SYSTEMS AND METHODS FOR FACET JOINT TREATMENT

• US 20110022089A1
• Filed: 07/24/2009
• Published: 01/27/2011
• Est. Priority Date: 07/24/2009
• Status: Active Grant

• Current Assignee: RTI Surgical Incorporated
• Original Assignee: Zyga Technology, Inc. (Surgalign Holdings, Inc.)
• Inventors: Dickhudt, Eugene A., Assell, Robert, Beaubien, Brian P.
• Granted Patent: US 8,394,125 B2
• Time in Patent Office: Days
• US Class Current: 606/247
• CPC Class Codes: A61F 2/4405 for apophyseal or facet joints, i.e. between adjacent spinous or transverse processes devices implanted between spinous or transverse processes A61B17/7062
• CPC Class Codes: A61F 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2002/3008 radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: A61F 2002/30299 umbrella-shaped or mushroom-shaped
• CPC Class Codes: A61F 2002/30578 having apertures, e.g. for receiving fixation screws
• CPC Class Codes: A61F 2002/30841 Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• CPC Class Codes: A61F 2002/30843 Pyramidally-shaped
• CPC Class Codes: A61F 2002/30845 with cutting edges
• CPC Class Codes: A61F 2002/3085 with a threaded, e.g. self-tapping, bone-engaging surface, e.g. external surface
• CPC Class Codes: A61F 2002/30878 with non-sharp protrusions, for instance contacting the bone for anchoring, e.g. keels, pegs, pins, posts, shanks, stems, struts
• CPC Class Codes: A61F 2002/30904 serrated profile, i.e. saw-toothed
• CPC Class Codes: A61F 2250/0098 radio-opaque, e.g. radio-opaque markers

Abstract

A system for treating a facet joint of a patient including superior and inferior resurfacing devices. The superior device includes a resurfacing body configured to conform to a shape of a superior facet articular face, and the inferior device includes a resurfacing body configured to conform to a shape of an inferior facet articular face. Each resurfacing body exhibits sufficient flexibility to transition from a relatively flat state to an inserted state in which the resurfacing body substantially matches any multi-planar concavities of the corresponding facet articular face in the presence of compressive forces. With this construction, the system is capable of establishing a new sliding interface within the facet joint, and can be inserted on a minimally-invasive basis. The resurfacing bodies can be formed of PEEK, and can include teeth that engage the corresponding facet articular face.

Claims

1. A system for treating a facet joint of a patient, the facet joint anatomy including opposing, superior and inferior articular faces, the system comprising:

a superior resurfacing device including a superior resurfacing body configured to selectively transition to a shape conforming to a shape of a superior articular face of a facet joint; and

an inferior resurfacing device apart from the superior resurfacing device and including an inferior resurfacing body configured to selectively transition to a shape conforming to a shape of an inferior articular face of a facet joint;

wherein each of the resurfacing bodies exhibits sufficient flexibility to transition from a relatively flat state to an inserted state in which the resurfacing body substantially matches any multi-planar curvatures of the corresponding facet joint articular face in the presence of compressive forces of a typical human adult facet joint.

2. The system of claim 1, wherein each of the resurfacing bodies is configured to transition from the relatively flat state to the inserted state in response to normal forces applied by a human adult body weight, musculature and capsular ligaments to a major surface of the respective resurfacing body.

3. The system of claim 1, wherein each of the resurfacing bodies is configured to conform to a radius of curvature of at least 20 mm in the inserted state.

4. The system of claim 1, wherein each of the resurfacing bodies defines an anchoring surface and an articulating surface, the system configured such that upon insertion to a facet joint, the articulating surfaces abut one another in a sliding interface.

5. The system of claim 1, wherein each of the resurfacing bodies defines a disc-like shape defined by a major diameter in the range of 5-13 mm and a minor diameter in the range of 4-11 mm.

6. The system of claim 5, wherein at least one of the resurfacing devices further includes a tab extending from the corresponding resurfacing body for attachment to bone outside of a zone of interface between the superior and inferior articular faces of the facet joint.

7. The system of claim 1, wherein the resurfacing bodies are identical.

8. The system of claim 1, wherein each of the resurfacing bodies has an overall thickness in the range of 0.25-4 mm.

9. The system of claim 8, wherein each of the resurfacing bodies exhibits a Conformability Factor of not more than 100 N.

10. The system of claim 1, wherein each of the resurfacing bodies is formed of plastic.

11. The system of claim 10, wherein the plastic is a polyetherketone-based plastic.

12. The system of claim 1, wherein each of the resurfacing bodies includes:

a base web forming opposing, first and second major surfaces; and

a plurality of teeth projecting from the second major surface.

13. The system of claim 12, wherein at least one of the teeth is defined by a leading face and a trailing face, an angle defined by the leading face and a plane of the first major surface being less than an angle defined by the trailing face and the plane of the first major surface such that the at least one tooth more overtly resists movement of the corresponding resurfacing body relative to a corresponding facet joint articular face in a first direction as compared to a second, opposite direction.

14. The system of claim 12, wherein the plurality of teeth include:

a first teeth set, each tooth of the first teeth set defining a first angle of extension relative to the second major surface; and

a second teeth set, each tooth of the second teeth set defining an angle of extension relative to the first major surface differing from the first angle of extension.

15. The system of claim 14, wherein the base web has an oval-like shape defining a perimeter having a leading end, a trailing end, and opposing sides, and further wherein the first teeth set is formed at and between the leading and trailing ends, and the second teeth set is formed at one of the opposing sides.

16. The system of claim 15, wherein the plurality of teeth further includes a third set teeth formed at an other of the opposing sides.

17. The system of claim 15, wherein each tooth of the first teeth set includes a leading face more proximate the leading end and a trailing face more proximate the trailing end, the leading and trailing faces intersecting at a tip opposite the first major surface, and further wherein a length of the leading face is greater than a length of the trailing face such that the corresponding tooth defines a direction of insertion of the corresponding resurfacing body from the leading end to the trailing end.

18. The system of claim 12, wherein the base web defines a substantially uniform thickness and the plurality of teeth include a first tooth proximate the leading end and a second tooth proximate the trailing end, a height of the first tooth being greater than a height of the second tooth.

19. The system of claim 14, wherein the base web forms a notch along the trailing end.

20. A method of treating a facet joint of a patient, the facet joint anatomy including opposing, superior and inferior articular faces, the method comprising:

inserting a superior resurfacing body into the facet joint and into engagement with the superior articular face, the superior resurfacing device including a superior resurfacing body defining an articulating surface, wherein inserting the superior resurfacing body includes the superior resurfacing body transitioning from a relatively flat state to an inserted state substantially conforming to a shape of the superior articular face in response to compressive forces of the facet joint; and

inserting a inferior resurfacing body into the facet joint and into engagement with the inferior articular face, the inferior resurfacing device including an inferior resurfacing body defining an articulating surface, wherein inserting the inferior resurfacing body includes the inferior resurfacing body transitioning from a relatively flat state to an inserted state substantially conforming with a shape of the inferior articular face in response to compressive forces of the facet joint;

wherein upon final insertion, the articulating surface of the superior resurfacing body slidably abuts the articulating surface of the inferior resurfacing body.

21. The method of claim 20, wherein the method is characterized by the absence of surgically removing normal healthy bone of the facet joint.

22. The method of claim 21, further comprising:

removing unusual bone formations, including osteophytes, prior to the steps of inserting the resurfacing bodies.

23. The method of claim 20, wherein the steps of inserting the superior and inferior resurfacing bodies occur simultaneously.

24. The method of claim 20, wherein the steps of inserting the superior and inferior resurfacing bodies are performed percutaneously.

25. The method of claim 20, wherein the resurfacing bodies are identical, each having a disc-like shape defined by a major diameter in the range of 5-13 mm, a minor diameter in the range of 4-11 mm, and a thickness in the range of 0.25-4 mm.

26. The method of claim 20, wherein each of the resurfacing bodies is formed of a polyetherketone-based material.

27. The method of claim 20, wherein each of the resurfacing bodies includes a base web defining the corresponding articulating surface and an opposing, second major surface, and a plurality of teeth projecting from the respective second major surface, and further wherein:

inserting the superior resurfacing body includes engaging the corresponding teeth with the superior articular face of the facet joint; and

inserting the inferior resurfacing body includes engaging the corresponding teeth with the inferior articular face of the facet joint.

28. The method of claim 20, further comprising:

loading the superior and inferior resurfacing devices into an internal passage of a delivery cannula in a stacked arrangement, the delivery cannula assembly having a distal end and defining the internal passage to be open at the distal end;

slidably disposing an elongate pusher tool into the passage;

wherein a distal portion of the pusher tool abuts the superior and inferior resurfacing devices;

delivering the distal end of the delivery cannula assembly to the facet joint; and

sliding the pusher tool distally within the passage to eject the resurfacing bodies from the distal end and into the facet joint.

29. The method of claim 28, wherein each of the resurfacing bodies forms a notch and the distal portion of the pusher tool forms a finger, and further wherein the finger is arranged within each of the notches when disposed within the cannula assembly.

30. A kit for treating a facet joint of a patient, the facet joint anatomy including opposing, superior and inferior articular faces, the kit comprising:

a superior resurfacing device including a superior resurfacing body configured to selectively transition to a shape conforming to a shape of a superior articular face of a facet joint;

an inferior resurfacing device apart from the superior resurfacing device and including an inferior resurfacing body configured to selectively transition to a shape conforming to a shape of an inferior articular face of a facet joint;

wherein each of the resurfacing bodies exhibits sufficient flexibility to transition from a relatively flat state to an inserted state in which the resurfacing body substantially matches any multi-planar curvatures of the corresponding facet joint articular face in the presence of compressive forces of a typical human adult facet joint; and

an insertion tooling set including;

a delivery cannula having a distal end and defining an internal passage open at the distal end,

an elongate pusher tool sized to be slidably received within the passage;

wherein the kit is configured to provide an insertion arrangement in which the resurfacing devices and the pusher tool are slidably received within the passage, the resurfacing devices being stacked against one another adjacent the distal end and a distal region of the pusher tool abutting the resurfacing devices opposite the distal end.

31. The kit of claim 30, wherein the resurfacing bodies are identical, each having a disc-like shape defined by a major diameter in the range of 5-13 mm, a minor diameter in the range of 4-11 mm, and a thickness in the range of 0.25-4 mm.

32. The kit of claim 30, wherein each of the resurfacing devices is formed of a polyetherketone-based material.