Orthopedic fixation system and method of use

• US 20050283153A1
• Filed: 06/17/2004
• Published: 12/22/2005
• Est. Priority Date: 06/17/2004
• Status: Active Grant

• Current Assignee: SDGI Holdings Incorporated (Medtronic Plc)
• Original Assignee: SDGI Holdings Incorporated (Medtronic Plc)
• Inventors: Poyner, Jeffrey W., Farris, Robert A.
• Granted Patent: US 7,303,563 B2
• Time in Patent Office: Days
• US Class Current: 606/53
• 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 17/7032 Screws or hooks with U-shaped head or back through which longitudinal rods pass
• 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 17/7044 also having plates, staples or washers bearing on the vertebrae
• 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 17/8061 specially adapted for particular bones A61B17/70 and A61B17/74 take precedence
• CPC Class Codes: A61B 2090/035 preventing further rotation

Abstract

A orthopedic fixation system comprising a plate with an outwardly-extending member. A saddle may be mounted on the member and includes spaced-apart arms that form a channel to receive a rod. An engagement member may be mounted within the saddle to prevent escape of the rod. In one embodiment, the engagement member is attached to the saddle to apply a downward force on the rod and an upward force on the saddle to lift the saddle relative to the plate. A method of attaching an orthopedic rod is also included. In one embodiment, a rod is positioned within a channel in the saddle and a downward force is applied against the anchor which results in an upward force on the saddle to lift the saddle relative to the anchor.

Claims

1. An orthopedic fixation system for attachment of a rod comprising:

a plate having a top surface and a bottom surface, the plate having at least one threaded aperture extending at least partially between the top surface and the bottom surface;

an elongated anchor comprising;

a first threaded end that mates with the threaded aperture to attach the anchor to the plate,

a mount at a second end opposite the first end, and

a flange extending outward at a position between the threaded end and the mount and having a width greater than the threaded aperture and being in contact with the plate when the anchor is fully mounted to the plate; and

a saddle attached to the mount, the saddle comprising upwardly extending arms spaced a distance apart to form a channel, the saddle being pivotally attached to the anchor to receive the rod within the channel at a variety of positions relative to the plate.

2. The orthopedic fixation system of claim 1 wherein the mount has a substantially spherical shape and the saddle has a bearing surface to accept the substantially spherical shape.

3. The orthopedic fixation system of claim 1 wherein a distance between the first threaded end and a bottom surface of the flange is less than or equal to the distance between the top surface and the bottom surface of the plate.

4. The orthopedic fixation system of claim 1 wherein the aperture extends through the thickness of the plate.

5. The orthopedic fixation system of claim 1 wherein a bottom surface of the flange contacts the top surface of the plate.

6. An orthopedic fixation system for attachment of a rod comprising:

a plate having a top surface and a bottom surface, the plate having at least one threaded aperture extending at least partially between the top surface and the bottom surface;

an anchor having a first threaded section, a head, and a flange positioned therebetween, the first threaded section engaged with the threaded aperture with the flange contacting the plate and the head extending above the top surface; and

a saddle having a plurality of upright portions that define a channel that receives the rod through the saddle member, and a lower portion that cooperates with the head to allow multi-axial movement of the saddle relative to the plate.

7. A method of fixing an orthopedic rod comprising:

rotating a threaded portion of an anchor into a threaded aperture within a plate;

positioning the anchor with a head of the anchor extending above a top surface of the plate;

contacting a flange on the anchor with the plate to limit an engagement depth of the anchor into the plate; and

pivoting a saddle on the head of the anchor about multiple axes to receive the rod within a channel portion of the saddle.

8. The method of claim 7, further comprising pivoting the saddle on the head of the anchor about a single axis to receive a rod within the channel portion of the saddle.

9. The method of claim 7, further comprising supporting the rod at three positions by placing the rod in a concave support feature and applying a downward force from above with an engagement member.

10. An orthopedic fixation system:

a plate having at least one aperture;

an anchor having a first end positioned within the aperture and a plurality of first locking features on the surface of the anchor;

a saddle having a plurality of upright portions that define a channel and an opening positioned on a lower section below the channel, the saddle further comprising a plurality of second locking features; and

an engagement member sized to fit within the channel and engage the plurality of upright portions,

engagement of the engagement member within the plurality of upright portions and with a rod causes upward movement of the saddle relative to the anchor to engage the plurality of first and second locking features.

11. The orthopedic fixation system of claim 10 wherein the anchor is a screw having threads on a first end that engage threads within the aperture of the plate.

12. The orthopedic fixation system of claim 10 wherein the engagement member is a setscrew having external threads that engage internal threads on the plurality of upright portions.

13. The orthopedic fixation system of claim 10 further comprising a rod positioned between the engagement member and the anchor.

14. The orthopedic fixation system of claim 10 wherein the upright portions of the saddle extend upwards from the lower section to define a substantially u-shaped channel.

15. The orthopedic fixation system of claim 10 wherein the opening is a hole positioned entirely within the lower section and surrounded in all directions by the plurality of second locking features.

16. The orthopedic fixation system of claim 10 wherein the lower section is substantially u-shaped and the opening is a slot.

17. An orthopedic fixation system comprising:

a plate;

a saddle having a lower section and spaced apart arms extending upward from the lower section;

an opening positioned within the lower section of the saddle;

an anchor having a neck and head, the neck extending upward from the plate through the opening and the head positioned between the arms;

an engagement member positioned between the arms and above the head;

engagement of the engagement member within the plurality of upright portions and with a rod causes upward movement of the saddle relative to the anchor causing contact between locking features on at least one of the anchor and lower section to prevent rotational movement of the saddle relative to the anchor.

18. The orthopedic fixation system of claim 17 wherein the head is wider than the neck.

19. The orthopedic fixation system of claim 18 wherein the neck is tapered.

20. The orthopedic fixation system of claim 19 wherein the locking features on the anchor are positioned on the tapered neck.

21. The orthopedic fixation system of claim 18 wherein the neck is curved.

22. The orthopedic fixation system of claim 19 wherein the locking features on the anchor are positioned on the curved neck.

23. The orthopedic fixation system of claim 17 wherein the locking features on the anchor are positioned on a lower side of the head.

24. The orthopedic fixation system of claim 17 wherein the head is larger than the opening to limit the extent of upward movement of the saddle relative to the anchor.

25. The orthopedic fixation system of claim 17 wherein the locking features are on both the anchor and the saddle.

26. The orthopedic fixation system of claim 17 wherein the opening is wider than the neck to allow axial rotation of saddle about the anchor.

27. The orthopedic fixation system of claim 17 wherein the locking features are splines.

28. The orthopedic fixation system of claim 17 wherein the locking features are knurls.

29. The orthopedic fixation system of claim 17 wherein the locking features are frictional features.

30. The orthopedic fixation system of claim 17 wherein the head has a concave support feature to support the rod.

31. An orthopedic fixation system for attachment of a rod comprising:

a plate;

a saddle having a lower section and spaced apart arms extending upward from the lower section, the spaced apart arms forming a channel into which the rod is positioned;

an opening positioned within the lower section of the saddle;

an anchor having a neck and head, the neck extending upward from the plate and extending through the opening, and the head positioned between the arms, the rod being placed on a top portion of the head;

an engagement member positioned between the arms and above the rod;

the engagement of the engagement member within the plurality of upright portions causes a downward force on the rod and upward movement of the saddle relative to the anchor.

32. A method of attaching an orthopedic rod comprising:

rotating a saddle about an anchor;

positioning the rod within a channel in the saddle;

applying a downward force on the rod against the anchor; and

applying an upward force on the saddle and lifting the saddle relative to the anchor.

33. The method of claim 32 further comprising interlocking the saddle and the anchor to prevent the saddle from rotating about the anchor.

34. The method of claim 32 wherein the step of applying a downward force on the rod against the anchor comprises engaging a setscrew within the channel to position the rod between the anchor and the setscrew.

35. The method of claim 32 wherein the steps of applying a downward force on the rod against the anchor and applying an upward force on the saddle and lifting the saddle relative to the anchor comprise engaging a setscrew within the channel to position the rod between the anchor and the setscrew.

36. A method of attaching an orthopedic rod comprising:

rotating a saddle about an anchor;

positioning the rod within a channel in the saddle;

threading a setscrew into the channel thereby applying a downward force on the rod against the anchor; and

further applying an upward force on the saddle and lifting the saddle relative to the anchor with the setscrew.

37. An orthopedic plate system comprising:

a plate having at least one threaded member extending outward from a surface of the plate;

a saddle having a plurality of upright portions that define a channel and a threaded opening positioned on a lower section below the channel; and

a rod positioned within the channel,

the threaded opening engaging with the threaded member and the saddle being rotatable about the threaded member.

38. The orthopedic plate system of claim 37 further comprising an engagement member positioned in the channel and above the rod, the engagement of the engagement member in the channel causes a downward force on the rod.

39. The orthopedic plate system of claim 38 wherein the engagement member is a setscrew that is threaded into mating threads on the upright portions.

40. The orthopedic plate system of claim 37 wherein the threaded member is a threaded post integrally formed in the plate.

41. The orthopedic plate system of claim 37 wherein the threaded member is a threaded insert inserted into the plate.

42. A method of attaching an orthopedic rod comprising:

rotating a saddle about a threaded member extending outward from a plate;

positioning the rod within a channel in the saddle;

threading a setscrew into the channel thereby applying a downward force on the rod against the threaded member; and

further applying an upward force on the saddle and lifting the saddle relative to the threaded member.

43. The method of claim 42 further comprising threading the saddle onto the threaded member.

44. The method of claim 42 further comprising threading the saddle onto the threaded member so that the bottom of the channel lies below an uppermost surface of the threaded member.

45. The method of claim 44 further comprising supporting the rod on the uppermost surface of the threaded member.

46. The method of claim 44 further comprising supporting the rod in a concave support feature in the threaded member.

47. The method of claim 44 further comprising supporting the rod in two places from below by a concave slot member and in one place from above by the setscrew.

48. The method of claim 42 further comprising deforming the threaded member against the rod to further support the rod.

49. An orthopedic fixation system for attachment of a rod comprising:

a plate having a top surface and a bottom surface, the plate having at least one threaded aperture extending at least partially between the top surface and the bottom surface;

an elongated anchor comprising;

a threaded section that mates with the threaded aperture to attach the anchor to the plate,

a mount, and

a flange extending outward from a centerline and having a width greater than the threaded aperture and being in contact with the plate when the anchor is fully mounted to the plate; and

a saddle attached to the mount, the saddle comprising upwardly extending arms spaced a distance apart to form a channel, the saddle being pivotally attached to the anchor to receive the rod within the channel at a variety of positions relative to the plate.

50. The system of claim 49, wherein the flange contacts the bottom surface of the plate.

51. The system of claim 49, wherein the mount comprises external threads positioned above the top surface of the plate and connects with an opening within the saddle.

52. An orthopedic fixation system:

a plate having at least one aperture;

an anchor having a first end positioned within the aperture and a second end extending upward above the plate;

a saddle having a plurality of upright portions that define a channel and an opening positioned on a lower section that connects with the anchor at a point above the plate; and

an engagement member sized to fit within the channel and engage the plurality of upright portions,

engagement of the engagement member within the plurality of upright portions and with a rod causes upward movement of the saddle relative to the plate.

53. An orthopedic fixation system comprising:

a plate;

a saddle having a lower section and spaced apart arms extending upward from the lower section;

an opening positioned within the lower section of the saddle;

an anchor having a neck and head, the neck extending upward from the plate through the opening and the head positioned between the arms;

an engagement member positioned between the arms and above the head engagement of the engagement member within the plurality of upright portions and with a rod causes upward movement of the saddle relative to the anchor.

54. The orthopedic fixation system of claim 53 wherein the head is wider than the neck.

55. The orthopedic fixation system of claim 54 wherein the head is larger than the opening to limit the extent of upward movement of the saddle relative to the anchor.

56. The orthopedic fixation system of claim 53 wherein the opening is wider than the neck to allow axial rotation of saddle about the anchor.

57. An orthopedic fixation system for attachment of a rod comprising:

a plate having a top surface and a bottom surface, the plate having an aperture extending at least partially between the top surface and the bottom surface;

an elongated anchor comprising;

a first end that mates with the aperture to attach the anchor to the plate, and

a mount at a second end opposite the first end, and

a saddle attached to the mount, the saddle comprising upwardly extending arms spaced a distance apart to form a channel, the saddle being pivotally attached to the anchor to receive the rod within the channel at a variety of positions relative to the plate.

58. The orthopedic fixation system of claim 57 wherein the mount has a substantially spherical shape and the saddle has a bearing surface to accept the substantially spherical shape.

59. The orthopedic fixation system of claim 57 wherein the aperture extends through the thickness of the plate.

60. The orthopedic fixation system of claim 57 wherein the anchor is deformed against the rod to further support the rod.

61. An orthopedic fixation system for attachment of a rod comprising:

a plate having a top surface and a bottom surface, the plate having at least one threaded aperture extending at least partially between the top surface and the bottom surface;

an anchor having a first threaded section and a head, the first threaded section engaged with the threaded aperture and the head extending above the top surface; and

a saddle having a plurality of upright portions that define a channel that receives the rod through the saddle member, and a lower portion that cooperates with the head to allow multi-axial movement of the saddle relative to the plate.

62. A method of fixing an orthopedic rod comprising:

threading a portion of an anchor into an aperture within a plate;

positioning the anchor with a head of the anchor extending above a top surface of the plate; and

pivoting a saddle on the head of the anchor about multiple axes to receive a rod within a channel portion of the saddle.

63. The method of claim 62, further comprising pivoting the saddle on the head of the anchor about a single axis to receive a rod within the channel portion of the saddle.

64. The method of claim 62, further comprising supporting the rod at three positions by placing the rod in a concave support feature and applying a downward force from above with an engagement member.

65. An orthopedic fixation system:

a plate having at least one aperture;

an anchor having a first end positioned within the aperture and a plurality of first locking features on the surface of the anchor;

a saddle having a plurality of upright portions that define a channel and an opening positioned on a lower section below the channel, the saddle further comprising a plurality of second locking features; and

an engagement member sized to fit within the channel and engage the plurality of upright portions,

engagement of the engagement member within the plurality of upright portions causes upward movement of the saddle relative to the anchor to engage the plurality of first and second locking features.