Repairing of Osteochondral Defects in Joint Using Beta-TCP/ Carboxymethyl Chitin Composite

Beta-tricalcium phosphate/carboxymethyl chitin composites [TCP/CMCh] of various ratios of TCP granules and CMCh were made and their mechanical properties, handling properties and repair performance for bone defects and for osteochondral defects were investigated. Water pooling ratio of CMCh was approximately 40 times the weight itself. TCP/CMCh of a higher TCP ratio had higher stress at 50%-strain. The stress at 50%-strain of TCP/CMCh with 0, 2.5, 5.0, 7.5, 10 TCP ratios was 0.12, 0.51, 1.08, 1.46, 1.67 (MPa, n=5), respectively. The TCP/CMCh with 5.0 TCP ratios had the best total scores in handling tests. The bone repair rate of TCP/CMCh was TCP ratio 2.5< Blank= TCP ratio 7.5< TCP ratio 5.0. In the implantation test for osteochondral defects, TCP/CMCh was completely absorbed at four weeks after surgery. Regeneration of the articular cartilage was seen with TCP/CMCh and HA/CMCh but not with TCP granules, which remained eight weeks after implantation. The regenerated articular cartilage had remained 32 weeks after implantation. In conclusion, it was demonstrated that this TCP/CMCh composite was a promising material for repairing osteochondral defects.