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.     

Differential diagnosis of traumatic skull findings in infants: residues after vacuum extraction

If autopsy findings in an infant show traumatic changes on the skullcap, these are not always the result of a postnatal trauma due to child abuse, a fall or another accidental event. With regard to differential diagnosis a birth trauma should also be kept in mind, so that the history of the delivery is important. The spectrum of possible residues after vacuum extraction (circular fracture and/or elevation of the outer table of skull bones, subperiostal and intraossal haematoma, extradural and subdural haemorrhage) is demonstrated by means of three examples from the forensic autopsy material.     

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.     

What can a baby's skull withstand? Testing the skull's resistance on an anatomical preparation

A fall scenario is often given to explain the reason for a head injury to an infant. Mostly the examining doctor or forensic expert has to rely on his own experience and to appraise the situation to be consistent or not with his finds. An experiment carried out on an anatomical preparation showed that the skull of a newborn baby was able to repeatedly resist forces of up to 1000 N before breaking in. Even then the fracture lines followed the bony spikes (spiculae) from the ossification centers of the skull bones. If fractures are running across these spiculae there is reason to believe that high local force has been used, and a blow against a sharp edge must be considered.     

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.     

A case of traumatic osteomyelitis in a victim of child abuse

A premature black female infant born at 31 weeks gestation with history of 4 weeks in the newborn intensive care unit was discharged healthy to the care of her mother and was lost to follow-up. At age 4 months the infant was found dead in bed. There was no history of trauma and no external injuries were noted. There was no attempt at resuscitation. Coroner's autopsy showed acute bronchopneumonia, 3 partially healed skull fractures, a chronic subdural hematoma, chronic intracerebral hemorrhage, retinal hemorrhages, multiple healing rib fractures, a fractured fibula, and a partially healed fracture of the distal right radius. The fracture of the right radius showed a medullary abscess of the bone surrounded by scar tissue and containing pus and granulation tissue. We believe this inflicted fracture became secondarily infected by a hematogenous route. The final diagnosis of the cause of death was pneumonia secondary to multiple blunt force trauma, and the manner of death was diagnosed as homicidal. This is believed to be the first reported case of osteomyelitis in a context of child abuse.     

An unusual blunt force trauma pattern and mechanism to the cranial vault: Investigation of an atypical infant homicide

This case report presents an unusual fracture pattern in the cranium of a four-month-old infant indicative of child abuse. Upon postmortem examination, the infant presented with numerous bilateral linear cranial fractures running perpendicular to the sagittal suture with depressed and curvilinear fractures apparent on the supra-auricular surfaces of the cranium. Histological evidence indicates multiple traumatic events to the cranium. In addition, the stair-step pattern of a parietal fracture may represent multiple contiguous fractures from repeated loading of the head at different times with variation of the focal points of compressive force. Additionally, the left humerus, left radius, and left ulna have healing metaphyseal fractures, and the left ulna also has an antemortem diaphyseal fracture which resulted in the distal metaphysis being rotated 45 degrees medially. Integration of autopsy, anthropological, and neuropathological reports for this case suggest multiple inflicted injury episodes with a repeated atypical mechanism(s) to the cranial vault of the infant. During investigative interviews, the caretaker admitted to squeezing the infant's head and neck on multiple occasions to quiet the child. This reported abusive mechanism is consistent with the pattern of symmetric cranial fractures and soft tissue injuries indicating asphyxiation. This case report provides forensic investigators with a potential trauma mechanism to explore in cases when a similar pattern of cranial trauma is observed and highlights the need for greater research on fracture propagation and fracture healing in the infant cranium.     

Morphometrical analysis of retinal hemorrhages in the shaken baby syndrome

A morphometrical analysis of retinal hemorrhages was performed in cases of physical child abuse including the shaken baby syndrome and in controls (severe head injury, intravital brain death, non-traumatic intracranial hemorrhage, SIDS including cardiopulmonary resuscitation). The extent of the retinal hemorrhages was significantly different between both groups. In all cases of physical child abuse, massive retinal hemorrhages in at least one eye could be found ranging between a maximum value of 19.2 and 73.2% of the entire retinal area. In contrast, only two cases of the control group (severe head injury with skull fractures and intracranial bleeding following traffic accident or fall) showed slight hemorrhages of 3.33 or 1.18% of the retinal area but only in one eye. Therefore, the results provide evidence that massive intraretinal hemorrhages indicate violent shaking — in particular in association with other signs of physical child abuse.     

Discrimination of falls and blows in blunt head trauma: systematic study of the hat brim line rule in relation to skull fractures

In the discrimination of falls from blows in blunt head trauma, the hat brim line rule is one of the most often used criteria. The present study assesses the validity of the hat brim line rule for skull fractures and looks at other possible criteria. All autopsy cases were retrospectively analyzed on a 5-year period. Cases selected consisted of downstairs falls (n = 13), falls from one's own height (n = 23), and homicidal blows (n = 44). Results show that fractures above the hat brim line are more in favor of blows, while fractures in the hat brim line zone are more difficult to distinguish. The majority of fractures were located on the left side for homicidal blows and on the right side for falls. A higher average number of lacerations was revealed for homicidal blows. In conclusion, this study establishes three criteria in favor of blows: (i) localization of a wound above the hat brim line; (ii) left side lateralization; and (iii) a high number of lacerations.     

Skull Fracture with Brain Expulsion in a One-Level Jumping-Fall

Abstract:  Here presented is the case of a one-level jumping-fall with extensive skull fractures and brain expulsion. The body was found on the basement floor at the foot of the stairs. At the autopsy, the skull was extensively fractured, with about half of the brain expulsed several feet away from the body. The cause of death was established as a craniocerebral trauma with brain expulsion. The circumstances and manner of death were still unclear at that time. A low fall seemed very unlikely considering the severity of the skull and brain damage. The police investigation clearly revealed that the man, in a paranoid psychotic state, attacked his wife with a knife and then was witnessed by his children to have hit his head several times with a hammer. Afterwards, they saw him running to the top of the basement stairs and jumping to the bottom of the stairs head first.     

A Unique Type of Birth Trauma Mistaken for Abuse

Pediatric abusive head trauma is a challenging subject across many disciplines. Of particular importance is the identification of mimics of abuse, so cause and manner of death can be properly assigned. We present the case of suspected child abuse involving an infant who presented unresponsive to the hospital with hypoglycemia, hypothermia, and bilateral parietal fractures. An autopsy revealed fractures associated with organizing scalp hemorrhage and gross leptomeningeal congestion and hemorrhage. The fractures were circular with external displacement, rounded margins, and subperiosteal new bone formation indicative of healing. Birth records revealed vacuum assist and cesarean section delivery. Although vacuum extraction‐related injuries are typically cephalohematomas and/or linear fractures, the outbending and circular morphology of the fractures are consistent with vacuum extraction. Moreover, microscopic neuropathological examination revealed hemorrhagic purulent leptomeningitis. This unique case demonstrates the importance of considering birth trauma in the determination of cause and manner of death of an infant.     

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.     

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.     

Diffuse axonal injury by simple fall.

Diffuse axonal injury (DAI) is the second most common lethal head trauma after subdural hematoma and probably the most frequent cause of traumatic coma in the absence of an expanding intracranial mass lesion. Though it occurs most often in traffic accidents, it may occasionally result from falls from a height. Previously, it has not been associated with a simple fall or a fall of a distance not more than the victim's own height. We report herein a case of DAI from a simple fall.     

Age‐Dependent Fracture Characteristics of Rigid and Compliant Surface Impacts on the Infant Skull—A Porcine Model*,†

Abstract: This study documents skull fracture characteristics on infant porcine specimens under known impact conditions with respect to age and interface. A single impact causing fracture was conducted on the skull of porcine specimens aged 2–28 days (n = 76). Paired rigid and compliant impacts at the same energy were conducted at each specimen age. Impact force, impact duration, and fracture length were recorded. Energy required to initiate skull fracture increased with specimen age. For a given energy, impact of the skull with a compliant interface caused more fracture damage than with a rigid interface for specimens aged under 17 days, but less damage for specimens aged 24–28 days. The documentation of energy required to cause fracture and resulting fracture propagation with respect to impact interface and age may be of critical importance in forensic investigations of infant skull trauma.     

Quasi-static and dynamic bending stress of the pediatric femur for producing a femoral fracture

At the Institute of Forensic Medicine of the University of Heidelberg, in the years 1986-1988 thigh loading tests were conducted in order to produce fractures in a total of 28 cadavers of babies and children who had died at ages ranging from 1 day to 6 years. In 18 tests a universal strength testing machine was used and each thigh was loaded quasi-statically from the outside with a blunt edge applied to the middle of the femur, bending it to the point of fracture. The loading velocity amounted 50 mm/min with a defined support distance. The breakage load amounted to 470 N in a 6-day-old baby and increased about evenly up to 2920 N in a 6-year-old child; however, in a newborn 2720 N was needed and in a 15-month-old child, 5700 N. The total deformation way ranged from 16 to 60 mm. The main types of fracture that occurred were: complete and incomplete transverse fractures, oblique fractures, Messerer fractures, and spongiosa fractures. Ten children ranging in age from 2 months up to 27 months were submitted to dynamical thigh loading by means of a failing weight impactor and a horizontal impactor. Only in one case did a transverse fracture occur, when the lateral thigh impacted on an edge at a falling height of 70-93 cm. The forces set up amounted to 320-600 N with the falling weight impactor and to 2370 N with the horizontal impactor. These results suggest that fracture of the femur does not occur if a baby or small child falls from a changing table or from an adult's arm.     

Fracture patterns on the infant porcine skull following severe blunt impact

The objective of this study was to document patterns of fracture on infant porcine skulls aged 2-28 days (n = 57) because of a single, high energy blunt impact to the parietal bone with rigid (nondeformable) and compliant (deformable) interfaces. Fracture patterns were mapped using Geographic Information System software. For the same generated impact force, the rigid interface produced more fractures than the compliant interface for all ages. This study also showed that this increased level of impact energy versus an earlier study using a lower energy resulted in new sites of fracture initiation and also caused previously defined fractures that propagate into an adjacent bone. Several unique characteristics of bone and diastatic fracture were documented as a function of specimen age, impact energy, and interface. These data describe some baseline characteristics of skull fracture using an animal model that may help guide future studies from forensic case files.     

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。     

Computational Study of Fracture Characteristics in Infant Skulls Using a Simplified Finite Element Model

Skull fracture characteristics are associated with loading conditions (such as the impact point and impact velocity) and could provide indication of abuse or accident‐induced head injuries. However, correlations between fracture characteristics and loading conditions in infant and toddler are ill‐understood. A simplified computational model representing an infant head was built to simulate skull responses to blunt impacts. The fractures were decided through a first principal strain‐based element elimination strategy. Simulation results were qualitatively compared with test data from porcine heads. This simplified model well captured the fracture pattern, initial fracture position, and direction of fracture propagation. The model also very well described fracture characteristics found in studies with human infant cadaveric specimens. A series of parametric studies was conducted, and results indicated that the parameters studied had substantial effects on fracture patterns. Additionally, the jagged shapes of sutures were associated with strain concentrations in the skull.     

Healed Depressed Parasagittal Skull Fractures—A Feature of Archaic Australian Aboriginal Remains

The skeletal remains of eight Australian Aboriginals with healed depressed skull fractures were examined. Male:female ratio 5:3; age range 20‐60 yrs. Burial dates by ¹⁴C dating in three cases were 500 years BP (n = 2) and 1300 BP. There were 13 healed depressed skull fractures manifested by shallow indentations of cortical bone and thinning of diploe, with no significant disturbance of the inner skull tables. Nine (69%) were located within 35 mm of the sagittal suture/midline. These lesions represent another acquired feature that might be helpful in suggesting that a skull is from a tribal Aboriginal individual and may be particularly useful if the remains are represented by only fragments of calvarium. While obviously not a finding specific to this population, these healed injuries would be consistent with the possible results of certain types of conflict behavior reported in traditional Aboriginal groups that involved formalized inflicted blunt head trauma.