Enhancement of new bone formation by hematoma at fracture site.

In order to study the osteogenetic potential of fracture hematoma, pellets which contain fluid components extracted from human fracture hematoma were transplanted to the subperiosteum of the rat parietal bone. Furthermore we have examined the effect of the fluid extract of the fracture hematoma and factors partially purified from this extract on DNA synthesis of cultured osteoblast-like cell line MC3T3E1. Implantation of the pellets containing the fluid extract did not promote new bone formation regardless of the presence of periosteum. This extract, in contrast, enhanced DNA synthesis of osteoblast-like cell line MC3T3E1 in a concentration dependent fashion. When this fluid extract was partially purified by ion exchange chromatography, the highest peak in DNA synthesis of MC3T3E1 was attained at 38mM NaCl, and the second highest peak at 290mM. These results suggest that the soluble extract from fracture hematoma contains growth factors which promote osteoblast proliferation, but does not possess osteogenetic potential.