Multi-axial bone anchor system

• US 6,858,031 B2
• Filed: 08/28/2001
• Issued: 02/22/2005
• Est. Priority Date: 04/16/1999
• Status: Expired due to Term

• Current Assignee: SDGI Holdings Incorporated (Medtronic Plc)
• Original Assignee: SDGI Holdings Incorporated (Medtronic Plc)
• Inventors: Morrison, Matthew M., Young, John Stewart, Beale, Jeffrey W., Barker, B. Thomas, Johnson, Chris E.
• Primary Examiner(s): Robert, Eduardo C.
• Application Number:
  US09/941,056
• Publication Number:
  US 20020029040A1
• Time in Patent Office: 1,274 Days
• Field of Search: 606/61, 606/69, 606/70, 606/71
• US Class Current: 606/292
• CPC Class Codes: A61B 17/7007 Parts of the longitudinal elements, e.g. their ends, being specially adapted to fit around the screw or hook heads
• CPC Class Codes: A61B 17/701 Longitudinal elements with a non-circular, e.g. rectangular, cross-section A61B17/7005, A61B17/7007 take precedence
• 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 17/7035 Screws or hooks, wherein a rod-clamping part and a bone-anchoring part can pivot relative to each other
• CPC Class Codes: A61B 17/7037 wherein pivoting is blocked when the rod is clamped
• CPC Class Codes: A61B 17/7041 with single longitudinal rod offset laterally from single row of screws or hooks A61B17/7044 takes precedence
• CPC Class Codes: A61B 17/7058 Plates mounted on top of bone anchor heads or shoulders
• CPC Class Codes: A61B 17/8033 having indirect contact with screw heads, or having contact with screw heads maintained with the aid of additional components, e.g. nuts, wedges or head covers
• 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 17/8695 Washers surrounding screw head in plate hole A61B17/8047, between bone plate and bone A61B17/8028
• CPC Class Codes: A61B 2090/037 with a frangible part, e.g. by reduced diameter

Abstract

A spinal implant system is disclosed for the fixation of bone segments in the spine. The system includes an elongated member, one or more bone anchor assemblies, and stabilizer members which are fitted within the elongated member. A bone anchor is attached to a bone, and the elongated member and stabilizer are fitted over the bone anchor. A rounded washer and nut having a corresponding rounded underside surface are fitted on to the bone anchor over the elongated member, and tightened. The configuration of the bone anchor assembly, including an intermediate portion of the bone anchor, the arcuate washer, and the nut, along with the configuration of the sliding support, allows multi-axial positioning of the bone anchor with respect to the elongated member at a plurality of locations along a slotted member.

Claims

1. An orthopedic implant, comprising:

a base member having a lower surface, an upper surface, and at least one aperture;

a stabilizer having an opening, said stabilizer being adjacent said base member in one of an infinite number of positions wherein said opening communicates with one of said apertures of said base member;

at least one second stabilizer each having an opening therethrough, said at least one second stabilizer further having at least one lateral finger abutting said base member, wherein said at least one second stabilizer is in one of an infinite number of positions such that said opening of said at least one second stabilizer communicates with an aperture of said base member;

a fixation member having a first portion for attachment to a bone, a second threaded portion, and an intermediate diametrally enlarged portion, said fixation member extending through said stabilizer and said base member so that said enlarged portion contacts said stabilizer;

a washer having a rounded top, said washer being around said second threaded part of said fixation member; and

a nut threaded onto said second threaded part of said fixation member, whereby said fixation member, said stabilizer and said base member can be locked relative to each other.

2. The implant of claim 1, further comprising at least one additional fixation member each having a first portion for fixing to a bone, a second threaded portion, and an intermediate diametrally enlarged portion, said at least one additional fixation member extending through a corresponding one of said at least one additional stabilizers and said base member so that said enlarged portion contacts a portion of said corresponding stabilizer.

3. The implant of claim 1, wherein said nut includes a break-off portion that is severed when a torque exceeding a predetermined amount is applied to said break-off portion.

4. The implant of claim 1, wherein said opening in said stabilizer in said stabilizer has a longitudinal axis, and said stabilizer substantially forms a parallelogram in a plane substantially perpendicular to said axis.

5. The implant of claim 4, wherein said stabilizer substantially forms a square in a plane substantially perpendicular to said axis.

6. The implant of claim 1, wherein said washer has a bottom surface that includes a projection extending substantially perpendicularly from said bottom surface.

7. The implant of claim 1, wherein said washer includes a hole therethrough bounded by a wall having a conical portion.

8. The implant of claim 1, wherein said washer includes a flange portion having a C-clip attached thereto.

9. The implant of claim 1, wherein said first portion for attachment to a bone of said fixation member includes threads.

10. The implant of claim 9, wherein said threads of said first portion has a root diameter that increases toward said intermediate diametrally enlarged portion so that at least a portion of said intermediate diametrally enlarged portion is substantially a continuation of said root diameter.

11. An orthopedic implant, comprising:

a base member having a lower surface, an upper surface, and at least one aperture;

a stabilizer having an opening, said stabilizer being adjacent said base member in one of an infinite number of positions wherein said opening communicates with one of said apertures of said base member, at least a portion of said stabilizer being between said upper and lower surfaces of said base member;

a fixation member having a first portion for attachment to a bone, a second threaded portion, and an intermediate diametrally enlarged portion, said fixation member extending through said stabilizer and said base member so that said enlarged portion contacts said stabilizer;

a washer having a rounded top, said washer being around said second threaded part of said fixation member; and

a nut threaded onto said second threaded part of said fixation member, whereby said fixation member, said stabilizer and said base member can be locked relative to each other.

12. The implant of claim 11, wherein said washer has a bottom surface that includes a projection extending substantially perpendicularly from said bottom surface.

13. The implant of claim 11, wherein said washer includes a hole therethrough bounded by a wall having a conical portion.

14. The implant of claim 11, wherein said washer includes a flange portion having a C-clip attached thereto.

15. The implant of claim 11, wherein said first portion for attachment to a bone of said fixation member includes threads.

16. The implant of claim 15, wherein said threads of said first portion has a root diameter that increases toward said intermediate diametrally enlarged portion so that at least a portion of said intermediate diametrally enlarged portion is substantially a continuation of said root diameter.

33. The implant of claim 11, wherein said opening in said stabilizer has a longitudinal axis, and said stabilizer substantially forms a parallelogram in a plane substantially perpendicular to said axis.

34. The implant of claim 33, wherein said stabilizer substantially forms a square in a plane substantially perpendicular to said axis.

17. An orthopedic implant, comprising:

a base member having a lower surface, an upper surface, and at least one aperture;

a stabilizer having an opening, said stabilizer being adjacent said base member in one of an infinite number of positions wherein said opening communicates with one of said apertures of said base member;

a fixation member having a first portion for attachment to a bone, a second threaded portion, and an intermediate diametrally enlarged portion, said fixation member extending through said stabilizer and said base member so that said enlarged portion contacts said stabilizer within said opening;

a washer having a rounded top, said washer being around said second threaded part of said fixation member; and

a nut threaded onto said second threaded part of said fixation member, whereby said fixation member, said stabilizer and said base member can be locked relative to each other.

18. The implant of claim 17, further comprising at least one additional stabilizer each having an opening therethrough, said at least one additional stabilizer further having at least one lateral finger abutting said base member, wherein said at least one additional stabilizer is in one of an infinite number of positions such that said opening of said at least one additional stabilizer communicates with an aperture of said base member.

19. The implant of claim 18, further comprising at least one additional fixation member each having a first portion for fixing to a bone, a second threaded portion, and an intermediate diametrally enlarged portion, said at least one additional fixation member extending through a corresponding one of said at least one additional stabilizers and said base member so that said enlarged portion contacts a portion of said corresponding stabilizer.

20. The implant of claim 17, wherein said nut includes a break-off portion that is severed when a torque exceeding a predetermined amount is applied to said break-off portion.

21. The implant of claim 17, wherein at least a portion of said stabilizer is between said upper and lower surfaces of said base member.

22. The implant of claim 17, wherein said opening in said stabilizer in said stabilizer has a longitudinal axis, and said stabilizer substantially forms a parallelogram in a plane substantially perpendicular to said axis.

23. The implant of claim 22, wherein said stabilizer substantially forms a square in a plane substantially perpendicular to said axis.

24. The implant of claim 17, wherein said washer has a bottom surface that includes a projection extending substantially perpendicularly from said bottom surface.

25. The implant of claim 17, wherein said washer includes a hole therethrough bounded by a wall having a conical portion.

26. The implant of claim 17, wherein said washer includes a flange portion having a C-clip attached thereto.

27. The implant of claim 17, wherein said first portion for attachment to a bone of said fixation member includes threads.

28. The implant of claim 27, wherein said threads of said first portion has a root diameter that increases toward said intermediate diametrally enlarged portion so that at least a portion of said intermediate diametrally enlarged portion is substantially a continuation of said root diameter.

29. An orthopedic implant, comprising:

a base member having a lower surface, an upper surface, and at least one aperture;

a stabilizer having an opening, said stabilizer being adjacent said base member in one of an infinite number of positions wherein said opening communicates with one of said apertures of said base member;

at least one second stabilizer each having an opening therethrough, said at least one second stabilizer further having at least one lateral finger abutting said base member, wherein said at least one second stabilizer is in one of an infinite number of positions such that said opening of said at least one second stabilizer communicates with an aperture of said base member;

a fixation member having a first portion for attachment to a bone, a second threaded portion, and an intermediate rounded diametrally enlarged portion, said fixation member extending through said stabilizer and said base member so that said enlarged portion contacts said stabilizer;

a washer having a rounded top, said washer being around said second threaded part of said fixation member; and

a nut threaded onto said second threaded part of said fixation member, whereby said fixation member, said stabilizer and said base member can be locked relative to each other.

30. The implant of claim 29, further comprising at least one additional fixation member each having a first portion for fixing to a bone, a second threaded portion, and an intermediate diametrally enlarged portion, said at least one additional fixation member extending through a corresponding one of said at least one additional stabilizers and said base member so that said enlarged portion contacts a portion of said corresponding stabilizer.

31. The implant of claim 29, wherein said nut includes a break-off portion that is severed when a torque exceeding a predetermined amount is applied to said break-off portion.

32. An orthopedic implant, comprising:

a base member having a lower surface, an upper surface, and at least one aperture;

a stabilizer having an opening, said stabilizer being adjacent said base member in one of an infinite number of positions wherein said opening communicates with one of said apertures of said base member, at least a portion of said stabilizer being between said upper and lower surfaces of said base member;

a fixation member having a first portion for attachment to a bone, a second threaded portion, and an intermediate rounded diametrally enlarged portion, said fixation member extending through said stabilizer and said base member so that said enlarged portion contacts said stabilizer;

a washer having a rounded top, said washer being around said second threaded part of said fixation member; and

a nut threaded onto said second threaded part of said fixation member, whereby said fixation member, said stabilizer and said base member can be locked relative to each other.