Osteosynthesis of diaphyseal fracture by Ossatite® Experimental study in rat

In order to develop a biodegradable interlocking nail for fracture fixation, hydoxylapatite pins and paste were implanted in the femoral bone of rats. A distal fracture was performed. The union and the tissue reaction to hydroxylapatite versus stainless-steel rods were studied after 15 days, 1, 2 and 6 months implantation. Metal pins induced a union. Hydroxylapatite pins (Ossatite®) did not prevent callus formation, but did not lead to consolidation in all cases due to weakness of gelatin matrix binding the apatite particles together. The biocompatility of material is satisfactory and the osteo-inductive properties of hydroxylapatite was confirmed. With injectable Ossatite®, we could not obtain rat femoral fracture consolidation. We can confirm good biomaterial tolerance in bone which contrasts with important soft tissue reactions. Use of such material should be carefully limited to filling intra-osseous cavities.