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US 4,644,942 AGranted
Production of porous coating on a prosthesis
AssigneeBattelle Development Corporation
InventorKenneth R. Sump
Life of this patent
Estimating the term…
Abstract
Preselected surface areas of a prosthesis are covered by a blend of matching primary metallic particles and expendable particles. The particles are compressed and heated to assure that deformation and metallurgical bonding occurs between them and between the primary particles and the surface boundaries of the prosthesis. Porosity is achieved by removal of the expendable material. The result is a coating including discrete bonded particles separated by a network of interconnected voids presenting a homogeneous porous coating about the substrate. It has strength suitable for bone implant usage without intermediate adhesives, and adequate porosity to promote subsequent bone ingrowth.
Claims25
A method of producing a porous coating for tissue ingrowth applications on a preselected metallic substrate area of a prosthesis, comprising the following steps:
- covering the metallic substrate area of the prosthesis with a blended mixture of primary particles and secondary particles, said primary particles being metallic and capable of metallurgically bonding to the substrate area, said secondary particles being solid phase and capable of mechanically supporting the primary particles in a matrix;
- raising the temperature of the mixture and metallic substrate area to an elevated temperature at which metallurgical bonding of the primary particles can occur under compression and at which melting of the secondary particles or reactions between the primary and secondary particles does not occur;
- compressing the mixture against the metallic substrate area while at the elevated temperature to metallurgically bond the contacting primary particles and portions of the substrate area as a result of the combination of elevated temperature and compression to which they are subjected;
- and
- removing the expendable secondary particles to present a homogeneously porous coating on the metallic substrate area in which bonded primary particles are separated from one another by a network of interconnected voids.
2 more elements
A method of producing a porous coating for tissue ingrowth applications on a preselected metallic substrate area of a prosthesis, comprising the following steps:
- positioning the prosthesis within a mold cavity with the metallic substrate area spaced inwardly from the mold cavity surfaces;
- filling the space between the metallic substrate area and mold cavity surfaces with a blended mixture of primary particles and secondary particles, said primary particles being metallic and capable of metallurgically bonding to the substrate area, said secondary particles being solid phase and capable of mechanically supporting the primary particles in a matrix;
- heating the prosthesis and mixture of particles to an elevated temperature at which metallurgical bonding can occur between adjacent primary particles and between the primary particles and the metallic substrate area under compression and at which melting of the secondary particles or reactions between the primary and secondary particles does not occur;
- compressing the mixture of particles against the metallic substrate area while at the elevated temperature to deform the primary particles and the portions of the metallic area engaged thereby and to metallurgically bond the contacting primary particles and portions of the substrate area as a result of the combination of elevated temperature and compression to which they are subjected;
- and
- subsequently removing the secondary particles from the resulting matrix of bonded primary particles to present a homogenously porous coating on the metallic substrate area in which bonded primary particles are separated from one another by a network of interconnected voids.
3 more elements
A method of producing a porous coating for tissue ingrowth applications on a preselected metallic substrate area of a prosthesis, comprising the following steps:
- positioning the prosthesis within a mold cavity with the preselected substrate area spaced inwardly from the mold cavity surfaces by a distance of approximately 0.5 to 1.5 millimeters while also filling the space between the preselected substrate area and mold cavity surfaces with a blended mixture of primary spherical particles and secondary spherical particles,, said primary particles being metallic and capable of metallurgically bonding to the substrate area, said secondary particles being solid phase and capable of mechanically supporting the primary particles in a matrix;
- the primary and secondary spherical particles having a narrow range of diameters less than 0.5 millimeters;
- heating the spherical particles within the mold to an elevated temperature at which metallurgical bonding can occur between the individual primary spherical particles under compression and at which melting of the secondary particles or reactions between the primary and secondary particles does not occur;
- compressing the primary and secondary spherical particles against the preselected substrate area of the prosthesis while at the elevated temperature to metallurgically bond the primary particles as a result of a combination of the elevated temperature and compression to which they are subjected;
- and
- removing the expendable material from the resulting coating.
3 more elements
A prosthesis for tissue ingrowth applications, comprising:
- a structural metallic substrate;
- and
- a coating in the form of a matrix presented by randomly dispersed discrete metal particles having a substantially uniform size joined to one another and to the substrate by metallurgical bonds, the particles and substrate being compressibly deformed to present an outer coating surface conforming to the size and configuration of a mold in which they were compressed and of proper dimensions for implant purposes without machining;
- the metal particles being separated from one another by a network of interconnected voids having an average size greater than the average size of the discrete metal particles to present a homogeneously porous coating about the substrate.
1 more element
A prosthesis having a porous coating for tissue ingrowth applications on a preselected metallic substrate area, wherein the coating is produced by the following method steps:
- covering the metallic substrate area of the prosthesis with a blended mixture of primary particles and secondary particles, said primary particles being metallic and capable of metallurgically bonding to the substrate area, said secondary particles being solid phase and capable of mechanically supporting the primary particles in a matrix;
- raising the temperature of the mixture and metallic substrate area to an elevated temperature at which metallurgical bonding of the primary particles can occur under compression and at which melting of the secondary particles or reactions between the primary and secondary particles does not occur;
- compressing the mixture against the metallic substrate area while at the elevated temperature to metallurgically bond the contacting primary particles and portions of the substate area as a result of the combination of elevated temperature and compression to which they are subjected;
- and
- removing the expendable secondary particles to present a homogenously porous coating on the metallic substrate area in which bonded primary particles are separated from one another by a network of interconnected voids.
2 more elements
A prosthesis having a porous coating for tissue ingrowth applications on a preselected metallic substrate area, wherein the coating is produced by the following method steps:
- positioning the prosthesis within a mold cavity with the metallic substrate area spaced inwardly from the mold cavity surfaces;
- filling the space between the metallic substrate area and mold cavity surfaces with a blended mixture of primary particles and secondary particles, said primary particles being metallic and capable of metallurgically bonding to the substrate area, said secondary particles being solid phase and capable of mechanically supporting the primary particles in a matrix;
- heating the prosthesis and mixture of particles to an elevated temperature at which metallurgical bonding can occur between adjacent primary particles and between the primary particles and the metallic substrate area under compression and at which melting of the secondary particles or reactions between the primary and secondary particles does not occur;
- compressing the mixture of particles against the metallic substrate area while at the elevated temperature to deform the primary particles and the portions of the metallic area engaged thereby and to metallurgically bond the contacting primary particles and portions of the substrate area as a result of the combination of elevated temperature and compression to which they are subjected;
- and
- subsequently removing the secondary particles from the resulting matrix of bonded primary particles to present a homogenously porous coating on the metallic substrate area in which bonded primary particles are separated from one another by a network of interconnected voids.
3 more elements
Dependencies are inferred from the claim text.