Patent ID: 6579532
Filing Date: 2003-06-17
Classification: A61F,A61L

Abstract:
A method for manufacturing an orthopedic mixture suitable for use as a bone substitute or bone filler, comprising:providing a reactor having a mixer; charging the reactor with starting materials that include a source of calcium ions, a matrix for the calcium ions, and a photoinitiator, the source of calcium ions being selected from the group consisting of calcium hydroxy apatite, tri-basic calcium phosphate, calcium salts of condensed phosphates, calcium sulfate, gypsum hemi-hydrate, gypsum dihydrate, monovalent, divalent, and multivalent complexes of salts of calcium acetate and other organic calcium salts, calcium edetate and other chelated complexes of calcium, and wherein the matrix for the calcium ions is a thermoplastic polymer, a thermoset polymer, or a combination of thermoplastic and thermoset polymers, the polymer being selected from the group consisting of hydroxy-methyl cellulose and its derivatives, polylactide-co-glycolide, polyethylene, polypropylene, polyvinyl chloride, polyvinyl alcohol, polyethylene-vinyl acetate, polyenol-ketone, polyacrylic acid, polycarbophil, polyacrylamides, poly-N-isopropyl acrylamide, polyacrylates, polyethylene glycol, polyglycolic acid, polylactic acid, poly-&egr;-caprolactone, poly-3-hydroxybutyrate, polyortho esters, polyanhydrides, polyamino acids, pseudo-polyamino acids, polyamide-enamines, polyamido amines, polyurethanes, azopolymers, polydimethylsiloxane, and polyphosphazenes; providing supercritical fluid in the reactor, the supercritical fluid being selected from the group consisting of carbon dioxide, water, nitrous oxide, methane, ethane, ethylene, propane, pentane, benzene, methanol ethanol, isopropanol, fluorocarbons, toluene, pyridine, cyclohexane, decalin, cyclohexanol, o-xylene, and tetralin; the starting materials and the supercritical fluid being present in the reactor in proportions by weight ranging from 10:90 to 90:10 and more preferably 40:60 to 60:40; mixing the starting materials and the supercritical fluid in the reactor for a period of time sufficient to form a supercritical fluid slurry; reducing the pressure in the reactor to ambient; and recovering an orthopedic mixture from the reactor.