The use of polylactic acid/polyglycolic acid copolymer and gelatin sponge complex containing human recombinant bone morphogenetic protein-2 following condylectomy in rabbits

Purpose: To examine the results of a polylactic acid/polyglycotic acid copolymer and gelatin sponge complex (PGS) with or without recombinant human bone morphogenetic protein-2 (rhBMP-2) used to treat condylar defects in rabbits. Material and methods: Adult male Japanese white rabbits (n = 60; 3 kg; 12-16 weeks old) were divided into three groups of 20 each. All rabbits underwent condytectomy. In the two implanted groups, PGS with or without 5 mug of rhBMP-2 was implanted to the condylar defect without fixation. No material was implanted into the control group. Animals were sacrificed at 2, 4, 8, 12 and 24 weeks postoperatively, and the temporomandibular joints (TMJs) were examined histologically. Results: Four weeks after implantation, growth of bone and cartilage-like tissue was observed in all rabbits that received PGS implants (with and without rhBMP-2). A cartilage-like layer was derived from the bone marrow at the operated surface. There was no growth of bone tissue in the control rabbits, but they also had a cartilage-like layer directly derived from the operated surface. Conclusion: This study demonstrated that PGS with or without rhBMP-2 could induce regeneration of new bone and cartilage-like tissue in the TMJ. (C) 2003 European Association for Cranio-Maxillofacial Surgery.