Effect of Vertebral Shell on Injection Pressure and Intravertebral Pressure in Vertebroplasty

Abstract

The presence of vertebral shell seems to be important for intravertebral pressure. However, the intravertebral shell pressure adds very little to the injection pressure.

The effect of pulsed jet lavage in vertebroplasty on injection forces of PMMA bone cement: an animal study

“…This fact could lead to higher injection forces in the control group of the in vitro study compared to the in vivo situation and thus providing a significant difference between the groups. No significant result on the injection forces herein support the conclusion of a related study [5], that the intravertebral pressure and the present bone marrow only contribute a small percentage to the injection force that has to be applied on the plunger during cement injection. Higher homogeneity of the injection speed values measured for the lavage group in comparison to the control, which reflects the subjective feeling of the surgeon, may lead to the conclusion that the lavage technique leads to a more standardized procedure in cement augmentation.…”

Novel methodology for assessing biomaterial–biofluid interaction in cancellous bone

“…The pore spacing of the Osteo surrogates (0.89 ± 0.03 mm) was comparable to that reported in the literature for human osteoporotic vertebral cancellous bone [23][24][25][26][27], suggesting that the surrogates were pathologically representative. The boundary of the surrogates simulated the vertebral shell which confines the flow and controls the intravertebral pressure, significantly affecting the filling pattern [28]. This is consistent with previous studies in which Loeffel et al [13] sealed their surrogates with a reusable acrylic enclosure, while Baroud et al [11] and Mohamed et al [14] coated their surrogates with a 1 mm layer of acrylic cement to mimic the vertebral shell.…”

A new cannula to ease cement injection during vertebroplasty

“…ID Internal diameter, OD outside diameter friction in the cannula, and less than 5% of the pressure is required to force the cement to infiltrate the trabecular bone and displace the bone marrow [4,11]. Once the theoretical findings are combined with the data obtained from experimental studies that confirm that intravertebral pressure is very small, the solution seems rather obvious [4,11,14,15,26]. Since the pressure bottleneck during the injection occurs in the cannula, its geometry must be changed.…”

“…The injection pressure during vertebroplasties was reported to exceed 1,500 kPa, which approaches the limit of what can be applied manually [4,5,7,11,28,29]. As a consequence of the excessive pressure, premature termination of the procedure may become necessary resulting in insufficient filling of the vertebra.…”

“…There are two methods employed to overcome the problem of high pressure: (1) to use a pressure applicator device, which increases the pressure that is applied to the cement [4,5,7,11,18,29], and (2) to increase the recommended liquid to powder ratio of cement, which lowers cement viscosity [12,17,18,23]. However, these methods introduce additional risks.…”