[A biomechanical evaluation of the effects of XW630 on the healing of experimental fracture].

The aim of this study was to evaluate whether tetracycline-estrone (XW630) plays a role in the healing of fracture. 120 rabbits were divided into 4 groups and subjected to osteotomies at the middle of both radials, and they were given XW630, estrone (E2), tetracycline (T) and 0.9% sodium chloride (C) respectively after operation by means of intramuscular injection (M) or local injection(L) in the fracture region. The biomechanical properties, including bending and compression, and the biochemical changes were tested at 30 days, 60 days and 90 days after osteotomy. The results showed that the bending stress and compression stress in the XW630(M) group were significantly higher than those in other groups at different periods after osteotomy. At 30 days after osteotomy, the bending ultimate stress in the XW630(M) group was 80% higher than that in group C, 76% higher than that in group E2, and 69% higher than that in group T. At 90 days after osteotomy, the bending ultimate stress in XW630(M) group increased to 80% of that of the normal radius, and it was 30% higher than that of group C, 34% higher than that of group E2 and 19.5% higher than that of group T. The biochemical changes corresponded with the changes biomechanical properties. These data suggest that XW630 given by intramuscular injection plays an obvious role in accelerating the healing of fracture. The medicine given by intramuscular injection is obviously more effective than that locally injected.