engleski

Vascularised Bone Created by Epigastric Flap Prefabrication Using BMP-7 Promotes Healing of Long Bone Defects in Rats.

The aim of this study was investigating conditions which promote healing of the long bone defects by means of prefabricated bone graft in the epigastric flap. Helistat (collagen sponge 0.5 cm) or demineralised bone matrix (0.5 cm from rat long bone diaphysis) were inserted in the epigastric flaps in rats under aseptic conditions. Two doses (low, 30 microg/ml and high 120 microg/ml) of BMP-7 were added to both Helistat and demineralised bone matrix. In the control group only implants were used. After 6 weeks the bone graft was transferred from the epigastric flap into 0.8 cm long defect in the femur and fixed with intramedullary K- wire. Two prefabricated bone grafts from each experimental and control groups were used for histological analysis. Eight weeks after surgery X-ray was performed and femurs harvested. Healing of the bone defect as assessed by x-rays was observed in animals treated with a high BMP-7 dose graft. Histologic analysis of the bone grafts showed that BMP-7 stimulated bone formation in both the Helistat and demineralised bone implants, but dose-effect was observed only for the Helistat implants. Histology of the femur specimens showed healing of bone defect with prefabricated implants only in the high dose BMP-7 groups (both Helistat and demineralised bone matrix) with optimal retention of the bony fragments. Demineralised bone matrix was found to be superior to Helistat in supporting bone formation both in the epigastric flap and in the femur bone defect. Non-union remained if prefabricated non-treated or low BMP-7 dose implants were transferred into the femur gap. Retention of bone defects was a primary technical problem in this study. In conclusion, results of this pilot study in rats suggest that BMP-7 prefabricated bone grafts accelerate healing of long bone defects.

Flaps; Prefabrication; BMP7

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