Effects Of ZA On Rat Osteoblasts And Osteoclasts In Vitro And Its Clinical Application In Thoracolumbar OVCF

Part I Effects of zoledronate acid on rat osteoblasts and osteoclasts in vitro[Objective]This study is aimed to observe the effect of ZA on rat osteoblasts and osteoclasts cultured in vitro,and to explore the drug concentration of ZA that inhibits osteoclasts while not affecting the growth of osteoblasts.To explore the toxic mechanism of ZA on osteoclasts.[Methods]Osteoblasts were isolated from the calvaria of neonatal SD rats,osteoclasts were cultured from the marrow monocytes of femoral bone of SD rats aged 2 weeks.Osteoblasts were identified by ALP staining and alizarin bordeaux staining,while osteoclasts were identified by TRAP staining and bone resorption lacunae examination.CCK-8 cell proliferation detection reagent and Annexin V-FITC/PI cell apoptosis detection reagent are used to detect the toxic effects of ZA on osteoblasts,and the toxic effect on osteoclasts was tested based on the number and area of osteoclasts and the number of bone resorption lacunae.The distribution of NFATc1 was determind by cell immunofluorescence.[Results]Cells cultured from the calvaria of neonatal SD rats were tested positive by ALP staining and alizarin bordeaux staining.Cells cultured from the marrow monocytes of femoral bone were tested positive by TRAP staining and bone absorption lacunae examination.ZA has no significant effect on the proliferation and apoptosis of osteoblasts in the low concentration range,but has significant effect on the number and size of osteoclasts and the number of bone resorption lacunae.Compared with control group,ZA treatment significantly reduced the nuclear distribution of NFATc1 in osteoclasts.[Conclusion]ZA treatment with low concentration has no obvious toxic effect on osteoblasts cultured in vitro,but can significantly inhibit the differentiation and activity of osteoclasts.Therefore clinically,selecting appropriate administration mode and dosage can inhibit bone absorption while not affecting bone formation.ZA affects the differentiation and function of osteoclasts by reducing the distribution of NFATc1 in the nucleus.Part ? Clinical efficacy of PKP combined with zoledronic acid in the treatment of thoracolumbar OVCF[Objective]To discuss the clinical efficacy of percutaneous kyphoplasty(PKP)combined with zoledronic acid(ZA)in the treatment of thoracolumbar osteoporotic vertebral compression fractures(OVCF).[Methods]A total of 63 patients treated with PKP in the First Affiliated Hospital of Suzhou University were included in this study during August 2016 to July 2017.Twenty-eight patients in ZA group received intravenous drip of zoledronic acid 2 days after operation and long-term oral administration of Calcium D and Rocaltrol.Thirty-five patients in the control group only received long-term oral administration of Calcium D and Rocaltrol after surgery.The VAS score,ODI score,height of anterior vertebral body,bone density were compared.Number of adverse events and re-fracture after operation were recorded.[Results]The VAS and ODI score of two groups after surgery were significantly decreased.Those of ZA group were significantly lower than control group one year after operation(p<0.05).The bone density of ZA group was significantly higher than that of control group one year after operation(p<0.05).The height of anterior vertebral body was significantly higher than that before operation(p<0.05),with no significant difference between two groups(p>0.05).1 case of adjacent vertebral fracture in ZA group and 2 cases of adjacent vertebral fracture in control group occurred within 1 year after operation.There were 2 cases of fever and 1 case of fatigue when zoledronic acid was used.[Conclusion]Zoledronic acid increases bone density,relieves pain and improves daily living abilities in patients with PKP.The adverse reactions are mild and all patients were well tolerated.PKP combined with zoledronic acid in the treatment of OVCF is worthy of clinical promotion.