Zoledronic acid combined with bone cement augmented pedicle screw for osteoporotic lumbar fusion

Objective 　To evaluate the clinical efficacy of zoledronic acid (ZA) combined with bone cement augmented pedicle screw for osteoporotic lumbar fusion. Methods 　A retrospective analysis of 56 patients with osteoporosis undergone lumbar internal fixation and fusion from Jul. 2015 to Dec. 2016 was carried out. The patients were randomly divided into treatment group and control group (28 each). All the operations were performed with pedicle screw fixation with poly methyl methacrylate (PMMA) bone cement augmentation, and postoperative anti osteoporosis basic treatment. Patients in treatment group were intravenously given zoledronic acid 5mg the 7th day after operation. Bone mineral density (BMD), the Oswestry disability index (ODI) score, inter vertebral fusion rate and cage subsidence rate were measured at different time points before and after operation. Results 　There was no significant difference in BMD between the two groups before operation (P>0.05), and the BMD was significantly higher in treatment group than in control group [(0.590±0.084)g/cm2 vs. (0.517±0.073)g/cm2, P 0.05). The cage subsidence rate was significantly lower in treatment group than in control group at 12-months after operation (P 0.05), and the ODI score declined obviously in the both groups at all the time points after operation compared with that before operation [22.22%(8/36) vs. 46.88%(15/32), P 0.05), but the ODI scores decreased significantly in treatment group than in control group at both 6-month and 12-month after operation (P<0.05). Conclusions 　Augmentation of pedicle screw fixation with bone cement can provide good early stability for osteoporotic spinal fusion. Combined use of ZA can improve the bone density, reduce cage subsidence rate, improve the life quality of patients, and do not affect the fusion rate. DOI: 10.11855/j.issn.0577-7402.2018.12.09