Porous Interbody Spacer

• US 20170156880A1
• Filed: 12/07/2016
• Published: 06/08/2017
• Est. Priority Date: 12/07/2015
• Status: Active Application

• Current Assignee: Nexus Spine, LLC
• Original Assignee: Nexus Spine, LLC
• Inventors: Halverson, Peter, Hawkes, David
• Application Number:
  US15/372,290
• Publication Number:
  US 20170156880A1
• Time in Patent Office: Days
• CPC Class Codes: A61F 2/0077 Special surfaces of prostheses, e.g. for improving ingrowth A61F2/30767 takes precedence
• CPC Class Codes: A61F 2/4455 for the fusion of spinal bodies, e.g. intervertebral fusion of adjacent spinal bodies, e.g. fusion cages intervertebral discs A61F2/442
• CPC Class Codes: A61F 2/447 substantially parallelepipedal, e.g. having a rectangular or trapezoidal cross-section
• CPC Class Codes: A61F 2002/0081 directly machined on the prosthetic surface, e.g. holes, grooves A61F2/30771 takes precedence
• CPC Class Codes: A61F 2002/30146 octagonal
• CPC Class Codes: A61F 2002/30149 pentagonal
• CPC Class Codes: A61F 2002/30153 rectangular
• CPC Class Codes: A61F 2002/30154 square
• CPC Class Codes: A61F 2002/30289 helically-coiled
• CPC Class Codes: A61F 2002/30566 Helical springs
• CPC Class Codes: A61F 2002/30568 Multiple spring systems including two or more helical springs
• CPC Class Codes: A61F 2002/30593 hollow
• CPC Class Codes: A61F 2002/30784 Plurality of holes
• CPC Class Codes: A61F 2002/3092 having an open-celled or open-pored structure
• CPC Class Codes: A61F 2002/3093 for promoting ingrowth of bone tissue
• CPC Class Codes: A61F 2002/3097 using laser
• CPC Class Codes: A61F 2002/4495 having a fabric structure, e.g. made from wires or fibres
• CPC Class Codes: A61F 2310/00023 Titanium or titanium-based alloys, e.g. Ti-Ni alloys
• CPC Class Codes: A61F 2310/00131 Tantalum or Ta-based alloys

Abstract

Orthopedic implants, particularly interbody spacers, have a combination of correct pore size and stiffness/flexibility. When the implants have the proper pore size and stiffness, osteocytes are able to properly bridge the pores of the implant and then experience a proper compressive load to stimulate the bone cells to form bone within the pores. An implant includes a body formed of an osteoconductive material and having a stiffness of between 400 megapascals (MPa) and 1,200 MPa. Additionally, the body includes a plurality of pores having an average size of between 150 microns and 600 microns. The pores permit the growth of bone therein. The body is formed of packs of coils which may be formed using an additive manufacturing process and using traditional orthopedic implant materials such as titanium and titanium alloys while still achieving desired stiffness and pore sizes of the implants.

Claims

1. An implant comprising:

a body formed of an osteoconductive material;

the body comprising a stiffness of between 400 megapascals (MPa) and 1,200 MPa; and

the body comprising a plurality of pores having an average size of between 150 microns and 600 microns.

2. The implant as recited in claim 1, wherein the osteoconductive material comprises a material selected from the group consisting of titanium, tantalum, and alloys thereof.

3. The implant as recited in claim 1, wherein the osteoconductive material comprises a material selected from the group consisting of titanium and alloys thereof.

4. The implant as recited in claim 1, wherein the implant comprises a stiffness of between 600 MPa and 1,000 MPa.

5. The implant as recited in claim 1, wherein the implant comprises a stiffness of between 750 MPa and 850 MPa.

6. The implant as recited in claim 5, wherein the implant comprises a stiffness of between 950 MPa and 1,050 MPa.

7. The implant as recited in claim 1, wherein the implant is manufactured using an additive manufacturing process.

8. The implant as recited in claim 1, wherein the implant comprises a coil spring construction.

9. The implant as recited in claim 8, wherein the coil spring construction comprises a vertical spacing between coils of between 250 microns and 350 microns.

10. The implant as recited in claim 8, wherein the coil spring construction comprises a coil diameter of between 400 microns and 600 microns.

11. The implant as recited in claim 1, wherein the implant comprises a nested coil spring construction.

12. The implant as recited in claim 1, wherein the implant comprises a plurality of overlapping coil packs.

13. The implant as recited in claim 10, wherein the plurality of overlapping coil packs comprise coils that are connected and coils that are intertwined without connecting.

14. The implant as recited in claim 1, wherein the implant comprises a plurality of coil springs joined in clockwise to counter-clockwise sweep directions.

15. The implant as recited in claim 14, wherein the implant is an interbody spacer.

16. An implant comprising:

a body comprising a plurality of coil springs formed of an osteoconductive material;

the body comprising a stiffness of between 400 megapascals (MPa) and 1,200 MPa; and

the body comprising a plurality of pores having an average size of between 150 microns and 600 microns.

17. The implant as recited in claim 16, wherein the osteoconductive material comprises a material selected from the group consisting of titanium and alloys thereof.

18. The implant as recited in claim 16, wherein the implant comprises a stiffness of between 750 MPa and 1,050 MPa.

19. The implant as recited in claim 16, wherein the implant is manufactured using an additive manufacturing process.

20. An implant comprising:

a body comprising a plurality of coil springs manufactured using an additive manufacturing process;

the coil springs being arranged into a plurality of overlapping coil packs comprising coils that are connected and coils that are intertwined without connecting;

the coil springs comprising coils having a clockwise sweep direction and coils having a counterclockwise sweep direction;

the body comprising a stiffness of between 400 megapascals (MPa) and 1,200 MPa; and

the body comprising a plurality of pores having an average size of between 150 microns and 600 microns.