Bou-Francis Antony, López Alejandro, Persson Cecilia, Hall Richard M, Kapur Nikil
School of Mechanical Engineering, University of Leeds, UK
Department of Engineering Sciences, Uppsala University, Sweden.
J Biomater Appl. 2014 Oct;29(4):582-94. doi: 10.1177/0885328214537858. Epub 2014 Jun 9.
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.
了解椎体成形术中骨水泥的注入行为并准确预测骨水泥在椎体内的分布极具挑战性。由于缺乏标准化方法，我们提出了一种新方法，使用可重复且具有病理代表性的流动模型来研究骨水泥特性对注入行为的影响。这些模型被限制在上部玻璃窗和下部铝板之间，先填充骨髓替代物，然后在骨水泥混合后4、6和8分钟，以恒定流速（3毫升/分钟）注入市售骨水泥（SimplexP、Opacity+、OsteopalV和Parallax）。使用称重传感器测量施加在注射器柱塞上的力并计算峰值压力。使用摄像头监测注入过程中的骨水泥流动，并在骨水泥到达模型边界时计算以下参数：到达边界的时间、填充面积和圆度。峰值压力与临床椎体成形术中报告的压力相当，并且随着注入时间呈现类似的增加。该研究突出了骨水泥配方和模型结构对注入行为的影响，表明组成/粒径相似的骨水泥具有相似的流动行为，而引入缺陷会减少到达边界的时间、填充面积和圆度。所提出的方法通过在不同时间间隔对骨水泥扩散进行可视化和定量分析，为快速、可靠地区分各种骨水泥配方提供了一种新工具。
