Assessing cement injection behaviour in cancellous bone: An in vitro study using flow models

Abstract

Understanding the cement injection behaviour during vertebroplasty and accurately predicting the cement placement within the vertebral body is extremely challenging. As there is no standardized methodology, we propose a novel method using reproducible and pathologically representative flow models to study the influence of cement properties on injection behaviour. The models, confined between an upper glass window and a lower aluminium plate, were filled with bone marrow substitute and then injected (4, 6 and 8 min after cement mixing) with commercially available bone cements (SimplexP, Opacity+, OsteopalV and Parallax) at a constant flow rate (3 mL/min). A load cell was used to measure the force applied on the syringe plunger and calculate the peak pressure. A camera was used to monitor the cement flow during injection and calculate the following parameters when the cement had reached the boundary of the models: the time to reach the boundary, the filled area and the roundness. The peak pressure was comparable to that reported during clinical vertebroplasty and showed a similar increase with injection time. The study highlighted the influence of cement formulations and model structure on the injection behaviour and showed that cements with similar composition/particle size had similar flow behaviour, while the introduction of defects reduced the time to reach the boundary, the filled area and the roundness. The proposed method provides a novel tool for quick, robust differentiation between various cement formulations through the visualization and quantitative analysis of the cement spreading at various time intervals.

Changes in the drug release pattern of fresh and set simvastatin-loaded brushite cement

“…This was confirmed by the non-arrival of the cement to the border of the box in all samples, in combination with the relatively low injection forces [40,56,57].…”

“…The materials were fully injectable, with a clinically relevant extrusion force ( Figure 3) [39,41] and did not show signs of filter pressing or phase separation. The injected cement exhibited a uniform ball-like shape (Figure 4), and while there is no literature data on specific sphericity values of CPC cements, it could be assumed that this shape would be beneficial in terms of a reduced risk for leakage in clinical applications such as vertebroplasty [55], as has been the hypothesis for PMMA cements [40,56,57].…”

A Review of PMMA Bone Cement and Intra-Cardiac Embolism

“…Severe leakage occurred in 83% of the samples suggesting monitoring during injection to avoid complications and minimize possible life-threatening risks to the patients [18]. The leakage pilfering to the nearby vasculature may reach distant locations of the body, such as the heart, and result in cardiac embolism [19].…”

“…Hydrogen peroxide used as hemostatic agent in arthroplasty has been shown to adversely affect the material properties of PMMA [19].Properties of PMMA cements such as time and shear rate are essential for examining cement flow behavior [23]. In addition, a greater chance of embolism and reduction in arterial oxygenation resulting in circulatory failure was observed in the hand-mixed PMMA when compared to the vacuum-mixed PMMA [24].…”

Novel methodology for assessing biomaterial–biofluid interaction in cancellous bone

“…A modified formulation for Simplex P was prepared using 10 mL liquid monomer, 9 g PMMA powder and 1 g BaSO4. The cement was mixed [20] then transferred into a 10 mL syringe and injected at 4 and 8 min from mixing (SP4 and SP8, respectively) to assess the effect on the flow behaviour. The same syringe, needle and cement were used to perform the two injection time points into separate surrogates.…”