Objective:To compare the antiosteoporosis effect of conventional treatment and conventional treatment combined with Denosumab after percutaneous kyphoplasty (PKP) for osteoporotic vertebral compression fractures (OVCF).Methods:A retrospective cohort study was conducted to analyze the clinical data of 211 patients with OVCF admitted to the Second Affiliated Hospital of Soochow University from September 2020 to September 2022. All the patients were female, aged 56-90 years [(71.4±8.1)years]. The bone mineral density T-score of the lumbar spine was (-2.6±1.0)SD before operation. Fracture segments included T 1-T 9 in 45 patients, T 10-L 2 in 146, and L 3-L 5 in 69. Of all, 174 patients were treated with single-segment surgery, 25 with two-segment surgery and 12 with surgery involving three or more segments. According to the wishes of the patients, 107 patients were treated with daily oral administration of calcium and active Vitamin D after PKP (conventional treatment group) and 104 patients with Denosumab combined with the conventional treatment after PKP (Denosumab therapy group). The bone mineral density T-scores of the lumbar spine of the two groups were compared before surgery and at the last follow-up. The visual analogue scale (VAS) and Oswestry disability index (ODI) before surgery, at 3 days, 6 months after surgery, and at the last follow-up were evaluated and the refracture rate after surgery was detected. Possible adverse effects after medication during anti-osteoporosis treatment were observed in two the groups. Results:All the patients were followed up for 12-24 months [(13.5±2.0)months]. Before surgery, the bone mineral density T-score of the lumbar spine was (-2.7±1.1)SD in the Denosumab therapy group and (-2.5±0.8)SD in the conventional treatment group ( P>0.05). At the last follow-up, the bone mineral density T-score of the lumbar spine was (-2.1±1.1)SD in the Denosumab therapy group, significantly higher than (-2.5±0.9)SD in the conventional treatment group ( P<0.05). In the Denosumab therapy group, the bone mineral density T-score of the lumbar spine at the last follow-up was significantly increased compared to that before surgery ( P<0.01), while there was no significant difference in the conventional treatment group ( P<0.05). Before surgery and at 3 days after surgery, the VAS scores and ODI values were (8.5±0.9)points, (2.8±0.8)points, 48.7±4.8 and 25.6±4.0 in the Denosumab therapy group, which was not statistically different from those in the conventional treatment group [(8.5±1.3)points and (2.8±0.9)points, 47.9±7.0 and 25.9±3.7] ( P>0.05). At 6 months after surgery and at the last follow-up, the VAS scores and ODI values were (2.2±0.8)points, (1.7±0.8)points, 24.2±3.6 and 23.2±4.1 in the Denosumab therapy group, significantly lower than those of the conventional treatment group [(2.8±0.9)points, (2.8±1.1)points, 26.4±3.2 and 27.3±4.0] ( P<0.01). The VAS scores at each time point after surgery in both groups decreased significantly compared with those before surgery ( P<0.05). The VAS scores continued to decrease after surgery in the Denosumab therapy group ( P<0.05), while no significant difference was found among those at different time points in the conventional treatment group ( P>0.05). The ODI values at each time point after surgery in both groups significantly decreased compared to those before surgery ( P<0.05). The ODI values continued to decrease after surgery in the Denosumab therapy group ( P<0.05), while in the conventional treatment group, no significant difference was found between those at 6 months after surgery and those at 3 days after surgery ( P>0.05) and they were improved at the last follow-up compared with those at 3 days after surgery ( P<0.05). The refracture rate after surgery was 6.7% (7/104) in the Denosumab therapy group, significantly lower than 16.8% (18/107) in the conventional treatment group ( P<0.05). No serious complications were observed during the antiosteoporosis period in either group. Conclusion:Compared with daily oral administration of Calcium and active Vitamin D after PKP, the conventional treatment combined with Denosumab after PKP can effectively increase the bone density, relieve pain continuously, improve functional restoration, and reduce the risk of refracture in OVCF patients.