Apparatus for treating spinal stenosis

• US 20070032790A1
• Filed: 08/05/2005
• Published: 02/08/2007
• Est. Priority Date: 08/05/2005
• Status: Active Grant

• Current Assignee: Synthes USA LLC (Johnson & Johnson)
• Original Assignee: Synthes USA LLC (Johnson & Johnson)
• Inventors: Mayer, Michael, Pavlov, Paul, Senn, Peter, Aschmann, Felix
• Granted Patent: US 7,753,938 B2
• Time in Patent Office: Days
• US Class Current: 606/249
• 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 17/848 Kirschner wires, i.e. thin, long nails
• CPC Class Codes: A61B 17/8897 Guide wires or guide pins

Abstract

A device for treating spinal stenosis having an implant body structure sized and configured to be positioned between the spinous processes of two adjacent vertebrae. The device may have a body portion having a first end portion, a second end portion and a sleeve between the first and second end portions. The device may also have at least two retainers positioned in and extendable from the body portion. A mechanism positioned within the body portion may be used to move the retainers between a retracted position and a deployed position. When the retainers are in the deployed position, the retainers may be positioned around the spinous process of at least one of two adjacent vertebrae. A plurality of installation tools may be used to install the device.

Claims

1. An apparatus for treating spinal stenosis, comprising:

an implant body structure configured to fit between spinous processes of two adjacent vertebrae;

at least two retainers operably associated with the body structure; and

a mechanism operative to move the retainers from a retracted position to a deployed position extending outward from the body structure beside the spinous process of one of the two adjacent vertebrae.

2. An apparatus as defined in claim 1 wherein the mechanism is a screw.

3. An apparatus as defined in claim 1 further comprising a third and fourth retainer operably associated with the body structure, the mechanism being operative to drive the third and fourth retainers from respective retracted positions to respective deployed positions extending outward from the body structure on opposite sides of the spinous process of the other of the two adjacent vertebrae.

4. An apparatus as defined in claim 1 wherein the mechanism is contained within the body structure.

5. An apparatus as defined in claim 1 wherein the mechanism comprise an elongated connector having an axis and mounted within the body structure and the body structure comprises first and second body end portions spaced apart along the axis;

wherein the mechanism is operative to move the first and second body end portions axially toward each other such that the at least two retainers move from the retracted position to the deployed position under the influence of the first and second body end portions as they are moved axially toward each other.

6. An apparatus as defined in claim 5 wherein the at least two retainers are mounted on the first body end portion by a hinge.

7. An apparatus as defined in claim 5 wherein the at least two retainers are fixed to the first body end portion to move axially with the first body portion and the at least two retainers slide axially with respect to the second body end portion upon movement of the first body end portion axially toward the second body end portion;

wherein the second body portion is configured to deflect and guide the retainers to move the retainers from the retracted position to the deployed position.

8. An apparatus as defined in claim 5 wherein each of the at least two retainers is a wire which extends between the first body end portion and the second body end portion.

9. An apparatus as defined in claim 8 wherein the wire of at least one retainer is generally U-shaped and has free ends, wherein the free ends are fixed to the first body end portion to move with the first body end portion as the first body end portion moves axially relative to the second body end portion.

10. An apparatus as defined in claim 9 wherein the first body end portion and second body end portion each have a cam surface for deflecting the wire.

11. An apparatus as defined in claim 5 wherein the mechanism comprises an elongated connector having a longitudinal axis, a screw thread in a first direction engaged with the first body end portion, and an oppositely extending screw thread in a second direction engaged with the second body end portion.

12. An apparatus as defined in claim 5 wherein the body structure further includes a sleeve located axially between the first and second body end portions.

13. An apparatus as defined in claim 12 wherein the peripheral sleeve is capable of rotating relative to the first and second body end portions under forces applied from the spinous processes of the two adjacent vertebrae.

14. An apparatus as defined in claim 12 wherein the sleeve is capable of deflecting under forces applied from the spinous processes of the two adjacent vertebrae.

15. An apparatus as defined in claim 14 wherein the sleeve has opposite end sections and a central section that is thinner than the opposite end sections.

16. An apparatus as defined in claim 14 wherein the sleeve has a first sleeve component formed of a material with a modulus of elasticity and a second sleeve component formed of a material with a different modulus of elasticity.

17. An apparatus as defined in claim 1 further comprising a screwdriver configured to actuate the mechanism to drive the retainers from the retracted positions to the deployed positions when the body structure is located between the spinous processes of the two adjacent vertebrae.

18. An apparatus as defined in claim 1 wherein the mechanism is further operative to retract the retainers from the deployed positions to the retracted positions.

19. An apparatus of claim 1 wherein the body structure comprises a first end portion and a second end portion, the mechanism comprises an elongated connector having a longitudinal axis at least a portion of which has external screw threads, the connector configured for rotation;

wherein the first end portion and second end portion each have internal threads and are mounted on the elongated connector and each retainer comprises a generally U-shaped wire having two free ends;

wherein the two free ends of a first retainer is fixed to the first end portion and the two free ends of a second retainer are fixed to the second end portion;

wherein, upon rotation of the connector in a first direction, the first and second end portions move axially along the connector closer together and deploy the retainers at an angle with respect to the axis of the connector.

20. An apparatus for treating spinal stenosis, comprising:

an implant body structure having a longitudinal axis and configured to be placed between spinous processes of two adjacent vertebrae;

at least two retainers pivotally connected to the body structure; and

a mechanism operative to pivot the at least two retainers from a retracted position, wherein the retainers are generally aligned with the axis, to a deployed position, wherein the at least two retainers extend at an angle with respect to the axis and beside the spinous process of one of the two adjacent vertebrae.

21. An apparatus as defined in claim 20 wherein the retainer comprises two pairs of retainers that are pivotally supported on the body structure by hinges, and the mechanism is operative to pivot the retainers between the retracted positions and the deployed positions.

22. An apparatus as defined in claim 20 wherein the body structure includes first and second body end portions that are spaced apart along the axis;

the mechanism is operative to move the first and second body end portions axially toward each other; and

the retainers are configured to pivot from the retracted position to the deployed position under the influence of the first and second body end portions as they are moved axially toward each other under the influence of the mechanism.

23. An apparatus as defined in claim 22 wherein the mechanism comprises an axially extending connector in screw-threaded engagement with the first and second body end portions.

24. An apparatus as defined in claim 22 wherein the body structure further includes a sleeve located axially between the first and second body end portions.

25. An apparatus as defined in claim 24 wherein a hinge supports at least two retainers pivotally on the first body portion;

wherein movement of the first body end portion axially toward the second body end portion moves the sleeve into contact with the retainers so that the at least two retainers pivot from the retracted position to the deployed position under the influence of the sleeve.

26. An apparatus as defined in claim 24 wherein the sleeve is configured to rotate relative to the first and second body end portions under forces applied from the spinous processes of the two adjacent vertebrae.

27. A spinal implant comprising:

a body structure having a longitudinal axis configured to be placed between spinous processes of two adjacent vertebrae, and having a peripheral middle portion configured to move under forces applied from the spinous processes of the two adjacent vertebrae; and

at least two retainer members configured to move from a retracted position wherein the retainer members are generally aligned with the axis and a deployed position wherein the retainer members generally extend from the body structure at an angle with respect to the axis and into a location beside a spinous process on a vertebrae.

28. A spinal implant as defined in claim 27 wherein the peripheral portion of the body structure is configured to rotate relative to the retainers under forces applied from the spinous processes of the two adjacent vertebrae.

29. A spinal implant as defined in claim 27 wherein the peripheral portion of the body structure is configured to deflect under forces applied from the spinous processes of the two adjacent vertebrae.

30. A spinal implant as defined in claim 29 wherein the peripheral portion of the body structure has opposite end sections and a central section that is thinner than the opposite end sections.

31. A spinal implant as defined in claim 29 wherein the peripheral portion of the body structure has a first component formed of a material with a modulus of elasticity and a second component formed of a material with a different modulus of elasticity.

32. A spinal implant as defined in claim 27 further comprising first and second end portions, wherein the first end portion has an extension with two pivot connections and the second end portion has two guide windows.

33. A spinal implant as defined in claim 32 wherein the at least two retainer members have a proximal end and a distal end, wherein the distal end of each retainer is pivotally connected to a pivot connection and wherein the at least two retainers may be sized and configured such that the proximal ends of the retainers pass through the guide windows when the end portions are moved towards each other.

34. A spinal implant as defined in claim 33 further comprising a third and fourth retainer having distal and proximal ends, wherein the first end portion has two pivot connections and the distal end of each of the third and fourth retainer is pivotally connected to a pivot connection of the first end portion.

35. A spinal implant as defined in claim 27 further comprising a mechanism that is operative within the body structure to drive the retainers from the retracted position to the deployed position.

36. A system for maintaining the space of vertebrae comprising:

a body structure configured to be placed between spinous processes of two adjacent vertebrae, and further having at least two retainers configured in a deployed position to project outward from the body structure beside the spinous process of one of the two adjacent vertebrae; and

a tube configured to receive the implant body structure, wherein the tube has at least one opening through which the retainers are movable to the deployed position.

37. An apparatus as defined in claim 36 wherein the opening is a slot.

38. An apparatus as defined in claim 36 wherein the tube has a tapered portion configured to dilate soft tissue and distract the spinous processes of the two adjacent vertebrae.

39. An apparatus as defined in claim 38 wherein the opening extends through the tapered portion of the tube.

40. An apparatus as defined in claim 36 wherein the tube further has visual markers that are offset from the opening on opposite sides of the tube such that the visual markers move into a predetermined orientation relative to each other upon rotation of the tube to a position in which the opening has a predetermined orientation relative to the deployed position of the retainer.

41. An apparatus as defined in claim 40 wherein the visual markers are oppositely inclined slots that are movable into an orientation defining the image of an “

X”

.

42. An apparatus as defined in claim 36 wherein the tube has an additional opening configured as a window for viewing the retainer within the tube.

43. A kit for treating spinal stenosis comprising

a plurality of differently sized spinal implants including:

an implant body structure configured to fit between spinous processes of two adjacent vertebrae;

at least two retainers operably associated with the body structure; and

a mechanism operative to move the retainers from a retracted position to a deployed position extending outward from the body structure beside the spinous process of one of the two adjacent vertebrae;

wherein each body structure is configured to fit between the spinous processes of two adjacent vertebrae.

44. A kit as defined in claim 43 further comprising a plurality of differently sized tubes configured to distract the spinous processes of the two adjacent vertebrae in succession as each larger tube is received over the next smaller tube, with each tube sized for a corresponding one of the spinal implants to slide through the tube when any smaller tubes have been removed from within the tube.

45. A kit as defined in claim 44 wherein the tubes are configured to limit movement of each larger tube over the next smaller tube such that inner end portions of the tubes overlap in a predetermined manner when the tubes are nested together.

46. A kit as defined in claim 45 wherein each larger tube has a stop member configured to move into abutment with the next smaller tube.

47. A kit as defined in claim 46 wherein each larger tube is configured to be deflected to a condition in which the respective stop member is displaced from abutment with the next smaller tube.

48. A kit as defined in claim 47 wherein each larger tube has slots defining opposed portions of the tube that are deflectable inwardly of the tube.

49. A kit as defined in claim 44 wherein each tube has an opening configured as a window for viewing a spinal implant within the tube.

50. A kit as defined in claim 44 wherein the tubes are cylindrical.

51. An apparatus for use with a spinal implant comprising a body structure configured to fit between spinous processes of two adjacent vertebrae, the apparatus comprising:

a tube configured for the body structure to slide to an inner end portion of the tube; and

an implant holder configured to engage the body structure, to move the body structure through the tube, and to engage the tube to limit movement of the body structure at the inner end portion of the tube.

52. An apparatus as defined in claim 51 wherein the implant holder is configured to attach to the body structure outside the tube, and to detach from the body structure inside the inner end portion of the tube.

53. An apparatus as defined in claim 51 wherein the tube is one of a plurality of differently sized tubes, each of which is configured for an implant body structure of a corresponding size to slide to the inner end portion of the tube;

and the implant holder is a single device configured to engage each body structure individually, to move each body structure through a corresponding one of the differently sized tubes, and to engage each of the differently sized tubes individually to limit movement of the body structure at the inner end portion of the tube.

54. An apparatus as defined in claim 51 wherein the tube is cylindrical.

55. A method for treating spinal stenosis comprising:

providing an implant having;

a body structure having first and second end portions and an intermediate portion between the first and second end portions;

at least two retainers operably associated with the end portions and positioned within the body structure in a retracted position; and

a connector operably connecting the first and second end portions;

inserting the implant between spinous processes of adjacent vertebrae; and

actuating the connector to move the ends portions relative to each other such that the retainers move between the retracted position and a deployed position, wherein, in the deployed position, the retainers extend outward from the body structure and engage at least one spinous process.