The value of bone transplantation is demonstrated by the frequency of its use today. Surgeons transplant bone at least 10 times more often than they do any other transplantable organ. The procedure has a rich history, dating back over 300 years to when Job van Meekeren performed the first bone graft using a canine xenograft to repair a cranial defect (138). Bone grafting became critical during World War II, prompting the US Navy to establish bone banks to better treat fractures sustained in battle (9). During that period a successful graft was thought to be one that could withstand the forces applied to it by the individual. Today we consider the bone graft to be a dynamic tool that should not only support normal forces, but also incorporate itself into the bed, revascularize as new bone forms, and assume the specific shape required for the healing defect. Furthermore, accelerating the normal healing process whenever possible is an obvious goal. Recombinant DNA technology might achieve this goal by allowing surgeons to apply growth factors to defects in therapeutic quantities in an effort to speed regeneration.