Introduction VEGF is a well known angiogenic peptide which has been shown to be central to endochondral ossification. Secondary fracture healing involves a combination of intramembranous and endochondral ossification. VEGF has been recently shown to be chemotactic for osteoblasts and chondroclasts. We therefore set out to examine the temporal and spatial expression of VEGF and its receptors in fracture healing. We report here the preliminary findings of our study.

Methods A closed mid-shaft fracture was produced in the right femora of nine 12 week old Sprague Dawley rats, stabilised by an intramedullary K-wire. The rats were sacrificed at one, two and four weeks. Through the use of immunohistochemistry, RT-PCR and in situ hybridisation.

Results We show that at each of the time points, VEGF is expressed in all of the cell types involved in fracture healing; the inflammatory cells, the osteo-progenitor cells,chondroblasts,chondrocytes,osteoblasts and osteoclasts as well as fibroblasts. We further show that there is persistent expression of VEGF in chondrocytes at four weeks.

Conclusions Our findings are consistent with the hypothesis that events in fracture healing reflect the processes that take place at the growth plate during embryonic development.