Germaneau A, Vendeuvre T, Saget M, Doumalin P, Dupré J C, Brémand F, Hesser F, Brèque C, Maxy P, Roulaud M, Monlezun O, Rigoard P
Institut Pprime UPR 3346, CNRS - Université de Poitiers - ISAE-ENSMA, France.
Institut Pprime UPR 3346, CNRS - Université de Poitiers - ISAE-ENSMA, France; Department of Orthopaedic Surgery and Traumatology, CHU, Poitiers, France.
Clin Biomech (Bristol). 2017 Nov;49:139-144. doi: 10.1016/j.clinbiomech.2017.09.007. Epub 2017 Sep 13.
Burst fractures represent a significant proportion of fractures of the thoracolumbar junction. The recent advent of minimally invasive techniques has revolutionized the surgical treatment of this type of fracture. However mechanical behaviour and primary stability offered by these solutions have to be proved from experimental validation tests on cadaveric specimens. Therefore, the aim of this study was to develop an original and reproducible model of burst fracture under dynamic impact.
Experimental tests were performed on 24 cadaveric spine segments (T11-L3). A system of dynamic loading was developed using a modified Charpy pendulum. The mechanical response of the segments (strain measurement on vertebrae and discs) was obtained during the impact by using an optical method with a high-speed camera. The production of burst fracture was validated by an analysis of the segments by X-ray tomography.
Burst fracture was systematically produced on L1 for each specimen. Strain analysis during impact highlighted the large deformation of L1 due to the fracture and small strains in adjacent vertebrae. The mean reduction of the vertebral body of L1 assessed for all the specimens was around 15%. No damage was observed in adjacent discs or vertebrae.
With this new, reliable and replicable procedure for production and biomechanical analysis of burst fractures, comparison of different types of stabilization systems can be envisaged. The loading system was designed so as to be able to produce loads leading to other types of fractures and to provide data to validate finite element modelling.
爆裂骨折在胸腰段交界处骨折中占相当大的比例。近年来微创技术的出现彻底改变了这类骨折的手术治疗方式。然而，这些治疗方案所提供的力学行为和初始稳定性必须通过对尸体标本的实验验证测试来证明。因此，本研究的目的是建立一种原创且可重复的动态冲击下爆裂骨折模型。
对24个尸体脊柱节段（T11 - L3）进行了实验测试。使用改良的夏比摆锤开发了一种动态加载系统。在冲击过程中，通过高速摄像机的光学方法获得节段的力学响应（椎体和椎间盘的应变测量）。通过X射线断层扫描对节段进行分析，验证爆裂骨折的产生。
每个标本的L1均系统性地产生了爆裂骨折。冲击过程中的应变分析突出显示了由于骨折导致的L1的大变形以及相邻椎体的小应变。所有标本L1椎体的平均压缩约为15%。相邻椎间盘或椎体未观察到损伤。
有了这种用于爆裂骨折产生和生物力学分析的新的、可靠且可重复的方法，就可以设想对不同类型的稳定系统进行比较。加载系统的设计使其能够产生导致其他类型骨折的载荷，并提供数据以验证有限元模型。
