The regeneration of bone remains an elusive yet important goal in the field
of orthopaedic surgery. Despite its limitations, autogenous cancellous bon
e grafting continues to the most effective means by which bone healing is e
nhanced clinically. Biosynthetic bone grafts currently are being developed
as an alternative to autogenous bone grafting. These grafts generally conta
in one or more of three critical components: (1) osteoprogenitor cells; (2)
an osteoconductive matrix; and (3) osteoinductive growth factors. The impo
rtance of each of these components based on preclinical data supports their
use in biosynthetic bone grafts. The use of growth factors such as bone mo
rphogenetic proteins, transforming growth factor, platelet derived growth f
actor, and fibroblastic growth factor is reviewed in preclinical long bone
defect and spinal fusion models. The use of bone marrow in preclinical and
clinical settings is presented with specific emphasis given to the use of b
one marrow as a source of osteoprogenitor cells and how the use of these ce
lls can be enhanced with the use of bone morphogenetic protein-2, These dat
a support the concept that although products that contain only one of the t
hree key components of a bone graft may regenerate bone successfully, compo
sites of the three key components will be more successful clinically.