Bone substitutes in 2003: an overview.

The authors review the various bone substitutes which are currently available on the market place in Belgium. After describing the requirements for clinical use of such materials, they compare the biological and mechanical values of bone autografts, bone allografts, demineralised bone, xenografts, coral and synthetic materials such as calcium sulfate, calcium phosphate, ionic cement and bioactive glass. They stress the current paucity of data pertaining to the biological value of these materials and call for in vivo validation tests. They also review biomolecules such as BMP-2 or OP-1, whose osteoinductive properties are currently under investigation. Finally, they present the emergent field of cell therapy, in which osteoprogenitor cells are isolated from the patient's bone marrow and reinjected after in vitro cultivation. They stress the therapeutic and medicolegal problems raised by the combination of medical devices, grafts, medicinal products and cells, all of which have a different status within the complex European legal framework.