Temporal bone fracture under lateral impact: biomechanical and macroscopic evaluation

Abstract

This work was conducted to study biomechanical properties and macroscopic analysis of petrous fracture by lateral impact. Seven embalmed intact human cadaver heads were tested to failure using an electrohydraulic testing device. Dynamic loading was done at 2 m/s on temporal region with maximal deflection to 12 mm. Anthropometric and pathological data were determined by pretest and posttest computed tomography images, macroscopic evaluation, and anatomical dissection. Biomechanical data were obtained. Results indicated the head to have nonlinear structural response. The overall mean values of failure forces, deflections, stiffness, occipital, and frontal peak acceleration were 7.1 kN (±1.1), 9.1 mm (±1.8), 1.3 kN/mm (±0.4), 90.5 g (±22.5), and 65.4 g (±16), respectively. The seven lateral impacts caused fractures, temporal fractures in six cases. We observed very strong homogeneity for the biomechanical and pathological results between different trials in our study and between data from various experiments and our study. No statistical correlation was found between anthropometric, biomechanical, and pathological data. These data will assist in the development and validation of finite element models of head injury.

Head/skull injury potential of empty 0.5-l beer glass bottles vs. 0.33-l Coke bottles

“…The sometimes high differences in reported fracture thresholds are presumably the consequence of the variability of the used measuring/testing methods and conditions. Research shows that the experimentally determined fracture tolerance of the frontal bone is at 4.0 kN [11], of the occipital bone at 13.6 kN [18], of the parietal bone at 5.8-17.0 kN [2], and of the temporal bone at 6.1 kN [10]. Our results show that a blow with the side aspect of a 0.5-l beer or 0.33-l Coke bottles to an object the size and form of the human skull (and covered with a skin-like, soft layer) reaches a maximum force transmission of approximately 1.3 kN and thus cannot fracture cranial bone.…”

“…Medical literature shows a variety of tolerance limits of the skin [3,6,7,[14][15][16][17] and cranial bones [2,10,11,18]. The sometimes high differences in reported fracture thresholds are presumably the consequence of the variability of the used measuring/testing methods and conditions.…”

“…The sometimes high differences in reported fracture thresholds are presumably the consequence of the variability of the used measuring/testing methods and conditions. Research shows that the experimentally determined fracture tolerance of the frontal bone is at 4.0 kN [ 11 ], of the occipital bone at 13.6 kN [ 18 ], of the parietal bone at 5.8–17.0 kN [ 2 ], and of the temporal bone at 6.1 kN [ 10 ].…”

Beer stein blast to the head a rare case of combined blunt and sharp force trauma

“…The fact that the shape and number of fractured beer stein pieces was unknown limited a forensicbiomechanical reconstruction. However, based on previous studies [10][11][12][13][14][15] and taking into account the high fracture threshold of the parietal region of the skull [16][17][18][19], a forcefully performed strike to the head with the mechanically robust bottom is likely to have caused the skull fracture at hand. A blast with the side of the beer stein transfers slightly less energy than with the bottom [11].…”

“…If one compares the maximum possible force transmission in beer stein blasts to the head with the fracture tolerances of the skull bones [16][17][18][19][20][21], it can be stated that it is at least possible, regardless of the striking technique, to cause skull fractures. Thus, the occurrence of a skull fracture is plausible in this case.…”