Department of Kinesiology and Physical Education, Canada.
Department of Kinesiology and Physical Education, Canada; Department of Health Sciences, Wilfrid Laurier University, Waterloo, Ontario, Canada.
Med Eng Phys. 2024 Aug;130:104194. doi: 10.1016/j.medengphy.2024.104194. Epub 2024 Jun 13.
Intervertebral disc herniation is not a common injury in the adolescent population, but the correlation between trauma and herniation warrants concern. Previous research demonstrated the capacity for rapid internal pressurization to reduce the mechanical integrity of the intervertebral disc's annulus fibrosus, even in the absence of fracture. The purpose of this study was to modify previous internal pressurization procedures towards a more transferable injury model, then investigate the capacity for these procedures to damage the mechanical integrity of the annulus fibrosus. Porcine cervical motion segments with intact facet joints were confined between a vice and force plate under 300 N of static compression, then a single, manual, rapid internal pressurization was delivered. Posterolateral annulus samples were extracted and situated in a 180° peel test configuration, exposing the interlamellar matrix of samples to separations of 0.5 mm/s, until complete separation of the sample occurred. Multilayer tensile testing was performed on superficial and mid-span samples of annulus by applying uniaxial tension of 1 %/s to 50 % strain. Compared to unpressurized controls, rapid pressurization causing fracture resulted in reduced lamellar adhesion and increased toe-region stress and strain properties in the annulus. Morphological assessment reported similar fracture patterns between endplate fractures achieved in the present experiment and endplate fractures documented in human patients. Mechanical plus morphological results suggest that rapid internal pressurization resulting in endplate fracture may represent a potent mechanism for subsequent damage to the intervertebral disc.
椎间盘突出症在青少年人群中并不常见，但创伤与椎间盘突出之间的相关性值得关注。先前的研究表明，即使没有骨折，快速内部加压也会降低纤维环的机械完整性。本研究的目的是对先前的内部加压程序进行修改，以建立一种更具可转移性的损伤模型，然后研究这些程序对纤维环机械完整性的破坏能力。完整的关节突关节的猪颈椎运动节段在 300N 静态压缩下被夹在虎钳和力板之间，然后进行单次手动快速内部加压。提取 posterolateral 环样并置于 180°剥离测试配置中，使样品的层间基质以 0.5mm/s 的速度分离，直到样品完全分离。通过将 1%/s 的单轴拉伸施加到 50%应变，对浅层和中层环样进行多层拉伸测试。与未加压的对照相比，导致骨折的快速加压会导致层间粘附力降低，并增加环的趾区应力和应变特性。形态评估报告称，本实验中获得的终板骨折与人类患者记录的终板骨折之间存在相似的骨折模式。力学加形态学结果表明，导致终板骨折的快速内部加压可能是椎间盘后续损伤的一个有力机制。
