Absorbable orthopedic implants

• US 20050177245A1
• Filed: 02/07/2005
• Published: 08/11/2005
• Est. Priority Date: 02/05/2004
• Status: Abandoned Application

• Current Assignee: OsteoBiologics Inc. (Smith & Nephew PLC)
• Original Assignee: OsteoBiologics Inc. (Smith & Nephew PLC)
• Inventors: Dinger, Fred B. III, Wrana, Jeffrey S., Caborn, David, Leatherbury, Neil C.
• Application Number:
  US11/052,626
• Publication Number:
  US 20050177245A1
• Time in Patent Office: Days
• US Class Current: 623/23.500
• CPC Class Codes: A61B 17/7059 Cortical plates A61B17/7007, A61B17/7058 take precedence
• CPC Class Codes: A61B 17/8095 Wedge osteotomy devices
• CPC Class Codes: A61B 2017/00004 (bio)absorbable, (bio)resorbable, resorptive for implantable prostheses A61F2210/0004
• CPC Class Codes: A61F 2/30965 Reinforcing the prosthesis by embedding particles or fibres during moulding or dipping
• CPC Class Codes: A61F 2/442 Intervertebral or spinal discs, e.g. resilient non-disc-shaped intervertebral inflatable pockets A61F2/441; non-disc-shaped intervertebral fusion implants A61F2/4455
• 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 2/447 substantially parallelepipedal, e.g. having a rectangular or trapezoidal cross-section
• CPC Class Codes: A61F 2002/2817 Bone stimulation by chemical reactions or by osteogenic or biological products for enhancing ossification, e.g. by bone morphogenetic or morphogenic proteins [BMP] or by transforming growth factors [TGF]
• CPC Class Codes: A61F 2002/2835 Bone graft implants for filling a bony defect or an endoprosthesis cavity, e.g. by synthetic material or biological material
• CPC Class Codes: A61F 2002/30011 differing in porosity
• CPC Class Codes: A61F 2002/30014 differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2002/30032 differing in absorbability or resorbability, i.e. in absorption or resorption time
• CPC Class Codes: A61F 2002/30062 (bio)absorbable, biodegradable, bioerodable, (bio)resorbable, resorptive
• CPC Class Codes: A61F 2002/302 toroidal, e.g. rings
• CPC Class Codes: A61F 2002/30383 made by laterally inserting a protrusion, e.g. a rib into a complementarily-shaped groove
• CPC Class Codes: A61F 2002/30448 using adhesives
• CPC Class Codes: A61F 2002/30578 having apertures, e.g. for receiving fixation screws
• CPC Class Codes: A61F 2002/30593 hollow
• CPC Class Codes: A61F 2002/30604 modular
• CPC Class Codes: A61F 2002/30904 serrated profile, i.e. saw-toothed
• CPC Class Codes: A61F 2210/0004 : bioabsorbable
• CPC Class Codes: A61F 2220/0025 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2220/005 : using adhesives
• CPC Class Codes: A61F 2230/0065 : toroidal, e.g. ring-shaped, doughnut-shaped
• CPC Class Codes: A61F 2250/0018 : differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2250/0023 : differing in porosity
• CPC Class Codes: A61F 2250/003 : differing in adsorbability or resorbability, i.e. in adsorption or resorption time
• CPC Class Codes: A61F 2310/00023 : Titanium or titanium-based alloys, e.g. Ti-Ni alloys
• CPC Class Codes: A61F 2310/00329 : Glasses, e.g. bioglass

Abstract

The invention provides orthopedic implants which are at least partially absorbable. The implants of the invention may include a biocompatible material in the form of a ring, which may be used in combination with a second, more porous, absorbable material. This second material may be a continuous body or discontinuous. The implant may also include a first material connected to a full or partial wedge of a second material, the wedge being connected to the inner surface of the more dense material. Suitable materials for the first and second materials include, but are not limited to, resorbable polymer composites. The implants of the invention may also include plates for anchoring of the implant.

Claims

1. An orthopedic implant comprising

a tissue spacer having a superior and an inferior surface, the tissue spacer comprising

a first region having a superior surface which forms part of the superior surface of the spacer, an inferior surface which forms part of the inferior surface of the spacer, an inner surface and an outer surface;

and

a second region in the form of a full or partial wedge, the second region having a superior surface which forms part of the superior surface of the spacer, an inferior surface which forms part of the inferior surface of the spacer, and an anterior surface connected to the inner surface of the first region;

wherein the second region is more porous than the first region and comprises absorbable material and the first region is not in the form of a complete ring.

2. The implant of claim 1 wherein the porosity of the first region is between zero and about 30%.

3. The implant of claim 1 wherein the porosity of the first region is between zero and about 15%.

4. The implant of claim 1 wherein the first region is substantially nonporous.

5. The implant of claim 1 wherein the porosity of the second region is between about 50% and about 90%.

6. The implant of claim 1 wherein the porosity of the second region is between about 70% and about 90%.

7. The implant of claim 1 wherein the first region comprises an absorbable polymer.

8. The implant of claim 7 wherein the first region additionally comprises ceramic particles.

9. The implant of claim 8 wherein the ceramic particles are beta-tricalcium phosphate particles.

10. The implant of claim 7 wherein the first region additionally comprises a buffer.

11. The implant of claim 10 wherein the buffer is calcium carbonate.

12. The implant of claim 1 wherein the second region comprises a porous composite of an absorbable polymer, ceramic particles, fibers, and surfactant.

13. The implant of claim 1 wherein the implant additionally comprises an anterior plate connected to the first region.

14. The implant of claim 13 wherein the angle between the midplane of the tissue spacer and the anterior plate is between about 55 degrees and about 90 degrees.

15. The implant of claim 13 wherein the angle between the midplane of the tissue spacer and the midplane of the anterior plate is between about 30 degrees and about 90 degrees.

16. The implant of claim 13 wherein the anterior plate additionally comprises at least one hole which can be used for attachment of the plate to a bone.

17. The implant of claim 13 wherein the anterior plate comprises an absorbable polymer.

18. The implant of claim 1, wherein the second region is loaded with a bioactive agent, drug, pharmaceutical agent, cells or combinations thereof.

19. An orthopedic implant comprising

a tissue spacer having a superior and an inferior surface, the tissue spacer comprising

a first region in the form of a ring, the ring having a superior surface which forms part of the superior surface of the spacer, an inferior surface which forms part of the inferior surface of the spacer, an inner surface and an outer surface;

and

a second region, the second region having a superior surface which forms part of the superior surface of the spacer, an inferior surface which forms part of the inferior surface of the spacer and an outer surface connected to the inner surface of the first region;

wherein the porosity of the first region is between zero and about 30%, the porosity of the second region is between about 50% and about 90%, and the second region comprises absorbable material.

20. The implant of claim 19 wherein the porosity of the first region is between zero and about 15%.

21. The implant of claim 19 wherein the first region is substantially nonporous.

22. The implant of claim 19 wherein the porosity of the second region is between about 70% and about 90%.

23. The implant of claim 19 wherein the first region comprises an absorbable polymer.

24. The implant of claim 23 wherein the first region additionally comprises ceramic particles.

25. The implant of claim 24 wherein the ceramic particles are beta-tricalcium phosphate particles.

26. The implant of claim 23 wherein the first region additionally comprises a buffer.

27. The implant of claim 26 wherein the buffer is calcium carbonate.

28. The implant of claim 19 wherein the second region comprises a porous composite of an absorbable polymer, a ceramic, fibers, and surfactant.

29. The implant of claim 19 wherein the implant additionally comprises an anterior plate connected to the ring.

30. The implant of claim 29, wherein the anterior plate additionally comprises at least one hole which can be used for attachment of the plate to a bone.

31. The implant of claim 29 wherein the anterior plate comprises an absorbable polymer.

32. The implant of claim 19 wherein the second region is loaded with a bioactive agent, drug, pharmaceutical agent, cells, or combinations thereof.

33. An absorbable orthopedic implant comprising

a tissue spacer having a superior and an inferior surface, the tissue spacer comprising

a ring, the ring having a superior surface which forms part of the superior surface of the spacer, an inferior surface which forms part of the inferior surface of the spacer, an inner and an outer surface;

and

an anterior plate connected to the ring

wherein the ring has porosity between zero and about 15%.

34. The implant of claim 33 wherein the ring comprises an absorbable polymer.

35. The implant of claim 34 wherein the ring additionally comprises ceramic particles.

36. The implant of claim 35 wherein the ceramic particles are beta-tricalcium phosphate particles.

37. The implant of claim 34 wherein the ring additionally comprises a buffer.

38. The implant of claim 37 wherein the buffer is calcium carbonate.