PROSTHETIC WIDE RANGE MOTION FACETS AND METHODS OF FABRICATING SAME

• US 20070179617A1
• Filed: 01/24/2007
• Published: 08/02/2007
• Est. Priority Date: 01/25/2006
• Status: Abandoned Application

• Current Assignee: Spinemedica, LLC (Mimedx Group Incorporated)
• Original Assignee: SpineMedica Corporation
• Inventors: Miller, Matthew, Denoziere, Guilhem, Brown, Rebeccah
• Application Number:
  US11/626,399
• Publication Number:
  US 20070179617A1
• Time in Patent Office: Days
• US Class Current: 623/17.130
• CPC Class Codes: A61B 17/562 Implants for placement in joint gaps without restricting joint motion, e.g. to reduce arthritic pain
• CPC Class Codes: A61B 17/842 Flexible wires, bands or straps A61B17/72, A61B17/82, A61B17/86 take precedence
• CPC Class Codes: A61B 17/86 Pins or screws or threaded wires; nuts therefor A61B17/72 take precedence
• CPC Class Codes: A61F 2/0095 Packages or dispensers for prostheses or other implants for intraocular lenses A61F2/1691; for dental surgery A61C19/02
• CPC Class Codes: A61F 2/30756 Cartilage endoprostheses A61F2/3603 takes precedence
• CPC Class Codes: A61F 2/3094 Designing or manufacturing processes
• 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 2002/30069 elastomeric
• CPC Class Codes: A61F 2002/30075 swellable, e.g. when wetted
• CPC Class Codes: A61F 2002/3008 radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: A61F 2002/30224 cylindrical
• CPC Class Codes: A61F 2002/30451 soldered or brazed or welded
• CPC Class Codes: A61F 2002/30576 with extending fixation tabs
• CPC Class Codes: A61F 2002/30617 Visible markings for adjusting, locating or measuring
• CPC Class Codes: A61F 2002/30677 Means for introducing or releasing pharmaceutical products, e.g. antibiotics, into the body
• CPC Class Codes: A61F 2002/30754 Implants for interposition between two natural articular surfaces
• CPC Class Codes: A61F 2002/30795 Blind bores, e.g. of circular cross-section
• CPC Class Codes: A61F 2002/30841 Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• CPC Class Codes: A61F 2002/30909 Nets
• CPC Class Codes: A61F 2002/30932 for retarding or preventing ingrowth of bone tissue
• CPC Class Codes: A61F 2002/30971 : Laminates, i.e. layered products
• CPC Class Codes: A61F 2002/443 : having two transversal endplates and at least one intermediate component
• CPC Class Codes: A61F 2002/4495 : having a fabric structure, e.g. made from wires or fibres
• CPC Class Codes: A61F 2210/0061 : swellable
• CPC Class Codes: A61F 2220/0058 : soldered or brazed or welded
• CPC Class Codes: A61F 2230/0069 : cylindrical
• CPC Class Codes: A61F 2250/0097 : Visible markings, e.g. indicia
• CPC Class Codes: A61F 2250/0098 : radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: A61F 2310/00365 : Proteins; Polypeptides; Degradation products thereof

Abstract

Facet joint prosthetics have a thin substantially elastomeric body configured to allow movement between adjacent facet joint bones. The facet joint includes bone, cartilage, synovial tissue, and menisci. Related methods of treating a spinal facet joint include inserting a first thin planar elastic body into a spinal facet joint where vertebral bodies meet and may optionally include inserting a second thin planar elastic body into a second spinal facet joint at the same spinal location as the first spinal facet joint thereby inhibiting bioreactive degeneration of a non-treated facet.

Claims

1. A facet prosthesis, comprising:

a thin elastically deformable elastomeric body configured to reside in a facet joint, wherein, in position, the elastomeric body is configured to allow motion between adjacent bones of the facet joint.

2. A facet prosthesis according to claim 1, wherein the prosthesis is a lumbar, thoracic or cervical facet joint prosthesis.

3. A facet prosthesis according to claim 2, wherein the elastomeric body is sized and configured to attach to one bone joint surface of a bone pair defined by meeting segments of adjacent spinal vertebral bones on a rear side of the spine and allows wide range motion between the bone pair.

4. A facet prosthesis according to claim 1, wherein the elastomeric body is configured to attach to a single bone joint surface of a bone pair defined by meeting segments of adjacent spinal vertebral bones on a rear side of the spine and allows wide range motion between the bone pair.

5. A facet prosthesis according to claim 1, wherein the elastomeric body is configured to float between bone joint surfaces of a bone pair defined by meeting segments of adjacent spinal vertebral bones on a rear side of the spine and allows wide range motion between the bone pair.

6. A facet prosthesis according to claim 1, wherein the prosthesis comprises a second implantable body that is substantially planar and cooperates with the thin elastomeric body, the second body being sized and configured to attach to one bone joint surface of a bone pair defined by meeting segments of adjacent spinal vertebral bones on a rear side of the spine and allows wide range motion between the bone pair.

7. A facet prosthesis according to claim 1, wherein the thin elastomeric body is a first implant member, the prosthesis further comprising second and third members that cooperate on opposing sides of the first member to trap the first member therebetween in a target spinal facet joint to allow wide range motion between the bone pair.

8. A facet prosthesis according to claim 1, wherein the thin elastomeric body is a first implant body, the prosthesis further comprising a second thin elastomeric implant body and a bridging member spanning between each of the first and second bodies, the bridging member configured to attach to a lamina bone, and wherein the first elastic body resides in a first facet joint and the second elastic body resides in a different second facet joint.

9. A facet prosthesis according to claim 2, wherein the elastomeric body comprises solid crystalline polyvinylalcohol hydrogel.

10. A facet prosthesis according to claim 2, further comprising at least one bone anchor segment extending outwardly beyond the bounds of the elastomeric body.

11. A facet prosthesis according to claim 1, further comprising a mesh covering moldably attached to at least one outer surface of the elastomeric body such that the mesh is at least partially embedded with solid elastmeric material.

12. A facet prosthesis according to claim 11, wherein the mesh covering extends beyond the bounds of the elastic body to define at least one bone anchor segment.

13. A facet prosthesis according to claim 1, wherein the elastomeric body is configured to define contact surface of a first bone in the facet joint, and wherein a second bone of the facet joint is configured to move against the contact surface in a manner substantially similar to a natural joint and variably compress the elastomeric body.

14. A facet prosthesis according to claim 1, wherein the elastomeric body is configured to define a contact superior surface on a lower bone in the facet joint.

15. A facet prosthesis according to claim 1, wherein the elastomeric body is configured to define a contact inferior surface on an upper bone in the facet joint.

16. A method of treating a spinal facet joint, comprising:

inserting a first thin substantially planar elastic body into a spinal facet joint where vertebral bodies meet to allow motion between bones forming the spinal facet joint.

17. A method according to claim 16, further comprising substantially conforming the shape of the elastic body to a target facet joint surface of the spinal facet joint.

18. A method according to claim 16, further comprising inserting a second thin planar elastic body into a second spinal facet joint at the same spinal location as the first spinal facet joint.

19. A method according to claim 16, further comprising:

surgically preparing a load bearing portion of a vertebral bone at the target spinal facet joint to promote tissue growth before the inserting step.

20. A method according to claim 16, further comprising attaching the thin planar body to local bone structure in a manner that allows movement of the adjacent vertebral bones meeting at the facet joint.

21. A spinal facet treatment kit, comprising:

an implantable prosthesis comprising a member with a flexible elastomeric body for insertion into a spinal facet joint to allow substantially normal motion between bones forming the joint; and

a sterile package enclosing the implantable prosthesis therein.

22. A kit according to claim 21, wherein the elastic prosthesis is configured to resurface one of the bone surfaces forming the spinal facet joint.

23. A kit according to claim 21, wherein the elastomeric body is sized and configured to attach to two bone joint surfaces of a bone pair defined by meeting segments of adjacent spinal vertebral bones on a rear side of the spine and allows wide range motion between the bone pair.

24. A kit according to claim 21, wherein the prosthesis elastomeric body is configured to attach to a single bone joint surface of a bone pair defined by meeting segments of adjacent spinal vertebral bones on a rear side of the spine and allows wide range motion between the bone pair.

25. A kit according to claim 21, wherein the elastomeric body is sized and configured to float between bone joint surfaces of a bone pair defined by meeting segments of adjacent spinal vertebral bones on a rear side of the spine and allows wide range motion between the bone pair.

26. A kit according to claim 21, wherein the prosthesis comprises a second implantable body that is cooperates with the elastomeric body, the second body being sized and configured to attach to one bone joint surface of a bone pair defined by meeting segments of adjacent spinal vertebral bones on a rear side of the spine and allows wide range motion between the bone pair.

27. A kit according to claim 21, wherein the elastomeric body is a first implant member, the prosthesis comprising second and third members that cooperate on opposing sides of the first member to trap the first member therebetween in a target spinal facet joint to allow wide range motion between the bone pair.

28. A kit according to claim 21, wherein the elastomeric body is a first thin implant body, the prosthesis comprising a second thin elastomeric implant body and a bridging member spanning between each of the first and second implant bodies, the bridging member configured to attach to a lamina bone, and wherein the first body resides in a first facet joint and the second body resides in a different second facet joint.

29. A kit according to claim 21, wherein the elastomeric body comprises solid crystalline polyvinylalcohol hydrogel with a moldably attached mesh on an outer surface thereof.

30. A method of fabricating a spinal facet implant, comprising:

molding an elastomeric primary body of PVA into a desired facet shape.

31. A method according to claim 30, further comprising molding at least one mesh layer to the implant body.

32. A method according to claim 31, wherein the at least one mesh layer is molded to the implant body defines a tissue ingrowth scaffold.

33. A method according to claim 31, wherein the at least one mesh layer is molded to the implant body so that at least one mesh layer extends beyond the bounds of the molded implant body to define a bone anchoring segment.

34. A method according to claim 31, wherein the mesh layer comprises a polyester mesh material having a thickness that is less than about 1 mm.

35. A facet joint prosthesis comprising a molded freeze-thaw hydrogel core with an outer surface having a partially embedded mesh layer defining a tissue ingrowth scaffold.