An immunohistochemical analysis of the temporal and spatial expression of growth factors FGF 1, 2 and 18, IGF 1 and 2, and TGFß1 during distraction osteogenesis
Distraction osteogenesis (DO) is a well
established surgical technique that generates new bone
by gradual distraction of two bony segments. In this
study, we investigated the temporal and spatial profile of
FGF 1, 2 and 18, IGF 1 and 2, and TGFß1 during
distraction osteogenesis using immunohistochemistry.
An osteotomy was performed on the right tibia of 13
white male New Zealand rabbits. After a delay of 7 days,
distraction was started at a rate of 0.25mm/12hrs for 3
weeks which was followed by a 3 week period of
consolidation. Immunohistochemical analysis was
performed on a weekly interval to determine the
expression of the growth factors. Staining of all growth
factors was apparent at various levels in the centre and
callus region in fibroblasts and chondrocyte cells. FGF2
however, showed continued high expression in
osteoblasts. Within two weeks after the end of
distraction all growth factors showed a reduction in
expression except for FGF18 which maintained high
levels of expression (up to 100% staining) throughout
the distraction and consolidation phases. The study
suggests that in comparison to the other investigated
growth factors, FGF18 may play in important role
throughout the entire process of distraction osteogenesis