Anterior lumbar plate and method

• US 7,060,069 B2
• Filed: 01/12/2004
• Issued: 06/13/2006
• Est. Priority Date: 10/25/2000
• Status: Expired due to Term

• Current Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Original Assignee: SDGI Holdings Incorporated (Medtronic Plc)
• Inventors: Boyd, Lawrence M., Estes, Bradley T., Kozak, Jeffrey
• Primary Examiner(s): Robert, Eduardo C.
• Assistant Examiner(s): RAMANA, ANURADHA
• Application Number:
  US10/755,583
• Publication Number:
  US 20040143266A1
• Time in Patent Office: 883 Days
• Field of Search: 606/60, 606/61, 606 69- 71, 606/72, 606/73, 623/17.11, 623/17.12, 623/17.16
• US Class Current: 606/279
• CPC Class Codes: A61B 17/7055 connected to sacrum, pelvis or skull
• CPC Class Codes: A61B 17/7059 Cortical plates A61B17/7007, A61B17/7058 take precedence
• CPC Class Codes: A61B 17/8042 the additional component being a cover over the screw head
• CPC Class Codes: A61B 17/8047 wherein the additional element surrounds the screw head in the plate hole A61B17/8052 takes precedence
• CPC Class Codes: Y10S 606/90 Lumbar stabilizer

Abstract

A plate of biocompatible material is provided having curvature in two planes such that it conforms to the curvature of the L5 vertebral body and to the patient'"'"'s lordotic curve. Holes are provided receiving screws for anchorage in the vertebral body and sacrum. A flange or foot portion on the plate provides a wider base end area for support in the L5-S1 interspace. The foot portion is also arranged for appropriate entry angle of screws into the sacrum such as to improve anchorage in the sacrum. Anti-backout and low profile features are incorporated. The anterior lumbar plate is situated to maintain the anterior interbody bone graft in compression by resisting tensile forces during extension.

Claims

1. A method of stabilizing a lumbar-sacral junction for fusion comprising:

installing a foot portion of a plate partially into the anterior portion of intervertebral space between L5 and S1;

installing first screws from the front of the plate through holes in an upper portion of the plate into L5;

installing second screws from the front of the foot portion of the plate downwardly through the foot portion and out the bottom of the foot portion into S1; and

seating a bottom surface of said foot portion atop the superior end plate of S1.

2. The method of claim 1 and further comprising:

installing said second screws through the foot portion on convergent paths in S1.

3. The method of claim 2 and further comprising:

extending said second screws through the S1-S2 junction.

4. The method of claim 3, further comprising the steps of providing said first screws and said second screws wherein said first screws and said second screws each comprise conical tapered head surfaces;

and

installing an anti-backout screw with a conical head surface adapted to engage and interlock with the conical tapered head surfaces of said first screws to prevent backout of said first screws when the anti-backout screw is fixed in said plate.

5. The method of claim 4 and further comprising:

screwing the anti-backout screw tightly into engagement with the plate after installing said first screws.

6. The method of claim 3 and further comprising:

seating said second screws in the plate and pulling L5 and S1 toward each other and compressing fusion material in said intervertebral space.

7. The method of claim 3 and further comprising:

seating a bottom surface of said foot portion atop the superior end plate of S1.

8. The method of claim 3 and further comprising:

engaging fusion material by the inferior end plate and superior end plate of L5 and S1, respectively, and

compressing fusion material between said end plates posterior to said foot portion in the L5-S1 junction while pulling L5 and S1 toward each other.

9. The method of claim 3, wherein at least one of said first and second screws has a conical tapered head surface;

and

installing an anti-backout screw with a conical head surface adapted to engage and interlock with the conical surface of said at least one of said first and second screws to prevent backout of said at least one of said first and second screws when the anti-backout screw is fixed in said plate.

10. The method of claim 9 and further comprising:

screwing the anti-backout screw tightly into engagement with the plate after installing said at least one of said first and second screws.

11. The method of claim 2 and further comprising:

seating the second screws in the plate and pulling L5 and S1 toward each other and compressing fusion material in said intervertebral space.

12. The method of claim 11 and further comprising:

providing anti-backout devices for said downwardly-installed screws.

13. The method of claim 1 and further comprising:

engaging fusion material by the inferior end plate and superior end plate of L5 and S1, respectively, and

compressing fusion material between said end plates posterior to said foot portion in the L5-S1 junction while pulling L5 and S1 toward each other.

14. The method of claim 1 and further comprising the steps of providing said first screws and said second screws, wherein said first screws and said second screws each comprise conical tapered head surfaces;

and

installing an anti-backout screw with a conical head surface adapted to engage and interlock with the conical tapered head surfaces of said first screws to prevent backout of said first screws when the anti-backout screw is fixed in said plate.

15. The method of claim 14 and further comprising:

screwing the anti-backout screw tightly into engagement with the plate after installing said first screws.

16. The method of claim 1 and further comprising:

engaging fusion material by the inferior end plate and superior end plate of L5 and S1, respectively.

17. The method of claim 1 and further comprising:

compressing fusion material between said end plates posterior to said foot portion in the L5-S1 junction while pulling L5 and S1 toward each other.

18. The method of claim 1 wherein at least one of said first and second screws has a conical tapered head surface;

and

installing an anti-backout screw with a conical head surface adapted to engage and interlock with the conical surface of said at least one of said first and second screws to prevent backout of said at least one of said first and second screws when the anti-backout screw is fixed in said plate.

19. The method of claim 18 and further comprising:

screwing the anti-backout screw tightly into engagement with the plate after installing said at least one of said first and second screws.

20. A method of stabilizing a lumbar-sacral junction for fusion comprising:

installing a foot portion of a plate partially into the anterior portion of intervertebral space between L5 and S1;

installing first screws from the front of the plate through holes in an upper portion of the plate into L5;

installing second screws from the front of the foot portion of the plate downwardly through the foot portion and out the bottom of the foot portion into S1; and

extending said second screws through the S1-S2 junction.

21. The method of claim 20, further comprising:

seating the second screws in the plate and pulling L5 and S1 toward each other and compressing fusion material in said intervertebral space.

22. The method of claim 20 and further comprising:

seating a bottom surface of said foot portion atop the superior end plate of S1.

23. The method of claim 22 and further comprising:

engaging fusion material by the inferior end plate and superior end plate of L5 and S1, respectively, and

compressing fusion material between said end plates posterior to said foot portion in the L5-S1 junction while pulling L5 and S1 toward each other.

24. The method of claim 20 and further comprising:

providing anti-backout devices for each of said second screws.

25. The method of claim 20 and further comprising the steps of providing said first screws and said second screws wherein said first screws and said second screws each comprise conical tapered head surfaces;

and

installing an anti-backout screw with a conical head surface adapted to engage and interlock with the conical tapered head surfaces of said first screws to prevent backout of said first screws when the anti-backout screw is fixed in said plate.

26. The method of claim 25 and further comprising:

screwing the anti-backout screw tightly into engagement with the plate after installing said first screws.

27. The method of claim 20 wherein at least one of said first and second screws has a conical tapered head surface;

and

installing an anti-backout screw with a conical head surface adapted to engage and interlock with the conical surface of said at least one of said first and second screws to prevent backout of said at least one of said first and second screws when the anti-backout screw is fixed in said plate.

28. The method of claim 27 and further comprising:

screwing the anti-backout screw tightly into engagement with the plate after installing said at least one of said first and second screws.

29. A method of stabilizing a lumbar-sacral junction for fusion comprising:

installing a foot portion of a plate partially into the anterior portion of intervertebral space between L5 and S1;

installing first screws from the front of the plate through holes in an upper portion of the plate into L5;

installing second screws from the front of the foot portion of the plate downwardly through the foot portion and out the bottom of the foot portion into S1;

installing said second screws through the foot portion on convergent paths in S1; and

extending said second screws through the S1-S2 junction.

30. The method of claim 29, further comprising the steps of providing said first screws and said second screws wherein said first screws and said second screws each comprise conical tapered head surfaces;

and

installing an anti-backout screw with a conical head surface adapted to engage and interlock with the conical tapered head surfaces of said first screws to prevent backout of said first screws when the anti-backout screw is fixed in said plate.

31. The method of claim 30 and further comprising:

screwing the anti-backout screw tightly into engagement with the plate after installing said first screws.

32. The method of claim 29 and further comprising:

seating said second screws in the plate and pulling L5 and S1 toward each other and compressing fusion material in said intervertebral space.

33. The method of claim 29 and further comprising:

seating a bottom surface of said foot portion atop the superior end plate of S1.

34. The method of claim 29 and further comprising:

engaging fusion material by the inferior end plate and superior end plate of L5 and S1, respectively, and

compressing fusion material between said end plates posterior to said foot portion in the L5-S1 junction while pulling L5 and S1 toward each other.

35. The method of claim 29, wherein at least one of said first and second has screws a conical tapered head surface;

and

installing an anti-backout screw with a conical head surface adapted to engage and interlock with the conical surface of said at least one of said first and second screws to prevent backout of said at least one of said first and second screws when the anti-backout screw is fixed in said plate.

36. The method of claim 35 and further comprising:

screwing the anti-backout screw tightly into engagement with the plate after installing said at least one of said first and second screws.