bone growth: osteoinduction, which involves cells that induce new
bone growth; osteoconduction, which involves spacer material on
which new bone grows; and osteogenesis, which is when new bone
actually fuses with a graft. Bone graft materials and bone graft substi-
tutes have some or all of these properties.
• Autograft bone grafts are taken directly from the patient's body,
most often at the iliac crest, and demonstrate all 3 properties of bone
growth. Donald Corenman, MD, DC, a board certified spine surgeon
in Vali, Colo., says spinal fusion procedures can involve obtaining a
local autograft by recycling bone spurs or lamina from the vertebra.
Dr. Corenman points to several benefits of using autograft bone: no
risk of disease transmission, easy acceptance by the body and optimal
healing for a healthy fusion. Potential drawbacks include longer surgi-
cal times to harvest the graft and additional post-op pain for the
patient. During spine surgery, fusion rates (the percentage of full
incorporation of the graft bone with the native vertebrae) involving
autograft bone is 95 to 98% at a single disc level, according to Dr.
Corenman. He says healing time (how long it takes new bone to
become fully incorporated in the body) takes about 6 weeks.
• Allograft bone grafts are taken from donors and provide a frame-
work for new bone cells to grow in and around before they eventually
replace the donor bone. An allograft is 100% conductive and hardly
inductive because it does not contain growth factors.
"Implanting allograft bone does not require additional surgical time,
but does carry a small risk of disease transmission," says Dr. Corenman.
"In addition, disinfecting the allograft bone before implantation to
reduce infection risk eliminates growth cells and the proteins that
strengthen the bone after implantation."
Dr. Corenman points out that fusion time is lengthened when allo-
graft bone is used because there are no host cells present in the graft
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