Porous implant with two sets of pores

• US 5,464,440 A
• Filed: 05/18/1994
• Issued: 11/07/1995
• Est. Priority Date: 01/13/1992
• Status: Expired due to Fees

• Current Assignee: Lucocer Aktiebolag
• Original Assignee: Lucocer Aktiebolag
• Inventors: Johansson, Thomas
• Primary Examiner(s): PREBILIC, PAUL B
• Application Number:
  US08/244,323
• Time in Patent Office: 538 Days
• Field of Search: 623/11, 623/13, 623/15, 623/16
• US Class Current: 623/23.55
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• CPC Class Codes: A61F 2002/30011 differing in porosity
• CPC Class Codes: A61F 2250/0023 differing in porosity
• CPC Class Codes: A61L 27/04 Metals or alloys
• CPC Class Codes: A61L 27/12 Phosphorus-containing materials, e.g. apatite
• CPC Class Codes: A61L 27/14 Macromolecular materials
• CPC Class Codes: A61L 27/227 Other specific proteins or polypeptides not covered by A61L27/222, A61L27/225 or A61L27/24
• CPC Class Codes: A61L 27/54 Biologically active materials, e.g. therapeutic substances A61L27/227 takes precedence
• CPC Class Codes: A61L 27/56 Porous materials, e.g. foams or sponges

Abstract

The present invention relates to an implant made of a porous non-toxic material having a total open porosity exceeding 5% by volume but not exceeding 80% by volume within at least one portion of the implant, which is characterized in that: communicating micropores, having a size of less than or equal to 10 μm, make up not more than 10% of the total pore volume in said at least one portion of the implant; and at least 5% of at least one section of the surface on the implant is covered by substantially evenly distributed pores having a pore size exceeding 50 μm.

Claims

1. An implant made of a porous non-toxic material having an outer surface, said porous non-toxic material having a total open porosity exceeding 5% by volume but not exceeding 80% by volume within at least one portion of the implant;

said at least one portion having communicating micropores with a size not larger than 10 μ

m but greater than 0 μ

m and making up not more than 10% but greater than 0% of the total pore volume in said at least one portion of the implant;

at least 5% of at least one section of said surface of the implant being covered by substantially evenly distributed pores having a pore size exceeding 50 μ

m, said pores existing only in a surface layer of the implant;

said micropores together with said pores existing only in said surface layer being completely or partially filled with a substance having a desirable medical or biological function.

2. An implant according to claim 1, wherein said micropores have a size less than 5 μ

m.

3. An implant according to claim 2, wherein the size of said micropores is less than 2 μ

m.

4. An implant according to claim 1, wherein said communicating micropores make up not more than 5% of said total pore volume.

5. An implant according to claim 1, wherein the surface within said at least one section of the implant is covered by pores having a diameter size in the range of 50-500 μ

m.

6. An implant according to claim 1, wherein in a main portion of said at least one section, said pores have a diameter size within the range of 75-400 μ

m.

7. An implant according to claim 1, wherein in a main portion of said at least one section, said pores have a diameter size within the range of 100-300 μ

m.

8. An implant according to claim 1, wherein in a main portion of said at least one section, said pores have a diameter size within the range of 150-250 μ

m.

9. An implant according to claim 1, wherein said surface layer has a thickness of 3 mm.

10. An implant according to claim 1, wherein said surface layer has a thickness of 2 mm.

11. An implant according to claim 1, wherein said surface layer has a thickness of 0.3 mm.

12. An implant according to claim 1, wherein said at least one portion of the implant is made of a material selected from the group consisting of calcium phosphate materials, titanium, cobalt-chromium-alloys, stainless steel, ceramics and polymers.

13. An implant according to claim 12, wherein said ceramic is silicon nitride.

14. An implant according to claim 1, wherein said substance having a desirable medical or biological function is a bone ingrowth-promoting agent.

15. An implant according to claim 14, wherein said bone ingrowth promoting agent is selected from the group consisting of insulin-like growth factor, platelet-derived growth factor, bone-morphogenetic protein, and transforming growth factor.

16. An implant according to claim 1, wherein said substance having a desirable medical or biological function is an antibiotic.

17. An implant according to claim 1, wherein said substance having a desirable medical or biological function is a calcium phosphate compound or a fluoride.

18. An implant according to claim 1, wherein said substance having a desirable medical or biological function is hyaluronic acid.

19. An implant according to claim 1, wherein said substance having a desirable medical or biological function is in a hydrogel, or in a polymer carrier.

20. An implant according to claim 1, wherein said substance having a desirable medical or biological function is differentially deposited in different zones in order to control bone growth rate and bone tissue quality.