Fresh autologous bone graft refers to bone harvested from one anatomical site and transplanted to another anatomic site in the same individual. These are widely considered the most desirable of grafting materials in patients undergoing spinal fusion. Autologous bone graft ideally contains all three properties of bone grafts: osteogenicity (containing numerous differentiated and undetermined stromal cells within the cavity lining), osteoinductivity (noncollagenous bone matrix proteins, including growth factors supporting arthrodesis), and osteoconductivity (hydroxyapatite and collagen scaffolding for the deposition of bone). Finally, complications such as immune rejection and disease transmission from allograft or xenograft, while rare, are obviated by the histocompatibility provided by autografts.

Autologous bone graft may harbor serious disadvantages in several clinical situations. This may potentially include an inability to provide sufficient graft material for use in multisegmental fusions and revision surgeries where prior bone harvests have been undertaken, and in children with large osseous defects requiring autograft beyond that available. Significant donor-site pain is one potential complication of autogenous bone graft harvesting with one study by Albert and coinvestigators reporting pain in 26% of patients at a mean 2-year follow-up. In another study of 100 patients with lumbar discectomy and fusion using iliac crest, donor-site pain was encountered at a rate of 37% after 10-year follow-up. Other options of bone graft harvesting such as fibular autograft or rib graft are associated with lower rates of reported donor-site pain, although the methods of harvest are increasingly morbid. Common complications associated with fibular graft harvests include peripheral nerve injury, compartment syndrome, and injury to the extensor hallucis longus muscle. Complications of rib graft harvesting include lung injury resulting in atelectasis, pneumonia, and even persistent bronchiectasis (Table 35.1).

One of the most frequently utilized sites for harvesting bone graft is the posterior iliac crest because it provides a large quantity of cancellous and corticocancellous bone. Strut grafts used for anterior interbody fusion must have some capacity to bear the mechanical compressive loads applied to the intervertebral location. These grafts require cortical integrity and can be fashioned as tricortical blocks (cortices include the inner and outer iliac tables and the iliac crest) or as bicortical blocks or dowels (cortices include the inner and outer iliac tables only; Fig. 35.1). Autografts used in nonloaded or tensile environments, such as the posterior and posterolateral (intertransverse process) spine, do not require cortical integrity. These grafts can be prepared as corticocancellous strips, morcellized fragments, or even particulate corticocancellous or cancellous bone.