LASER-PRODUCED POROUS STRUCTURE

• US 20110014081A1
• Filed: 07/29/2010
• Published: 01/20/2011
• Est. Priority Date: 12/30/2004
• Status: Active Grant

• Current Assignee: University of Liverpool
• Original Assignee: Howmedica Osteonics Corp. (Stryker Corporation)
• Inventors: Stamp, Robin, Sutcliffe, Christopher J., Jones, Eric
• Granted Patent: US 9,456,901 B2
• Time in Patent Office: Days
• US Class Current: 419/2
• CPC Class Codes: A61F 2/2803 for mandibular reconstruction temporo-mandibular joints A61F2/3099; bone plates for the jaw A61B17/8071
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• CPC Class Codes: A61F 2/30771 applied in original prostheses, e.g. holes or grooves
• CPC Class Codes: A61F 2/30907 Nets or sleeves applied to surface of prostheses or in cement
• CPC Class Codes: A61F 2/3094 Designing or manufacturing processes
• CPC Class Codes: A61F 2/30965 Reinforcing the prosthesis by embedding particles or fibres during moulding or dipping
• CPC Class Codes: A61F 2/36 Femoral heads ; Femoral endoprostheses
• CPC Class Codes: A61F 2/3662 Femoral shafts
• CPC Class Codes: A61F 2/3859 Femoral components
• CPC Class Codes: A61F 2/389 Tibial components A61F2/3868 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 2002/30011 differing in porosity
• CPC Class Codes: A61F 2002/30113 circular
• CPC Class Codes: A61F 2002/30143 hexagonal
• CPC Class Codes: A61F 2002/30146 octagonal
• CPC Class Codes: A61F 2002/30153 rectangular
• CPC Class Codes: A61F 2002/30154 square
• CPC Class Codes: A61F 2002/30199 Three-dimensional shapes
• CPC Class Codes: A61F 2002/30243 the overall spherical surface being composed of a plurality of adjacent circular or polygonal segments, e.g. football-like shaped
• CPC Class Codes: A61F 2002/3028 polyhedral different from parallelepipedal and pyramidal
• CPC Class Codes: A61F 2002/30329 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2002/305 : Snap connection
• CPC Class Codes: A61F 2002/30593 : hollow
• CPC Class Codes: A61F 2002/30594 : slotted, e.g. radial or meridian slot ending in a polar aperture, non-polar slots, horizontal or arcuate slots
• CPC Class Codes: A61F 2002/30736 : Augments or augmentation pieces, e.g. wedges or blocks for bridging a bone defect
• CPC Class Codes: A61F 2002/30785 : parallel
• CPC Class Codes: A61F 2002/30789 : perpendicular with respect to each other
• CPC Class Codes: A61F 2002/30879 : Ribs
• CPC Class Codes: A61F 2002/30892 : parallel
• CPC Class Codes: A61F 2002/30904 : serrated profile, i.e. saw-toothed
• 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 2002/30925 : etched
• CPC Class Codes: A61F 2002/30952 : using CAD-CAM techniques or NC-techniques
• CPC Class Codes: A61F 2002/30962 : using stereolithography
• CPC Class Codes: A61F 2002/30968 : Sintering
• CPC Class Codes: A61F 2002/3097 : using laser
• CPC Class Codes: A61F 2002/30971 : Laminates, i.e. layered products
• CPC Class Codes: A61F 2002/3403 : Polar aperture
• CPC Class Codes: A61F 2002/3417 : the outer shell having protrusions on meridian lines, e.g. equidistant fins or wings around the equatorial zone
• CPC Class Codes: A61F 2002/3425 : the outer shell having non-meridian protrusions, e.g. fins or wings, located in planes inclined or perpendicular with respect to the equatorial plane
• CPC Class Codes: A61F 2220/0025 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2230/0006 : circular
• CPC Class Codes: A61F 2230/0017 : Angular shapes
• CPC Class Codes: A61F 2230/0019 : rectangular
• CPC Class Codes: A61F 2230/0021 : square
• CPC Class Codes: A61F 2230/0063 : Three-dimensional shapes
• CPC Class Codes: A61F 2230/0071 : spherical
• CPC Class Codes: A61F 2240/001 : Designing or manufacturing processes
• CPC Class Codes: A61F 2250/0023 : differing in porosity
• CPC Class Codes: A61F 2310/00017 : Iron- or Fe-based alloys, e.g. stainless steel
• CPC Class Codes: A61F 2310/00023 : Titanium or titanium-based alloys, e.g. Ti-Ni alloys
• CPC Class Codes: A61F 2310/00029 : Cobalt-based alloys, e.g. Co-Cr alloys or Vitallium
• CPC Class Codes: A61F 2310/00095 : Niobium or Nb-based alloys
• CPC Class Codes: A61F 2310/00131 : Tantalum or Ta-based alloys
• CPC Class Codes: A61F 2310/00401 : Coating made of iron, of stainless steel or of other Fe-based alloys
• CPC Class Codes: A61F 2310/00407 : Coating made of titanium or of Ti-based alloys
• CPC Class Codes: A61F 2310/00413 : Coating made of cobalt or of Co-based alloys
• CPC Class Codes: A61F 2310/00491 : Coating made of niobium or Nb-based alloys
• CPC Class Codes: A61F 2310/00544 : Coating made of tantalum or Ta-based alloys
• CPC Class Codes: A61L 27/04 : Metals or alloys
• CPC Class Codes: A61L 27/56 : Porous materials, e.g. foams or sponges
• CPC Class Codes: B22F 10/20 : Direct sintering or melting
• CPC Class Codes: B22F 10/28 : Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM]
• CPC Class Codes: B22F 10/36 : of energy beam parameters
• CPC Class Codes: B22F 10/38 : to achieve specific product aspects, e.g. surface smoothness, density, porosity or hollow structures
• CPC Class Codes: B22F 10/80 : Data acquisition or data processing
• CPC Class Codes: B22F 12/43 : pulsed; frequency modulated
• CPC Class Codes: B22F 12/52 : Hoppers
• CPC Class Codes: B22F 3/1109 : Inhomogenous pore distribution composite layers of porous nature B22F7/002
• CPC Class Codes: B23K 2101/35 : Surface treated articles
• CPC Class Codes: B23K 2103/02 : Iron or ferrous alloys
• CPC Class Codes: B23K 2103/05 : Stainless steel
• CPC Class Codes: B23K 2103/08 : Non-ferrous metals or alloys
• CPC Class Codes: B23K 2103/14 : Titanium or alloys thereof
• CPC Class Codes: B23K 2103/18 : Dissimilar materials
• CPC Class Codes: B23K 2103/26 : Alloys of Nickel and Cobalt and Chromium
• CPC Class Codes: B23K 2103/50 : Inorganic material, e.g. metals, not provided for in B23K2103/02 – B23K2103/26
• CPC Class Codes: B23K 2103/52 : Ceramics
• CPC Class Codes: B23K 26/082 : Scanning systems, i.e. devices involving movement of the laser beam relative to the laser head
• CPC Class Codes: B23K 26/342 : Build-up welding
• CPC Class Codes: B23K 26/382 : by boring
• CPC Class Codes: B23K 26/40 : taking account of the properties of the material involved
• CPC Class Codes: B23K 26/402 : involving non-metallic material, e.g. isolators
• CPC Class Codes: B33Y 10/00 : Processes of additive manufacturing
• CPC Class Codes: B33Y 80/00 : Products made by additive manufacturing
• CPC Class Codes: C23C 24/10 : with intermediate formation of a liquid phase in the layer
• CPC Class Codes: C23C 26/02 : applying molten material to the substrate
• CPC Class Codes: C23C 4/02 : Pretreatment of the material to be coated, e.g. for coating on selected surface areas
• CPC Class Codes: C23C 4/18 : After-treatment
• CPC Class Codes: Y02P 10/25 : Process efficiency

Abstract

The present invention disclosed a method of producing a three-dimensional porous tissue in-growth structure. The method includes the steps of depositing a first layer of metal powder and scanning the first layer of metal powder with a laser beam to form a portion of a plurality of predetermined unit cells. Depositing at least one additional layer of metal powder onto a previous layer and repeating the step of scanning a laser beam for at least one of the additional layers in order to continuing forming the predetermined unit cells. The method further includes continuing the depositing and scanning steps to form a medical implant.

Claims

1. A method of producing a three-dimensional porous tissue in-growth structure comprising the steps of:

depositing a first layer of a powder made from a metal selected from the group consisting of titanium, titanium alloys, stainless steel, cobalt chrome alloys, tantalum and niobium onto a substrate;

scanning a beam to form a portion of a plurality of predetermined unit cells within said metal powder layer;

depositing at least one additional layer of said powder onto said first layer; and

repeating said scanning step to form additional portions of said plurality of predetermined unit cells, said portions forming at least one strut extending in an oblique direction with respect to said substrate,

wherein each said predetermined unit cell includes a plurality of edges, and no edge exceeds 2000 μ

m in length.

2. The method of producing a three-dimensional porous tissue in-growth structure according to claim 1, wherein the beam has a power (P) for a period of time (μ

sec) with a point distance (μ

m).

3. The method of producing a three-dimensional porous tissue in-growth structure according to claim 2, wherein the beam is an electron beam.

4. The method of producing a three-dimensional porous tissue in-growth structure according to claim 2, wherein the beam is a laser beam.

5. The method of producing a three-dimensional porous tissue in-growth structure according to claim 1, wherein at least some of said predetermined unit cells are a tetrahedron.

6. The method of producing a three-dimensional porous tissue in-growth structure according to claim 1, wherein at least some of said predetermined unit cells are a dodecahedron.

7. The method of producing a three-dimensional porous tissue in-growth structure according to claim 1, wherein at least some of said predetermined unit cells are an octahedron.

8. The method of producing a three-dimensional porous tissue in-growth structure according to claim 1, wherein at least some of said predetermined unit cells are truncated.

9. The method of producing a three-dimensional porous tissue in-growth structure according to claim 1, wherein said first layer of metal powder has a thickness between 5 μ

m to 2000 μ

m.

10. The method of producing a three-dimensional porous tissue in-growth structure according to claim 1, wherein said at least one additional layer of powder has a thickness between 5 μ

m to 2000 μ

m.

11. The method of producing a three-dimensional porous tissue in-growth structure according to claim 1, further comprising predetermining a porosity range for at least one deposited powder layer and scanning said at least one deposited powder layer in a manner to provide said deposited powder layer with a porosity within said porosity range.

12. The method of producing a three-dimensional porous tissue in-growth structure according to claim 1, wherein said substrate is a base or core made of a metal selected from the group consisting of titanium, titanium alloys, stainless steel, cobalt chrome alloys, tantalum and niobium, wherein said first layer is fused to said base or core.

13. The method of producing a three-dimensional porous tissue in-growth structure according to claim 12, further comprising sintering at least a portion of said first powder layer to said base or core.

14. The method of producing a three-dimensional porous tissue in-growth structure according to claim 12, wherein said base or core is separated from said first layer.

15. The method of producing a three-dimensional porous tissue in-growth structure according to claim 14, wherein said base or core is integral with said first layer and imparts additional physical properties to an overall construct.

16. The method of producing a three-dimensional porous tissue in-growth structure according to claim 4, wherein said laser power is in a range between 5 to 1000 watts.

17. The method of producing a three-dimensional porous tissue in-growth structure according to claim 1, wherein a solid or a semi-pervious layer is placed between said substrate and said first metal powder layer.

18. The method of producing a three-dimensional porous tissue in-growth structure according to claim 1, wherein during the step of scanning said powder layer a plurality of satellites are formed on portions of said predetermined unit cells.

19. The method of producing a three-dimensional porous tissue in-growth structure according to claim 18, further comprising an acid etching process to remove said satellites.

20. The method of producing a three-dimensional porous tissue in-growth structure according to claim 4, wherein said laser power is 90.5 W, said exposure time is 1000 μ

sec and said point distance is 90 μ

m.

21. The method of producing a three-dimensional porous tissue in-growth structure according to claim 1, wherein at least some of said predetermined unit cells are truncated to provide a barb effect.