Repair of rabbit segmental femoral defects by using a combination of tetrapod-shaped calcium phosphate granules and basic fibroblast growth factor-binding ion complex gel.

Abstract The effect of tetrapod-shaped alpha tricalcium phosphate granules (TB) as a scaffold combined with basic fibroblast growth factor (bFGF)-binding ion complex gel (f-IC gel) on neovascularization and bone regeneration was evaluated in segmental femoral defects of rabbits. The defects were stabilized using a plate with a polypropylene mesh cage (PMC) containing one of the following: PMC alone (PMC group), TB (TB group), TB and bFGF (TB/f group), TB and IC gel (TB/IC group), or TB and f-IC gel (TB/f-IC group). Four rabbits from each group were euthanized at 2 and 4 weeks after surgery. Histomorphometry showed that the number of vessels and the volume of new bone in the TB/f-IC group were significantly higher than those in the other groups at all time points. There were no differences in the extent of neovascularization and new bone formation between the TB and TB/f groups. These findings suggest that the combination of TB and f-IC gel facilitated both neovascularization and new bone formation in segmental femoral defects of rabbits. This combination may be of considerable use for treating segmental long bone defects.