Porous calcium phosphate cement
AssigneeHowmedica Osteonics Corp.
InventorsBrian Edwards, Paul Higham, Joseph Zitelli
Life of this patent
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Abstract
A kit and a method for making a porous cement which self sets to hydroxyapatite and has an interconnected porosity is produced by mixing a calcium source and a phosphate source with a carbonate source and mixing this powdered component with a liquid component having an acid component. The liquid component comprises water or an aqueous solution containing an acid. The acid and the carbonate react to form carbon dioxide thereby producing an interconnected porosity in the normally solid self-hardening bone cement. The method requires only a relatively low weight percent of the acid and base to be mixed with the liquid and powder cement components.
Claims26
A kit for producing a self-setting bone cement comprising:
- water;
- an acid source selected from the group consisting of citric acid, malic acid, phosphoric acid, fumaric acid, lactic acid, succinic acid and a combination thereof;
- and
- a powdered composition containing dicalcium phosphate and tetra-calcium for reacting with said water to form said self-setting bone cement and containing a carbonate selected from the group consisting of sodium carbonate, sodium bicarbonate, calcium carbonate, calcium bicarbonate and a combination thereof.
A method for making a porous cement from calcium and phosphate sources which self sets to hydroxyapatite as the predominant product at ambient temperatures after contact with an aqueous solution comprising:
- mixing tetracalcium phosphate and dicalcium phosphate and a base to form a powdered component;
- mixing a liquid component comprising an aqueous solution containing an acid;
- and
- mixing said powdered component and said liquid component causing said acid and base to react to form a gas while said calcium and phosphate source combine to form the hydroxyapatite cement.
A bone treatment material comprising:
- a powdered component containing tetracalcium phosphate and dicalcium phosphate, an aqueous component and a gas source, said powdered component and said aqueous component reacting to form a settable bone treatment material, said gas source present while the reaction is occurring to form a porous structure in said set bone treatment material.
A bone cement kit comprising:
- a powdered component comprising methacrylate polymer and a member selected from the group consisting of sodium carbonate, sodium bicarbonate, calcium carbonate, calcium bicarbonate and a combination thereof;
- a liquid component comprising methacrylate monomer and a member selected from the group consisting of citric acid, malic acid, orthophosphoric acid, fumaric acid, lactic acid, succinic acid and a combination thereof.
Dependencies are inferred from the claim text.