Articulating spinal fixation rod and system

• US 20050038432A1
• Filed: 08/15/2003
• Published: 02/17/2005
• Est. Priority Date: 04/25/2003
• Status: Active Grant

• Current Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Original Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Inventors: Shaolian, Samuel M., Nguyen, Thanh Van, Pham, To V., Teitelbaum, George P.
• Granted Patent: US 7,083,621 B2
• Time in Patent Office: Days
• US Class Current: 606/86.A
• CPC Class Codes: A61B 17/1615 Drill bits, i.e. rotating tools extending from a handpiece to contact the worked material
• CPC Class Codes: A61B 17/1642 for producing a curved bore
• CPC Class Codes: A61B 17/1671 for the spine
• CPC Class Codes: A61B 17/1757 for the spine
• CPC Class Codes: A61B 17/3468 for implanting or removing devices, e.g. prostheses, implants, seeds, wires devices for implanting seeds A61M37/0069
• CPC Class Codes: A61B 17/3472 for bones, e.g. intraosseus injections
• CPC Class Codes: A61B 17/7001 Screws or hooks combined with longitudinal elements which do not contact vertebrae A61B17/7058 takes precedence
• CPC Class Codes: A61B 17/7004 with a cross-section which varies along its length A61B17/7019 takes precedence
• CPC Class Codes: A61B 17/7005 Parts of the longitudinal elements, e.g. their ends, being specially adapted to fit in the screw or hook heads
• CPC Class Codes: A61B 17/7011 Longitudinal element being non-straight, e.g. curved, angled or branched adjustable length longitudinal elements A61B17/7014; A61B17/7019 takes precedence, e.g. coil springs
• CPC Class Codes: A61B 17/7019 Longitudinal elements having flexible parts, or parts connected together, such that after implantation the elements can move relative to each other
• CPC Class Codes: A61B 17/702 having a core or insert, and a sleeve, whereby a screw or hook can move along the core or in the sleeve
• CPC Class Codes: A61B 17/704 the longitudinal element passing through a ball-joint in the screw head
• CPC Class Codes: A61B 17/7082 for driving, i.e. rotating, screws or screw parts specially adapted for spinal fixation, e.g. for driving polyaxial or tulip-headed screws driving other bone screws A61B17/8875
• CPC Class Codes: A61B 17/7083 Tools for guidance or insertion of tethers, rod-to-anchor connectors, rod-to-rod connectors, or longitudinal elements
• CPC Class Codes: A61B 17/7086 Rod reducers, i.e. devices providing a mechanical advantage to allow a user to force a rod into or onto an anchor head other than by means of a rod-to-bone anchor locking element; rod removers
• CPC Class Codes: A61B 17/7089 wherein insertion is along an arcuate path
• CPC Class Codes: A61B 17/861 specially shaped for gripping driver
• CPC Class Codes: A61B 17/864 hollow, e.g. with socket or cannulated
• CPC Class Codes: A61B 17/8861 Apparatus for manipulating flexible wires or straps devices for inserting Kirschner wires A61B17/1697
• CPC Class Codes: A61B 17/8897 : Guide wires or guide pins
• CPC Class Codes: A61B 17/90 : Guides therefor

Abstract

The present invention relates generally to systems and methods for aligning and implanting orthopedic fixation or stabilization implants within the body. In one embodiment, the system includes at least two bone anchors, at least one of which is provided with a transverse portal and a locking member. In one aspect, the system also includes at least one linkage rod, for linking two or more bone anchors through their respective locking members. The linking rod may include at least one angularly adjustable joint, which may be fixed by actuating the locking member. The bone anchors and the linkage rod may be locked into place to form a spinal fusion or fixation prosthesis.

Claims

1. An implantable fixation rod, comprising:

a first segment, having a proximal end and a distal end;

a second segment, having a proximal end and a distal end; and

a joint between the first segment and the second segment;

wherein the joint is convertable between a first state in which the first and second segments are movable with respect to each other, and a second state in which the first and second segments are fixed with respect to each other.

2. An implantable fixation rod as in claim 1, wherein the joint is convertable from the first state to the second state in response to lateral external compression.

3. An implantable fixation rod as in claim 1, further comprising a third segment, movably connected to the second segment by a second joint.

4. An implantable fixation rod as in claim 1, wherein in the second state the fixation rod will exhibit a static compression within the range of from about 120 to about 200 lbs.

5. An implantable fixation rod as in claim 1, wherein in the second state the fixation rod will exhibit a static compression within the range of from about 30 to about 100 lbs.

6. An implantable fixation rod as in claim 1, wherein the joint is configured such that the longitudinal axes of the first and second segments may be angularly adjusted up to 7.5 degrees with respect to each other.

7. An implantable fixation rod as in claim 1, wherein the joint is configured such that the longitudinal axes of the first and second segments may be angularly adjusted up to 15 degrees with respect to each other.

8. An implantable fixation rod as in claim 1, wherein the joint is configured such that the longitudinal axes of the first and second segments may be angularly adjusted up to 45 degrees with respect to each other.

9. A prosthesis assembly for minimally invasive posterior fixation, comprising:

a linkage rod, having a proximal end and a distal end, and releasable coupling on the proximal end, the linkage rod comprising at least a first segment and a second segment coupled together at a joint configured such that the first segment and the second segment can be positioned at a variety of angular orientations with respect to each other; and

a bone anchor provided with an opening through which at least a portion of said linkage rod may extend and a lock configured to fix the angular orientation between the first segment and the second segment.

10. The prosthesis assembly of claim 9, wherein the linkage rod comprises a third segment coupled to the second segment by a second joint configured such that the third segment and the second segment can be positioned at a variety of angular orientations with respect to each other.

11. The prosthesis assembly of claim 10, comprising a second bone anchor also provided with an opening through which at least a portion of said linkage rod may extend and a lock configured to securely engage said linkage rod and fix the angular orientation between the third segment and the second segment.

12. The prosthesis assembly of claim 9, wherein the bone anchor comprises a head in which said opening is formed and said lock comprises a rotatable connector disposed within said head, said rotatable connector adapted to securely engage said linkage rod and fix the angular orientation between the first segment and the second segment.

13. A prosthesis for minimally invasive posterior fixation, comprising:

a bone anchor having a head;

a transverse portal extending through said head along an axis transverse to a central axis of said bone anchor;

a first segment of a rod extending through said transverse portal, said first segment defining a first surface;

a second segment of a rod having a second complementary surface;

a joint formed at least in part by said first surface and said second surface; and

a locking cap which in response to lateral movement secures said first segment within said portal and fixes the angular relationship of the joint.

14. The prosthesis of claim 13, wherein said first segment further comprises at least one compression gap.

15. The prosthesis of claim 13, wherein said rod is adapted to be detachably secured to an insertion tool used to insert said rod into said portal.

16. The prosthesis of claim 13, wherein further comprising a third segment of a rod, said third segment defining a socket for receiving a ball positioned on said second segment.

17. The prosthesis of claim 16, further comprising a second bone anchor having a head, a transverse portal and a locking cap which in response to lateral movement secures said third segment within the portal of the second bone anchor and fixes the angular relationship between the third and second segments.

18. The prosthesis assembly of claim 17, wherein the third segment is configured to be secured to an insertion tool used to insert said rod into said portals of said bone anchors.

19. A method of treating the spine, comprising the steps of:

securing a first bone anchor to a first vertebral body;

securing a second bone anchor to a second vertebral body;

positioning an articulating connector between the first and second bone anchors; and

transforming the connector from a flexible configuration to a rigid configuration to secure the first bone anchor to the second bone anchor.

20. A method of treating the spine as in claim 19, wherein the first bone anchor is positioned in the sacrum, the second bone anchor is positioned in the L5 vertebrae.

21. A method of treating the spine as in claim 19, wherein the securing a first bone anchor step comprises advancing a threaded bone screw into the first verterbral body.

22. A method of treating the spine as in claim 19, wherein the positioning an articulating connector step comprises advancing the articulating connector through an aperture in at least one of the first and second bone screws.

23. A method of treating the spine as in claim 22, wherein the positioning an articulating connector step comprises advancing the articulating connector through an aperture in each of the first and second bone screws.

24. A method of treating the spine as in claim 19, wherein the positioning an articulating connector step comprises advancing the articulating connector percutaneously through tissue.

25. A method of treating the spine as in claim 19, wherein the transforming step comprises locking at least one pivotable joint on the connector.

26. A method of treating the spine as in claim 25, wherein the transforming step comprises manipulating a portion on the bone anchor to transform the connector.

27. A method of treating the spine as in claim 26, wherein the transforming step comprises rotating a threaded shaft on the bone anchor to apply compression to the connector.

28. A method for minimally invasive posterior fixation, comprising:

securing a bone anchor to a vertebral body, said bone anchor being provided with an opening and a locking device;

inserting a rod with at least one angularly adjustable joint between a first segment of the rod and a second segment of the rod over a guidewire along a path through said opening connector; and

adjusting said locking device to fix an angular position between said first segment and said second segment.

29. The method of claim 28 further comprising:

securing a second bone anchor to a second vertebral body, said second bone anchor provided with a second locking device;

inserting said rod through said second bone anchor; and

securing said second locking device to fix said rod with respect to said second bone anchor and to fix a second angularly adjustable joint which exists between a third segment and a second segment of said rod.

30. The method of claim 28, wherein said first vertebral body and said second vertebral body are adjacent vertebral bodies.

31. The method of claim 28, wherein said first vertebral body and said second vertebral body are separated by one or more other vertebral bodies.

32. A method of implanting spinal fusion hardware, comprising the steps of:

positioning a first bone anchor, having a first aperture, in a first vertebral body;

positioning a second bone anchor, having a second aperture, in a second vertebral body;

advancing a guide wire through the first and second apertures to form a non-linear path; and

advancing a fixation rod having at least one angularly adjustable joint along the non-linear path defined by the guidewire and through the first and second apertures.

33. A method of implanting spinal fusion hardware as in claim 32, wherein the first and second vertebral bodies are adjacent vertebral bodies.

34. A method of implanting spinal fusion hardware as in claim 32, wherein the first and second vertebral bodies are separated by a third vertebral body.

35. A method of implanting spinal fusion hardware as in claim 32, additionally comprising the step of advancing a guide tube along the guide wire and through the first and second apertures.

36. A method of implanting spinal fusion hardware as in claim 35, additionally comprising the step of advancing the fixation device through the guide tube.

37. A method of implanting spinal fusion hardware, comprising the steps of:

positioning a first bone anchor, having a first aperture, in a first vertebral body;

positioning a second bone anchor, having a second aperture, in a second vertebral body;

mounting an alignment tool to at least one bone anchor, the alignment tool comprising a curved guide needle;

advancing a guide wire through the first and second apertures using the alignment tool; and

advancing a segmented fixation rod along the guidewire and through the first and second apertures.

38. A method of implanting spinal fusion hardware as in claim 37, wherein at least a portion of the alignment tool is mounted to the bone anchor before the positioning a bone anchor step.

39. A method of implanting spinal fusion hardware as in claim 37, wherein the first and second vertebral bodies are adjacent vertebral bodies.

40. A method of implanting spinal fusion hardware as in claim 37, wherein the first and second vertebral bodies are separated by a third vertebral body.

41. A method of implanting spinal fusion hardware as in claim 37, wherein the mounting an alignment tool comprises mounting a central arm on the bone anchor, the central arm pivotably attached to a radial arm, and the guide needle is carried by the radial arm.

42. A method of implanting spinal fusion hardware as in claim 41, wherein the guide needle has a radius of curvature within the range of from about 6 cm to about 15 cm.

43. A method of implanting spinal fusion hardware as in claim 37, additionally comprising the step of manipulating a component of a bone anchor to lock the fixation rod.

44. A method of implanting spinal fusion hardware as in claim 37, additionally comprising the step of advancing a guide tube along the guide wire and through the first and second apertures.

45. A method of implanting spinal fusion hardware as in claim 44, additionally comprising the step of advancing the fixation rod through the guide tube.