Devices and techniques for a posterior lateral disc space approach

• US 6,764,491 B2
• Filed: 05/15/2001
• Issued: 07/20/2004
• Est. Priority Date: 10/21/1999
• Status: Expired due to Term

• Current Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Original Assignee: SDGI Holdings Incorporated (Medtronic Plc)
• Inventors: Frey, George, Josse, Loic, Liu, Mingyan, White, John L.
• Primary Examiner(s): Shaver, Kevin
• Assistant Examiner(s): Priddy, Michael B.
• Application Number:
  US09/858,197
• Publication Number:
  US 20020019637A1
• Time in Patent Office: 1,162 Days
• Field of Search: 606/79, 606/84-86, 606/99, 606/167, 606/170, 407/29.1
• US Class Current: 606/85
• 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 17/1604 Chisels; Rongeurs; Punches; Stamps
• CPC Class Codes: A61B 17/1615 Drill bits, i.e. rotating tools extending from a handpiece to contact the worked material
• CPC Class Codes: A61B 17/1631 Special drive shafts, e.g. flexible shafts A61B17/1642, A61B17/164 take precedence
• CPC Class Codes: A61B 17/1642 for producing a curved bore
• CPC Class Codes: A61B 17/1659 Surgical rasps, files, planes, or scrapers
• CPC Class Codes: A61B 17/1671 for the spine
• CPC Class Codes: A61B 2017/0256 for the spine
• CPC Class Codes: A61F 2/442 Intervertebral or spinal discs, e.g. resilient non-disc-shaped intervertebral inflatable pockets A61F2/441; non-disc-shaped intervertebral fusion implants A61F2/4455
• CPC Class Codes: A61F 2/4455 for the fusion of spinal bodies, e.g. intervertebral fusion of adjacent spinal bodies, e.g. fusion cages intervertebral discs A61F2/442
• CPC Class Codes: A61F 2/4465 having a circular or kidney shaped cross-section substantially perpendicular to the axis of the spine
• 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 2002/2835 Bone graft implants for filling a bony defect or an endoprosthesis cavity, e.g. by synthetic material or biological material
• CPC Class Codes: A61F 2002/3008 radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: A61F 2002/30115 circular-O-shaped
• CPC Class Codes: A61F 2002/30133 kidney-shaped or bean-shaped
• CPC Class Codes: A61F 2002/30235 tubular, e.g. sleeves
• CPC Class Codes: A61F 2002/30329 Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2002/30593 : hollow
• CPC Class Codes: A61F 2002/30774 : internally-threaded
• CPC Class Codes: A61F 2002/30777 : Oblong apertures
• CPC Class Codes: A61F 2002/30785 : parallel
• CPC Class Codes: A61F 2002/30787 : inclined obliquely with respect to each other
• CPC Class Codes: A61F 2002/30789 : perpendicular with respect to each other
• CPC Class Codes: A61F 2002/30828 : parallel
• CPC Class Codes: A61F 2002/30912 : made of expanded metal, e.g. diamond mesh or metal nets having lozenge-shaped apertures
• CPC Class Codes: A61F 2002/448 : comprising multiple adjacent spinal implants within the same intervertebral space or within the same vertebra, e.g. comprising two adjacent spinal implants
• 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 2002/4635 : using minimally invasive surgery
• CPC Class Codes: A61F 2220/0025 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2230/0006 : circular
• CPC Class Codes: A61F 2230/0015 : Kidney-shaped, e.g. bean-shaped
• CPC Class Codes: A61F 2230/0069 : cylindrical
• CPC Class Codes: A61F 2250/0098 : radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: A61F 2310/00017 : Iron- or Fe-based alloys, e.g. stainless steel
• CPC Class Codes: A61F 2310/00023 : Titanium or titanium-based alloys, e.g. Ti-Ni alloys

Abstract

This invention relates to methods and instruments for performing disc space preparation and implant insertion from a unilateral approach to the spine through a posterior lateral opening to the disc space. The instruments include spreaders, distractors, reamers, scrapers, cutters, chisels, rasps, pushers and implant inserters. A surgical procedure is provided that allows bilateral support of the adjacent vertebrae with at least one interbody fusion device inserted into the disc space via a unilateral approach. Implants for insertion into the disc space are also provided.

Claims

1. A surgical instrument for performing a surgical procedure in a spinal disc space, comprising:

a shaft extending generally along a longitudinal axis, said shaft having a proximal portion along said longitudinal axis and a distal portion offset laterally in a first direction from said longitudinal axis; and

a rasp head at a distal end of said shaft extending from said distal portion transversely to said longitudinal axis.

2. The instrument of claim 1, wherein said rasp head has a first rasping surface positionable against the endplate of an upper vertebral body and an opposite second rasping surface positionable against the endplate of a lower vertebral body.

3. The instrument of claim 1, wherein said shaft includes a connecting portion extending along a second axis, said second axis forming a first angle with said longitudinal axis, and said distal portion extending from said connecting portion to said distal end along a third axis, said third axis forming a second angle with said second axis.

4. The instrument of claim 3, wherein said first angle is different than said second angle.

5. The instrument of claim 3, wherein said longitudinal axis and said third axis intersect distally of said rasp head at an angle of about 5 degrees.

6. The instrument of claim 1, wherein said rasp head has an anterior wall, an opposite posterior wall, a trailing end wall extending between said anterior wall and said posterior wall, and a leading end wall extending between said anterior wall and said posterior wall opposite said trailing end wall.

7. The instrument of claim 6, wherein said leading end wall is tapered.

8. The instrument of claim 6, wherein said anterior wall, said posterior wall, said leading end wall and said trailing end wall are smooth.

9. The instrument of claim 6, wherein said anterior wall is convex and said posterior wall is concave.

10. The instrument of claim 9, wherein said anterior wall is longer than said posterior wall.

11. The instrument of claim 1, wherein said distal portion is laterally offset by a distance of 10 millimeters.

12. A surgical instrument for performing a surgical procedure in a spinal disc space, comprising:

a shaft having a length extending substantially along a longitudinal axis, wherein said shaft includes a proximal portion extending along said longitudinal axis, a connecting portion extending from a distal end of said proximal portion along a second axis, said second axis forming a first angle with said longitudinal axis, and a distal portion extending distally from a distal end of said connecting portion along a third axis, said third axis forming a second angle with said second axis such that said distal portion is non-parallel to said proximal portion; and

a rasp head extending from a distal end of said distal portion of said shaft.

13. The instrument of claim 12, wherein:

said distal portion of said shaft is offset laterally in a first direction from said proximal portion of said shaft; and

said rasp head extends further laterally than said distal portion in said first direction.

14. The instrument of claim 13, wherein said distal portion is laterally offset by a distance of 10 millimeters.

15. The instrument of claim 12, wherein said shaft has a handle along said proximal portion.

16. The instrument of claim 12, wherein said shaft has a circular cross-section.

17. The instrument of claim 12, wherein said rasp head has a shape that generally corresponds to the shape of an implant to be inserted into the intradiscal space.

18. The instrument of claim 12, wherein said rasp head has a first rasping surface positionable against the endplate of an upper vertebral body and an opposite second rasping surface positionable against the endplate of a lower vertebral body.

19. The instrument of claim 12, wherein said first angle is different than said second angle.

20. The instrument of claim 12, wherein a distal extension of said longitudinal axis and a distal extension of said third axis intersect to form an angle of about 5 degrees.

21. The instrument of claim 12, wherein said rasp head has an anterior wall, an opposite posterior wall, a trailing end wall extending between said anterior wall and said posterior wall, and a leading end wall extending between said anterior wall and said posterior wall opposite said trailing end wall.

22. The instrument of claim 21, wherein said leading end wall is tapered.

23. The instrument of claim 21, wherein said anterior wall is convex and said posterior wall is concave.

24. The instrument of claim 23, wherein said anterior wall is longer than said posterior wall.

25. A surgical instrument for performing a surgical procedure in a spinal disc space, comprising:

a shaft having a length extending substantially along a longitudinal axis, wherein said shaft includes;

a proximal portion extending along said longitudinal axis;

a connecting portion extending from a distal end of said proximal portion along a second axis, said second axis forming a first angle with said longitudinal axis;

a distal portion extending distally from a distal end of said connecting portion along a third axis, said third axis forming a second angle with said second axis, wherein a distal extension of said longitudinal axis and a distal extension of said third axis intersect at an angle of about 5 degrees; and

a rasp head extending from a distal end of said distal portion of said shaft.

26. A method of preparing a spinal disc space for insertion of an implant, comprising:

providing a posterior lateral opening into the disc space;

providing a rasp including a shaft extending generally along a longitudinal axis, said shaft having a proximal portion along said longitudinal axis and a distal portion offset laterally to a first side of said longitudinal axis, said rasp further including a rasp head extending from a distal end of said shaft towards said first side; and

orienting said shaft so that the spinous process is positioned adjacent said proximal portion on said first side of said longitudinal axis.

27. The method of claim 26, further comprising:

positioning a leading end wall of said rasp head at the opening and the proximal portion of the shaft adjacent the spinous process; and

applying a pivoting force to the rasp to move the leading end wall of the rasp towards a distal portion of the disc space and the proximal portion of the shaft away from the spinous process.

28. The method of claim 27, further comprising rasping the vertebral endplates.

29. The method of claim 28, wherein rasping the vertebral endplates includes rasping each endplate separately.

30. The method of claim 28, further comprising inserting an implant into the rasped disc space.

31. The method of claim 30, comprising:

securing a trailing end of the implant to an implant inserter;

positioning a leading end of the implant at the opening;

engaging a pusher to the implant inserter;

applying an impaction force to the implant with the pusher to push the implant through the opening and into the disc space; and

applying a pivoting force to the implant with the implant inserter to move the leading end of the implant towards a distal portion of the disc space.

32. The method of claim 31, further comprising alternating between applying an impaction force and applying a pivoting force.

33. The method of claim 31, further comprising removing disc material from the disc space prior to positioning the leading end wall of the implant at the opening.

34. The method of claim 31, further comprising forming a square entrance port at the opening prior to positioning the leading end of the implant at the opening.

35. The method of claim 31, further comprising:

positioning the implant at a distal portion of the disc space; and

inserting a second implant into the disc space through the opening after positioning the implant at the distal portion of the disc space.

36. A surgical instrument for performing a surgical procedure in a spinal disc space, comprising:

a shaft extending generally along a longitudinal axis, said shaft having a proximal portion along said longitudinal axis and a distal portion offset laterally in a first direction from said longitudinal axis; and

a rasp head at a distal end of said shaft extending in said first direction laterally further from said longitudinal axis than said distal portion, wherein said rasp head has an anterior wall, an opposite posterior wall, a trailing end wall extending between said anterior wall and said posterior wall, and a leading end wall extending between said anterior wall and said posterior wall opposite said trailing end wall and said leading end wall is tapered.

37. The instrument of claim 36, wherein said rasp head has a first rasping surface positionable against the endplate of an upper vertebral body and an opposite second rasping surface positionable against the endplate of a lower vertebral body.

38. The instrument of claim 36, wherein said shaft includes a connecting portion extending along a second axis, said second axis forming a first angle with said longitudinal axis, and said distal portion extending from said connecting portion to said distal end along a third axis, said third axis forming a second angle with said second axis.

39. The instrument of claim 38, wherein said first angle is different that said second angle.

40. The instrument of claim 38, wherein said longitudinal axis and said third axis intersect distally of said rasp head at an angle of about 5 degrees.

41. The instrument of claim 36, wherein said anterior wall, said posterior wall, said leading end wall and said trailing end wall are smooth.

42. The instrument of claim 36, wherein said anterior wall is convex and said posterior wall is concave.

43. The instrument of claim 42, wherein said anterior wall is longer than said posterior wall.

44. The instrument of claim 36, wherein said distal portion is laterally offset by a distance of 10 millimeters.

45. A surgical instrument for performing a surgical procedure in a spinal disc space, comprising:

a shaft extending generally along a longitudinal axis, said shaft having a proximal portion along said longitudinal axis and a distal portion offset laterally in a first direction from said longitudinal axis; and

a rasp head at a distal end of said shaft extending in said first direction laterally further from said longitudinal axis than said distal portion, wherein said rasp head has an anterior wall, an opposite posterior wall, a trailing end wall extending between said anterior wall and said posterior wall, and a leading end wall extending between said anterior wall and said posterior wall opposite said trailing end wall, wherein said anterior wall, said posterior wall, said leading end wall and said trailing end wall are smooth.

46. The instrument of claim 45, wherein said rasp head has a first rasping surface positionable against the endplate of an upper vertebral body and an opposite second rasping surface positionable against the endplate of a lower vertebral body.

47. The instrument of claim 45, wherein said shaft includes a connecting portion extending along a second axis, said second axis forming a first angle with said longitudinal axis, and said distal portion extending from said connecting portion to said distal end along a third axis, said third axis forming a second angle with said second axis.

48. The instrument of claim 45, wherein said first angle is different that said second angle.

49. The instrument of claim 45, wherein said longitudinal axis and said third axis intersect distally of said rasp head at an angle of about 5 degrees.

50. The instrument of claim 45, wherein said leading end wall is tapered.

51. The instrument of claim 45, wherein said anterior wall is convex and said posterior wall is concave.

52. The instrument of claim 51, wherein said anterior wall is longer than said posterior wall.

53. The instrument of claim 45, wherein said distal portion is laterally offset by a distance of 10 millimeters.

54. A surgical instrument for performing a surgical procedure in a spinal disc space, comprising:

a shaft extending generally along a longitudinal axis, said shaft having a proximal portion along said longitudinal axis and a distal portion offset laterally in a first direction from said longitudinal axis; and

a rasp head at a distal end of said shaft extending in said first direction laterally further from said longitudinal axis than said distal portion, wherein in said rasp head has a convex anterior wall, an opposite concave posterior wall, a trailing end wall extending between said anterior wall and said posterior wall, and a leading end wall extending between said anterior wall and said posterior wall opposite said trailing end wall.

55. The instrument of claim 54, wherein said rasp head has a first rasping surface positionable against the endplate of an upper vertebral body and an opposite second rasping surface positionable against the endplate of a lower vertebral body.

56. The instrument of claim 54, wherein said shaft includes a connecting portion extending along a second axis, said second axis forming a first angle with said longitudinal axis, and said distal portion extending from said connecting portion to said distal end along a third axis, said third axis forming a second angle with said second axis.

57. The instrument of claim 56, wherein said first angle is different that said second angle.

58. The instrument of claim 56, wherein said longitudinal axis and said third axis intersect distally of said rasp head at an angle of about 5 degrees.

59. The instrument of claim 54, wherein said leading end wall is tapered.

60. The instrument of claim 54, wherein said anterior wall, said posterior wall, said leading end wall and said trailing end wall are smooth.

61. The instrument of claim 54, wherein said anterior wall is longer than said posterior wall.

62. The instrument of claim 54, wherein said distal portion is laterally offset by a distance of 10 millimeters.