Are the additional grafts necessary?

The goals of surgery for spinal deformity are to correct or improve the deformity to get a stable, balanced and fused spine. The long-term success of any procedure for scoliosis depends on a solid arthrodesis. Getting fusion of the instrumented segment with the aid of copious autogenous iliac graft has been the most important goal of treatment. However, harvesting copious graft from teenage iliac bone has its limitation in the quantity of graft, surgical time, and other complications of graft sites. Bone substitute is a promising concept, but there is not ideal bone substitute with all the characteristics of an autogenous bone graft. Several alternative graft materials like tricalcium phosphate, hydroxyapatite, and demineralized bone matrix have osteoinductive properties. Bone morphogenic protein has osteoconductive properties. The limitations with bone substitutes are osteoinduction and osteoconduction properties, sterilization, chances of transmitting infective disease and cost. We consider that the introduction of segmental spinal instrumentation which enables strong and firm correction and fixation of the scoliotic deformity has enabled getting fusion with less graft. We can obtain that quantity of graft after laminae and spinous process decortication. This retrospective study has been done in our hospital from January 2002 to December 2004. A total of 188 patients underwent posterior corrections for adolescent idiopathic scoliosis using segmental fixation by Moss-Miami. No autogenous iliac crest graft was taken or graft substitutes. After meticulous decortication and destruction of facet joints, we used local graft taken from spinous process and laminae. All patients had minimum thirty months follow-up. We have excellent results. Out of these 188 patients, 177 patients have fused spine, no implant failure, no pain, no infection and no loss of correction. Eleven (5.8%) patients underwent re-operation; four among them because of infection, three for symptomatic implants and four due to pseudarthrosis. We consider that the use of local harvesting graft is enough for getting good spondylodesis.