EFFECTS OF BASIC FIBROBLAST GROWTH-FACTOR ON BONE ALLOGRAFTS - A STUDY USING BONE HARVEST CHAMBERS IN RABBITS

Bone grafts which have been supplemented with a growth factor might in corporate faster. In this study we investigated the effect of basic fi broblast growth factor (bFGF). Titanium bone harvest chambers were imp lanted bilaterally in the proximal tibia of rabbits. These chambers we re pierced by a transverse bone ingrowth canal from which 1 x 1 x 5 mm cancellous bone rods were repeatedly harvested at 5 weeks intervals. The bone rods to be used as allografts were frozen as ordinary bank bo ne, and then lipid-extracted. This treatment yields a graft which elic its less of an immunologic response than allografts which are only fro zen and thawed. Before implantation, the bone rods were soaked in a ce llulose gel containing 0.5 mu g/ml recombinant human bFGF or gel witho ut bFGF as a control. The grafts were then implanted pair wise (bFGF a nd control) in the chambers of recipient rabbits. These chambers were harvested after 2 weeks. Evaluation was made by Tc-MDP scintimetry, hi stomorphometry and histology. Upon histology new living tissue had fil led the grafted chambers entirely and partly replaced the graft. bFGF induced an increased amount of preosteoblastic tissue in the bFGF-trea ted grafts (p < 0.02), but there was no difference in the amount of os teoid or new bone.