Abstract:

Objective To investigate the effects of topical application of Duan Gu Gao on bony callus development in early stage after osteoporotic fracture. Methods Rat osteoporosis models were prepared by ovariectomy (ovariectomy group, n=45), and sham operations were performed in another 25 rats (normal control group).  Three months after operation, 5 rats were selected from each group, and model establishment was verified. The models of tibia fracture were constructed in the other 60 rats, and those in ovariectomy group were subdivided into osteoporosis control group (topical application of blank control ointment, n=20) and osteoporosis Duan Gu Gao group (topical application of San Qi Duan Gu Gao, n=20). The development of bony callus was detected by X ray, histomorphology and Micro-CT 1 week, 2 weeks, 3 weeks and 4 weeks after fracture. Results Three months after ovariectomy, Micro-CT revealed that rats in ovariectomy group had less bone trabecula, decreased space between bone trabecula and reduced bone density, and osteoporosis models were verified. Two to four weeks after fracture, the volume of bony callus in osteoporosis control group was larger, while the bone density 3 weeks after fracture was significantly lower that that in normal control group (P<0.05). After topical application of Duan Gu Gao, the volume of bony callus was similar to that in normal control group, and the bone density 3 weeks after fracture was significantly higher than that in osteoporosis control group (P<0.05). Histological observations indicated that the process from chondral callus to osseous callus delayed in ovariectomy group, which was improved by topical application of Duan Gu Gao. Conclusion Duan Gu Gao can improve the process from chondral callus to osseous callus in early stage after osteoporotic fracture, reduce the overdevelopment of chondral callus in early stage, and increase density of bone callus.

Key words: Duan Gu Gao, osteoporotic fracture, bony callus