Yasko AW, Lane JM, Fellinger EJ, Rosen V, Wozney JM, Wang A. The healing of segmental bone defects, induced by recombinant human bone morphogenetic protein (rhBMP-2): a radiographic, histological, and biomechanical study in rats. J Bone Joint Surg Am 1992; 74: 659–670.
- The osteoinductive properties of rhBMP-2 in promoting bone healing were firmly established in this animal model. The mechanism of action of rhBMP-2 involves osteoinductive signalling and regulation of a number of gene expression pathways involving the differentiation of mesenchymal progenitor cells into osteoblasts.
- This was an animal study that provided significant evidence that rhBMP-2 was capable of inducing union of a bony defect. By showing a 100% union rate the authors concluded that rhBMP-2 could act as alternative or enhancer of autologous bone graft in bone regeneration.
- The authors used a well defined femoral-defect model that had been extensively used to study osteoinductive, osteoconductive and osteogenic factors. The model results in a predictable non-union, observations and quantification of bone formation by radiographs can be easily determined and the rigid fixation obtained with the plate maintains a coaxial relationship of the ends of the bone for mechanical testing.
- Bone morphogenetic proteins constitute at least 15 growth factors originally identified to stimulate de novo bone formation. They play a critical role in regulating cell growth, differentiation and apoptosis in a variety of cells during development including osteoblasts and chondrocytes. It is thought BMPs are expressed in the early stages of facture healing. It is thought BMPs are primary activators of differentiation in osteoprogenitor and mesenchymal cells destined to become osteoblasts and chondrocytes.
- rhBMP-2 is one of the most studied osteoinductive molecules. Purified rhBMP-2 has been established to induce de novo bone formation and bone repair in adult animals and chondrogenic and osteogenic differentiation in various cellular systems in vitro.
- Studies have shown BMP-2 (rhBMP-2) can induce osteogenic differentiation in multipotent cells, progenitor cells and osteoblasts.