Abstract: BACKGROUND: In recent years, the new method of curved vertebroplasty had been applied in clinic. It remains unclear whether there is any advantage over the traditional straight approach.  
OBJECTIVE: To investigate the advantages of unilateral multidirectional curved vertebroplasty in the treatment of thoracolumbar osteoporotic vertebral compression fractures by comparing with two kinds of straight vertebroplasty.
METHODS:  From January 2017 to December 2019, 85 patients with osteoporotic vertebral compression fractures undergoing thoracolumbar vertebroplasty in Guangzhou Huadu District People’s Hospital (Huadu Hospital, Southern Medical University) were enrolled in this study. There were 21 males and 64 females at the age of 65 to 91 years. They were divided into group A (unilateral multidirectional curved; n=25), group B (unilateral straight line; (n=32), and group C (bilateral straight line; n=28). The bone cement injection volume, leakage rate, refracture rate, and bone cement good distribution rate were compared among groups. The vertebral height compression ratio, local kyphotic Cobb angle, visual analogue scale at 1 day and 12 months after surgery, and Oswestry Dysfunction Index at 12 months were compared among the three groups. The protocols were approved by the Ethics Committee of Guangzhou Huadu District People’s Hospital (Huadu Hospital, Southern Medical University).  
RESULTS AND CONCLUSION: (1) The bone cement injection volume in group B was less than that in groups A and C (P < 0.05). The refracture rate was higher in group B than that in groups A and C (P < 0.05). The leakage rate in group A was lower than that in groups B and C (P < 0.05). The bone cement good distribution rate was higher in group A than that of group B. (2) The vertebral height compression ratio and local kyphotic Cobb angle of the three groups were lower after the operation than those before the operation (P < 0.05). The vertebral height compression ratio and local kyphotic Cobb angle of group A were lower than groups B and C at 12 months after operation (P < 0.05). (3) The postoperative visual analogue scale scores and Oswestry Dysfunction Index of the three groups were lower than those before the operation (P < 0.05). There was no significant difference in the visual analogue scale scores of the three groups at 1 day and 12 months after surgery (P > 0.05). There was no significant difference in the Oswestry Dysfunction Index at 12 months after the operation among the three groups (P > 0.05). (4) Both curved and straight vertebroplasty could achieve good short-term clinical results, but unilateral multi-directional vertebroplasty had more advantages in reducing bone cement leakage and maintaining vertebral height and Cobb angle.

Key words: vertebroplasty, spinal fractures, osteoporosis, thoracic vertebrae, lumbar vertebrae, visual analogue scale score, Oswestry disability index score, bone cement