Cartilage repair mixture containing allograft chondrocytes

Abstract

The invention is directed toward a sterile cartilage defect implant material comprising milled lyophilized allograft cartilage pieces ranging from 0.01 mm to 1.0 mm in size in a bioabsorbable carrier taken from a group consisting of sodium hyaluronate, hyaluronic acid and its derivatives, gelatin, collagen, chitosan, alginate, buffered PBS, Dextran or mixed polymers with allograft chondrocytes added in an amount ranging from 2.5×10 5 to 2.5×10 7 .

1 - 20 . (canceled) 
     
     
         21 . A method of repairing an articular cartilage defect in a human being, comprising the step of placing in a cartilage defect site, allograft chondrocytes and lyophilized, freeze-milled allograft cartilage pieces, the allograft cartilage pieces having a size not greater than 1 mm. 
     
     
         22 . A method as claimed in  claim 21 , wherein the allograft cartilage pieces are included in a mixture that also includes a bioabsorbable carrier selected from the group consisting of sodium hyaluronate, hyaluronic acid and its derivatives, gelatin, collagen, chitosan, alginate, buffered PBS, Dextran and polymers. 
     
     
         23 . A method as claimed in  claim 22 , wherein the allograft cartilage pieces are present in the mixture in an amount within the range from about 15% to about 50% by weight, and the bioabsorbable carrier is present in the mixture in an amount within the range from about 50% to about 85% by weight. 
     
     
         24 . A method as claimed in  claim 21 , wherein the allograft chondrocytes are derived from allograft cartilage taken from a human donor having an age in the range from about 3 months to about 20 years. 
     
     
         25 . A method as claimed in  claim 24 , wherein the allograft cartilage pieces are formed from allograft cartilage taken from a human donor having an age in the range from about 3 months to about 20 years. 
     
     
         26 . A method as claimed in  claim 21 , wherein the allograft chondrocytes are derived from allograft cartilage taken from a human donor having an age in the range from about 3 months to about 12 years. 
     
     
         27 . A method as claimed in  claim 21 , wherein the allograft chondrocytes are derived from allograft cartilage taken from a human donor and the allograft cartilage pieces are formed from allograft cartilage taken from the same human donor. 
     
     
         28 . A method as claimed in  claim 21 , wherein the allograft chondrocytes are placed in the cartilage defect site in an amount ranging from about 2.5×10 5  to about 2.5×10 7  allograft chondrocytes. 
     
     
         29 . A method as claimed in  claim 28 , wherein the allograft chondrocytes are placed in the cartilage defect site in an amount of about 2.5×10 6  allograft chondrocytes. 
     
     
         30 . A method as claimed in  claim 28 , wherein the allograft chondrocytes include expanded growth chondrocytes. 
     
     
         31 . A method as claimed in  claim 21 , wherein the allograft cartilage pieces are formed from allograft articular cartilage. 
     
     
         32 . A method as claimed in  claim 21 , wherein the allograft cartilage pieces are formed from allograft cartilage selected from the group consisting of hyaline cartilage and fibrous cartilage. 
     
     
         33 . A method as claimed in  claim 21 , further comprising the step of placing a growth factor in the cartilage defect site. 
     
     
         34 . A method as claimed in  claim 21 , wherein the allograft cartilage pieces have a water content ranging from about 0.1% to about 8.0% by weight prior to being placed in the cartilage defect site. 
     
     
         35 . A method as claimed in  claim 21 , wherein the allograft cartilage pieces are formed from allograft cartilage which has been lyophilized so as to reduce its water content to an amount within the range from about 0.1% to about 8.0% by weight. 
     
     
         36 . A method as claimed in  claim 21 , wherein the size is in the range from about 0.01 mm to 1.0 mm. 
     
     
         37 . A method as claimed in  claim 21 , wherein the allograft cartilage pieces are formed from a donor tissue material consisting of allograft articular cartilage. 
     
     
         38 . A method as claimed in  claim 21 , wherein the allograft cartilage pieces are formed by a method including the steps of:
 (a) harvesting a donor tissue material consisting of allograft articular cartilage; and   (b) lyophilizing and freeze-milling the donor tissue material.   
     
     
         39 . A method as claimed in  claim 21 , wherein the allograft cartilage pieces are formed by freezing allograft cartilage with liquid nitrogen and milling the frozen cartilage. 
     
     
         40 . A method as claimed in  claim 21 , wherein the allograft cartilage pieces are formed by freeze-milling allograft cartilage that has been lyophilized. 
     
     
         41 . A method as claimed in  claim 21 , wherein said placing step includes the steps of:
 (a) cutting a patient's tissue to remove a diseased area of cartilage from the cartilage defect site;   (b) placing the allograft chondrocytes and allograft cartilage pieces into the cartilage defect site; and   (c) placing a cover over the allograft chondrocytes and allograft cartilage pieces so as to contain the allograft chondrocytes and allograft cartilage pieces in the cartilage defect site.   
     
     
         42 . A method as claimed in  claim 21 , further comprising the step of fixing the allograft cartilage pieces in the cartilage defect site with an organic glue. 
     
     
         43 . A method as claimed in  claim 41 , further comprising the step of keeping the cover over the allograft chondrocytes and allograft cartilage pieces for a predetermined period of time that is sufficient to promote articular cartilage growth at the cartilage defect site. 
     
     
         44 . A method as claimed in  claim 41 , wherein the cover includes one of a periosteal flap and a perichondrial flap. 
     
     
         45 . A method as claimed in  claim 22 , wherein the mixture further includes the allograft chondrocytes. 
     
     
         46 . A method as claimed in  claim 21 , wherein the allograft cartilage pieces lack viable cells. 
     
     
         47 . A method as claimed in  claim 21 , wherein the allograft cartilage pieces have an ability to stimulate growth of new articular cartilage at the defect site. 
     
     
         48 . A method as claimed in  claim 22 , wherein the mixture further includes a growth factor selected from the group consisting of FGF-2, FGF-5, IGF-1, TGF-β, BMP-2, BMP-7, PDGF, and VEGF. 
     
     
         49 . A method as claimed in  claim 48 , wherein said placing step includes (i) the step of placing said allograft chondrocytes in the cartilage defect site; and (ii) placing the lyophilized, freezer-milled cartilage pieces in the cartilage defect site, said step (i) being performed separately from said step (ii).