System and method for spinal implant placement

• US 8,002,798 B2
• Filed: 08/12/2005
• Issued: 08/23/2011
• Est. Priority Date: 09/24/2003
• Status: Expired

• Current Assignee: Stryker European Operations Holdings, LLC (Stryker Corporation)
• Original Assignee: Stryker Spine
• Inventors: Butters, Joshua A., Justin, Daniel F., Chin, Kingsley Richard, Fallin, T. Wade
• Primary Examiner(s): WOODALL, NICHOLAS W
• Application Number:
  US11/202,487
• Publication Number:
  US 20060264962A1
• Time in Patent Office: 2,202 Days
• Field of Search: 606/60, 606/246, 606/279
• US Class Current: 606/246
• 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 17/3201 Scissors for biopsy A61B10/02
• CPC Class Codes: A61B 17/3417 Details of tips or shafts, e.g. grooves, expandable, bendable; Multiple coaxial sliding cannulas, e.g. for dilating syringe needles A61M5/32; dilators A61M29/00
• CPC Class Codes: A61B 17/3421 Cannulas
• CPC Class Codes: A61B 17/701 Longitudinal elements with a non-circular, e.g. rectangular, cross-section A61B17/7005, A61B17/7007 take precedence
• CPC Class Codes: A61B 17/7032 Screws or hooks with U-shaped head or back through which longitudinal rods pass
• CPC Class Codes: A61B 17/7035 Screws or hooks, wherein a rod-clamping part and a bone-anchoring part can pivot relative to each other
• CPC Class Codes: A61B 17/7037 wherein pivoting is blocked when the rod is clamped
• 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 17/7091 for applying, tightening or removing longitudinal element-to-bone anchor locking elements, e.g. caps, set screws, nuts or wedges
• CPC Class Codes: A61B 2017/00738 part of the tool being offset with respect to a main axis, e.g. for better view for the surgeon
• CPC Class Codes: A61B 2017/3443 with means for adjusting the length of a cannula
• CPC Class Codes: A61B 2017/3445 used as instrument channel for multiple instruments catheters A61B2017/22072
• CPC Class Codes: A61B 2017/3492 against the outside of the body
• CPC Class Codes: A61B 2090/036 abutting on tissue or skin
• CPC Class Codes: A61B 2090/037 with a frangible part, e.g. by reduced diameter
• CPC Class Codes: A61B 90/00 Instruments, implements or accessories specially adapted for surgery or diagnosis and not covered by any of the groups A61B1/00 - A61B50/00, e.g. for luxation treatment or for protecting wound edges protective face masks A41D13/11; surgeon's or patient's gowns or dresses A41D13/12; devices for carrying-off, for treatment of, or for carrying-over, body liquids A61M1/00
• CPC Class Codes: A61B 90/39 Markers, e.g. radio-opaque or breast lesions markers

Abstract

A posterior spinal fusion system may include a plurality of cannulas that mate with cages polyaxially coupled to pedicle screws. The cannulas maintain access to the pedicle screws to facilitate percutaneous insertion of a fusion rod into engagement with the cages. Each cannula has a pair of blades that may be held together by an abutment member that at least partially encircles the blades. Each abutment member abuts the skin to define a variable subcutaneous length of the corresponding cannula. Each abutment members is also lockably removable from the corresponding blades to enable the blades to pivot with respect to the connecting element to a position in which they can be withdrawn from the connecting element. The blades of each cannula are spaced apart to provide first and second slots of each cannula, through which the fusion rod can be percutaneously inserted.

Claims

1. A system for providing access to a spine of a patient, the system comprising:

a first connecting element implantable in a first vertebra of a spine; and

a first cannula adapted to receive at least a portion of a spinal fusion rod therealong, the first cannula comprising;

a first blade; and

a second blade discrete from the first blade;

wherein the first and second blades are configured to be assembled together substantially parallel to each other and mated with the first connecting element, without being directly connected to one another, in order to provide the first cannula such that the first cannula has a distal end terminating at the connecting element, whereby the first cannula provides access to the spine when the first connecting element is implanted in the first vertebra of the spine; and

wherein the first and second blades are independently detachable from the first connecting element such that the first and second blades are independently removable from the patient.

2. The system of claim 1, wherein the connecting element comprises a pedicle screw implantable in a pedicle of the first vertebra, and a cage polyaxially movable with respect to the pedicle screw.

3. The system of claim 1, wherein the first and second blades are configured to be disassembled from one another without removing the distal end from within the patient.

4. The system of claim 3, wherein each of the first and second blades comprises a locked configuration, in which the blade is secured to the connecting element, and an unlocked configuration, in which the blade is removable from the connecting element, wherein each of the first and second blades is movable between the locked and unlocked configurations in response to rotation of the blade with respect to the connecting element.

5. The system of claim 4, wherein each of the first and second blades is movable between the locked and unlocked configurations in response to rotation of the blade about an axis substantially perpendicular to a longitudinal axis of the first cannula.

6. The system of claim 1, further comprising an abutment member configured to engage the first and second blades to restrict relative motion between the first and second blades.

7. The system of claim 6, wherein the abutment member is lockable with respect to the first and second blades by a locking mechanism that restricts withdrawal of the abutment member from the first and second blades.

8. The system of claim 7, wherein the locking mechanism comprises a plurality of proximal tabs of the first and second blades, wherein the proximal tabs are bendable to permit withdrawal of the abutment member from the first and second blades.

9. The system of claim 1, further comprising an abutment member encircling at least a portion of the first cannula to abut an exterior skin surface of the patient, wherein the abutment member is movable along the first cannula to define a variable subcutaneous length of the first cannula.

10. The system of claim 9, wherein the abutment member is shaped such that a combined length of the first cannula and the abutment member does not change in response to motion of the abutment member along the first cannula.

11. The system of claim 1, wherein the first and second blades are shaped such that, when positioned to define the first cannula, the first and second blades provide a first slot in a side wall of the first cannula.

12. The system of claim 11, wherein the first and second blades are further shaped such that, when positioned to define the first cannula, the first and second blades provide a second slot in the side wall, wherein the second slot is arranged with respect to the first slot to permit passage of a rod through the first cannula along a direction transverse to a longitudinal axis of the first cannula.

13. The system of claim 12, wherein the distal end is insertable into the patient proximate the spine such that each of the first and second slots extends unbroken along an entire subcutaneous length of the cannula.

14. The system of claim 1, further comprising a second cannula securable to a second connecting element implantable in a second vertebra of the spine, and a third cannula securable to a third connecting element implantable in a third vertebra of the spine, wherein the first, second, and third cannulas cooperate to facilitate attachment of a rod to the first, second, and third connecting elements to restrict relative motion of the first, second, and third vertebrae.

15. The system of claim 1, wherein the first and second blades have arcuate profiles, whereby the first cannula is defined by a partially cylindrical shape.

16. The system of claim 1, wherein the first and second blades each have a distal end including a tab insertable into a corresponding slot of the first connecting element.

17. The system of claim 1, further comprising an abutment member configured to prevent the first and second blades from becoming disconnected from the first connecting element.

18. A system for providing access to a spine of a patient, the system comprising:

a cannula adapted to receive at least a portion of a spinal fusion rod therealong, the cannula comprising a proximal end and a distal end insertable into the patient proximate the spine, the distal end comprising a docking element discrete from and securable to a connecting element implantable in a first vertebra of the spine;

wherein the docking element is receivable by the connecting element in both a docked configuration and an undocked configuration, the distal end being secured to the connecting element in the docked configuration, and the distal end being received by and removable from the connecting element in the undocked configuration, and wherein the docking element is movable between the docked and undocked configurations in response to rotation about an axis substantially perpendicular to a longitudinal axis of the cannula.

19. The system of claim 18, wherein the connecting element comprises a pedicle screw implantable in a pedicle of the first vertebra, and a cage polyaxially movable with respect to the pedicle screw, wherein the docking element is configured to dock with the cage.

20. The system of claim 19, wherein the cannula comprises:

a first blade; and

a second blade discrete from the first blade;

wherein the first and second blades are positionable substantially parallel to each other to provide the first cannula;

wherein each of the first and second blades comprises a locked configuration, in which the blade is secured to the connecting element, and an unlocked configuration, in which the blade is removable from the connecting element.

21. The system of claim 18, wherein the docking element includes a plurality of tabs, each of the first and second blades comprising at least one of the tabs at a distal end thereof, the tabs enabling rotation of the blades between the locked configuration and the unlocked configuration.

22. The system of claim 18, further comprising an abutment member configured to engage the first and second blades to restrict relative motion between the first and second blades to restrict motion of the blades to the unlocked configuration.

23. The system of claim 22, wherein the abutment member is lockable with respect to the first and second blades by a locking mechanism that restricts withdrawal of the abutment member from the first and second blades.

24. The system of claim 23, wherein the locking mechanism comprises a proximal tab of each of the first and second blades, wherein the proximal tabs are bendable to permit withdrawal of the abutment member from the first and second blades.

25. A system for providing access to a spine of a patient, the system comprising:

a cannula adapted to receive at least a portion of a spinal fusion rod therealong, the cannula comprising a distal end insertable into the patient proximate the spine and securable to a connecting element implantable in a first vertebra of the spine, the cannula further comprising a proximal end and a longitudinal axis extending between the proximal and distal ends; and

an abutment member encircling at least a portion of the cannula and adapted to abut an outward facing surface of skin of the patient, the entire length of the abutment member along the longitudinal axis of the cannula being disposed between the proximal and distal ends of the cannula, wherein the abutment member is adapted to move along the cannula from the proximal end to the distal end such that the abutment member can be moved to a position abutting the outward facing surface of skin when the distal end of the cannula is secured to the connecting element, whereby a variable subcutaneous length of the cannula is defined, and wherein a combined length of the cannula and the abutment member does not change in response to motion of the abutment member along the cannula.

26. The system of claim 25, wherein the cannula comprises:

a first blade; and

a second blade discrete from the first blade;

wherein the first and second blades are positionable substantially parallel to each other to provide the cannula.

27. The system of claim 26, wherein the abutment member is configured to engage the first and second blades to restrict relative motion between the first and second blades.

28. The system of claim 25, wherein the abutment member is lockable with respect to the cannula by a locking mechanism that restricts withdrawal of the abutment member from the cannula.

29. The system of claim 28, wherein the locking mechanism comprises a plurality of proximal tabs of the cannula, wherein the proximal tabs are bendable to permit withdrawal of the abutment member from the cannula.

30. The system of claim 25, wherein the cannula comprises a first slot extending longitudinally along a side wall of the cannula.

31. The system of claim 25, wherein the cannula comprises a docking element that couples the cannula to a connecting element implantable in a vertebra of the spine, wherein the docking element comprises a frangible coupling configured to fracture in response to application of a threshold force against the frangible coupling to permit removal of the distal end from the connecting element.

32. A system for providing access to a spine of a patient, the system comprising:

a cannula comprising;

a first component; and

a second component discrete from the first component;

and

an abutment member;

wherein the first and second components are configured to be assembled to a connecting element implantable in a first vertebra of the spine, wherein each of the first and second components has a distal end receivable in the connecting element in a receiving position and a locked position, each of the first and second components being movable between the receiving position and the locked position in response to rotation about an axis substantially perpendicular to a longitudinal axis of the cannula, wherein the abutment member configured to engage the first and second components to restrict relative motion between the first and second components, and wherein the abutment member is lockable with respect to the first and second components by a locking mechanism that restricts withdrawal of the abutment member from the first and second blades.

33. The system of claim 32, wherein the first component comprises a first blade, and the second component comprises a second blade, wherein the first and second blades are positionable substantially parallel to each other to provide the cannula.

34. The system of claim 33, wherein the distal end comprises a docking element securable to a connecting element implantable in a first vertebra of the spine, wherein each of the first and second blades is secured to the connecting element in the locked position and received within but removable from the connecting element in the receiving position.

35. The system of claim 32, wherein the locking mechanism comprises a plurality of proximal tabs of the first and second components, wherein the proximal tabs are bendable to permit withdrawal of the abutment member from the first and second components.

36. The system of claim 32, wherein the first and second components have arcuate surfaces, whereby the cannula is defined by a partially cylindrical shape.

37. A system for providing access to a spine of a patient, the system comprising:

a cannula adapted to receive at least a portion of a spinal fusion rod therealong, the cannula having a longitudinal axis and comprising a distal end insertable into the patient proximate the spine, and a proximal end, the distal end comprising a docking element securable to a connecting element implantable in a first vertebra of the spine; and

an abutment member encircling at least a portion of the cannula, the abutment member having an abutment surface substantially normal to the longitudinal axis, the abutment surface adapted to abut an exterior skin surface of the patient, wherein the abutment member is adapted to move along the cannula from the proximal end to the distal end such that the abutment member can be moved to a position wherein the abutment surface abuts the exterior skin surface when the docking element is secured to the connecting element implanted in the first vertebra of the spine, whereby a variable subcutaneous length of the cannula is defined.

38. The system of claim 37, wherein the connecting element comprises a pedicle screw implantable in a pedicle of the first vertebra, and a cage polyaxially movable with respect to the pedicle screw.

39. The system of claim 37, wherein the abutment member is lockable with respect to the cannula by a locking mechanism that restricts withdrawal of the abutment member from the cannula.

40. The system of claim 39, wherein the locking mechanism comprises a plurality of proximal tabs of the cannula, wherein the proximal tabs are bendable to permit withdrawal of the abutment member from the cannula.

41. The system of claim 37, wherein the abutment member is shaped such that a combined length of the cannula and the abutment member does not change in response to motion of the abutment member along the cannula.

42. The system of claim 37, wherein the cannula further comprises a first slot portion formed in a side wall of the cannula.

43. The system of claim 42, wherein the cannula further comprises a second slot portion formed in the side wall, wherein the second slot is arranged with respect to the first slot to permit passage of a rod through the cannula along a direction transverse to the longitudinal axis of the cannula.

44. The system of claim 43, wherein the distal end is insertable into the patient proximate the spine such that each of the first and second slots extends unbroken along the entire subcutaneous length.

45. The system of claim 37, wherein the docking element comprises a frangible coupling configured to fracture in response to application of a threshold force against the frangible coupling to permit removal of the distal end from the connecting element.

46. The system of claim 37, wherein the cannula comprises:

a first blade; and

a second blade discrete from the first blade;

wherein the first and second blades are positionable substantially parallel to each other to provide the cannula, and wherein the abutment member is configured to engage the first and second blades to restrict relative motion between the first and second blades.

47. A system for providing access to a spine of a patient, the system comprising:

a cannula adapted to receive at least a portion of a spinal fusion rod therealong, the cannula comprising a distal end insertable into the patient proximate the spine and securable to a connecting element implantable in a first vertebra of the spine, the cannula further comprising a proximal end and a first slot extending longitudinally between the distal and proximal ends; and

an abutment member encircling at least a portion of the cannula, the abutment member having an abutment surface extending substantially laterally from an outer surface of the cannula, the abutment surface adapted to abut an exterior skin surface of the patient, wherein the abutment member is adapted to move along the cannula from the proximal end to the distal end such that the abutment member can be moved to a position wherein the abutment surface abuts the exterior skin surface when the distal end of the cannula is secured to the connecting element implanted in the first vertebra of the spine, whereby a variable subcutaneous length of the cannula is defined.

48. The system of claim 47, wherein the abutment member is lockable with respect to the cannula by a locking mechanism that restricts withdrawal of the abutment member from the cannula.

49. The system of claim 48, wherein the locking mechanism comprises a plurality of proximal tabs of the cannula, wherein the proximal tabs are bendable to permit withdrawal of the abutment member from the cannula.

50. The system of claim 47, wherein the abutment member is shaped such that a combined length of the cannula and the abutment member does not change in response to motion of the abutment member along the cannula.

51. The system of claim 47, wherein the cannula further comprises a second slot portion formed in the side wall, wherein the second slot is arranged with respect to the first slot to permit passage of a rod through the cannula along a direction transverse to a longitudinal axis of the cannula.

52. The system of claim 51, wherein the distal end is insertable into the patient proximate the spine such that each of the first and second slots extends unbroken along the entire subcutaneous length.

53. The system of claim 47, wherein the cannula comprises a docking element that couples the cannula to a connecting element implantable in a vertebra of the spine, wherein the docking element comprises a frangible coupling configured to fracture in response to application of a threshold force against the frangible coupling to permit removal of the distal end from the connecting element.

54. The system of claim 47, wherein the cannula comprises:

a first blade; and

a second blade discrete from the first blade;

wherein the first and second blades are positionable substantially parallel to each other to provide the cannula, and wherein the abutment member is configured to engage the first and second blades to restrict relative motion between the first and second blades.