Less invasive surgical system and methods

• US 20060074445A1
• Filed: 09/29/2004
• Published: 04/06/2006
• Est. Priority Date: 09/29/2004
• Status: Active Grant

• Current Assignee: Synthes USA LLC (Johnson & Johnson)
• Original Assignee: Synthes USA LLC (Johnson & Johnson)
• Inventors: Hu, Xiaoping, Gerber, David, Kephart, Douglas Scott, Lee, Andrew Max, Kuntz, Kyle, Hanson, Shaun
• Granted Patent: US 7,666,189 B2
• Time in Patent Office: Days
• US Class Current: 606/191
• CPC Class Codes: A61B 17/0206 with antagonistic arms as supports for retractor elements
• CPC Class Codes: A61B 17/7074 Tools specially adapted for spinal fixation operations other than for bone removal or filler handling A61B17/7062, A61B17/808, A61B17/8858 take precedence; for spinal image producing devices A61B90/36, A61B34/20; markers A61B90/39
• CPC Class Codes: A61B 17/7076 for driving, positioning or assembling spinal clamps or bone anchors specially adapted for spinal fixation
• CPC Class Codes: A61B 17/7082 for driving, i.e. rotating, screws or screw parts specially adapted for spinal fixation, e.g. for driving polyaxial or tulip-headed screws driving other bone screws A61B17/8875
• CPC Class Codes: A61B 17/7083 Tools for guidance or insertion of tethers, rod-to-anchor connectors, rod-to-rod connectors, or longitudinal elements
• CPC Class Codes: A61B 17/7085 for insertion of a longitudinal element down one or more hollow screw or hook extensions, i.e. at least a part of the element within an extension has a component of movement parallel to the extension's axis
• CPC Class Codes: A61B 17/7089 wherein insertion is along an arcuate path
• CPC Class Codes: A61B 17/7091 for applying, tightening or removing longitudinal element-to-bone anchor locking elements, e.g. caps, set screws, nuts or wedges

Abstract

A system for performing a less invasive surgical procedure and, in particular, devices and methods for spinal fixation. The system comprises dilation tool(s), at least one working/insertion cannula, a plurality of screws, at least one fixation rod for connecting the screws, and a rod inserter. The dilation tool(s) may be used to dilate an incision made in a patient to form an opening. Thereafter, a drill may be used to form holes in the vertebrae. An insertion cannula may be attached to a screw and inserted into the opening. The screws may be polyaxial screws and may be inserted into the vertebrae using a screwdriver. An operator may then move the insertion cannula to manipulate a head portions of the screws such that the head portions may be aligned to receive a fixation rod. A rod inserter may be used to insert a fixation rod into the head portions. After the fixation rod is in place, it may be locked to the screws, thereby fixing the system in place on the spine.

Claims

1. A system for implanting spinal fixation devices in vertebrae through an opening in a patient comprising:

a cannula having a proximal end, a distal end, a passageway from the proximal end to the distal end, at least one slot intersecting the passageway, and a flexible portion for engaging the spinal fixation device, wherein the at least one slot is sized and configured to receive an elongated fixation device.

2. The system of claim 1, further comprising a dilation mechanism for increasing the size of an incision to form the opening.

3. The system of claim 2, wherein the dilation mechanism comprises a retractor having at least two blades for being inserted through the incision, wherein the at least two blades are configured to spread apart to form the opening.

4. The system of claim 2, wherein the dilation mechanism comprises at least one dilator having a elongated cylindrical shape with a channel passing therethrough.

5. The system of claim 4, wherein the dilation mechanism further comprises a retractor, the retractor having at least two blades having an opened position and a closed position, wherein the blades are configured to be inserted over the at least one dilator in the closed position and are configured to move to the opened position to create the opening.

6. The system of claim 4, wherein the dilation mechanism further comprises an inserter, the inserter comprising:

an elongated portion, a proximal end and a distal end; and

an enlarged portion on the distal end of the elongated portion;

wherein the at least one dilator is configured to receive the inserter therein.

7. The system of claim 6, wherein the dilation mechanism further comprises a working cannula having a proximal end, a distal end, and a channel extending from the proximal end to the distal end, wherein the channel of the working cannula is sized and configured to receive the at least one dilator.

8. The system of claim 2, wherein the dilation mechanism comprises an inserter, the inserter comprising:

an elongated portion, a proximal end and a distal end; and

an enlarged portion on the distal end of the elongated portion;

wherein the inserter is sized and configured to be received within the passageway of the cannula.

9. The system of claim 1, wherein the flexible portion is a pair of arms defined by two diametrically opposed slots, the pair of arms being configured to snap onto the spinal fixation device.

10. The system of claim 1, wherein the flexible portion comprises at least one flexible member having a first end portion and a second end portion, the first end portion being operably connected to the cannula and the second end portion being freely moveable with respect the cannula, the second end portion sized and configured to engage the spinal fixation device

11. The system of claim 1, wherein the cannula comprises:

an inner cannulated shaft having a proximal end, a distal end and a bore therethrough; and

an outer cannulated shaft having a proximal end, a distal end, and a bore therethrough, wherein the bore of the outer cannulated shaft is sized and configured to receive the inner cannulated shaft.

12. The system of claim 11, wherein the flexible portion comprises at least one flexible member having a first end portion and a second end portion, the first end portion being operably connected to the inner cannulated shaft and the second end portion being freely moveable with respect the inner cannulated shaft, and wherein the outer cannulated shaft is sized and configured to travel along the inner cannulated shaft from a first position to a second position and move the second end portion of the at least one flexible member towards the spinal fixation device.

13. The system of claim 11, wherein the inner cannulated shaft comprises a slot and the outer cannulated shaft comprises a protrusion engagable with the slot.

14. The system of claim 13, wherein the slot has at least one notch, the slot being sized and configured for positioning the outer cannulated shaft at at least one location on the inner cannulated shaft.

15. The system of claim 11, further comprising an implantation mechanism for implanting the spinal fixation device into vertebrae, the implantation mechanism comprising a shaft having a proximal end, a distal end, and an engagement portion on the distal end sized and configured to engage the spinal fixation device, wherein the implantation mechanism is sized and configured to be inserted into the passageway of the cannula.

16. The system of claim 15, wherein the implantation mechanism comprises a protrusion on the engagement portion and the inner cannulated shaft comprises a longitudinal recess, the protrusion being moveable along the recess, and wherein the protrusion and longitudinal recess are configured to align the at least one slot of the cannula relative to the spinal fixation device.

17. The system of claim 1, wherein the cannula comprises:

a cannulated shaft having a longitudinal recess; and

an elongated member positionable within the recess.

18. The system of claim 17, wherein the flexible portion comprises at least one flexible member having a first end portion and a second end portion, the first end portion being operably connected to the cannulated shaft and the second end portion being freely moveable with respect the cannulated shaft, and wherein the elongated member is sized and configured to engage the at least one flexible member such that the at least one flexible member is moved towards the spinal fixation device.

19. The system of claim 1, further comprising an implant positioner sized and configured to be inserted into the passageway of the cannula, the implant positioner having an elongated shaft, a proximal end, a distal end and an engaging portion on the distal end sized and configured to engage the spinal fixation device and manipulate the spinal fixation device relative to the cannula.

20. The system of claim 1, further comprising an implantation mechanism for implanting the spinal fixation device into a vertebrae, the implantation mechanism comprising a shaft having a proximal end, a distal end, and an engagement portion on the distal end sized and configured to engage the spinal fixation device, wherein the implantation mechanism is sized and configured to be inserted into the passageway of the cannula.

21. The system of claim 20, wherein the implantation mechanism further comprises a first sleeve having a proximal end and a distal end, the first sleeve being positionable around the shaft.

22. The system of claim 21, wherein the spinal fixation device comprises a head portion and a shank portion, the head portion having a channel for receiving the elongated fixation device, and wherein the engagement portion of the implantation mechanism comprises a protruding portion and at least one shoulder portion, the protruding portion engages the shank portion of the spinal fixation device and the at least one shoulder portion engages the channel of the head portion of the spinal fixation device.

23. The system of claim 22, wherein the head portion of the spinal fixation device has internal threads and the distal end of the first sleeve has a threaded portion, the threaded portion of the first sleeve being sized and configured to engage the internal threads of the head portion of the spinal fixation device.

24. The system of claim 23, the implantation mechanism further comprising a second sleeve, wherein the first sleeve comprises a recess and the second sleeve comprises a protrusion, the protrusion configured to engage the recess to enable the second sleeve to rotate relative to the first sleeve while preventing the second sleeve from moving axially relative to the first sleeve.

25. The system of claim 24, wherein the implantation mechanism further comprises a connecting portion at the proximal end of the shaft, the connecting portion being attachable to a driving mechanism.

26. The system of claim 1, further comprising a fixation device inserter for inserting the elongated fixation device into the spinal fixation device.

27. The system of claim 26, wherein the fixation device inserter comprises:

an elongated shaft;

a moveable member positioned within the elongated shaft for engaging the elongated fixation rod; and

an actuation mechanism operably associated with the moveable member, the actuation mechanism configured to move the moveable member between a first position and a second position.

28. The system of claim 27, wherein the fixation device inserter further comprises a handle portion.

29. The system of claim 27, wherein the elongated fixation rod comprises an engaging portion configured to be coupled to the moveable member.

30. The system of claim 26, wherein the fixation device inserter comprises:

a coupling portion configured to connect the fixation device inserter to the cannula;

a receiving portion configured to pivotally engage the elongated fixation device and to allow the elongated fixation device to be pivoted through an arc and into the spinal fixation device.

31. The system of claim 30, wherein the elongated fixation device is an arcuate rod.

32. The system of claim 26, wherein the fixation device inserter comprises:

a first elongated member having a first jaw portion; and

a second elongated member have a second jaw portion, the second elongated member being pivotally connected to the first elongated member; and

wherein the first and second jaw portions define an engagement portion for engaging the elongated fixation device.

33. The system of claim 32, wherein the inserter further comprises a locking mechanism configured to fix the relative position of the first and second elongated members.

34. The system of claim 1, wherein the spinal fixation device comprises a head portion having a channel and a shank portion, and wherein the cannula further comprises a visual indicator designed and configured to enable an operator to align the at least one slot of the cannula with the channel of the head portion of the spinal fixation device.

35. The system of claim 1, wherein the spinal fixation device comprises a head portion having an outer periphery and at least one recess in the outer periphery, the distal end of the cannula being configured to engage the at least one recess of the head portion.

36. The system of claim 1, further comprising a locking cap, wherein the passageway of the cannula is configured to receive the locking cap.

37. The system of claim 36, further comprising a locking cap screwdriver having an elongated shaft, a proximal end, a distal end and a engaging portion at the distal end, the locking cap screwdriver configured to be positioned within the passageway of the cannula, wherein the engaging portion of the locking cap engages the locking screw.

38. A system for implanting spinal fixation devices in vertebrae through an opening in a patient comprising:

a cannula having a proximal end, a distal end, a surface and a passageway from the proximal end to the distal end, wherein the distal end comprises a threaded portion on the surface for engaging the spinal fixation device, and wherein the at least one slot is configured to receive an elongated fixation device.

39. The system of claim 38, further comprising a dilation mechanism for increasing the size of an incision in a patient to form the opening.

40. The system of claim 39, wherein the dilation mechanism comprises at least one dilator having a elongated cylindrical shape with a channel passing therethrough.

41. The system of claim 40, wherein the dilation mechanism further comprises a retractor, the retractor having at least two blades with an opened position and a closed position, wherein the blades are configured to be inserted over the at least one dilator in the closed position and are configured to move to the opened position to form the opening.

42. The system of claim 40, wherein the at least one dilator comprise an outer periphery and wherein the dilation mechanism further comprises a working cannula having a proximal end, a distal end, and a passageway extending from the proximal end to the distal end, the working cannula being configured to be inserted over the outer periphery of the at least one dilator.

43. The system of claim 38, wherein the dilation mechanism comprises an inserter, the inserter comprising:

an elongated portion, a proximal end and a distal end; and

an enlarged portion on the distal end of the elongated portion;

wherein the passageway of the cannula is sized and configured to receive the inserter.

44. The system of claim 38, wherein the cannula comprises:

an inner cannulated shaft having a proximal end, a distal end; and

an outer cannulated shaft having a proximal end, a distal end and a bore therethrough, wherein the outer cannulated shaft is configured to receive the inner cannulated shaft within the bore and to move on the inner cannulated shaft.

45. The system of claim 44, wherein the cannula further comprises an insert having a plurality of fingers configured to receive a tool.

46. The system of claim 44, wherein the spinal fixation device comprises a head portion having internal threads and a channel therethrough, and wherein the threaded portion is located on the distal end of the inner cannulated shaft, the threaded portion being sized and configured to engage the internal threads of the head portion of the spinal fixation device.

47. The system of claim 46, wherein the inner cannulated shaft comprises at least one recess and the outer cannulated shaft comprises at least one protrusion, the protrusion being configured to move in the recess such that the outer cannulated shaft is moveable between a first position and a second position.

48. The system of claim 47, wherein the outer cannulated shaft comprises at least one extended portion at its distal end, the at least one extended portion being configured to be positionable within the channel of the head portion of the spinal fixation device.

49. The system of claim 38 further comprising an implantation mechanism for implanting the spinal fixation device into vertebrae, the implantation mechanism comprising a shaft having a proximal end, a distal end, and an engagement portion on the distal end sized and configured to engage the spinal fixation device, wherein the implantation mechanism is sized and configured to be inserted into the passageway of the cannula.

50. The system of claim 38, further comprising a fixation device inserter for inserting the elongated fixation device into the spinal fixation device.

51. The system of claim 50, wherein the fixation device inserter comprises:

an elongated shaft;

a moveable member positioned within the elongated shaft for engaging the elongated fixation rod; and

an actuation mechanism operably associated with the moveable member, the actuation mechanism configured to move the moveable member between a first position and a second position.

52. The system of claim 51, wherein the fixation device inserter further comprises a handle portion.

53. The system of claim 51, wherein the elongated fixation rod comprises an engaging portion configured to be coupled to the moveable member.

54. A system for implanting spinal fixation devices in vertebrae through an opening in a patient comprising:

a cannula having a proximal end, a distal end and at least one sidewall, the at least one sidewall defining a passageway from the proximal end to the distal end, the cannula having at least one slot in the at least one sidewall communicating with the passageway, and a flexible portion for engaging the spinal fixation device, the flexible portion comprising a first end portion and a second end portion, the first end portion operably connected to the at least one sidewall of the cannula and the second end portion freely moveable into and out of the passageway of the cannula, the second end portion engagable with the spinal fixation device.

55. The system of claim 54, further comprising an implantation mechanism for implanting the spinal fixation device into a vertebrae, the implantation mechanism comprising a shaft having a proximal end, a distal end, and an engagement portion on the distal end sized and configured to engage the spinal fixation device, wherein the implantation mechanism is sized and configured to be inserted into the passageway of the cannula.

56. The system of claim 55, wherein the implantation mechanism further comprises a first sleeve having a proximal end and a distal end, the first sleeve being positionable around the shaft.

57. The system of claim 56, wherein the spinal fixation device comprises a head portion and a shank portion, the head portion having a channel for receiving the elongated fixation device, and wherein the engagement portion of the implantation mechanism comprises a protruding portion and at least one shoulder portion, the protruding portion engages the shank portion of the spinal fixation device and the at least one shoulder portion engages the channel of the head portion of the spinal fixation device.

58. The system of claim 57, wherein the head portion of the spinal fixation device has internal threads and the distal end of the first sleeve has a threaded portion, the threaded portion of the first sleeve being sized and configured to engage the internal threads of the head portion of the spinal fixation device.

59. The system of claim 54, wherein the cannula has an inner diameter between about 3 mm and about 20 mm.

60. The system of claim 59, wherein the cannula has an inner diameter between about 12 mm and about 16 mm.

61. The system of claim 59, wherein the cannula has an outer diameter between about 3 mm and about 20 mm

62. The system of claim 61, wherein the cannula has an outer diameter between about 14 mm and about 17 mm.

63. The system of claim 61, wherein the cannula has a length between about 40 mm and about 200 mm

64. The system of claim 63, wherein the cannula has a length between about 140 mm and about 160 mm.

65. The system of claim 63, wherein the at least one slot has a width between about 3 mm and about 10 mm, and wherein the at least one slot has a height between about 30 mm and about 160 mm.

66. The system of claim 65, wherein the at least one slot has a width between about 5 mm and about 8 mm, and wherein the at least one slot has a height between about 110 mm and about 130 mm.