Tất cả 11 bệnh nhân ngẫu nhiên vào nhóm rhBMP được hợp nhất 6 tháng postoperatively, trong khi một trong ba bệnh nhân ngẫu nhiên vào nhóm kiểm soát được autograft trong lồng của mình cuối cùng đã được coi là một nonunion 1 năm (82). Kể từ thời điểm đó, | 234 Boatright and Boden have reported on a pilot study of single-level anterior lumbar interbody fusions in humans comparing rhBMP-2 collagen sponge-filled cages with iliac crest autograft-filled cages. All 11 patients randomized to the rhBMP group were fused at 6 mo postoperatively while one of the three patients randomized to the control group receiving autograft in their cages was finally deemed a nonunion at 1 yr 82 . Since that time over 350 patients have received that combination of cage BMP-2 collagen sponge and the extremely high success rate resulted in approval of rhBMP-2 InFuse Bone Graft Medtronic Sofamor Danek Memphis TN by the US Food and Drug Administration for use inside tapered fusion cages for anterior lumbar interbody fusion. Early pilot studies using rhBMP-2 with a hydroxyapatite tricalcium phosphate carrier matrix have yielded encouraging results for posterolateral lumbar spine fusions. Other bone-inducing growth factors that have been evaluated include rhBMP-7 and growth and differentiation factor-5. Cook et al. have investigated rhBMP-7 also known as osteogenic protein-1 Stryker Biotech Hopkinton MA extensively in long-bone defect models where it has been found to be an effective bone generator in combination with collagen matrix 83 84 . Further work by this group utilized a canine spinal fusion model to demonstrate successful rapid posterior spinal fusion when comparing rhBMP-7 to autograft 85 . rhBMP-2 has also yielded a high rate of posterolateral spine fusions in the rabbit model. Early results from clinical trials in posterolateral spine have demonstrated fusion rates based only on plain radiographs not CT scans of 50-70 . Growth and differentiation factor 5 GDF-5 another member of the transforming growth factor-P TGF-P superfamily has also been shown to be effective in a long-bone defect model in rats and subsequently in a rabbit spinal fusion model. Spiro et al. used a rabbit posterolateral intertransverse process fusion model to .
