The effect of striking angle on the buckling mechanism in blowout fracture
The effect of striking angle on the buckling mechanism in blowout fracture
复制标题
DOI：
10.1097/01.prs.0000218792.70483.1f
复制
发表时间：
2006-06-01
影响因子：
3.6
通讯作者：
Nakajima, Tatsuo
中科院分区：
文献类型：
--
作者：
Nagasao, Tomohisa;Miyamoto, Junpei;Nakajima, Tatsuo
背景：屈曲机制与水力机制一起被广泛认为是井喷裂缝的一种机制。虽然已有很多关于屈曲机理的研究，但都没有考虑到冲击力的方向。由于眶底与水平面不平行，冲击力方向的不同可能会影响最终的断裂模式。本研究旨在探讨轨道底板的断裂模式是否受冲击力方向的影响。方法：在模拟8个干颅骨的工作站上制作三维模型，并从3个不同角度（向上0度、15度和30度）对每个模型的眶缘施加冲击力。利用有限元分析，作者计算了合成应力超过骨屈服准则的区域宽度。该宽度被称为“理论裂缝宽度”，因为理论上该区域预计会发生裂缝。然后，在三种不同的冲击力角度下，对理论裂缝宽度进行分组比较。最后，通过实际颅骨模型的实验验证了理论宽度的有效性。结果：当冲击力为向上30度时，理论裂缝宽度最大。结论：对于屈曲机制而言，向上用力时眶底骨折发生的区域比水平用力时更大。这一发现将有助于井喷裂缝裂缝宽度的预测。
Background: The buckling mechanism is widely accepted as a mechanism of blowout fractures, along with the hydraulic mechanism. Although many studies have been performed related to the buckling mechanism, none of them have taken the direction of the striking force into consideration. As the orbital floor is not parallel to the horizontal plane, a difference in the striking force direction might affect resultant fracture patterns. The present study aims to investigate whether fracture patterns in the orbital floor were influenced by the striking force direction in terms of the buckling mechanism.Methods: The authors produced three-dimensional models on a workstation simulating eight dry skulls and applied striking forces on the orbital rim of each model from three different angles (0, 15, and 30 degrees in the upward direction). Using finite element analysis, the authors calculated the width of the area where the resultant stresses exceed the bone's yielding criterion. The width was termed the "theoretical fracture width" because, theoretically, fracture was expected to occur in the area. Then, the authors compared the theoretical fracture width in groups with the three different striking force angles. Finally, the validity of the theoretical width was verified with an experiment on actual skull models.Results: The theoretical fracture width was the greatest when the striking force was directed at 30 degrees in the upward direction.Conclusions: For the buckling mechanism, fracture would occur in a wider area of the orbital floor when striking force was directed upward than when the force was horizontally directed. This finding would be helpful in predicting fracture width in blowout fractures.