ABSTRACT
Bone repair is a complex process that involves the interaction of numerous cells and cell products in a carefully controlled milieu, regulated locally and systemically by hormones and other growth factors. Bone healing and repair are of paramount importance in orthopedic surgery, especially as they relate to fracture nonunion, delayed union, segmental defect repair, spinal fusion, osteoporosis, and bony ingrowth to prostheses. Autogenous bone grafting and allografts are commonly used to remedy these problems. In fact, 100,000 to 200,000 such operations are performed annually in the United States [1]. The results are good or excellent in most instances. However, they do not solve all cases of bone deficiency and are not free of complications. Failure rates as high as 1330% have been reported in the literature with autologous bone grafting, not to mention the clinically significant donor and recipient site morbidity [2, 3]. Allogeneic bone grafts have an even higher complication rate, including the risk of disease transmission. Thus, supplements and alternatives for bone grafting are being developed [4].
