Instruments, implants and methods for positioning implants into a spinal disc space

• US 20060235426A1
• Filed: 04/15/2005
• Published: 10/19/2006
• Est. Priority Date: 04/15/2005
• Status: Active Grant

• Current Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Original Assignee: SDGI Holdings Incorporated (Medtronic Plc)
• Inventors: DeRidder, Steven D., Lim, Roy
• Granted Patent: US 7,575,580 B2
• Time in Patent Office: Days
• US Class Current: 606/99
• 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 2002/30133 kidney-shaped or bean-shaped
• CPC Class Codes: A61F 2002/30538 for adjusting angular orientation
• CPC Class Codes: A61F 2002/30593 hollow
• CPC Class Codes: A61F 2002/30772 Apertures or holes, e.g. of circular cross section
• CPC Class Codes: A61F 2002/30787 inclined obliquely with respect to each other
• CPC Class Codes: A61F 2002/30843 Pyramidally-shaped
• 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 2002/4628 with linear motion along or rotating motion about an axis transverse to the instrument axis or to the implantation direction, e.g. clamping
• CPC Class Codes: A61F 2230/0015 Kidney-shaped, e.g. bean-shaped
• CPC Class Codes: A61F 2250/0006 for adjusting angular orientation

Abstract

Instruments, implants and methods are provided for positioning spinal implants in a spinal disc space between adjacent vertebrae. The instruments provide a low profile engagement with the implants and facilitate insertion while minimizing tissue retraction and exposure of the tissue and neural elements to the instrumentation in the approach to the disc space.

Claims

1. An instrument for inserting a spinal implant, comprising:

a proximal handle assembly;

a shaft assembly extending distally from said handle assembly along a longitudinal axis; and

a grasper assembly at a distal end of said shaft assembly, said grasper assembly including first and second arms remotely operable for movement relative to one another between an engaging position to engage the implant therebetween and a release position to disengage the implant from therebetween, said first and second arms further being remotely pivotal relative to a distal end of said shaft assembly when in the engaging position from an initial position for insertion of the implant into the spinal disc space to a final position for implantation of the implant in the spinal disc space.

2. The instrument of claim 1, wherein said shaft assembly includes a first shaft and a second shaft forming a passage therebetween and a locking shaft movably received in said passage.

3. The instrument of claim 2, wherein:

said first arm includes a proximal lever portion with a first end pivotally coupled to said first shaft and a second end pivotally coupled to said second shaft; and

said second arm includes a proximal heel portion articulably coupled to and translatable relative to said second shaft and a toe portion extending from said heel portion pivotally coupled to said first shaft about a common pivot with said first end of said lever portion of said first arm.

4. The instrument of claim 3, wherein said locking shaft includes a distal end contactable with said heel portion to distally translate said second arm about said second shaft and to pivot said second arm about said common pivot to move said grasper assembly to said engaging position.

5. The instrument of claim 4, wherein said first shaft is distally moveably along said second shaft to pivot said first and second arms about said second shaft from said initial position to said final position.

6. The instrument of claim 5, wherein said heel portion includes a circular perimeter in contact with said distal end of said locking shaft, said circular perimeter maintaining contact with said distal end as said grasper assembly is moved from said initial position to said final position thereby maintaining said first and second arms in said engaging position.

7. The instrument of claim 6, wherein:

said first shaft includes an articulator screw at a proximal end thereof threadingly engaged with an articulator driver of said handle assembly; and

said locking shaft includes a lock screw at a proximal end thereof threadingly engaged with a locking driver of said handle assembly.

8. The instrument of claim 7, wherein said handle assembly includes a handle member between said articulator driver and said locking driver.

9. The instrument of claim 7, wherein said handle assembly includes a proximal end member structured to receive impaction forces.

10. The instrument of claim 1, wherein said grasper assembly is structured to hold the implant in an orientation extending generally along the longitudinal axis in the initial position and in an orientation substantially obliquely oriented to the longitudinal axis in the final position.

11. The instrument of claim 1, wherein the first and second arms each include concavely curved surfaces positionable in contact with the implant, the concavely curved surfaces being oriented toward one another.

12. A spinal instrumentation system for interbody procedures, comprising:

a spinal implant positionable in a spinal disc space comprising a body formed by a convexly curved anterior wall portion, a concavely curved posterior wall portion, a convexly curved leading end wall portion, and a convexly curved trailing end wall portion, said leading and trailing end wall portions extending between and connecting said anterior and posterior wall portions;

an inserter instrument engageable about said trailing end wall portion, said inserter instrument comprising;

a proximal handle assembly;

a shaft assembly extending distally from said handle assembly along a longitudinal axis; and

a grasper assembly at a distal end of said shaft assembly, said grasper assembly including a first arm and a second arm pivotal relative to said first arm for movement between an engaging position to engage said implant between said first and second arms and a release position to disengage the implant from between said first and second arms, said first and second arms further being simultaneously pivotal when in the engaging position about a distal end of said shaft assembly between an initial position wherein said implant is generally aligned along the longitudinal axis and a final position wherein said implant is substantially obliquely oriented to said longitudinal axis.

13. The system of claim 12, wherein said first arm is positionable along said anterior wall portion and said second arm is positionable along said posterior wall portion.

14. The system of claim 13, wherein said body includes a recessed area along said trailing end wall portion and said anterior wall portion for receiving said first arm, and said posterior wall portion includes a receptacle for receiving said second arm.

15. The system of claim 12, wherein said body includes a hole in said recessed area, and said first arm includes a pin positionable in said hole.

16. The system of claim 12, wherein said first arm includes a concavely curved inner surface positionable against said anterior wall portion and said second arm includes a concavely curved surface positionable against said trailing end wall portion.

17. The system of claim 12, wherein said shaft assembly includes a first shaft and a second shaft forming a passage therebetween, said shaft assembly further including a locking shaft moveably received in said passage.

18. The system of claim 17, wherein:

said first arm includes a proximal lever portion having a first end pivotally coupled to said first shaft and at a second end pivotally coupled to said second shaft; and

said second arm includes a proximal heel portion articulably coupled to and translatable relative to said second shaft and a toe portion extending from said heel portion pivotally coupled to said first shaft at a common pivot with said first end of said lever portion of said first arm.

19. The system of claim 18, wherein said locking shaft includes a distal end contactable with said heel portion to distally translate said second arm along said second shaft and to pivot said second arm about said common pivot to move said grasper assembly to said engaging position.

20. The system of claim 18, wherein said first shaft is distally moveable along said second shaft to pivot said first and second arms about said second shaft from said initial position to said final position.

21. The system of claim 17, wherein:

said first shaft includes an articulator screw at a proximal end thereof threadingly engaged with an articulator driver of said handle assembly;

said locking shaft includes a lock screw at a proximal end thereof threadingly engaged with a locking driver of said handle assembly; and

said handle assembly includes a handle member between said articulator driver and said locking driver.

22. A method for manipulating a spinal implant with an inserter instrument, comprising:

positioning a trailing end of the spinal implant adjacent first and second arms at a distal end of the inserter instrument;

engaging the spinal implant to at least one of the first and second arms with the spinal implant generally aligned along a longitudinal axis of the inserter instrument;

pivoting the spinal implant to a final position substantially obliquely oriented to the longitudinal axis; and

releasing the implant from between the first and second arms when the spinal implant is in the final position.

23. The method of claim 22, wherein positioning the trailing end of the spinal implant includes gripping the trailing end of the implant between the first and second arms of the inserter instrument.

24. The method of claim 23, wherein gripping the trailing end includes pivoting the second arm relative to and towards the first arm to grasp the trailing end of the spinal implant between the first and second arms.

25. The method of claim 22, wherein pivoting the implant to the final position includes simultaneously pivoting the first and second arms about a distal end of a shaft assembly of the inserter instrument.

26. The method of claim 22, wherein engaging the spinal implant includes positioning a distal end of the first arm in a recessed area adjacent a posterior wall of the spinal implant.

27. The method of claim 26, wherein pivoting the spinal implant to the final position includes pivoting the spinal implant about the distal end of the first arm to align a receptacle in a trailing end wall of the spinal implant with the second arm.

28. The method of claim 27, wherein engaging the spinal implant includes linearly advancing a distal end portion of the second arm into the receptacle.

29. An instrument for inserting a spinal implant, comprising:

a proximal handle assembly;

a shaft assembly extending distally from said handle assembly along a longitudinal axis; and

a grasper assembly at a distal end of said shaft assembly, said grasper assembly including a first arm and a second arm remotely moveable between an engaging position to engage an implant between said first and second arms and a release position to disengage the implant from between said first and second arms, said first arm being structured for rotatable receipt in a recessed area of the implant in said release position and said second arm being linearly movable relative to said first arm for positioning in a receptacle of the implant in said engaging position to prevent said first arm from rotating in the receptacle.

30. The instrument of claim 29, wherein said first arm includes a spherically shaped ball at a distal end thereof and said recessed area includes a complementary spherical shape.

31. The instrument of claim 30, wherein said shaft assembly includes an outer shaft having a passage extending longitudinally therethrough and a locking shaft positioned in said passage, said first arm being integrally formed with said outer shaft at a distal end thereof and said second arm being integrally formed at a distal portion of said locking shaft.

32. The instrument of claim 31, wherein said locking shaft includes a locking screw at a proximal end thereof and said handle assembly includes a locking driver threadingly engaged about said locking screw, said locking driver being rotatable to linearly translate said locking shaft in said passage of said outer shaft.

33. The instrument of claim 32, wherein said handle assembly includes a hub extending proximally from said shaft assembly along said longitudinal axis, and said locking driver is rotatably mounted in said hub.

34. The instrument of claim 29, wherein said handle assembly includes a handle member transversely oriented to said longitudinal axis.

35. A spinal instrumentation system for interbody procedures, comprising:

a spinal implant positionable in a spinal disc space comprising a body formed by a wall including a leading end wall portion and a trailing end wall portion, said body further including a recessed area and a receptacle adjacent to said trailing end wall portion;

an inserter instrument engageable at said trailing end wall portion, said inserter instrument comprising;

a proximal handle assembly;

a shaft assembly extending distally from said handle assembly along a longitudinal axis; and

a grasper assembly at a distal end of said shaft assembly, said grasper assembly including a first arm positionable in said recessed area of said spinal implant and a second arm along said axis linearly movable into said receptacle of said spinal implant when said receptacle is aligned on said longitudinal axis to lock said implant in position in said grasper assembly.

36. The system of claim 35, wherein said spinal implant is pivotal about said first arm when said second arm is removed from said receptacle.

37. The system of claim 36, wherein said first arm includes a spherically-shaped distal end and said recessed area includes a spherical shape complimentary to said distal end.

38. The system of claim 35, wherein said shaft assembly includes an outer shaft having a passage extending longitudinally therethrough and a locking shaft positioned in said passage, said first arm being integrally formed with said first shaft at a distal end thereof and said second arm being integrally formed at a distal portion of said locking shaft.

39. The system of claim 38, wherein said locking shaft includes a locking screw at a proximal end thereof and said handle assembly includes a locking driver threadingly engaged about said locking screw, said locking driver being rotatable to linearly translate said locking shaft in said passage of said outer shaft.

40. The system of claim 39, wherein said handle assembly includes a hub extending proximally from said shaft assembly along said longitudinal axis, and said locking driver is rotatably mounted in said hub.

41. The system of claim 35, wherein said body of said implant includes a concavely curved posterior wall portion and a convexly curved anterior wall portion, said anterior and posterior wall portions extending between said leading and trailing end wall portions.

42. The system of claim 41, wherein said leading and trailing end wall portions are convexly curved and said recessed area is formed in said trailing end wall portion adjacent said posterior wall portion and said receptacle is formed in said trailing end wall portion adjacent said anterior wall portion.

43. The system of claim 42, wherein:

said receptacle is an elongated bore through said trailing end wall portion; and

said recessed area is a spherically shaped recess extending into said trailing end wall portion toward said receptacle, said implant forming a toe between said recessed area and said receptacle adjacent an outer surface of said trailing end wall portion.

44. The system of claim 43, wherein said outer shaft of said inserter instrument includes a distal end surface about said passage positionable in contact with said outer surface of said trailing end portion of said implant, said outer shaft further including a recessed portion at a junction of said first arm with said distal end surface, said toe being positionable in said recessed portion in a dovetail arrangement when said implant is locked in position in said grasper assembly.