Developments in Bone Grafting and Spinal Fusion

Bruno Gomes, Orthopaedic Research Registrar, Department of Clinical Research, Royal Newcastle Hospital.

Spinal fusion is widely practised for a number of spinal disorders. Its effectiveness is limited by non-union, which occurs in up to 56% of lumbar fusions. The majority of these are symptomatic.

Historically autologous bone graft has achieved the highest union rates. This is thought to result from its function as an osteoconductive scaffold, and the presence of osteoinductive proteins and osteogenic cells. Its disadvantages however include limited supply and donor site comorbidity. Allograft bone has been used as an alternative but lower union rates probably result from the absence of osteogenic cells and reduced osteoinductive proteins. The use of osteoinductive substances may improve union rates.

A prospective multi-hospital study was undertaken to compare the lumbar posterolateral fusion rates for different graft materials. The three groups were allograft alone, allograft plus bone morphogenic protein 7 (OP-1^Ò), and allograft plus coralline hydroxyapatite (ProOsteon^Ò) and Autologous Growth Factor (AGF^Ò). The results will be presented.