ABUNDANT POSTOPERATIVE CALCIFICATION OF AN ELASTOMER - MATRIX CALCIUMPHOSPHATE-POLYMER COMPOSITE FOR BONE RECONSTRUCTION

In this experiment the behaviour of an 80/20 PEO/PBT copolymer in bone defects was assessed. Porous cylinders were press-fit inserted into t he diaphyseal femur of goats and evaluated by light and electron micro scopy and X-ray microanalysis. The most important finding in this stud y was that almost complete calcification throughout the implant was di splayed after 26 weeks. The 80/20 PEO/PBT copolymer did not contain ca lcium and phosphorus prior to implantation, however, it apparently has the ability to take up considerable amounts of calcium and phosphate postoperatively, resulting in a calcium phosphate-polymer composite. A s a consequence of the high calcification rate of 80/20 cylinders, bon e-bonding (a continuum between calcification of the material surface a nd bone) was encountered as early as 3 weeks after implantation. Union of the 5 mm defect was observed at 6 weeks and ingrowth was frequentl y centripetal. After 26 weeks bone tissue occupied most of the pore ar ea and was often seen in continuity with the calcified polymer. We con clude that an elastomeric matrix that is capable of abundant postopera tive calcification behaves favourably with respect to the repair of bo ne defects. Porous 80/20 PEO/PBT copolymer is, therefore, a promising alternative for bone-replacement applications.