McElhaney J H, Hopper R H, Nightingale R W, Myers B S
Department of Biomedical Engineering, Duke University, Durham, North Carolina, USA.
J Neurotrauma. 1995 Aug;12(4):669-78. doi: 10.1089/neu.1995.12.669.
Basilar skull fractures comprise a broad category of injuries that have been attributed to a variety of causal mechanisms. The objective of this work is to develop an understanding of the biomechanical mechanisms that result in basilar skull fractures, specifically focusing on mandibular impact and neck loading as potential mechanisms. In the characterization of the injury mechanisms, three experimental studies have been performed. The first study evaluated the response of the base of the skull to midsymphysis loading on the mental protuberance (chin) of the mandible. Five dynamic impacts using a vertical drop track and one quasi-static test in a servohydraulic test frame have been performed. In each test, clinically relevant mandibular fractures were produced but no basilar skull fractures were observed. The second study assessed the fracture tolerance of the base of the skull subject to direct loading on the temporomandibular joint in conjunction with tensile loading imposed locally around the foramen magnum to simulate the effect of the ligaments and musculature of the neck. Among four specimens that sustained either complete or incomplete basilar skull ring fractures remote from the sites of load application, the mean load at fracture was 4300 +/- 350 N. Energy to fracture was computed in three of those tests and averaged 13.0 +/- 1.7 J. Injuries produced were consistent with clinical observations that have attributed basilar skull ring fractures to mandibular impacts. In the third series of experimental tests, loading responses resulting from cranial vault impacts were investigated using unembalmed human cadaver heads and ligamentous cervical spines. Multiaxis load cells and accelerometers, coupled with high-speed digital video, were used to quantify impact dynamics. The results of these experiments suggest that while there is a greater probability of cervical spine injury, basilar skull ring fractures can result when the head is constrained on the impact surface and the inertia of the torso drives the vertebral column onto the occiput.
颅底骨折是一类广泛的损伤，其成因多种多样。本文的目的是深入了解导致颅底骨折的生物力学机制，特别关注下颌撞击和颈部负荷这两种潜在机制。在损伤机制的研究中，进行了三项实验研究。第一项研究评估了颅底对下颌骨颏隆突（下巴）中点联合处加载的反应。使用垂直下落轨道进行了五次动态撞击，并在伺服液压试验框架中进行了一次准静态试验。在每次试验中，均产生了临床上相关的下颌骨骨折，但未观察到颅底骨折。第二项研究评估了颅底在颞下颌关节直接加载并结合枕骨大孔周围局部施加拉伸负荷以模拟颈部韧带和肌肉组织作用时的骨折耐受性。在四个标本中，有三个在远离加载部位处发生了完全或不完全的颅底环形骨折，骨折时的平均负荷为4300 +/- 350 N。其中三项试验计算了骨折能量，平均为13.0 +/- 1.7 J。所产生的损伤与临床观察结果一致，临床观察将颅底环形骨折归因于下颌撞击。在第三系列实验测试中，使用未防腐的人类尸体头部和韧带完整的颈椎研究了颅顶撞击产生的加载反应。使用多轴载荷传感器和加速度计，结合高速数字视频，对撞击动力学进行量化。这些实验结果表明，虽然颈椎损伤的可能性更大，但当头部在撞击表面受到限制且躯干的惯性将脊柱推向枕骨时，可能会导致颅底环形骨折。
