Ring fractures of the base of the skull

Besides complete ring fracture, also incomplete fractures open to the front, back, or side(s) are discussed on the basis of 61 ring fractures of the base of the skull. The fractures were found in casualties from traffic accidents (car passengers, cyclists and motorcyclists, pedestrians), after falls and other accidents. In traffic accidents, compression, traction, hyperextension, extreme lateral movements, and torsional forces can lead to ring fractures. In falls, compression and traction are the main forces. A fall in one plane is also capable of producing an incomplete ring fracture. Incomplete ring fractures may show lateral emphasis. The greater fracture length is found on the impact side (e.g., in falls). In contrast to complete ring fractures, incomplete ring fractures are compatible with longer survival times. Ring fractures are to be classified under direct fractures. This does not exclude the possibility that overall deformations of the skull with bursts can partly determine the course of the fracture.     

The specificity of healing of fractures in the skull base

On the basis of actual observations we elucidated the main processes occurring in the reparation of fractures in the skull base. The specificity of reparation was shown to be conditioned by the structure of base bones and of surrounding tissues as well as by the nature of blood supply to them. Criteria are suggested for the determination if the lesions were inflicted in life time and when.     

Replica casting of the skull base

A new technique is described of obtaining a replica cast of the human skull base by making an epoxy resin case from a silicone rubber mould of the skull base. The replica provides an accurate and permanent record of the shape and dimensions of the base of the cranial cavity, together with the location and extent of any fractures of the skull. The method gives a good correlation between these characteristics and the type and extent of brain damage.     

多层螺旋CT诊断颅底骨折及其法医学应用价值

目的 比较多层螺旋CT三种重建方法在显示颅底骨折方面的差异,探讨其在法医学鉴定中的应用价值。方法 对40例颅脑外伤后怀疑颅底骨折的伤者进行多层螺旋CT扫描,然后将容积数据输入工作站进行横断面重建、多平面重建(MPR)和三维重建,三维重建采用表面显示法(SSD)。结果 24例颅前窝骨折,其中横断面显示骨折9例,MPR显示骨折24例,SSD显示9例;3组比较有显著性差异(P<0.001)。24例颅中窝骨折,横断面显示骨折15例,MPR显示骨折24例,SSD显示骨折4例;3组比较有显著性差异(P<0.001)。横断面重建和MPR均显示颅后窝骨折3例,两者无明显差异,SSD有1例显示。结论 SSD成像直观立体地显示了骨折的形态、走行、空间位置等情况,但对细小骨折显示不佳;多层螺旋CT检查可用于颅底骨折的法医学鉴定。     

Classification of fractures of the skull vault bones

The proposed classification of fractures of the skull vault bones is based on fracture morphogenesis. Russian and foreign published data on skull vault fractures and the authors' own observations allowed some analogies and helped develop a new classification.     

Experimental studies of skull fractures in infants

According to pediatric statements, falls from a standing position may cause skull fractures in infants without specific symptoms. Nearly every infant has at some time fallen from the changing table or the baby carriage, etc. From the forensic aspect it is the duty of experts to discuss the "battered child syndrome." Evidence given by the defendants concerning the height of the fall are unreliable. Experimental test series concerned with the stumbling height (82 cm in free fall) and three various types of floor-stone, carpet, and foam-backed linoleum -were carried out. In each case skull fractures were seen. In three cases the fractures crossed the sutures. Conclusions: (1) Each fall of an infant from the height of a table may cause a skull fracture, which may lead to death; (2) when child mishandling is suspected, all circumstances must be taken into consideration.     

Predilection sites of infantile skull fractures following blunt force

Previous investigations on calvarial fractures in infants have shown that the flexibility and displacement of the infant calvarial are not sufficient to avoid fractures as a result of fall. From a table height onto hard ground - and in special cases, fractures cannot be avoided even after falls onto softly cushioned ground. The skull fractures are located in paper-thin, transparent, single-layer bone areas without diploe. The results of previous literature were compared with investigations of the skulls of 82 infants (from neonates up to infants 14 months of age). Congenital fissures, cranioschisis, locally retarded ossification in the cranium and craniotabes are all weak points where fracture has a tendency to occur even if the impact is minor. These ossification defects are increased in the ossa parietalia, but can also be found in the os frontale or in the os occipitale. The location is not always the same but can be detected by locating the skull transparency using diaphanoscopy.     

Forensic-medical significance of the characteristics of gunshot perforating fractures of the skull bones

The study was made of gunshot perforating fractures of calvarial bones in cases of lethal perforating head wounds in long distance shots from a 9-mm Makarov gun. Morphological characteristics of inlet and outlet perforating fractures and bone fragments were found to differ. Gunshot fractures in calvarial bones inflicted by bullets from a 9-mm Makarov gun were studied in experiments with different kinetic energy. In low kinetic energy, bullets make oval holes on the outer table of the skull and round holes on the inner table with radial prominences on the walls of bullet channels, large bone fragments; in moderate kinetic energy--make round holes in the outer table and oval on the inner table with skew prominences on the walls of the outlet part of the channels, large and middle-sized flat bone fragments; in high kinetic energy injuries on both tables were round, prominences were cross, bone fragments were flat, small and middle-sized.     

The correlation between skull fractures and intracranial lesions due to traffic accidents

In this study, it was aimed to investigate the relationship between skull fractures and intracranial lesions following head injury. For this purpose, 500 cases, which were referred to the Third Committee of Council of Forensic Medicine in Istanbul due to traffic accidents by the courts of laws between 1998 and 2000, were examined retrospectively. They were categorized in 3 groups based on findings of their cranium x-rays and brain tomographies. 1- The cases who have fractures in skull bones with brain lesions 2- The cases who have fractures in skull bones with no brain lesions 3- The cases who have brain lesions with no skull fractures. They were examined in detail according to age, sex, localization of skull fractures and brain lesions, and if surgery was applied or not.Of the cases, 152 (30.4%) had only linear fractures, 69 (13.8%) had depressed fractures, 92 (18.4%) had linear fractures plus intracranial lesions, 49 (9.8%) had depressed fractures plus intracranial lesions and 138 (27.6%) had only intracranial lesions. The rate of intracranial lesion among the cases with the skull fracture was 38.9% (141/362), while the rate of skull fracture among the cases with the intracranial lesion was 50.3% (141/279) (P < 0.001). Male to female ratios were 2.4/1 for linear fractures, 5.2/1 for depressed fractures, and 3.5/1 for intracranial lesions. Linear fractures were more frequent among females whereas depressed fractures were often among males (chi2: 9.68, df: 4, p: 0.046). The mean age was 26.3. The rate of depressed fractures was higher the age groups of 0-30 years. (chi2: 16.28, df: 4, p: 0.003). Depressed fractures in the regions of frontal and parietal and, linear fracture in the regions of temporal and occipital were found at higher rates (P < 0.001).In conclusion, we reviewed skull fractures and/or intracranial lesions due to traffic accidents, and found depressed fractures to be more common among males whereas linear fractures to be more common among females and young males. In the male, the skull architecture is thicker and stronger than females and young males. We can state that presence of skull fractures lowers the incidence of intracranial lesions by lowering the intracranial pressure.     

Fracture pattern interpretation in the skull: differentiating blunt force from ballistics trauma using concentric fractures

There have been several anthropological studies on trauma analysis in recent literature, but few studies have focused on the differences between the three mechanisms of trauma (sharp force trauma, blunt force trauma and ballistics trauma). The hypothesis of this study is that blunt force and ballistics fracture patterns in the skull can be differentiated using concentric fractures. Two-hundred and eleven injuries from skulls exhibiting concentric fractures were examined to determine if the mechanism of trauma could be determined by beveling direction. Fractures occurring in buttressed and non-buttressed regions were examined separately. Contingency tables and Pearson's Chi-Square were used to evaluate the relationship between the two variables (the mechanism of trauma and the direction of beveling), while Pearson's r correlation was used to determine the strength of the relationship. Contingency tables and Chi-square tests among the entire sample, the buttressed areas, and the non-buttressed areas led to the null hypothesis (no relationship) to be rejected. Pearson's r correlation indicated that the relationship between the variables studied is greater than chance allocation.     

Longitudinal brainstem laceration associated with complex basilar skull fractures due to a fall: an autopsy case

This report describes an autopsy case of a rare longitudinal brainstem laceration associated with complex basilar skull fractures. The victim was a 40-year-old male who died immediately after falling from a roof (9.2m in height) of a factory onto a concrete floor. The postmortem examination revealed an incomplete ring fracture of the base of the skull with longitudinal fractures of the sphenoid (clivus of the dorsum sellae turcicae) and occipital bones, cerebral contusions in the frontal and temporal poles, a longitudinal brainstem laceration at the posterior median sulcus of the pons accompanied with multiple contusional hemorrhages in the brainstem and corpus callosum. Related blunt-force injuries were observed in the parieto-occipital region of the head, shoulder and upper back involving the fractures of the cervical and thoracic vertebrae, and sternum and ribs, indicating a huge impact to the occiput and subsequent impression of the vertebral column into the base of the skull due to violent anteroflexion of the neck, which caused the complex basilar skull fractures, contusions and longitudinal laceration of the brainstem.     

The colour of the human skull

The colour of the human skull was determined from 124 fresh skull samples using the tristimulus colour measurement system "Micro Color" and listed as The Commission Internationale de l'Eclairage (CIE) L*a*b*-values. The skulls were found to be relatively light (L*=72.5), nearly colourless on the a*-axis (a*=-7.4), and slightly yellow (b*=16.4). No difference was found between the colours of the outer and the inner surfaces of the skulls. Including a small number (n=8) of skulls from diabetic patients in the study, we detected no colour difference between the samples from diabetics and non-diabetics. However, a hitherto unknown correlation between the subjects' age and the yellowness (b*-value) of the skull could be demonstrated.     

Biomechanical fragility of the infant skull

Following previous experiments on postmortem skull fractures of infants, falls from 82-cm heights onto stone (A), carpet (B) and foam-backed linoleum (C), 35 further falling tests were carried out onto softly cushioned ground. In 10 cases a 2-cm thick foam rubber mat (D) was chosen and in 25 further cases a double-folded (8-cm-thick) camel hair blanket (E). Hence the results of altogether 50 tests could be evaluated. In test groups A-C on a relatively hard surface, skull fractures of the parietale were observed in every case; in test group D this fracture was seen in one case and in test group E in four cases. Measurements along the fracture fissures showed bone thickness of 0.1-0.4 mm. The fracture injuries originated in paper-thin single-layer bone areas without diploe, which can also be considered the preferred regions for skull fractures of older infants following falls from low heights. These results indicate that it is no longer possible to assume that the skull of infants is not damaged after falls from table height.     

Destruction of the skull during compression

The article contains the results of an experimental modeling of the destruction of the head of a bio-mannequin by compressing it between two blunt objects with the hard, flat and broad surfaces and by using a mechanical press (with slow motion) and freely falling object (with fast motion). The obtained results were compared with two opposite-direction blows by a similar object. The author studied the main regularities of fractures of the skull of the main shapes, i.e. ellipsoid or ovoid as well as spheroid and rhomboid shapes, at different directions of its compression (sagittal, lateral, diagonal, vertical or moving). A comparison of local, constructional and local-and-constructional zones of the inflicted fractures made it possible to establish the succession in the formation of the destruction of the skull at the static and dynamic compression types.     

Forensic medical assessment of the skull bone fractures owing to blow impacts depending on anatomical characteristics and a nature of a trauma-causing objects

Fractures in bones of the skull base (BSB) are preconditioned by the contact zone of interaction between the two below surfaces, i.e. the trace-forming one (object) and the trace-receiving one (bone). On the basis of their independent research, the authors suggest a set of criteria for the expert evaluation of fractures in BSB for the purpose of specifying the properties of the trauma-causing object, which is made with due regard for the anatomic specific features of the trauma zone.