الملخص

The biological calcium hydroxyapatite was isolated and purified from local cow bones in laboratories of the University of Mosul. The chemical analysis of the product shows that the purity of the biological calcium hydroxyapatite is 99%. The biological calcium hydroxyapatite was prepared locally as bone graft substitute from cheap unlimited resource. The biological calcium hydroxyapatite was implanted around induced fracture of forearm in 4 white male rabbits. The forearm fracture united thirty days after the experiment. The biological calcium hydroxyapatite was implanted inside the medullary cavity of the femur and around fracture ends in another 4 male white rabbits. The implanted biological calcium hydroxyapatite was replaced by callus around the bone and in medullary cavity of bone without any chronic inflammatory changes or foreign body reaction. We conclude that biological calcium hydroxyapatite can be used as bone graft substitute. Key words: calcium hydroxyapatite, cow bone, bone graft substitute.