Bioabsorbable fixation devices

Abstract

A new material was assessed in a patellar reattachment model in sheep and evaluated using histology and biomechanical testing. Overall, these materials showed they produced minimal reactivity histologically. The new material had higher failure strength overall compared to a previous study with the control material as repairs completed with PLG/CS/TCP anchors were significantly stronger compared to repairs with PLLA anchors.

1 . An internal fixation device made from a bioabsorbable polymer composition comprising:
 about 50 to 80 percent by weight of a copolymer, based on the weight of said bioabsorbable polymer composition, wherein said copolymer is selected from the group consisting of poly 1-lactide:co-glycolide, poly 1-lactide:d,l-lactide, and mixtures thereof; and   about 20 to 50 percent by weight of a ceramic filler, based on the weight of the bioabsorbably polymer composition, wherein said ceramic filler comprises calcium carbonate.   
     
     
         2 . The internal fixation device of  claim 1 , comprising:
 (a) about 50 percent by weight of a copolymer, based on the weight of said bioabsorbable polymer composition, wherein said copolymer is selected from the group consisting of poly 1-lactide:co-glycolide, poly 1-lactide:d,l-lactide, and mixtures thereof; and   (b) about 50 percent by weight of a ceramic filler, based on the weight of the bioabsorbably polymer composition, wherein said ceramic filler comprises calcium carbonate.   
     
     
         3 . The internal fixation device of  claim 1 , wherein the copolymer comprises poly(lactide-coglycolide) in a ratio of about 85:15 lactide and glycolide units. 
     
     
         4 . The internal fixation device of  claim 1 , comprising only poly(lactide-coglycolide) in a ratio of about 85:15 lactide and glycolide units and about 20 to 50 percent calcium carbonate by weight. 
     
     
         5 . A method comprising securing soft tissue to a bone using at least one suture anchor comprising an internal fixation device made from a bioabsorbable polymer composition, the composition comprises:
 (a) from 20 to 80 percent by weight of a copolymer, based on the weight of said bioabsorbable polymer composition, wherein said copolymer is selected from the group consisting of poly 1-lactide:co-glycolide, poly 1-lactide:d,l-lactide, and mixtures thereof; and   (b) from 20 to 50 percent by weight of a ceramic filler, based on the weight of the bioabsorbable polymer composition, wherein said ceramic filler comprises calcium sulphate and optionally tricalcium phosphate.   
     
     
         6 . The method of  claim 5 , wherein the soft tissue is selected from the group consisting of ligament, tendon, muscle, and cartilage. 
     
     
         7 . The method of  claim 5 , wherein the bone is patella bone. 
     
     
         8 . The method of  claim 5 , wherein the ceramic filler comprises material purified from natural sources. 
     
     
         9 . The method of  claim 5 , wherein the ceramic filler comprises synthetic material. 
     
     
         10 . The method of  claim 5 , wherein the ceramic filler comprises a mixture of synthetic material and material purified from natural sources. 
     
     
         11 . The method of  claim 5 , wherein the composition comprises:
 (a) about 50 percent by weight of a copolymer, based on the weight of said bioabsorbable polymer composition, wherein said copolymer is selected from the group consisting of poly 1-lactide:co-glycolide, poly 1-lactide:d,l-lactide, and mixtures thereof; and   (b) about 50 percent by weight of a ceramic filler, based on the weight of the bioabsorbably polymer composition, wherein said ceramic filler comprises calcium carbonate.   
     
     
         12 . The method of  claim 5 , wherein the copolymer comprises poly(lactide-coglycolide) in a ratio of about 85:15 lactide and glycolide units. 
     
     
         13 . The method of  claim 5 , wherein the composition comprises only poly(lactide-coglycolide) in a ratio of about 85:15 lactide and glycolide units and about 20 to 50 percent calcium carbonate by weight. 
     
     
         14 . An internal fixation device made from a bioabsorbable polymer composition comprising only poly(lactide-coglycolide) in a ratio of about 85:15 lactide and glycolide units and about 20 to 50 percent calcium carbonate by weight. 
     
     
         15 . The internal fixation device of  claim 14 , wherein said poly(lactide-coglycolide) comprises poly 1-lactide:co-glycolide. 
     
     
         16 . The internal fixation device of  claim 14 , comprising:
 (a) about 50 percent by weight of a copolymer, based on the weight of said bioabsorbable polymer composition, wherein said copolymer is selected from the group consisting of poly 1-lactide:co-glycolide, poly 1-lactide:d,l-lactide, and mixtures thereof; and   (b) about 50 percent by weight of a ceramic filler, based on the weight of the bioabsorbably polymer composition, wherein said ceramic filler comprises calcium carbonate.