Clinical observation of two bone cement distribution modes after percutaneous vertebroplasty for osteoporotic vertebral compression fractures.BACKGROUND
 Current findings suggest that percutaneous vertebroplasty(PVP) is a suitable therapeutic approach for osteoporotic vertebral compression fractures (OVCFs).  The present retrospective study aimed to investigate the differences in clinical efficacy and related complications between the two bone cement distribution modes.


 We retrospectively reviewed the medical records of the patients with single-segment OVCFs who underwent bilateral percutaneous vertebroplasty.  Patients were divided into blocky and spongy group according to the type of postoperative bone cement distribution.  Clinical efficacy and related complications was compared between the two bone cement distribution modes on 24 h after the operation and last follow-up.


 A total of 329 patients with an average follow up time of 17.54 months were included.  The blocky group included 131 patients, 109 females(83.2 %) and 22 males(16.8 %) with a median age of 72.69 ± 7.76 years, while the Spongy group was made up of 198 patients, 38 females(19.2 %) and 160 males(80.8 %) with a median age of 71.11 ± 7.36 years.  The VAS and ODI after operation improved significantly in both two groups.  The VAS and ODI in the spongy group was significantly lower than that in the blocky group, 24 h postoperatively, and at the last follow-up.  There were 42 cases (12.8 %) of adjacent vertebral fractures, 26 cases (19.8 %) in the blocky group and 16 cases (8.1 %) in the spongy group.  There were 57 cases (17.3 %) of bone cement leakage, 18 cases (13.7 %) in blocky group and 39 cases (19.7 %) in the spongy group.  At 24 h postoperatively and at the last follow-up, local kyphosis and anterior vertebral height were significantly corrected in both groups, but gradually decreased over time, and the degree of correction was significantly higher in the spongy group than in the block group.  The change of local kyphosis and loss of vertebral body height were also less severe in the spongy group at the last follow-up.


 CONCLUSIONS
 Compared with blocky group, spongy group can better maintain the height of the vertebral body, correct local kyphosis, reduce the risk of the vertebral body recompression, long-term pain and restore functions.
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