BMP AS AN ALTERNATIVE TO AUTOGRAFT FOR SPINAL ARTHRODESIS

The gold standard in spinal arthrodesis is still given by the use of autograft. Additional operations to obtain bone grafts increase morbidity and strain for the patient, but do not always provide bone with sufficient primary stability and high osteogenic potential. Despite the use of large-scale conventional techniques, applying posterior and anterior access, failures still occur and lead to loss of correction or, even worse, to persistent instability. Therefore, a study has been designed to determine whether spinal arthrodesis could improved by the use of BMP-7, a potent growth factor with osteogenic properties, in comparison with autograft. Following disc removal and monosegmental instrumentation of the sheep lumbar spine, we compared interbody fusion at six months after administration of autogenous iliac crest bone graft, and BMP-7 (rhOP-1). Spinal arthrodesis quality was examined by plain X-ray, computed tomography (CT scan), biomechanical testing and histological evaluation. All examination methods demonstrated superior fusion after administration of BMP. Autograft eventually produced bony healing in most cases, however of a lower quality than with BMP. The results indicate that the use of BMP is enhancing vertebral arthrodesis in sheep. As well as offering the potential for improved bone healing, the use of BMP may permit less invasive surgery, such as vertebroplasty, kyphoplasty or application of cages, and help to avoid donor site morbidity.