BACKGROUND: Percutaneous vertebroplasty (PVP) is usually used for osteoporotic thoracolumbar fractures,which has various advantages such as easy to operate, short operation time, less trauma, rapid recovery,analgesic effect and so on. But its application is restricted due to nerve compression symptoms and pulmonary embolism caused by bone cement leakage. Thereafter, how to reduce the leakage of bone cement is an issue of concern.OBJECTIVE: To investigate the relationship between the lumbar quantitative computed tomography (QCT) values and contrast agent dispersion in osteoporotic thoracolumbar fractures. METHODS: Sixty cases of osteoporotic thoracolumbar fractures undergoing PVP were enrolled, and received QCT examination before surgery, and contrast agent was injected intraoperatively. X-ray examination was conducted to detect the bone mineral density, contrast agent dispersion and leakage of bone cement, and the relationship between the lumbar QCT values and contrast agent dispersion as well as leakage of bone cement.RESULTS AND CONCLUSION: (1) There were 110 vertebral fractures, and 74 vertebrae with contrast agent diffusing more than vertebral midline, accounting for 67.3%. There was significant difference in the contrast agent dispersion among groups (P < 0.05). (2) The bone cement leakage showed no significant difference among groups after injected with bone cement by unilateral or bilateral approach (P > 0.05). (3) These results suggest that contrast agent dispersion in osteoporotic thoracolumbar fractures has a certain relationship with the lumbar QCT values, and lumbar QCT values with more contrast agent dispersion, but the lumbar QCT values have no correlation with bone cement leakage. Therefore, choosing a appropriate approach based on the QCT values and contrast agent dispersion can reduce leakage and improve the safety of PVP.