Bone morphogenetic proteins and growth factors: Emerging role in regenerative orthopaedic surgery

Bone morphogenetic proteins (BMPs) were discovered by Urist and colleagues in 1965 and later defined as multifunctional cytokines involved in osteoinduction. BMPs are members of the transforming growth factor-β superfamily, with the exception of the BMP-1. Presently, at least 20 BMPs have been identified and studied, but only BMP 2, 4 and 7 have been able in vitro to stimulate the entire process of stem cell differentiation into osteoblastic mature cells. In preclinical and clinical studies, BMPs have demonstrated potential in osteoinduction and have been approved for clinical use in treating open fractures of the long bones and nonunions and in vertebral arthrodesis. Additional clinical uses of these molecules are under investigation and the possibility of using gene therapy in selected pathologies seems the most appealing.