Fully or Partially Bioresorbable Orthopedic Implant

• US 20070260324A1
• Filed: 05/04/2007
• Published: 11/08/2007
• Est. Priority Date: 05/05/2006
• Status: Abandoned Application

• Current Assignee: Ceramatec, Inc. (Trelleborg AB)
• Original Assignee: Ceramatec, Inc. (Trelleborg AB)
• Inventors: Joshi, Ashok V., Akash, Akash
• Application Number:
  US11/744,560
• Publication Number:
  US 20070260324A1
• Time in Patent Office: Days
• US Class Current: 623/23.510
• CPC Class Codes: A61F 2/30744 End caps, e.g. for closing an endoprosthetic cavity
• CPC Class Codes: A61F 2/30965 Reinforcing the prosthesis by embedding particles or fibres during moulding or dipping
• 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 2002/30011 differing in porosity
• 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 2002/30593 hollow
• CPC Class Codes: A61F 2002/30677 Means for introducing or releasing pharmaceutical products, e.g. antibiotics, into the body
• CPC Class Codes: A61F 2002/30777 Oblong apertures
• CPC Class Codes: A61F 2002/30784 Plurality of holes
• CPC Class Codes: A61F 2002/30841 Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• CPC Class Codes: A61F 2002/30892 parallel
• CPC Class Codes: A61F 2002/30911 having a honeycomb structure
• CPC Class Codes: A61F 2002/30915 made of a stack of bonded perforated sheets, grids or wire meshes
• CPC Class Codes: A61F 2002/3092 having an open-celled or open-pored structure
• CPC Class Codes: A61F 2002/30968 Sintering
• CPC Class Codes: A61F 2002/30971 Laminates, i.e. layered products
• CPC Class Codes: A61F 2210/0004 bioabsorbable
• CPC Class Codes: A61F 2230/0065 toroidal, e.g. ring-shaped, doughnut-shaped
• 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 2310/00011 : Metals or alloys
• CPC Class Codes: A61F 2310/00179 : Ceramics or ceramic-like structures
• CPC Class Codes: A61F 2310/00329 : Glasses, e.g. bioglass

Abstract

A fully or partially bioresorbable orthopedic implant to provide support along a load-bearing axis and a method for producing the same. The implant may include an implant body and a reinforcement material, where the reinforcement material is integrated into the implant body and oriented to provide support along one or more load-bearing axes. The reinforcement material may include a rate of bioresorption that is less than a rate of bioresorption associated with the implant body. In this manner, the fully or partially bioresorbable orthopedic implant of the present invention may facilitate bone ingrowth while providing increased mechanical strength, increased load-bearing capacity, increased bone ingrowth, and decreased propensity for fracture.

Claims

1. An orthopedic implant to provide support along a load-bearing axis, the implant:

comprising;

a biocompatible implant body having a first rate of bioresorption; and

a reinforcement material integrated into the implant body and oriented to provide support along the load-bearing axis, the reinforcement material having a second rate of bioresorption that is less than the first rate of bioresorption.

2. The implant of claim 1, wherein the implant body comprises a patterned pore structure.

3. The implant of claim 1, wherein the implant body further comprises a material having multiple rates of bioresorption.

4. The implant of claim 1, wherein the implant body comprises at least one material chosen from a ceramic and a polymer.

5. The implant of claim 1, wherein the implant body comprises a material chosen from tricalcium phosphate (“

TCP”

), calcium sulfate, calcium carbonate, poly-L lactic acid (“

PLLA”

), polyglycolic acid (“

PGA”

), and poly lactic acid (“

PLA”

).

6. The implant of claim 1, wherein the bioceramic implant body comprises at least one material chosen from iodine, iodine compounds, silver, silver compounds, and combinations thereof.

7. The implant of claim 1, wherein the reinforcement material comprises a material chosen from tricalcium phosphate (“

TCP”

), calcium sulfate, calcium carbonate, poly-L lactic acid (“

PLLA”

), polyglycolic acid (“

PGA”

), and poly lactic acid (“

PLA”

).

8. The implant of claim 1, wherein the reinforcement material is bioinert and biocompatible and comprises at least one material chosen from ceramics, metals and plastics.

9. The implant of claim 1, wherein the reinforcement material comprises material chosen from alumina, zirconia, silicon carbide, silicon nitride, tantalum carbide, titanium carbide, titanium nitride, titanium oxide, titania, titanium, titanium silicon, tantalum, tantalum carbide, tantalum nitride, tantalum alloys, stainless steel, niobium, niobium alloys, cobalt-chromium alloys, polytetrafluoroethylene, hydroxyapatite, Bioglass®

, tricalcium phosphate (“

TCP”

), calcium carbonate, calcium sulfate, polyether ether ketone (“

PEEK”

), carbon fiber reinforced plastic (“

CFRP”

), polyethylene (“

PE”

), and ultra high molecular weight polyethylene (“

UHMWPE”

).

10. The implant of claim 1, wherein the reinforcement material comprises a form chosen from grains, powders, grain boundary constituents, beads, chopped fiber, wires, strands, rod structures, plate structures, cage structures, lattice structures, mesh, and combinations thereof.

11. The implant of claim 10, wherein the cage structure comprises a top surface, a bottom surface, and ribs extending between the top and bottom surfaces in a direction substantially corresponding to the load-bearing axis.

12. The implant of claim 10, wherein the reinforcement material comprises a structure oriented in a direction substantially parallel to the load-bearing axis.

13. The implant of claim 10, wherein the reinforcement material comprises a structure chosen from a zig zag, a curve, and an annular orientation with respect to the implant body.

14. The implant of claim 1, wherein the reinforcement material comprises a structure chosen from a hollow structure, a porous structure, a substantially solid structure, and combinations thereof.

15. The implant of claim 14, wherein the reinforcement material comprises a predetermined porosity to substantially match bone stiffness and accommodate bone ingrowth.

16. The implant of claim 14, wherein the predetermined porosity comprises between about zero percent (0%) and about eighty percent (80%) by volume.

17. The implant of claim 14, wherein the reinforcement material comprises pores ranging between about 1 μ

m and about 700 μ

m in diameter.

18. The implant of claim 1, wherein the implant body comprises beads ranging in size between about 0.5 mm and about 3.0 mm.

19. The implant of claim 18, wherein the beads comprise at least one of a round, spherical, cubical, conical, granular, pyramidal, elongated and hemi-spherical shape.

20. The implant of claim 1, wherein the implant body comprises pores having diameters ranging between less than about 1 μ

m to about 700 μ

m.

21. The implant of claim 1, wherein the implant body comprises a porosity of between about greater than zero percent (0%) and about eighty percent (80%) of the implant body by volume.

22. The implant of claim 1, wherein the first rate of bioresorption substantially corresponds to a rate of biological material ingrowth.

23. The implant of claim 1, further comprising an end cap coupled to at least one of the implant body and the reinforcement material.

24. The implant of claim 23, wherein the end cap comprises at least one material chosen from alumina, zirconia, silicon carbide, silicon nitride, tantalum carbide, titanium carbide, titania, hydroxyapatite, tri-calcium phosphate (“

TCP”

), calcium sulfate, calcium carbonate, Bioglass®

, titanium, titanium alloys, tantalum, tantalum alloys, stainless steel, niobium, niobium alloys, cobalt-chromium alloys, PEEK, CFRP, PE, and UHMWPE.

25. The implant of claim 1, further comprising a reagent releasably attached to at least one of the implant body and the reinforcement material.

26. The implant of claim 25, wherein the reagent comprises at least one agent chosen from an antimicrobial agent, a bactericidal agent, an anti-inflammatory agent, an anti-cancer agent, an anti-infection agent, a pain-relieving agent, a local drug delivery agent, and a bone growth agent.

27. A method for producing an orthopedic implant to provide support along a load-bearing axis, the method comprising:

providing an implant body having a first rate of bioresorption;

providing a reinforcement structure having a second rate of bioresorption, wherein the second rate of bioresorption is less than the first rate of bioresorption;

integrating the reinforcement structure into the implant body; and

orienting the reinforcement structure to provide additional support along the load-bearing axis.

28. The method of claim 27, wherein providing an implant body further comprises integrating a patterned pore structure into the implant body.

29. The method of claim 27, wherein providing an implant body further comprises substantially matching the first rate of bioresorption to a rate of biological material ingrowth.

30. The method of claim 27, further comprising coupling an end cap to at least one of the implant body and the reinforcement structure.

31. The method of claim 27, further comprising releasably coupling a reagent to at least one of the implant body and the reinforcement structure.

32. The implant of claim 31, wherein the reagent comprises at least one agent chosen from an antimicrobial agent, a bactericidal agent, an anti-inflammatory agent, an anti-cancer agent, an anti-infection agent, a pain-relieving agent, a local drug delivery agent, and a bone growth agent.

33. An orthopedic implant produced by the steps of:

providing an implant body having a first rate of bioresorption;

providing a reinforcement structure having a second rate of bioresorption, wherein the second rate of bioresorption is less than the first rate of bioresorption;

integrating the reinforcement structure into the implant body; and

orienting the reinforcement structure to provide support along the load-bearing axis.

34. The implant of claim 33, wherein providing an implant body further comprises integrating a patterned pore structure into the implant body.

35. The implant of claim 33, wherein providing an implant body further comprises substantially matching the first rate of bioresorption to a rate of biological material ingrowth.

36. The implant of claim 33, further comprising coupling an end cap to at least one of the implant body and the reinforcement structure.

37. The implant of claim 36, further comprising releasably coupling a reagent to at least one of the implant body, the end cap, and the reinforcement structure.

38. The implant of claim 37, wherein the reagent comprises at least one agent chosen from an antimicrobial agent, a bactericidal agent, an anti-inflammatory agent, an anti-cancer agent, an anti-infection agent, a pain-relieving agent, a local drug delivery agent, and a bone growth agent.