Staged-injection procedure to prevent cement leakage during vertebroplasty: an in vitro study

Epidural leaks or canal intrusion are often found in vertebroplasty, which can lead to several complications. To the best of our knowledge, this is the first report on using two-stage injection procedure in vertebroplasty to reduce cement leakage rate.

Fifty cadaveric vertebrae (L1-L5) were harvested from 10 osteoporotic lumbar spines. The age of the female donors ranged from 60 to 72 y; the bone mineral density (BMD) of the vertebrae ranged from 0.226 to 0.631 g/cm(2). Polymethylmethacrylate (PMMA) was injected into vertebral bodies by either novel two-stage injection (1 mL cement was injected at first stage and another 4 mL cement was injected at second stage after the cement solidified) or standard conventional injection procedure. After injection, all vertebral bodies (VBs) were checked for cement leakage into spinal canal by vision and fluoroscopy. Cement leakage rates were recorded.

The two-stage injection procedure resulted in a significant decrease in the epidural or canal leakage rate (P = 0.032). In addition, the paravertebral leakage rate was significantly higher in two-stage injection procedure group (48%) than in conventional injection procedure group (16%). However, no significant difference was found for the total cement leakage rate between the two groups.

Compared with conventional procedure, the two-stage injection procedure in vertebroplasty decreased incidence of epidural and canal leaks. The first-stage injecting PMMA can be a barrier to the epidural extravasation of cement during vertebroplasty. Further in vivo and clinical researches are needed to evaluate the new procedure.