| Objective To investigate the effect of parathyroid hormone combined with alendronate on osteophyte formation and fracture healing in rats with osteoporotic fractures. Methods Seventy-five female SD rats were randomly divided into 5 groups: sham operation group, ovariectomized group, parathyroidism group, alendronate group, and combination drug group, with 15 rats in each group, Bilateral ovariectomy was performed. After 4 weeks of the operation, intramedullary fixation of the right femoral shaft was performed to establish the animal model of rat osteoporotic fractures. The fracture healing, biomechanics and bone mineral density (BMD) of the osteophyte were observed. Serum levels of VEGF and BMP-2 were detected. The morphology of the epiphysis was observed. VEGF expression in osteophytes was detected. Results The fracture healing score, osteophyte biomechanical strength, osteophyte BMD, serum BMP-2 and VEGF concentrations, osteophyte VECF protein expression, and epiphyseal microvascular count were significantly lower in the ovariectomized group than those in the sham operation group (P<0.05). The above indicators increased in the parathyroidism group, the alendronate group, and the combination group. Among them, the increase in combination group was the most significant (P<0.05). Conclusion Parathyroid hormone combined with alendronate up-regulates BMP-2 expression, promotes osteophyte angiogenesis in rats with osteoporotic fracture, increases BMD, improves biomechanical strength and bone histomorphology, and accelerates fracture healing via mediation of VEGF. |