Spine distraction implant and method

• US 5,836,948 A
• Filed: 01/02/1997
• Issued: 11/17/1998
• Est. Priority Date: 01/02/1997
• Status: Expired due to Term

• Current Assignee: Kyphon SARL (Medtronic Plc)
• Original Assignee: Saint Francis Medical Technologies, LLC
• Inventors: Fallin, T. Wade, Klyce, Henry A., Zucherman, James F., Hsu, Ken Y.
• Primary Examiner(s): Buiz, Michael
• Assistant Examiner(s): Reip, David O.
• Application Number:
  US08/778,093
• Time in Patent Office: 684 Days
• Field of Search: 606/61, 606/105, 623/17
• US Class Current: 606/249
• CPC Class Codes: A61B 17/66 Alignment, compression or distraction mechanisms
• CPC Class Codes: A61B 17/7062 Devices acting on, attached to, or simulating the effect of, vertebral processes, vertebral facets or ribs rib fixation devices A61B17/8076; Tools for such devices
• CPC Class Codes: A61B 17/7065 Devices with changeable shape, e.g. collapsible or having retractable arms to aid implantation; Tools therefor
• CPC Class Codes: A61B 17/7068 Devices comprising separate rigid parts, assembled in situ, to bear on each side of spinous processes; Tools therefor
• CPC Class Codes: A61B 17/7071 Implants for expanding or repairing the vertebral arch or wedged between laminae or pedicles; Tools therefor
• CPC Class Codes: A61B 2017/0256 for the spine
• CPC Class Codes: A61K 31/37 Coumarins, e.g. psoralen

Abstract

A spine distraction implant alleviates pain associated with spinal stenosis and facet arthropathy by expanding the volume in the spine canal and/or neural foramen. The implant provides a spinal extension stop while allowing freedom of spinal flexion.

Claims

1. An implant for flattening the spine in order to increase the volume of at least one of the spinal canal and the neural foramen comprising:

a central body with first and second saddles which are adapted to receive adjacent spinous processes;

first and second arms projecting from the first saddle and third and fourth arms projecting from the second saddle;

said first and fourth arms are longer than the central body with the first arm being longer than the fourth arm; and

the second and third arms are about the length of the central body and/or shorter than the central body with the second arm being shorter than the third arm.

2. The implant of claim 1 wherein:

said third arm is below said first arm and said fourth arm is below said second arm.

3. The implant of claim 1 wherein:

said third arm is substantially shorter than the first arm so that the implant can be directed between the space between adjacent spinous processes with the first arm first urged through the space and the spinous processes distracted so that the third arm can be urged through the space with the central body positioned between the spinous processes.

4. The implant of claim 1 wherein:

said first arm is sloped in a direction away from the central body in order to accommodate the shape of a vertebra.

5. The implant of claim 1 wherein:

said first, third, and fourth arms are sloped in a direction away from the central body in order to accommodate the shape a vertebra.

6. The implant of claim 1 wherein:

said central body includes a bore therein.

7. The implant of claim 1 wherein:

said central body includes a bore therein so that the implant has a modulus of elasticity that is compatible with that of bone.

8. The implant of claim 1 wherein:

at least one of said saddles is sloped in order to accommodate a vertebra.

9. The implant of claim 1 wherein:

at least one of said saddles is sloped about approximately 30°

so as to accommodate a vertebra.

10. The implant of claim 1 wherein:

at least one of said arms is sloped about approximately 30°

so as to accommodate a vertebra.

11. The implant of claim 1 wherein:

said first arm has a sloped portion which is sloped in a direction away from the central body; and

said first arm has a recess located at a distal end of said sloped portion followed by a convex portion in order to accommodate the shape of a vertebra.

12. The implant of claim 1 wherein:

said implant has a modulus of elasticity which is compatible with bone.

13. The implant of claim 1 wherein:

said implant has as modulus of elasticity which is approximately about twice that of bone.

14. An implant for flattening the spine in order to increase the volume of at least one of the spinal canal and the neural foramen comprising:

a central body with first and second saddles which are adapted to receive adjacent spinous processes;

first and second arms projecting from the first saddle and third and fourth arms projecting from the second saddle;

said first and fourth arms are longer than the second and third arms; and

said third arm is located below said first arm and said fourth arm is located below said second arm, with said fourth arm located diametrically opposite said first arm in order to facilitate the implantation of the implant between adjacent spinous.

15. The implant of claim 14 wherein:

said third arm is substantially shorter than the first arm so that the implant can be directed between the space between adjacent spinous processes with the first arm first urged through the space and the spinous processes distracted so that the third arm can be urged through the space with the central body positioned between the spinous processes.

16. The implant of claim 14 wherein:

said first arm is sloped in a direction away from the central body in order to accommodate the shape of a vertebra.

17. The implant of claim 14 wherein:

said first, third, and fourth arms are sloped in a direction away from the central body in order to accommodate the shape a vertebra.

18. The implant of claim 14 wherein:

said central body includes a bore therein.

19. The implant of claim 14 wherein:

said central body includes a bore therein so that the implant has a modulus of elasticity that is compatible with that of bone.

20. The implant of claim 14 wherein:

at least one of said saddles is sloped in order to accommodate a vertebra.

21. The implant of claim 14 wherein:

at least one of said saddles is sloped about approximately 30°

so as to accommodate a vertebra.

22. The implant of claim 14 wherein:

at least one of said arms is sloped about approximately 30°

so as to accommodate a vertebra.

23. The implant of claim 14 wherein:

said first arm has a sloped portion which is sloped in a direction away from the central body; and

said first arm has a recess located at a distal end of said sloped portion followed by a convex portion in order to accommodate the shape of a vertebra.

24. The implant of claim 14 wherein:

said implant has a modulus of elasticity which is compatible with bone.

25. The implant of claim 14 wherein:

said implant has as modulus of elasticity which is approximately about twice that of bone.