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

Abstract

Percutaneous vertebroplasty, comprising of the injection of polymethylmethacrylate (PMMA) into vertebral bodies, is an efficient procedure to stabilize osteoporotic compression fractures as well as other weakening lesions. Besides fat embolism, cement leakage is considered to be one of the major and most severe complications during percutaneous vertebroplasty. The viscosity of the PMMA during injection plays a key role in this context. It was shown in vitro that the best way to lower the risk of cement leakage is to inject the cement at higher viscosity, which is requires high injection forces. Injection forces can be reduced by applying a newly developed lavage technique as it was shown in vitro using human cadaver vertebrae. The purpose of this study was to prove the in vitro results in an in vivo model. The investigation was incorporated in an animal study that was performed to evaluate the cardiovascular reaction on cement augmentation using the lavage technique. Injection forces were measured with instrumentation for 1 cc syringes, additionally acquiring plunger displacement. Averaged injection forces measured, ranged from 12 to 130 N and from 28 to 140 N for the lavage group and the control group, respectively. Normalized injection forces (by viscosity and injection speed)showed a trend to be lower for the lavage group in comparison to the control group (P = 0.073). In conclusion, the clinical relevance on the investigated lavage technique concerning lowering injection forces was only shown by trend in the performed animal study. However, it might well be that the effect is more pronounced for osteoporotic vertebral bodies.

Cardiovascular changes after PMMA vertebroplasty in sheep: the effect of bone marrow removal using pulsed jet-lavage

“…The same effect of injection pressure reduction could be shown as a side investigation of this study [18].…”

A Review of PMMA Bone Cement and Intra-Cardiac Embolism

“…However, PVP technique is much more prone to adverse cement leaks than kyphoplasty, because the PMMA is injected in a liquid state in case of PVP and the cement would flow through bone path of least resistance [3]. The popularity of the procedure is increasing and used more frequently [7].…”

Lavage prior to vertebral augmentation reduces the risk for cement leakage

“…The study showed a reduction of injection forces that allows the use of more viscous PMMA cement. This lowers potentially the risk of cement leakage and fat embolization and makes vertebral augmentation safer [29]. It could be shown in a sheep model that lavage of the bone marrow prior to VP prevents cardiovascular complications, reduces injection forces and allows a better control of cement distribution pattern with less leakage [30,31].…”

“…This leads theoretically to a reduction of fat embolism by reducing the intravertebral resistance and injection forces [28]. In a cadaveric feasibility study Benneker et al tested the lavage technique in 24 intact vertebral bodies harvested from five osteopenic or osteoporotic human cadaver spines [29]. The study showed a reduction of injection forces that allows the use of more viscous PMMA cement.…”