Frequency and pattern of skull base and vault fracture in isolated head trauma

In the literature, the number of studies on cases of injury due to isolated head trauma is limited. In addition, there are very few studies and publications on skull base and vault fractures in the forensic literature. This study aims to investigate the frequency and pattern of skull base and vault fractures in individuals exposed to isolated fatal and non-fatal head trauma.

This retrospective cross-sectional and descriptive study includes 1260 cases who were injured due to isolated head trauma during the 10-year period between Jan 1, 2010 and Nov 30, 2019. In cases of fatal head trauma, only cases in which isolated head injury was reported as the cause of death in the autopsy report were included. In cases of non-fatal head trauma, cases with life-threatening injuries in areas other than the head (such as chest, abdomen, and extremities), and cases without cranial CT images and reports on the Hospital Information Management System were excluded from the study. Our cases were divided into 2 groups: fatal head trauma (n = 783) and non-fatal head trauma (n = 477). All cases (n = 1260) were evaluated retrospectively in terms of age, gender, cause of trauma, skull base fracture, skull vault fracture, facial bone fracture, intracranial injury, and scalp injury. While examining the distribution of categorical variables, Chi-square tests were applied and the appropriate one was reported from Pearson Chi-square test, Yates Chi-square test, Fisher's exact test, and likelihood ratio test. The coefficients of the models, the odds ratio of the factors in the model, 95% confidence interval, Hosmer-Lemeshow statistics, and the correct classification rate were accorded. The statistical significance level in the study was accepted as p < 0.05.

Base fractures were observed in 87.5% of cases with fatal head trauma and in 32.3% of cases with non-fatal head trauma. Vault fracture was observed in 88.4% of cases with fatal head trauma and in 75.3% of cases with non-fatal head trauma. The middle fossa was more fractured than the anterior and posterior fossa. Anterior and middle fossa combined fracture and anterior, middle, and posterior fossa combined fracture were significantly higher in the fatal head trauma than in the non-fatal head trauma. Base fracture was strongly associated with death (odd ratio = 15.253, p < 0.001) and vault fracture did not have a statistically significant effect on death (odd ratio = 1.052, p = 0.805). While intracranial injury was found to be significantly higher in patients with base fractures (p < 0.001), no significant difference was found in patients with vault fractures (p = 0.229).

In conclusion, it was observed that skull base fractures were frequently associated with especially fatal head traumas and this fracture was strongly associated with death. In the antemortem and postmortem examination of cases injured due to head trauma, skull base fracture should be investigated with high care. In cases with fractures, a detailed examination should be performed in terms of the size and type of the fracture and intracranial lesions that may be associated with the fracture.