Bone plate and bone screw guide mechanism

• US 6,235,034 B1
• Filed: 10/23/1998
• Issued: 05/22/2001
• Est. Priority Date: 10/24/1997
• Status: Expired due to Term

• Current Assignee: RSB Spine LLC
• Original Assignee: Robert S. Bray
• Inventors: Bray, Robert S.
• Primary Examiner(s): Recla, Henry J.
• Assistant Examiner(s): Woo, Julian W.
• Application Number:
  US09/177,885
• Time in Patent Office: 942 Days
• Field of Search: 606/69, 606/70, 606/71, 606/61, 623/17
• US Class Current: 606/71
• CPC Class Codes: A61B 17/16 Bone cutting, breaking or removal means other than saws, e.g. Osteoclasts; Drills or chisels for bones; Trepans arthroscopic bone cutters A61B17/320016; dental implant drills potentially for other surgical use A61C8/0089; bone grinders A61F2/4644, A22C17/06; A61B17/1662 takes precedence over all other subgroups except A61B17/17
• CPC Class Codes: A61B 17/1655 for tapping
• CPC Class Codes: A61B 17/1671 for the spine
• CPC Class Codes: A61B 17/1728 for holes for bone plates or plate screws
• CPC Class Codes: A61B 17/1757 for the spine
• CPC Class Codes: A61B 17/70 Spinal positioners or stabilisers ; Bone stabilisers comprising fluid filler in an implant
• CPC Class Codes: A61B 17/8042 the additional component being a cover over the screw head
• CPC Class Codes: A61B 17/8877 characterised by the cross-section of the driver bit
• CPC Class Codes: A61B 2090/033 Abutting means, stops, e.g. abutting on tissue or skin

Abstract

A bone plate comprises a base plate having at least two screw holes and at least two bone screws capable of securing the bone plate to a bone by insertion through the screw holes into the bone. The bone screws have heads shaped to toggle within the screw holes. A retaining plate is provided that is fixedly attachable to the base plate. The retaining plate covers at least a portion of each of the bone screws. The retaining plate and base plate each contain set screw apertures. A set screw is provided to retain the retaining plate in place over the base plate by screwing the set screw through the set screw apertures in the retaining plate and base plate. This design prevents the bone screw from backing out from the bone once screwed in through the base plate.

Claims

1. A bone plate comprising:

a base plate having at least two screw holes;

at least two bone screws capable of securing the bone plate to a bone by insertion through the screw holes into the bone, wherein the bone screws have heads shaped to toggle within the screw holes; and

a bone screw locking means capable of securedly covering the bone screws so that the bone screws cannot back out from the bone once screwed in through the base plate;

wherein the bone screws and bone screw locking means are designed such that when the bone screw locking means covers the bone screws and is fixedly attached to said base plate, the top of each bone screw mates with the bone screw locking means and each bone screw can toggle within its corresponding screw hole.

2. A bone plate according to claim 1, wherein the bone screw locking means comprises:

a retaining plate fixedly attachable to the base plate, wherein the retaining plate covers at least a portion of each of the bone screws, and

a retaining plate fixing means for fixedly attaching the retaining plate to the base plate.

3. A bone plate according to claim 2, wherein the fixing means comprises a set screw and wherein the base plate also has a set screw aperture.

4. A bone plate according to claim 2, wherein the retaining plate covers 100 percent of at least one bone screw.

5. A bone plate according to claim 1, wherein each bone screw can toggle within the corresponding screw hole in at least two directions at an angle of about 0 to about 20 degrees from normal.

6. A bone plate according to claim 1, wherein each bone screw can toggle within the corresponding screw hole in at least two directions at an angle of about 0 to about 15 degrees from normal.

7. A bone plate according to claim 1, wherein each bone screw can toggle within the corresponding screw hole in any direction at an angle of about 0 degrees to about 20 degrees from normal.

8. A bone plate according to claim 1, wherein each bone screw can toggle within the corresponding screw hole in any direction at an angle of about 0 to about 15 degrees from normal.

9. A bone plate according to claim 1, wherein each bone screw has a radiused head.

10. A bone plate according to claim 2, wherein each bone screw head contains a depression and wherein the retaining plate contains protrusions that correspond in shape, size and number to and that are capable of fitting within the depressions in the bone screw heads.

11. A bone plate according to claim 10, wherein each bone screw has a radiused head.

12. A bone plate according to claim 1, wherein the base plate comprises at least two pairs of adjacent screw holes.

13. A bone plate according to claim 1, wherein the base plate is made of titanium or a titanium alloy.

14. A bone plate comprising

a base plate having two screw holes and a set screw hole between the screw holes;

two bone screws capable of securing the bone plate to a bone by insertion through the screw holes into the bone;

a retaining plate fixedly attachable to the base plate, wherein the retaining plate has a size sufficient to cover the bone screws and a set screw aperture extending therethrough so that the set screw aperture is aligned with the set screw hole in the base plate when the retaining plate is placed on the base plate; and

a set screw for fixedly attaching the retaining plate to the base plate by extending through the set screw aperture in the retaining plate and into the set screw hole in the base plate;

wherein the bone screws and retaining plate are designed such that, when the retaining plate covers the bone screws the top of each bone screw mates with the retaining plate and the covered bone screws can toggle within the screw holes.

15. A bone plate according to claim 14, wherein each bone screw has a radiused head.

16. A bone plate according to claim 14, wherein each bone screw head contains a depression and wherein the retaining plate contains protrusions that correspond in shape, size and number to and that are capable of fitting within the depressions in the bone screw heads.

17. A bone plate according to claim 16, wherein each bone screw has a radiused head.

18. A bone plate according to claim 14, wherein each bone screw can toggle within the corresponding screw hole in at least two directions at an angle of about 0 to about 20 degrees from normal.

19. A bone plate according to claim 14, wherein each bone screw can toggle within the corresponding screw hole in at least two directions at an angle of about 0 to about 15 degrees from normal.

20. A bone plate according to claim 14, wherein each bone screw can toggle within the corresponding screw hole in any direction at an angle of about 0 to about 20 degrees from normal.

21. A bone plate according to claim 14, wherein each bone screw can toggle within the corresponding screw hole in any direction at an angle of about 0 to about 15 degrees from normal.

22. A bone plate according to claim 14, wherein the base plate and retaining plate are both made of titanium or a titanium alloy.

23. A bone plate comprising

a base plate having two screw holes, a set screw hole between the screw holes and at least two raised edges;

two bone screws capable of securing the base plate to a bone by insertion through the screw holes into the bone wherein each bone screw is adapted to toggle within each screw hole;

a retaining plate fixedly attachable to the base plate, wherein the retaining plate has a size sufficient to cover the bone screws and fit within the at least two raised edges, and wherein the retaining plate includes a set screw aperture extending therethrough so that the set screw aperture is aligned with the set screw hole in the base plate when the retaining plate is placed on the base plate; and

a set screw for fixedly attaching the retaining plate to the base plate by extending through the set screw aperture in the retaining plate and into the set screw hole in the base plate.

24. A bone plate according to claim 23, wherein the bone screws have heads shaped to toggle within the screw holes, and wherein, in use, the bone screw locking means covers the at least one bone screw, and the at least one covered bone screw can toggle within its corresponding screw hole.

25. A bone plate according to claim 23, wherein each bone screw has a radiused head.

26. A bone plate according to claim 23, wherein each bone screw head contains a depression and wherein the retaining plate contains protrusions that correspond in shape, size and number to and that are capable of fitting within the depressions in the bone screw heads.

27. A bone plate according to claim 26, wherein each bone screw has a radiused head.

28. A bone plate according to claim 23, wherein each bone screw can toggle within the corresponding screw hole in at least two directions at an angle of about 0 to about 20 degrees from normal.

29. A bone plate according to claim 23, wherein each bone screw can toggle within the corresponding screw hole in at least two directions at an angle of about 0 to about 15 degrees from normal.

30. A bone plate according to claim 23, wherein each bone screw can toggle within the corresponding screw hole in any direction at an angle of about 0 to about 20 degrees from normal.

31. A bone plate according to claim 23, wherein each bone screw can toggle within the corresponding screw hole in any direction at an angle of about 0 to about 15 degrees from normal.