobile dynamic internal system as defined in claim 4, wherein said first anchor is articulated to said mobile carrier by a ball and socket joint.

6. A mobile dynamic internal system as defined in claim 3, wherein said first anchor is articulated to said body of said mobile carrier at a location spaced-laterally from said oblong holes, said first anchor having a head defining a socket in which a ball secured to the body is retained captive.

7. A mobile dynamic internal system as defined in claim 6, wherein said head is at least partly received in a recess defined in a bottom surface of said body, said recess and said head defining a play for allowing limited relative movements between said first anchor and said body.

8. A mobile dynamic internal system as defined in claim 1, wherein said second anchor is articulated to said fixed bracket for limited angular relative movement with respect thereto.

9. A mobile dynamic internal system as defined in claim 1, wherein said mobile carrier has two degrees of freedom relative to said correcting rod, and wherein said first anchor has three degrees of freedom with respect to said mobile carrier.

10. A mobile dynamic internal system as defined in claim 9, wherein said mobile carrier is adapted to slide along said correcting rod and pivot with respect thereto in a plane parallel to the sagittal plane of the spinal column, and wherein said first anchor is articulated to said mobile carrier by a ball and socket joint.

11. A mobile dynamic internal system as defined in claim 1, wherein said fixed bracket includes a clamp collar adapted to be contracted in secure engagement with said correcting rod, and coupling means adapted to be engaged with said clamp collar to articulate said second anchor to said clamp collar, while at the same time securing said clamp collar to said correcting rod.

12. A mobile dynamic internal system as defined in claim 11, wherein said clamp collar extends between opposed first and second ends, and wherein said securing means include a pin extending through said first and second ends, and a nut adapted to be threadably engaged on said pin to draw said first and second ends towards each other, said pin being provided at one end thereof with a ball formation disposed on one external side of said first and second ends opposite said nut, said ball formation being received in a socket defined in said second anchor to form an articulated joint allowing for relative movements between said second anchor and said fixed bracket.

13. A mobile dynamic internal system as defined in claim 12, wherein said second anchor has a head, said socket being defined in said head.

14. A mobile dynamic internal system as defined in claim 1, further including an implantable stabilizing rod adapted to be mounted on one side of the spinal column opposite said correcting rod via a selected number of fixed brackets and mobile carriers, and a cross-link for articulately joining said correcting and stabilizing rods.

15. A mobile dynamic internal system as defined in claim 14, wherein said cross-link includes first and second links articulated to one another between said correcting and stabilizing rods.

16. A mobile dynamic internal system as defined in claim 15, wherein said first and second links are articulated to one another by a ball and a socket joint.

17. A mobile dynamic internal system as defined in claim 15, wherein said first and second links have respective rod coupling distal ends, each said rod coupling distal end being adapted to selectively cooperate with one of a locking member and a sliding member for respectively securing and slidably mounting said rod coupling distal end to a corresponding one of said correcting and stabilizing rods.

18. A mobile dynamic internal system as defined in claim 1, wherein stoppers are provided at opposed ends of said correcting rod to prevent said at least one mobile carrier from sliding off said correcting rod.

19. A mobile dynamic internal system as defined in claim 8, wherein said second anchor is articulated to said fixed bracket via a ball and socket joint.

20. A mobile dynamic internal system as defined in claim 1, wherein a selected number of mobile carriers are provided on opposed sides of a central fixed bracket.

21. A mobile dynamic anchoring assembly comprising an implantable rod, a carrier mounted to said implantable rod for sliding movement thereon and limited pivotal movement with respect thereto about an axis perpendicular to the rod, and a bone anchor articulately connected to said carrier for allowing the mobility of said carrier to be preserved once said anchor has been engaged with a bone.

22. A mobile dynamic anchoring assembly as defined in claim 21, wherein said carrier includes a body defining a pair of opposed oblong holes disposed in registry and communicating with a socket formed within said body, a roller mounted for free rotation in said socket, said roller defining a through bore for slidably receiving the rod therethrough, said through bore being adapted to be placed in registry with said oblong holes for allowing said roller to be engaged on the rod, and wherein said oblong holes are sized so that the pivotal movement of said body relative to the rod is limited by the mobility of the spine.

23. A mobile dynamic anchoring assembly as defined in claim 22, wherein said bone anchor is articulated to said body of said carrier at a location spaced-laterally from said oblong holes, said bone anchor having a head defining a socket in which a ball secured to the body is retained captive to form a ball and socket joint.

24. A mobile dynamic anchoring assembly as defined in claim 23, wherein said head is at least partly received in a semi-spherical recess defined in a bottom surface of said body, said semi-spherical recess and said head defining a play for allowing limited relative movements between said anchor and said body.

25. A mobile dynamic cross-link for structurally connecting a pair of implantable spinal rods together, comprising opposed first and second ends adapted to be connected to corresponding ones of a pair of implantable spinal rods, and a permanent point of articulation between said first and second ends to prevent the implantable spinal rods from pivoting apart while allowing any other limited relative movements therebetween in response to movements of a patient'"'"'s spinal column.

26. A mobile dynamic cross-link as defined in claim 25, wherein said cross-link includes first and second links articulated to one another between the rods.

27. A mobile dynamic cross-link as defined in claim 26, wherein said first and second links are articulated to one another by a ball and a socket joint.

28. A mobile dynamic cross-link as defined in claim 25, wherein said first and second ends are adapted to selectively cooperate with one of a locking member and a sliding member for respectively securing and slidably mounting said cross-link to the implantable spinal rods.