Orthopaedic surgery is currently in the midst of a transformation from bone
grafting and the use of bone graft substitutes to bone tissue engineering.
Bioactive bone growth factors likely will. play a particularly important r
ole in this emerging field. This article will review the three leading stra
tegies for using bioactive factors for bone tissue engineering: extraction
and partial purification of growth factors, recombinant protein synthesis,
and gene therapy. Preclinical and early clinical trial results with bone mo
rphogenetic protein-2, bone morphogenetic protein-7 (osteogenic protein-1),
and NeOsteo bovine bone protein extract will be reviewed. In addition, the
current obstacles to clinical implementation of bone tissue engineering wi
ll be reviewed.