Bone plate with captive clips

• US 9,220,548 B2
• Filed: 11/22/2010
• Issued: 12/29/2015
• Est. Priority Date: 09/03/2003
• Status: Active Grant

• Current Assignee: Depuy Synthes Products Incorporated (Johnson & Johnson)
• Original Assignee: Depuy Synthes Products Incorporated (Johnson & Johnson)
• Inventors: Duong, Lan Anh Nguyen, Suh, Sean S, Rathbun, David S, Keyer, Thomas R, Binder, Lawrence J Jr.
• Primary Examiner(s): Isabella, David
• Assistant Examiner(s): NELSON, CHRISTINE L
• Application Number:
  US12/951,929
• Publication Number:
  US 20120065682A1
• Time in Patent Office: 1,863 Days
• Field of Search: 606/280, 606/286, 606/289, 606/290
• US Class Current: 1/1
• CPC Class Codes: A61B 17/1728 for holes for bone plates or plate screws
• 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: A61B 17/8605 Heads, i.e. proximal ends projecting from bone

Abstract

A fixation system includes a plate comprising a top surface, a bottom surface, a central longitudinal axis, at least one fixation hole extending between the top and bottom surfaces and comprising an undercut therein, and at least one passage intersecting one of the undercuts. At least one resilient clip is disposed in at least a portion of the undercut, with the at least one clip having a pair of generally parallel sides and an end tab. At least one fastener is provided and comprises a head and a threaded shaft, with the head comprising a perimetral groove extending around at least a portion thereof and an instrument receiving portion. The at least one clip is configured and dimensioned to seat in the undercut with the end tab extending within the passage, and the at least one fastener is configured and dimensioned to be received in the at least one fixation hole and securable therein when the at least one clip abuts the perimetral groove of the head.

Claims

1. A bone plating system for stabilizing bones or bone fragments, including segments of the spinal column, comprising:

a bone plate having an upper plate surface, a lower plate surface, a longitudinal axis, at least one fixation hole, the fixation hole passing through the upper surface and lower surface and having an undercut portion and a lower hole portion, the lower hole portion including a tapered section;

at least one resilient clip disposed within the undercut portion of the at least one fixation hole;

a first fastener elongate along a first fastener axis, the first fastener having a first head and a first shaft that extends out from the first head, the first head including a first lower portion and a first clip portion disposed above the first lower portion, wherein a diameter of the first clip portion is less than a diameter of the first lower portion, and the first clip portion includes a first upper tapered surface and a first lower tapered surface opposite the first upper tapered surface so as to define a first perimetral groove therebetween that is configured to receive the at least one resilient clip when the first fastener is seated in the at least one fixation hole to resist the first fastener from backing out of the plate, the first lower portion having a spherical portion that is configured to be operatively associated with the tapered section of the lower hole portion when the first fastener is seated in the lower hole portion to permit the first fastener to be inserted at a variety of insertion angles relative to the plate, wherein the first upper and lower tapered surfaces diverge from each other along a direction away from the first fastener axis and are each oriented at a non-zero angle with respect to a plane that is perpendicular to the first fastener axis; and

a second fastener different from the first fastener, the second fastener elongate along a second fastener axis, and having a second head and a second shaft that extends out from the second head, the second head including a second lower portion and a second clip portion disposed above the second lower portion, wherein a diameter of the second clip portion is less than a diameter of the second lower portion, and the second clip portion includes a second upper tapered surface and a second lower tapered surface opposite the second upper tapered surface so as to define a second perimetral groove therebetween that is configured to receive the at least one resilient clip when the second fastener is seated in the at least one fixation hole to resist the second fastener from backing out of the plate, the second lower portion configured to be operatively associated with the lower hole portion when the second fastener is seated in the lower hole portion so that the second fastener is insertable at a fixed angle relative to the plate, wherein the second upper and lower tapered surfaces diverge from each other along a direction away from the second fastener axis and are each oriented at a non-zero angle with respect to a plane that is perpendicular to the second fastener axis,

wherein at least one of the respective non-zero angles of the first upper and lower tapered surfaces is greater than at least one of the respective non-zero angles of the second upper and lower tapered surfaces so as to permit the first fastener to be inserted at the variety of insertion angles relative to the plate and so as to permit the second fastener to be inserted at the fixed angle relative to the plate.

2. The system of claim 1, wherein the first fastener further comprises:

an instrument receiving portion which intersects the first center portion in at least one location.

3. The system of claim 1, wherein the at least one resilient clip comprises a generally circular portion.

4. The system of claim 1, wherein the at least one resilient clip is separate and distinct from and operatively associated with the bone plate.

5. The system of claim 1, wherein the at least one resilient clip includes a slit.

6. The system of claim 1, wherein the at least one resilient clip is configured to be resiliently expandable during insertion of the first fastener into the at least one fixation hole.

7. The system of claim 6, wherein the at least one resilient clip is configured to be resiliently expandable during insertion of the second fastener into the at least one fixation hole.

8. The system of claim 6, wherein the at least one resilient clip is configured to resiliently contract about the clip portion of the first or second fasteners and resist back out when the lower portion of the first or second fastener is brought into contact with the at least one resilient clip.

9. The system of claim 1, wherein at least part of the undercut portion is disposed closer to the upper surface than the lower surface.

10. The system of claim 1, wherein the undercut portion extends completely around the at least one fixation hole.

11. The system of claim 1, wherein the lower hole portion has a first maximum inner dimension and the undercut portion has a second maximum inner dimension, wherein the first maximum inner dimension is less than the second maximum inner dimension.

12. The system of claim 1, wherein the first fastener can be inserted into the fixation hole at a range of insertion angles, the range of angles being about 15 degrees.

13. The system of claim 12, wherein the edges of the fixation hole at the upper surface of the plate form a horizontal plane and the range of insertion angles for the first fastener is offset between about 10 degrees and about 25 degrees from an axis perpendicular to the horizontal plane.

14. The system of claim 1, wherein the first fastener and its respective plate fixation hole is configured to permit the trajectory of the first fastener to change relative to the plate after insertion of the first fastener into a bone.

15. The system of claim 14, wherein the trajectory of the first fastener changes up to 15 degrees.

16. The system of claim 1, wherein the edges of the fixation hole at the upper surface form a horizontal plane and the second fastener is inserted into the fixation hole at an angle that is offset between about 10 degrees and about 25 degrees relative to an axis perpendicular to the horizontal plane.

17. The system of claim 1, wherein the first or second fastener further comprises a ledge extending beyond the diameter of the first clip portion.

18. The system of claim 1, wherein the first perimetral groove extends around a perimeter of the first clip portion.

19. The system of claim 1, wherein the fasteners are bone screws.

20. The system of claim 1, wherein the plate comprises a plurality of fixation holes, each fixation hole passing through the upper surface and lower surface and having an undercut portion and a lower hole portion, the lower hole portion including a tapered section;

and at least one resilient clip disposed within the undercut portion of each of the plurality of fixation holes.

21. The system of claim 1, wherein the at least one resilient clip has a hollow center portion for receiving at least one of the first or second fasteners and at least one of the first or second fasteners has an upper portion forming a lip which has an outer dimension larger than a dimension of the hollow center portion of the at least one resilient clip to assist in retaining the at least one resilient clip on the first or second fastener.

22. The system of claim 1 wherein the at least one resilient clip has a hollow center portion for receiving at least one of the first or second fasteners, and a diameter of the lower portion of the first or second fastener is larger than a dimension of the hollow center portion of the at least one resilient clip so that the lower portion of first or second fastener contacts and expands the at least one resilient clip during insertion of the first or second fastener.

23. The bone plating system of claim 1, wherein the non-zero angle of the first upper surface is greater than the non-zero angle of the second upper surface.

24. A kit for use with bone stabilization procedures comprising:

a first plate having an upper plate surface, a lower plate surface, a longitudinal axis, a plurality of fixation holes having an undercut portion and a lower hole portion, the lower hole portion having a tapered section;

at least one resilient clip disposed within the undercut portion of the plurality of fixation holes;

a plurality of variable angle fasteners and a plurality of fixed angle fasteners;

wherein the variable angle fasteners are each elongate along a first fastener axis and each have a first head and a first shaft that extends out from the first head, the first head including a first upper portion and a first lower portion, wherein a diameter of the first upper portion is less than a diameter of the first lower portion and the first upper portion includes a first upper tapered surface and a first lower tapered surface opposite the first upper tapered surface so as to define a first perimetral groove therebetween that is configured to receive the at least one resilient clip when the first fastener is seated in a one of the fixation holes to resist the first fastener from backing out of the plate, the first lower portion having a spherical portion that is configured to be operatively associated with the tapered section of the lower hole portion when the at least one variable angle fastener is seated in the lower hole portion to permit the at least one variable angle fastener to be inserted at a variety of insertion angles relative to the plate, wherein the first upper and lower tapered surfaces diverge from each other along a direction away from the first fastener axis and are each oriented at a non-zero angle with respect to a plane that is perpendicular to the first fastener axis; and

wherein the fixed angle fasteners are each elongate along a second fastener axis and each have a second head and a second shaft that extends out from the second head, the second head including a second upper portion and a second lower portion, wherein a diameter of the second upper portion is less than a diameter of the second lower portion and the second upper portion includes a second upper tapered surface and a second lower tapered surface opposite the second upper tapered surface so as to define a second perimetral groove therebetween that is configured to receive the at least one resilient clip when the second fastener is seated in a one of the fixation holes to resist the second fastener from backing out of the plate, the second lower portion configured to be operatively associated with the lower hole portion when the at least one fixed angle fastener is seated in the lower hole portion so that the at least one fixed angle fastener is insertable at a pre-determined fixed angle relative to the plate, wherein the second upper and lower tapered surfaces diverge from each other along a direction away from the second fastener axis and are each oriented at a non-zero angle with respect to a plane that is perpendicular to the second fastener axis,

wherein at least one of the respective non-zero angles of the first upper and lower tapered surfaces is greater than at least one of the respective non-zero angles of the second upper and lower tapered surfaces so as to permit any of the plurality of variable angle fasteners to be inserted at the variety of insertion angles relative to the plate and so as to permit any of the plurality of fixed angle fasteners to be inserted at the fixed angle relative to the plate.

25. The kit of claim 24, wherein the fasteners are bone screws.

26. The kit of claim 24, wherein the at least one resilient clip is configured to be resiliently expandable during insertion of any of the plurality of variable angle fasteners or fixed angle fasteners into any of the plurality of fixation holes.

27. The kit of claim 24, wherein the first fastener and its respective plate fixation hole is configured to permit the trajectory of the first fastener to change relative to the plate after insertion of the first fastener into a bone.

28. The kit of claim 24, wherein at least two of the plurality of fasteners are substantially the same length.

29. The kit of claim 24, wherein the undercut portion extends completely around each of the plurality of fixation holes.

30. The kit of claim 24, wherein the lower hole portion has a first maximum inner dimension and the undercut portion has a second maximum inner dimension, wherein the first maximum inner dimension is less than the second maximum inner dimension.

31. The kit of claim 24, wherein the upper portion of the first or second fastener further comprises a lip at its upper end.