Use of osteoinductive implants in the treatment of bone defects.

Osteogenic proteins (OPs) are a family of bone matrix polypeptides isolated from a variety of mammalian species, including mouse, rat, bovine, monkey, and man. OPs initiate chondroblastic differentiation in pluripotent mesenchymal progenitor cells, followed by the synthesis of new bone by endochondral ossification. OPs have the ability to induce healing of osteoperiosteal defects in several animal models, supporting a possible therapeutic role in the reconstruction of bone defects. OPs are responsible for the osteoinductive capacity of demineralized bone matrix (DBM) implants, which may also prove to be clinically useful. Preliminary studies using purified, naturally occurring human osteogenic proteins in the clinical management of non-unions have reported promising results. A prospective, randomized clinical trial is currently underway, comparing recombinant human osteogenic protein-1 (rhOP-1) to autograft in the treatment of tibial non-unions. The use of osteogenic protein implants to augment or replace autogenous and allogenous bone grafts will reduce morbidity, and circumvent the risk of disease transmission associated with transplantation.