BACKGROUND:Related studies have shown that after kyphoplasty with bone cement injection, the vertebral height restoration is closely related to the injury time. Surgical timing also has an important influence on the incidence of postoperative complications. OBJECTIVE:To compare the clinical efficacy of kyphoplasty with bone cement injection at 2 and 2-4 weeks after thoracolumbar vertebral compression fractures, and to investigate the best timing for kyphoplasty. METHODS:Eighty-two thoracolumbar fracture patients, aged 55-85 years old, were included. Thirty-nine cases were subjected to kyphoplasty with bone cement injection within 2 weeks after injury. Another 43 cases were subjected to kyphoplasty with bone cement injection within 2-4 weeks after injury. The visual analog scale score, restoration of anterior and central vertebral height, volume and leakage of bone cement after treatment were compared between two groups. At 6 months after treatment, the daily activities of patients in the two groups were evaluated using Oswestry disability index. RESULTS AND CONCLUSION:Immediately and at the 6th month after treatment, the scores on the visual analog scale and the Oswestry disability index were lower than those before treatment (P < 0.05). The visual analog scale score immediately after treatment in the treatment group within 2 weeks was higher than that in the treatment group within 2-4 weeks (P< 0.05). After 6 months of treatment, there was no significant difference in the restoration rate of anterior and central vertebral height between these two groups, but the loss rate of the anterior and central vertebral height in the treatment group within 2 weeks was lower than that in the treatment group within 2-4 weeks (P< 0.05). Bone cement injection volume and leakage rate had no significant differences between two groups. These results demonstrate that patients appeared to have obvious pain after percutaneous kyphoplasty with bone cement injection within 2 weeks, but the percutaneous kyphoplasty with bone cement injection had smal influence on the short-term loss rate of vertebral height. Therefore, percutaneous kyphoplasty with bone cement injection with 2 weeks after injury is the optimal treatment timing for patients with thoracolumbar compression fractures.