The tissue used in bone grafting can come from three places: your own body, a bone-tissue bank, or from a medical device company that makes synthetic bone.
When the bone is harvested from your own skeleton, it is usually taken from your hip. This is a surgical procedure in which the doctor extracts some of the bone for use in the spinal fusion (or other operation). After the surgery, you may have pain at the harvest site, as well as the surgical site. Pain at the harvest site can be significant, and sometimes lasts up to five years. Bone grafting can also change the look of the harvest site.
Whether it is natural or synthetic, bone graft material can encourage new bone to grow in and fuse together the area it fills. This is what creates the mechanical strength and support. Most of the time bone grafting works just fine, but some conditions can affect results. For example, if you smoke, have diabetes or use steroids, or if the medical staff cannot obtain enough grafting material, there could be a problem with the outcome of your spinal fusion surgery. Also, the procedure is sometimes not recommended for older adults. Ask your doctor for more information on whether you might be a good candidate.
Sources:
Sasso RC, LeHuec JC, Shaffrey C; Spine Interbody Research Group. Iliac crest bone graft donor site pain after anterior lumbar interbody fusion: a prospective patient satisfaction outcome assessment. J Spinal Disord Tech. 2005 Feb
Singh K, Phillips FM, Kuo E, Campbell M. A prospective, randomized, double-blind study of the efficacy of postoperative continuous local anesthetic infusion at the iliac crest bone graft site after posterior spinal arthrodesis: a minimum of 4-year follow-up. Spine. 2007 Dec 1
Weill Cornell Medical College. Spinal Fusion Surgery and Bone Morphogenic Protein. Weill Cornell Physicians website. 2004.
Bone Graft Alternatives. North American Spine Society Public Education Series.

