Devices and techniques for a minimally invasive disc space preparation and implant insertion

• US 20050049623A1
• Filed: 09/02/2003
• Published: 03/03/2005
• Est. Priority Date: 09/02/2003
• Status: Active Grant

• Current Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Original Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Inventors: Duncan, James P., Moore, Jeffrey D., Foley, Kevin T., Scifert, Jeffrey L., Branch, Charles L.
• Granted Patent: US 7,578,820 B2
• Time in Patent Office: Days
• US Class Current: 606/170
• 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 17/1604 Chisels; Rongeurs; Punches; Stamps
• CPC Class Codes: A61B 17/1631 Special drive shafts, e.g. flexible shafts A61B17/1642, A61B17/164 take precedence
• 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 17/3423 Access ports, e.g. toroid shape introducers for instruments or hands access sites for liquids A61M39/0247
• CPC Class Codes: A61B 2017/320032 Details of the rotating or oscillating shaft, e.g. using a flexible shaft
• 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 2/4603 for insertion or extraction of endoprosthetic joints or of accessories thereof
• CPC Class Codes: A61F 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2002/4622 having the shape of a forceps or a clamp
• 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

Abstract

Methods and instruments are provided for performing spinal disc space preparation and implant insertion in minimally invasive procedures. The instruments include cutting instruments and implant insertion instruments adapted for insertion through a minimally invasive access portal to a spinal disc space. The proximal portions of the instruments are adapted to facilitate viewing through a proximal end opening of the access portal with the instruments positioned through the access portal while also enhancing the surgeon'"'"'s control of the distal working end of the instruments while in the disc space.

Claims

1. A cutting instrument assembly for removal of disc material through a minimally invasive surgical access portal, comprising:

a rotary cutting instrument, comprising;

a hollow elongate outer shaft including a distal portion and a proximal portion, said distal portion including a first length between a distal end and a proximal end thereof and extending along a distal longitudinal axis, said proximal portion extending along a proximal longitudinal axis and including an enlarged handle therealong, said distal portion and said proximal portion being connected with a lateral bend with said distal longitudinal axis intersecting said proximal longitudinal axis at an angle between said distal longitudinal axis and said proximal longitudinal axis ranging from 90 degrees to 165 degrees;

a cutting element rotatably mounted to said distal end of said hollow shaft;

an inner shaft including a flexible portion connected at a distal end thereof with said cutting element, said flexible portion extending proximally from distal end through said distal portion and said lateral bend, said inner shaft including a rigid portion in said proximal portion of said outer shaft rotatably mounted in a proximal end opening of said proximal portion, said rigid portion including a tool engaging member at a proximal end thereof spaced proximally from said proximal end of said proximal portion, said tool engaging portion engageable to rotate said inner shaft and said cutting element relative to said outer shaft; and

a retractor sleeve including a second length extending between a proximal end and a distal end thereof, said first length being greater than said second length, wherein said distal portion of said outer shaft is positionable through a working channel of said retractor sleeve with said cutting element spaced distally of said distal end of said retractor sleeve and said lateral bend spaced proximally from said proximal end of said retractor sleeve.

2. The assembly of claim 1, wherein said angle is 150 degrees.

3. The assembly of claim 1, wherein said cutting element includes a body with a first arm and a second arm spaced from said first arm, said first and second arms extending parallel with said distal longitudinal axis and defining a chamber therebetween.

4. The assembly of claim 3, wherein said first and second arms each include a first cutting blade and an opposite second cutting blade along respective one of said first and second arms.

5. The assembly of claim 1, wherein said enlarged handle is positioned outside a zone defined by a profile of said working channel extending proximally along a proximal extension of a longitudinal axis of said retractor sleeve when said cutting instrument is positioned through said retractor sleeve.

6. An instrument for scraping tissue material from a spinal disc space, comprising:

an elongate member including a scraper head at a distal end thereof, said elongate member including a distal linear shaft portion extending along a distal longitudinal axis and a proximal linear shaft portion including a handle, wherein said scraper head includes a body having a first scraper blade and a second scraper blade at a distal end thereof offset to opposite sides of said distal longitudinal axis, said proximal linear shaft portion being offset from said distal longitudinal to a same side as one of said first and second blades, said proximal linear shaft portion extending along a proximal longitudinal axis that is parallel to said distal longitudinal axis.

7. The instrument of claim 6, wherein said body includes a first arm and a second arm extending generally parallel to one another in the direction of said distal longitudinal axis, said first and second arms forming a trough therebetween.

8. The instrument of claim 7, wherein said first and second blades comprise a distal end wall of said scraper head, said distal end wall extending transversely to said distal longitudinal axis between said first and second arms.

9. The instrument of claim 6, wherein said distal linear shaft portion is connected with said proximal linear shaft portion with an offset portion extending along an offset axis.

10. The instrument of claim 9, wherein said offset axis forms an angle with said distal longitudinal axis ranging from 90 degrees to 150 degrees.

11. The instrument of claim 10, wherein said angle is 120 degrees.

12. The instrument of claim 6, wherein said first and second cutting blades include proximally facing cutting edges.

13. The instrument of claim 6, wherein said proximal longitudinal axis lies in a plane extending through said distal longitudinal axis and an axis orthogonally oriented to said distal longitudinal axis and bisecting said first and second blades.

14. An instrument for forming an implant insertion path in a spinal disc space, comprising:

a linear elongate member extending along a longitudinal axis between a proximal end and a distal end, said proximal end including an impaction head;

a chisel head extending distally from said distal end along said longitudinal axis; and

a handle member transversely oriented to said elongate member and connected with said elongate member between said distal end and said proximal end.

15. The instrument of claim 14, wherein said elongate member includes a distal portion between said distal end and said connection with said handle member and a proximal portion between said proximal end and said connection with said handle member.

16. The instrument of claim 15, wherein handle member extends along a second axis, said second axis and said longitudinal axis forming an angle between said distal portion and said handle member.

17. The instrument of claim 16, wherein said angle is 120 degrees.

18. The instrument of claim 14, wherein said chisel head includes upper and lower cutting blades extending transversely to said longitudinal axis.

19. The instrument of claim 18, wherein said handle member extends along a second axis, said second axis lying in a plane extending between and parallel to said upper and lower cutting blades and including said longitudinal axis.

20. The instrument of claim 18, wherein said chisel head includes a first arm and a second arm extending distally from said elongate member to a body, said first and second arms defining a cavity therebetween.

21. The instrument of claim 20, wherein said upper and lower cutting blades extend along a distal end of respective ones of upper and lower plates of said body, and further comprising a first flange extending distally from said distal end of said body and forming an extension of said first arm and a second flange extending distally from said distal end of said body and forming an extension of said second arm.

22. The instrument of claim 21, wherein said body includes a distal opening between said first and second flanges and said first and second cutting blades.

23. An instrument for inserting an implant insertion path in a spinal disc space, comprising:

a linear elongate member extending along a longitudinal axis between a proximal end and a distal end, said proximal end;

an implant engaging portion extending distally from said distal end along said longitudinal axis; and

a handle member transversely oriented to said elongate member and connected with said elongate member between said distal end and said proximal end, said elongate member including a handle offset laterally from said longitudinal axis.

24. The instrument of claim 23, wherein said elongate member includes a distal portion between said distal end and said connection with said handle member and a proximal portion between said proximal end and said connection with said handle member.

25. The instrument of claim 24, wherein handle member extends along a second axis, said second axis and said longitudinal axis forming an angle between said distal portion and said handle member.

26. The instrument of claim 25, wherein said angle is 120 degrees.

27. The instrument of claim 23, wherein said implant engaging portion includes a body having a distal end wall, and further comprising a projection extending through said distal end wall for engaging an implant to said implant engaging portion.

28. The instrument of claim 27, wherein said body includes first and second flanges extending distally from said distal end wall on opposite sides of said longitudinal axis.

29. The instrument of claim 28, wherein one of said first and second flanges includes a length greater than the other of said first and second flanges.

30. The instrument of claim 27, further comprising an inner shaft extending through and movable relative to said elongate member, said projection being at a distal end of said inner shaft, said inner shaft further including a proximal end extending proximally from said proximal end of said elongate member.

31. The instrument of claim 30, wherein said proximal end of said inner shaft includes an adjustment mechanism operable to rotate said projection.

32. A method for spinal disc space surgery, comprising:

placing a retractor sleeve through skin and tissue of the patient to provide working channel access to the spinal disc space;

inserting a distal cutting element of a cutting instrument through the working channel and into the spinal disc space with an elongate member of the cutting instrument extending through the working channel, the elongate member including a linear distal portion and a proximal portion offset relative to the distal portion, the proximal portion including a handle member positioned outside a zone defined by a profile of a proximal extension of the working channel extending longitudinally from a proximal end of the retractor sleeve; and

manipulating the cutting element to remove tissue material in the disc space with the handle remaining outside the zone.

33. The method of claim 32, wherein the cutting element is a rotary cutter and the elongate member includes a bend to angle the proximal portion relative to the distal portion, the distal portion including a length sufficient to position the bend proximally of the proximal end of the retractor sleeve while manipulating the cutting element in the disc space.

34. The method of claim 32, wherein the cutting element is a scraper head and the elongate member includes an offset member between the distal portion and the proximal portion configured such that a longitudinal axis of the proximal portion is parallel to a longitudinal axis of the distal portion, the distal portion including a length sufficient to position the offset member proximally of a proximal end of the retractor sleeve while manipulating the cutting element in the disc space.

35. The method of claim 34, wherein the scraper head includes a first blade and an opposite second blade, each of the first and second blades extending from the scraper head toward an adjacent endplate in the spinal disc space, the longitudinal axis of the proximal portion lying in a plane extending through the longitudinal axis of the distal portion and through an axis bisecting the first and second blades and orthogonally oriented to the longitudinal axis of the distal portion.

36. The method of claim 32, wherein the cutting element is a chisel head including parallel upper and lower blades oriented transversely to a longitudinal axis of the distal portion, the proximal portion extending along a second longitudinal axis transverse to the longitudinal axis of the distal portion, the second longitudinal axis lying in a plane including the longitudinal axis of the distal portion and extending between and parallel to the upper and lower cutting blades.

37. The method of claim 36, wherein the elongate member includes an impaction head at a proximal end of the elongate member and spaced proximally from a junction of the proximal portion with the distal portion.

38. The method of claim 32, further comprising:

removing the cutting instrument from the retractor sleeve;

engaging an implant to an implant engaging portion of an implant inserter; and

inserting the implant through the retractor sleeve into the disc space with the implant inserter.

39. The method of claim 38, wherein the implant inserter includes an elongate member extending through the working channel, the elongate member including a linear distal portion and a proximal portion offset relative to the distal portion, the proximal portion including a handle member positioned outside the zone when the implant inserted in the disc space.

40. The method of claim 39, wherein the distal portion of the implant inserter extends along a longitudinal axis and the proximal portion extends along a second longitudinal axis transverse to the longitudinal axis of the distal portion, the second longitudinal axis lying in a plane including the longitudinal axis of the distal portion and extending between and parallel to upper and lower vertebral endplates on each side of the spinal disc space when the implant is inserted in the spinal disc space.