Methods and instrumentation for positioning implants in spinal disc space in an anterior lateral approach

• US 20040199168A1
• Filed: 04/02/2003
• Published: 10/07/2004
• Est. Priority Date: 04/02/2003
• Status: Active Grant

• Current Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Original Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Inventors: Josse, Loic, Bertagnoli, Rudolf, Liu, Mingyan
• Granted Patent: US 7,326,216 B2
• Time in Patent Office: Days
• US Class Current: 606/99
• CPC Class Codes: A61B 17/00234 for minimally invasive surgery A61B17/0218, A61B17/0469, A61B17/12013, A61B17/1285, A61B17/29, A61B17/320016 take precedence
• CPC Class Codes: A61B 17/025 Joint distractors
• CPC Class Codes: A61B 2017/0256 for the spine
• CPC Class Codes: A61B 2017/2904 curved, but rigid
• CPC Class Codes: A61F 2/4603 for insertion or extraction of endoprosthetic joints or of accessories thereof
• CPC Class Codes: A61F 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2002/30153 rectangular
• CPC Class Codes: A61F 2002/30601 telescopic
• CPC Class Codes: A61F 2002/4627 with linear motion along or rotating motion about the instrument axis or the implantation direction, e.g. telescopic, along a guiding rod, screwing inside the instrument
• CPC Class Codes: A61F 2230/0019 rectangular

Abstract

Instruments and methods are provided for positioning one or more implants into a spinal disc space. The instruments and methods have application in an anterior lateral approach to the disc space between the L4 and L5 vertebrae. The instruments include a distractor, a housing, a guide member to facilitate positioning of the housing, and a partition member engageable to the housing to facilitate positioning of one or more implants into the disc space.

Claims

1. A surgical instrument insertable in a spinal disc space between an upper vertebra and a lower vertebra, comprising:

a head including an upper surface positionable adjacent an endplate of the upper vertebra and an opposite lower surface positionable adjacent an endplate of the lower vertebra; and

a shaft extending proximally from said head, said shaft including a distal portion, a proximal portion, and an offset portion therebetween, said distal portion including a guide portion adjacent said head and engageable to guide an instrument therealong to the spinal disc space, said head and said guide portion extending along a first axis and said offset portion extending proximally from said guide portion and transversely oriented thereto.

2. The instrument of claim 1, wherein said proximal portion extends along a second axis generally parallel to said first axis.

3. The instrument of claim 2, wherein said proximal portion includes a handle oriented transversely to said second axis.

4. The instrument of claim 2, wherein said offset portion extends along a third axis oriented at an angle to said first axis.

5. The instrument of claim 1, wherein said guide portion includes a cross-sectional dimension along a length thereof that is greater than a cross-sectional dimension along a length of said proximal portion.

6. A surgical instrument for spinal surgery having an operative orientation including an anterior lateral approach to a spinal disc space between L4 and L5 vertebrae of a patient, comprising:

a distal end portion positionable adjacent the spinal disc space and a proximal portion offset from said distal portion to avoid an iliac crest of the patient when the surgical instrument is the operative orientation.

7. The instrument of claim 6, wherein the instrument is a distractor including a head at said distal portion positionable in the spinal disc space and said proximal portion includes a shaft extending distally from said head, said proximal portion being offset anteriorly of the iliac crest in the operative orientation.

8. The instrument of claim 6, wherein the instrument is a guide instrument including a guide member at said distal portion and said proximal portion includes a shaft extending distally from said head, said proximal portion being offset cephaladly of the iliac crest in the operative orientation.

9. A surgical instrument assembly for providing access to a spinal disc space, comprising:

a distractor including a head positionable in a spinal disc space and a shaft extending proximally from said head, said shaft including a guide portion along at least a portion thereof adjacent said head;

a housing including an opening therethrough for providing access to the spinal disc space when positioned adjacent thereto; and

a guide instrument including a shaft and a guide member at a distal end of said shaft, said guide member removably engaged to said housing, said guide member moveable along said guide portion of said distractor with said shaft of said guide instrument in side-by-side relation to said shaft of said distractor to guide said housing along said distractor to the spinal disc space when said head is positioned in the spinal disc space.

10. The assembly of claim 9, wherein said housing includes a frame portion defining said opening therethrough, said housing further including a first extension along one side of said opening extending distally from said frame portion and a second extension along an opposite side of said opening extending distally from said frame portion, said first and second extensions positionable in the spinal disc space to maintain a disc space distraction when said head is removed from the spinal disc space.

11. The assembly of claim 10, wherein said first extension is longer than said second extension.

12. The assembly of claim 10, wherein said frame portion includes an upper wall positionable adjacent an upper vertebra and a lower wall positionable adjacent a lower vertebra, said upper and lower walls each including a distal end curvature corresponding to a curvature of a lateral profile of the upper and lower vertebrae, respectively.

13. The assembly of claim 9, wherein said opening includes a rectangular shape.

14. The assembly of claim 9, wherein said guide member includes a distal portion positionable in said opening to engage said guide member in said opening and a proximal portion forming a lip around said distal portion, said lip in abutting engagement with a proximal end of said housing when said distal portion is positioned in said opening.

15. The assembly of claim 14, wherein said housing includes a proximally-opening notch in a wall thereof and said guide member includes a protrusion positionable in said notch.

16. The assembly of claim 9, wherein said guide member includes a passage extending between a distal end and a proximal end of said guide member and said guide portion of said distractor is movably received in said passage.

17. The assembly of claim 16, wherein said guide member includes tapered surfaces forming an opening into said passage along one side thereof.

18. The assembly of claim 16, wherein said passage extends along a center of said guide member and said shaft of said guide instrument is offset from said passage.

19. The assembly of claim 18, wherein said shaft of said guide instrument includes a distal portion, a proximal portion, and an offset portion therebetween, said offset portion positioning said proximal portion cephaladly of said distal portion in an operative orientation of said guide instrument.

20. The assembly of claim 18, wherein said shaft is offset posteriorly of said passage in said operative orientation of said guide instrument.

21. The assembly of claim 9, wherein said shaft of said distractor includes a distal portion, a proximal portion, and an offset portion therebetween, said distal portion including said guide portion, said head and said guide portion extending along a first axis and said offset portion extending proximally from said guide portion along a second axis oriented at a first angle relative to said first axis.

22. The assembly of claim 21, wherein said proximal portion extends along a third axis generally parallel to said first axis.

23. The instrument of claim 22, wherein said proximal portion includes a handle oriented transversely to said third axis.

24. The instrument of claim 21, wherein said guide portion includes a cross-sectional dimension along a length thereof that is greater than a cross-sectional dimension along a length of said proximal portion.

25. An instrument assembly for facilitating placement of an implant in a spinal disc space, comprising:

a housing including a frame defining an opening therethrough between side walls of said housing, said housing positionable adjacent the spinal disc space and providing access thereto through said opening; and

a partition member engageable to said frame in said opening, said partition member including an extension extending distally from said frame and positionable in the spinal disc space, said partition member being movable relative to said frame between said side walls.

26. The assembly of claim 25, further comprising a displacer instrument positionable through said opening in contact with said partition member, said displacer instrument including a displacer head configured to move said partition member relative to said housing as said distal end portion is advanced distally into the spinal disc space.

27. The assembly of claim 26, wherein said displacer head includes a wedge shape tapering distally.

28. The assembly of claim 26, wherein said displacer head includes a box shape.

29. The assembly of claim 25, wherein:

said housing include an upper wall and a lower wall extending between said side walls and forming said opening in a rectangular shape; and

said partition member includes a body, an upper flange extending from said body and forming a first space therebetween, and a lower flange extending from said body and forming a second space therebetween, said upper wall being received in said first space and said lower wall being received in said second space when said body of said partition member is positioned in said opening of said housing.

30. The assembly of claim 29, further comprising a mounting member extending from said upper flange.

31. The assembly of claim 30, wherein said mounting member includes a receptacle for removable engagement with a shaft assembly.

32. The assembly of claim 31, wherein said body includes a receptacle for removable engagement with a shaft assembly.

33. A surgical instrument assembly, comprising:

a body including a portion positionable in a spinal disc space, said body including a mounting member extending therefrom; and

a shaft assembly removably engageable to said mounting member, said shaft assembly including an outer shaft defining a distally opening receptacle and an inner shaft movable relative to said outer shaft and extending distally therefrom, said inner shaft including a distal engagement member engageable to said mounting member, wherein said inner shaft and said outer shaft are movable relative to one another to position said mounting member in said receptacle to secure said body to said shaft assembly.

34. The assembly of claim 33, wherein said distally opening receptacle is a slot.

35. The assembly of claim 33, wherein said engagement member includes a distal extension and a hook at a distal end of said extension extending transversely thereto.

36. The assembly of claim 33, wherein in an operative orientation said mounting member extends cephaladly from said body.

37. The assembly of claim 36, wherein said mounting member includes a slot and said engagement member is positionable in said slot.

38. The assembly of claim 37, wherein said engagement member includes a distal extension and a hook at a distal end of said extension extending transversely thereto, said hook positionable in said slot.

39. A method for positioning an implant in a spinal disc space of a patient, comprising:

accessing the spinal disc space between L4 and L5 vertebrae from a lateral approach; and

positioning a distractor in the spinal disc space with a shaft of the distractor oriented laterally to the patient, the shaft comprising a distal portion extending laterally from the spinal disc space and a proximal portion offset relative to the distal portion anteriorly of the iliac crest.

40. The method of claim 39, further comprising:

guiding a housing along the distal portion of the distractor to a position adjacent the L4 and L5 vertebrae, the housing including a frame portion defining an opening therethrough for accessing the spinal disc space, said housing further including a posterior extension and an anterior extension each extending distally from said frame portion and positionable in the spinal disc space with said frame portion positioned adjacent the L4 and L5 vertebrae.

41. The method of claim 40, further comprising:

positioning a partition member in the opening of the housing, the partition member including a central extension extending into the spinal disc space;

moving the partition member relative to the housing to position the central extension adjacent the posterior extension.

42. The method of claim 41, further comprising inserting an implant into the spinal disc space through the opening of the housing between the central extension and the anterior extension.

43. The method of claim 42, further comprising moving the partition member anteriorly to move the implant anteriorly in the spinal disc space.

44. The method of claim 43, further comprising inserting a second implant into the spinal disc space through the opening of the housing and posterior of the anteriorly positioned implant.

45. The method of claim 44, further comprising removing the partition member from the housing before inserting the second implant.

46. The method of claim 43, wherein moving the partition member includes inserting a displacer head of a displacer instrument between the posterior extension and the central extension.

47. The method of claim 46, wherein inserting the displacer head includes inserting a wedge-shaped displacer head to provide an initial separation between the posterior extension and the central extension.

48. The method of claim 47, further comprising inserting a box-shaped displacer head between the posterior extension and the central extension after inserting the wedge-shaped displacer head.

49. A method for positioning a spinal implant in a spinal disc space of a patient, comprising:

positioning a housing adjacent the spinal disc space between the L4 and L5 vertebrae in an anterior lateral approach;

positioning a partition member through the housing into the spinal disc space;

positioning an implant in the spinal disc space anterior of the partition member; and

displacing the partition member anteriorly to move the implant anteriorly in the spinal disc space.

50. The method of claim 49, wherein displacing the partition member includes inserting a displacer head of a displacer instrument between a posterior wall of the housing and the partition member.

51. The method of claim 50, wherein inserting the displacer head includes inserting a wedge-shaped displacer head to provide an initial separation between the posterior wall and the partition member.

52. The method of claim 51, further comprising inserting a box-shaped displacer head between the posterior wall and the partition member after inserting the wedge-shaped displacer head.

53. The method of claim 50, wherein the posterior wall includes a posterior extension extending into the spinal disc space from the posterior wall of the housing, the housing further including an anterior extension opposite the posterior extension extending into the spinal disc space from an anterior wall of the housing.

54. The method of claim 53, wherein displacing the partition member anteriorly includes displacing the implant to a location at least partially anterior of the anterior extension.

55. The method of claim 49, further comprising inserting a second implant posteriorly of the anteriorly positioned implant.

56. The method of claim 51, wherein the first and second implant are medially-laterally oriented in the spinal disc space.