Instruments and techniques for separating bony structures

• US 20030225416A1
• Filed: 05/20/2003
• Published: 12/04/2003
• Est. Priority Date: 05/21/2002
• Status: Active Grant

• Current Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Original Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Inventors: Lange, Eric C., DeRidder, Steven D., Francis, Tom J., Bonvallet, Todd C.
• Granted Patent: US 7,749,231 B2
• Time in Patent Office: Days
• US Class Current: 606/105
• CPC Class Codes: A61B 17/0206 with antagonistic arms as supports for retractor elements
• CPC Class Codes: A61B 17/025 Joint distractors
• CPC Class Codes: A61B 2017/0256 for the spine
• CPC Class Codes: A61F 2/4611 of spinal prostheses

Abstract

Instruments and techniques separate or spread adjacent bony structures by inserting a distal spreader assembly into the space between the adjacent bony structures and actuating the spreading members with a proximal actuator assembly.

Claims

1. An instrument for separating bony structures, comprising:

an actuator assembly; and

a spreader assembly at a distal end of said actuator assembly, wherein said spreader assembly includes first and second spreading members positionable between the bony structures and movable away from and toward one another with said actuator assembly, at least one of said spreading members including a bone contacting surface comprising an etched surface profile.

2. The instrument of claim 1, wherein said each of said first and second spreading members comprises a body portion including a distal end wall and a pair of extension members spaced from one another and extending distally from said distal end wall.

3. The instrument of claim 1, wherein said each of said first and second spreading members includes an extension member positionable in a space between the bony structures and said bone contacting surface extends along said extension member of at least one of said spreading members.

4. The instrument of claim 3, wherein each of said extension members includes a bone contacting surface comprising an etched surface profile.

5. The instrument of claim 3, wherein each of said extension members includes a laterally oriented flange portion and a vertically oriented web portion extending along said flange portion, said web portion and said flange portion defining a receptacle opening toward the other extension member.

6. The instrument of claim 5, wherein said first and second spreading members include a low profile configuration in an unactuated state for insertion in the space and in said low profile configuration said web portion of said extension member of said first spreading member is received in said receptacle of said extension member of said second spreading member and said web portion of said extension of said second spreading member is received in said receptacle of said extension member of said first spreading member.

7. The instrument of claim 3, wherein said first and second spreading members include a low profile configuration in an unactuated state for insertion in the space and said extension members of said first and second spreading members are parallel with one another in said low profile configuration and remain parallel during movement away from one another.

8. The instrument of claim 7, wherein said extension members of said first and second spreading members are in contact with one another along substantially the entire length thereof in said low profile configuration.

9. An instrument for separating bony structures, comprising:

an actuator assembly; and

a spreader assembly at a distal end of said actuator assembly, wherein said spreader assembly includes first and second spreading members positionable between the bony structures and movable away from and toward one another with said actuator assembly, at least one of said spreading members including a bone contacting surface with bone engagement features for engaging the bony structure positioned thereagainst.

10. The instrument of claim 9, wherein said bone engagement features include a number of teeth extending from said bone contacting surface.

11. The instrument of claim 9, wherein said bone contacting surface includes a convex curvature therealong.

12. The instrument of claim 11, wherein said bone contacting surface includes a number of grooves in said convexly curved portion forming said bone engagement features.

13. The instrument of claim 12, wherein said grooves extend transversely to said convexly curved surface.

14. The instrument of claim 9, wherein said each of said first and second spreading members includes an extension member positionable in a space between, the bony structures and each of said extension members includes a bone contacting surface extending therealong.

15. The instrument of claim 14, wherein said bone contacting surface of each of said extension members includes a convex curvature.

16. The instrument of claim 14, wherein each of said extension members includes a laterally oriented flange portion and a vertically oriented web portion extending along said flange portion, said web portion and said flange portion defining a receptacle opening toward the other extension member.

17. The instrument of claim 16, wherein said first and second spreading members include a low profile configuration in an unactuated state of said actuator assembly for insertion in the space and in said low profile configuration said web portion of said extension member of said first spreading member is received in said receptacle of said extension member of said second spreading member and said web portion of said extension member of said second spreading member is received in said receptacle of said extension member of said first spreading member.

18. The instrument of claim 16, wherein said web portion of each of said extension members includes a substantially uniform height along said flange portion.

19. The instrument of claim 9, wherein said first and second spreading members each include:

a body portion;

a first extension member extending distally from a first side of said body portion, said first extension member including a bone contacting surface therealong; and

a second extension member spaced from said first extension member and extending distally from a second side of said body portion, said second extension member including a bone contacting surface therealong.

20. The instrument of claim 19, wherein said body portion of each of said first and second spreading members includes an outer surface, an inner surface oriented opposite said bone contacting surfaces of said first and second extension members, and a distal end wall concavely curved between said first and second extension members.

21. The instrument of claim 20, wherein said first and second extension members of each of said first and second spreading members extend from said distal end wall adjacent said inner surface.

22. The instrument of claim 19, wherein for each of said first and second spreading members said first extension member extends distally further than said second extension member.

23. The instrument of claim 19, wherein said body portion of at least one of said first and second spreading members includes a stepped region extending from said actuator assembly, said stepped region spacing first and second extension members of said at least one of said first and second spreading members from said first and second extension members of the other of said first and second spreading members with said actuator assembly in an unactuated position.

24. The instrument of claim 19, wherein said body portion of each of said first and second spreading members includes an outer surface, an inner surface oriented opposite said bone contacting surfaces of said extension members, a distal end wall, and a proximal end wall, said body portion further comprising a slot extending between said proximal and distal end walls sized to receive a cutting instrument therethrough.

25. The instrument of claim 24, wherein said slot is sized to guide the cutting instrument between said bone contacting surfaces of said first and second extension members.

26. The instrument of claim 25, wherein said body portion includes a groove in communication with said slot to maintain alignment of the cutting instrument.

27. The instrument of claim 19, wherein said body portion of each of said first and second spreading members includes an outer surface, an inner surface oriented opposite said bone contacting surfaces of said first and second extension members, a distal end wall, and a proximal end wall, said body portion further comprising a support surface extending along said inner surface and each of said first and second extension members to support a cutting instrument therealong.

28. The instrument of claim 19, wherein said body portion of each of said first and second spreading members includes an outer surface, an inner surface oriented opposite said bone contacting surfaces of said first and second extension members, a distal end wall, and a proximal end wall, said body portion further comprising a guide member including a distal end between said first and second extension members and including a length extending to a proximal end spaced proximally from said proximal end wall of said body portion.

29. The instrument of claim 28, wherein said guide members of each of said body members are angled relative to one another so that a spacing between said guide members tapers distally.

30. An instrument for separating bony structures, comprising:

an actuator assembly; and

a spreader assembly at a distal end of said actuator assembly, wherein said spreader assembly includes first and second spreading members movable away from and toward one another with said actuator assembly, said spreading members each including at least one distal extension member including a length positionable in a space between the adjacent bony structures, wherein with said actuator assembly unactuated said distal extensions members are positioned adjacent one another in an overlapping configuration to provide a low profile for positioning in a space between adjacent bony structures, wherein in said overlapping configuration said distal extension members contact one another along a substantial portion of said length thereof.

31. The instrument of claim 30, wherein each of said extension members includes a laterally oriented flange portion and a vertically oriented web portion extending along said flange portion, said web portion and said flange portion defining a receptacle opening toward the other extension member.

32. The instrument of claim 31, wherein said web portion of each of said extension members includes a substantially uniform height along said flange portion.

33. The instrument of claim 31, wherein each of said extension members includes a thickness between an inner surface of said web portion and an outer surface of said flange portion, wherein in said overlapping configuration said extension members include an overall thickness between said outer surfaces of said extension members that is at least 25 percent less than the sum of the thicknesses of each of said first and second extension members.

34. The instrument of claim 31, wherein in said overlapping configuration said web portion of said extension member of said first spreading member is received in said receptacle of said extension member of said second spreading member and said web portion of said extension of said second spreading member is received in said receptacle of said extension member of said first spreading member.

35. The instrument of claim 30, wherein said extension members of said first and second spreading members are parallel with one another in said overlapping configuration and remain parallel during movement away from one another.

36. The instrument of claim 30, wherein said extension members of said first and second spreading members each include an etched bone contacting surface.

37. The instrument of claim 30, wherein said extension members of said first and second spreading members each include a convexly curved bone contacting surface.

38. The instrument of claim 37, wherein said convexly curved bone contacting surfaces each include a number of transverse grooves.

39. An instrument for separating bony structures, comprising:

an actuator assembly; and

a spreader assembly at a distal end of said actuator assembly, wherein said spreader assembly includes first and second spreading members movable away from and toward one another with said actuator assembly, said spreading members each including a body portion and a pair of extension members extending distally from said body portion, said spreading members further each including a support surface extending along said body portion for guiding a cutting instrument between said pair of extension members.

40. The instrument of claim 39, wherein said body portion of each of said first and second spreading members includes an outer surface, an inner surface oriented toward the inner surface of the other body portion, a distal end wall, and a proximal end wall, said body portion further comprising a slot including said support surface, said slot extending between and opening at said proximal and distal end walls.

41. The instrument of claim 40, wherein said slot is offset toward said outer surface of said body portion from a bone contacting surface of each of said first and second extension members.

42. The instrument of claim 41, wherein said body portion includes a groove in communication with said slot to maintain alignment of the cutting instrument during distal and proximal movement of the cutting instrument in said slot.

43. The instrument of claim 39, wherein said body portion of each of said first and second spreading members includes an outer surface, an inner surface oriented toward the inner surface of the other body portion, a distal end wall, and a proximal end wall, said support surface extending along said inner surface of said body portion and along each of said first and second extension members.

44. The instrument of claim 39, wherein said body portion of at least one of said first and second spreading members includes a stepped region extending from said actuator assembly, said stepped region spacing said first and second extension members of said at least one of said first and second spreading members from said first and second extension members of the other of said first and second spreading members with said actuator assembly in an unactuated position.

45. The instrument of claim 39, wherein each one of said pair of extension members of each of said spreading members includes a number of teeth extending from a bone contacting surface thereof.

46. The instrument of claim 39, further comprising an adjustment mechanism coupled to said actuator assembly.

47. An instrument for separating bony structures, comprising:

an actuator assembly; and

a spreader assembly at a distal end of said actuator assembly, wherein said spreader assembly includes first and second spreading members movable away from and toward one another with said actuator assembly, said spreading members each including a body portion and a pair of extension members extending distally from said body portion, said spreading members further each including a guide member extending between said extension members and providing a guide surface therebetween.

48. The instrument of claim 47, wherein said guide member comprises a flat plate-like body.

49. The instrument of claim 47, wherein said body portion of each of said first and second spreading members includes an outer surface, an inner surface oriented toward the inner surface of the other body portion, a distal end wall, and a proximal end wall, said guide member extending including a distal end between said first and second extension members and including a length extending along said inner surface to a proximal end of said guide member spaced proximally from said proximal end wall of said body portion.

50. The instrument of claim 49, wherein said guide members of each of said body members are angled relative to one another so that a spacing between said guide members tapers distally.

51. The instrument of claim 49, wherein said guide members of said spreading members are parallel to one another.

52. The instrument of claim 49, wherein said guide members are each oriented relative to said distal extensions such that with said distal extensions positioned in the space between the adjacent bony structures said guide member extends along one of the adjacent surfaces of the adjacent bony structures.

53. The instrument of claim 47, wherein each one of said pair of extension members of each of said spreading members includes a number of teeth extending from a bone contacting surface thereof.

54. The instrument of claim 47, further comprising an adjustment mechanism coupled to said actuator assembly.

55. An instrument for separating adjacent vertebrae, comprising:

an actuator assembly; and

a spreader assembly at a distal end of said actuator assembly, wherein said spreader assembly includes first and second spreading members positionable between the adjacent vertebrae and movable away from and toward one another with said actuator assembly, said spreading members each including a body portion and first and second extension members spaced from one another and extending distally from said body portion, said first extension member including a length that is greater than a length of said second extension member.

56. The instrument of claim 55, wherein said first and second extension members are adapted for each of said body portions to be positioned along an anterior-oblique aspect of the adjacent vertebrae.

57. The instrument of claim 55, wherein said first and second extension members of each of said spreading members each include a number of teeth extending from a bone contacting surface thereof.

58. The instrument of claim 55, further comprising an adjustment mechanism coupled to said actuator assembly.

59. An instrument for separating adjacent vertebrae, comprising:

an actuator assembly; and

a spreader assembly at a distal end of said actuator assembly, wherein said spreader assembly includes first and second spreading members positionable between the adjacent vertebrae and movable away from and toward one another with said actuator assembly, said spreading members each including a body portion and an extension member extending distally from said body portion adjacent a first side of said body portion for positioning in contact with an adjacent vertebrae, said body portion extending from said first side to an opposite second side and including a guide member along an inner surface thereof extending between said first side and said second side.

60. The instrument of claim 59, wherein said guide member extends from a leading end spaced distally of a distal end wall of said body portion to a trailing end spaced proximally from a proximal end wall of said body portion.

61. The instrument of claim 60, wherein a distal end of said extension member is coextensive with said leading end of said guide member.

62. The instrument of claim 61, wherein said guide member includes a guide member extension adjacent said second side of said body, said guide member extension including an inner surface lying in the same plane as said inner surface of said body portion and said extension member projecting from said inner surface toward the other of said first and second spreading members.