Method for installing dynamic multilock anterior cervical plate system having detachably fastened and moveable segments

• US 7,621,943 B2
• Filed: 04/09/2005
• Issued: 11/24/2009
• Est. Priority Date: 06/06/2001
• Status: Active Grant

• Current Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Original Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Inventors: Michelson, Gary K.
• Primary Examiner(s): Philogene; Pedro
• Application Number:
  US11/102,112
• Publication Number:
  US 20050192576A1
• Time in Patent Office: 1,690 Days
• Field of Search: 606/61, 606/69, 606/70, 606/71, 606/72, 606/281, 606/247, 606/295
• US Class Current: 606/281
• CPC Class Codes: A61B 17/7059 Cortical plates A61B17/7007, A61B17/7058 take precedence
• CPC Class Codes: A61B 17/8009 the plate having a ratchet
• CPC Class Codes: A61B 17/8019 where the means are a separate tool rather than being part of the plate
• CPC Class Codes: A61B 17/8042 the additional component being a cover over the screw head
• CPC Class Codes: Y10S 606/902 Cortical plate specifically adapted for a particular bone
• CPC Class Codes: Y10S 606/908 Bioabsorbable material
• CPC Class Codes: Y10S 606/909 Bone

Abstract

An anterior cervical plating system having moveable plate segments to vary the overall length of the plate, moveable to allow and/or cause intersegmental compression of vertebral bodies, and coupled together by a non-detachable fastener. The plating system includes locking elements, each locking element adapted to lock at least two bone screws to the plate, instrumentation, and method for installation thereof. The plating system is capable of both passive and active dynamization and the ability to produce the former from the latter.

Claims

1. A method comprising:

providing a plate of appropriate length adapted to overlap at least an anterior portion of two adjacent vertebral bodies, the plate having at least a first plate segment adapted to be attached to one of the adjacent vertebral bodies to be fused and a second plate segment adapted to be attached to another one of the adjacent vertebral bodies to be fused, the first and second plate segments being in moveable relationship to one another along a longitudinal axis of the plate, the first and second plate segments overlapping one another at least in part along the longitudinal axis of the plate, the first and second plate segments fastened together by a rotatable fastener being non-detachably attached to at least one of the first and second plate segments so as to prevent complete uncoupling of the first and second plate segments from one another, the fastener, when rotated, being non-detachable from the at least one of the first and second plate segments;

inserting at least two bone screws through the first plate segment of the plate and into one of the vertebral bodies adjacent the disc space to be fused;

inserting at least two bone screws through the second plate segment and into the other of the vertebral bodies adjacent the disc space to be fused;

locking at least two of the bone screws with at least one bone screw lock adapted to lock to the plate at least two bone screws;

rotating the fastener from a first position to a second position to tighten the first and second plate segments together and to resist movement of the first and second plate segments in a direction away from one another along the longitudinal axis of the plate; and

permitting, with the fastener being in the second position, movement of the first and second plate segments attached to the adjacent vertebral bodies relative to one another in a direction toward one another along the longitudinal axis of the plate and resisting movement of the first and second plate segments in a direction away from one another along the longitudinal axis of the plate.

2. The method of claim 1, wherein the permitting movement includes permitting movement of the first and second plate segments in only a single direction toward one another.

3. The method of claim 1. wherein the permitting movement includes allowing but not causing the movement of the adjacent vertebral bodies by movement of the first and second plate segments of the plate.

4. The method of claim 1, wherein the permitting movement includes allowing movement of the first and second plate segments of the plate in response to movement of the adjacent vertebral bodies.

5. The method of claim 1, wherein the permitting movement includes limiting the movement of the first and second plate segments relative to one another to sequential increments along the longitudinal axis of the plate.

6. The method of claim 1, wherein the permitting movement includes causing movement of the adjacent vertebral bodies by moving the first and second plate segments relative to one another.

7. The method of claim 6, wherein the causing movement of the adjacent vertebral bodies includes generating a compressive load across the disc space between the adjacent vertebral bodies.

8. The method of claim 7, wherein the permitting movement includes the first and second plate segments being free to move toward one another.

9. The method of claim 6, wherein the causing movement of the adjacent vertebral bodies includes storing a compressive load across the disc space between the adjacent vertebral bodies.

10. The method of claim 6, further comprising simultaneously rotating the fastener and moving the first and second plate segments relative to one another along a mid-longitudinal axis of the plate.

11. The method of claim 1, wherein the permitting movement occurs prior to the locking at least two of the bone screws.

12. The method of claim 1, wherein the permitting movement includes moving the first and second plate segments relative to one another after the inserting the bone screws.

13. The method of claim 1, wherein the permitting movement includes moving the first and second plate segments relative to one another before the inserting the bone screws.

14. The method of claim 1, further comprising applying a compressive load to the adjacent vertebral bodies.

15. The method of claim 1, wherein the permitting movement includes applying a compressive load to the adjacent vertebral bodies.

16. The method of claim 1, wherein the permitting movement includes moving the first and second plate segments from a first position to a second position.

17. The method of claim 1, wherein the rotating the fastener includes limiting the movement of the first and second plate segments relative to one another to one direction along the longitudinal axis of the plate.

18. The method of claim 1, wherein the rotating the fastener includes limiting the movement of the first and second plate segments relative to one another to sequential increments along the longitudinal axis of the plate.

19. The method of claim 1, wherein the rotating the fastener includes tightening the fastener to cause the fastener to tighten to the first plate segment while permitting movement of the first and second plate segments relative to one another.

20. The method of claim 1, further comprising adjusting the overall length of the plate by moving the first and second plate segments relative to each other.

21. The method of claim 1, wherein the providing a plate includes providing a plate having at least a third plate segment.

22. The method of claim 1, further comprising combining the plate with an interbody spinal fusion implant.

23. The method of claim 22, wherein the implant comprises at least in part bone.

24. The method of claim 22, wherein the implant is an allograft interbody bone graft implant.

25. The method of claim 22, wherein the implant is an artificial implant.

26. The method of claim 1, further comprising combining the plate with a fusion promoting substance.

27. The method of claim 26, wherein the fusion promoting substance is at least in part other than bone.

28. The method of claim 26, wherein the fusion promoting substance is at least in part bone.

29. The method of claim 26, wherein the fusion promoting substance is hydroxyapatite.

30. The method of claim 26, wherein the fusion promoting substance comprises bone morphogenetic protein.

31. The method of claim 1, wherein the providing a plate further comprises providing bone screws for engaging the plate to the cervical spine, wherein at least a portion of one of the plate, the at least one bone screw lock, and the bone screws is a bioresorbable material.

32. The method of claim 31, wherein the bioresorbable material is at least in part bone.

33. The method of claim 1, further comprising combining the plate with a substance for inhibiting scar formation.

34. The method of claim 1, further comprising combining the plate with an antimicrobial material.

35. The method of claim 1, further comprising treating the plate with an antimicrobial material.

36. The method of claim 1, further comprising electrifying at least one of the plate, the fastener, the bone screws, and the bone screw lock for purposes of stimulating bone growth and contributing to bone fusion.

37. The method of claim 1, further comprising attaching the at least one bone screw lock to the plate before inserting the at least two bone screws.

38. The method of claim 1, wherein the first and second plate segments have a lower facing surface adapted to be oriented toward the vertebral bodies and an upper facing surface opposite the lower facing surface, the lower facing surface of the first and second plate segments being concave along at least a portion of the longitudinal axis thereof.