The classification of bone fissures]

A classification of bone fissures, suggested by the authors, is based on the results of their studies of bone destruction. Relationship between the fissures and bone tissue structural arrangement, and the sequence of the fissure emergence and development, starting from a microfissure (at the level of bone plates) progressing to a major fissure, resulting in final destruction of the bone, underlie this classification.     

Identification of traumatic injury in burned cranial bone: an experimental approach.

Interpreting patterns of injury in victims of fire-related deaths poses challenges for forensic investigators. Determining manner of death (accident, suicide or homicide) using charred remains is compounded by the thermal distortion and fragmentation of soft and skeletal tissues. Heat degrades thin cranial structures and obscures the characteristic signatures of perimortem ballistic, blunt, and sharp force trauma in bone, making differentiation from thermal trauma difficult. This study documents the survivability and features of traumatic injury through all stages of burning for soft tissue reduction and organic degradation of cranial bone. Forty cadaver heads were burned in environments simulating forensic fires. Progression of thermal degradation was photographically documented throughout the destructive stages for soft tissues and bone to establish expected burn sequence patterns for the head. In addition to testing intact vaults, a percentage were selectively traumatized to introduce the variables of soft tissue disruption, fractures, impact marks, and incisions throughout the cremation process. Skeletal materials were recovered, reconstructed, and correlated with photographs to discern burn patterns and survivability of traumatic features. This study produced two important results: (1) Identification of preexistent trauma is possible in reconstructed burned cranial bone. Signatures of ballistic (internal and external bevel, secondary fractures), blunt force (impact site, radiating fractures), and sharp force (incisions, stabs, sectioning) survive the cremation process. (2) In non-traumatized specimens, the skull does not explode from steam pressure but does fragment as a result of external forces (collapsed debris, extinguishment methods) and handling. The features of both results are sequentially described throughout the progression of thermal destruction.     

Identification of traumatic injury in burned cranial bone: an experimental approach.

Interpreting patterns of injury in victims of fire-related deaths poses challenges for forensic investigators. Determining manner of death (accident, suicide or homicide) using charred remains is compounded by the thermal distortion and fragmentation of soft and skeletal tissues. Heat degrades thin cranial structures and obscures the characteristic signatures of perimortem ballistic, blunt, and sharp force trauma in bone, making differentiation from thermal trauma difficult. This study documents the survivability and features of traumatic injury through all stages of burning for soft tissue reduction and organic degradation of cranial bone. Forty cadaver heads were burned in environments simulating forensic fires. Progression of thermal degradation was photographically documented throughout the destructive stages for soft tissues and bone to establish expected burn sequence patterns for the head. In addition to testing intact vaults, a percentage were selectively traumatized to introduce the variables of soft tissue disruption, fractures, impact marks, and incisions throughout the cremation process. Skeletal materials were recovered, reconstructed, and correlated with photographs to discern burn patterns and survivability of traumatic features. This study produced two important results: (1) Identification of preexistent trauma is possible in reconstructed burned cranial bone. Signatures of ballistic (internal and external bevel, secondary fractures), blunt force (impact site, radiating fractures), and sharp force (incisions, stabs, sectioning) survive the cremation process. (2) In non-traumatized specimens, the skull does not explode from steam pressure but does fragment as a result of external forces (collapsed debris, extinguishment methods) and handling. The features of both results are sequentially described throughout the progression of thermal destruction.     

Do bone elasticity and postmortem interval affect forensic fractographic analyses?

Forensic fractographic features of bone reliably establish crack propagation in perimortem injuries. We investigated if similar fracture surface features characterize postmortem fractures. Experimentally induced peri- and postmortem fractures were used to assess if fractographic features vary as bone elasticity decreases during the postmortem interval (PMI). Thirty-seven unembalmed, defleshed human femoral shafts from males and females aged 33–81 years were fractured at varying PMIs with a drop test frame using a three-point bending setup and recorded with a high-speed camera. Vital statistics, cause of death, PMI length, temperature, humidity, collagen percentage, water loss, fracture energy, and fractography scores were recorded for each sample. Results showed that fractographic features associated with perimortem fractures were expressed in PMIs up to 40,600 accumulated degree hours (ADH), or 60 warm weather days. Hackle was the most consistently expressed feature, occurring in all fractures regardless of ADH. The most variable characteristics were wake features (78.4%) and arrest ridges (70.3%). Collagen percentage did not correlate strongly with ADH (r = −0.04, p = 0.81); however, there was a strong significant correlation between ADH and water loss (r = 0.74, p < 0.001). Multinomial logistic regression showed no association between fractographic feature expression and ADH or collagen percentage. In conclusion, forensic fractographic features reliably determine initiation and directionality of crack propagation in experimentally induced PMIs up to 40,600 ADH, demonstrating the utility of this method into the recent postmortem interval. This expression of reliable fractographic features throughout the early PMI intimates these characteristics may not be useful standalone features for discerning peri- versus postmortem fractures.     

Mechano- and morphogenesis of gunshot fractures in the flat bones

Gunshot fractures in flat bones, bullet defects in the continuum were studied in experiment. The laws of gunshot fracture formation were formulated. In far distance, bullet has a direct and radial blow action. The direct blow induces comminution and disintegration of the bone tissue with dislocation of bone fragments; radial blow potentiates bone destruction. Morphological characteristics of gunshot fractures of flat bones depend on the force of the direct and radial impact action and can be used for estimation of the far shot distance, kinetic energy and shape of the head of the shell.     

Patterns in the destruction of the ribs

The article deals with study of some patterns of long spongy rib bone destruction in static and dynamic load of thorax. Model of bone destruction is suggested. Multiple microfissures preceding formation of complete bone destruction were detected in border areas with fracture. They have peculiar mosaic depending on load conditions. Microfissure localization in relation to osteon structure of rib cortical lamina was stated. The results of investigations may have theoretical and applied value both in medicolegal and clinical traumatology.     

Reconstructing the Sequence of Events Surrounding Body Disposition Based on Color Staining of Bone*

Abstract: Literature regarding bone color is limited to determining location of primary and secondary dispositions. This research is the first to use bone color to interpret the sequence of events surrounding body disposition. Two scenarios were compared—bones buried and then exposed on the ground surface and bones exposed then buried. Forty juvenile pig humeri with minimal tissue were used in each scenario with an additional 20 controls to determine if decomposing tissue affects bone color. Munsell Color Charts were used to record bone color of surface and 2.5 cm cross‐sections. Results reveal five main surface colors attributed to soil, sun, hemolysis, decomposition, and fungi. Fungi on buried bones suggests prior surface exposure. Cross‐sections of strictly buried bones are identical to buried then exposed bone, stressing the importance of bone surface analysis. Cross‐sectioning may help verify remains have been exposed then buried. Decomposition of excess tissue creates minimal color staining.     

Genetic markers in human bone: II. Studies on ABO (and IGH) grouping.

A combination absorption-elution, two-dimensional absorption-inhibition procedure was used to determine the ABH antigen composition of a series of human bone specimens of known ABO type that had been aged up to nine months under dry and humid conditions at ambient temperature, 37 degrees C, and 56 degrees C; at ambient temperature in dry and wet soil; and buried in soil outdoors. Grouping data for the separate elution and inhibition testing, as well as for the combination procedure, are given. The combination method was found to be a highly reliable procedure for bone tissue ABH typing. Some data on microbial contaminants of human bone specimens aging in soil, and their effects on ABH typing results, are presented. No direct correlation between the properties of microbial contaminants and specific changes in the ABH antigenic composition of aging bone tissue specimens could be ascertained. Data on IGH antigen determination and on the quantitation of immunoglobulin G (IgG) in human bone tissue extracts indicated that immunoglobulin levels were typically too low to expect routinely successful Gm antigen testing results. However, these factors can sometimes be determined in fresh bone tissue extracts, particularly if the extracts are concentrated.     

Morphology of fractures of long tubular bones in children upon trauma due to solid blunt objects

Morphologic features of diaphyseal fractures of lond tubular bones in different age groups in childhood were studied experimentally on biodummy using direct stereomicroscopy (MBC-9). Blow effect was induced by solid blunt objects at the middle diaphyseal parts at a right angle. A series of specific morphologic features which help to diagnose the specific bone tissue lesions in different fracture zones as well as in different age periods was obtained. Experimental data were confirmed by expert observations which proves the possibility of using these specific morphologic features of diaphyseal fractures of long tubular bones in childhood for medicolegal purposes.     

Destruction of a long tubular bone in combined mechanical and thermal exposures

Recent data on character of long tubular bone destruction in different combinations of exposure to mechanical and thermal factors are given. Patterns of bone lesions peculiar to high temperature effect were determined. Qualitative values of temperature effect on morphologic pattern of mechanical bone injury were obtained.     

Macroscopical estimation of the post mortem interval (PMI) and exclusion of the forensically relevant resting period--a comparison of data presented in the literature with recent osteological findings

The aim of the present study was to determine to what extent macroscopical parameters mentioned in the literature are suitable for the estimation of the post mortem interval (PMI) and particularly for the exclusion of the forensically relevant resting period for recent bone material. The macroscopical examination of recent bone material with a known PMI showed that only one published parameter (relics of adipocere in the cross section of the compacta) was consistent with our findings for this particular resting period (27-28 years). Other macroscopical parameters presented in the literature were contradictory to the results observed in this study. Among those are the rigidity of bones, the adhesion of soft tissue, the filling of the marrow cavity, and the permeation of the epiphyses with adipocere. Concerning the exclusion of the forensically relevant resting period, a similar result was observed. This study identified some diagnostic findings in bones with a resting period of less than 50 years which according to the literature should only be present after a resting period of more than 50 years. These features included the lack of macroscopical traces of adipocere, degradation of the compacta surface, detachment of the cortical substance, the ability of bone to be broken with bare hands, and superficial usures. Moreover, in one-third of our cases we identified some intra-individual differences not previously described in the literature. In addition to the other results, those intra-individual differences make an estimation of the PMI more difficult. However it should be noted that those published parameters were collected from bone material which was stored in a "relatively arid sand-grit-clay soil of the broken stone layer of Munich". The bones in the present study were stored in acidic and clayey-loamy soil, partly with lateral water flow. In conclusion, the present study demonstrates that one should use caution estimating the post mortem interval and excluding the forensically relevant resting period, even when all available results are considered.     

Forensic imaging of projectiles using cone-beam computed tomography

In patients with gunshot injuries, it is easy to detect a projectile within the body due to the high-density of the object, but artefacts make it difficult to obtain information about the deformation and the exact location of the projectile in surrounding tissues. Cone-beam computed tomography (CBCT) is a new radiological imaging modality that allows radio-opaque objects to be localised and assessed in three dimensions. The full potential of the use of CBCT in forensic medicine has not yet been explored.In this study, three different modern projectiles were fired into the heads of pig cadavers (n = 6) under standardised conditions. Tissue destruction and the location of the projectiles were analysed separately using CBCT and multi-slice computed tomography (MDCT).The projectiles had the same kinetic energy but showed considerable differences in deformation behaviour. Within the study groups, tissue destruction was reproducible. CBCT is less severely affected by metallic artefacts than MDCT. Therefore CBCT is superior in visualising bone destruction in the immediate vicinity of the projectile and projectile deformation, whereas MDCT allows soft tissue to be evaluated in more detail.CBCT is an improved diagnostic tool for the evaluation of gunshot injuries. In particular, it is superior to MDCT in detecting structural hard-tissue damage in the immediate vicinity of high-density metal projectiles and in identifying the precise location of a projectile in the body.     

Fractography of the long tubular bones of the lower extremities in trauma by blunt objects

New data on micromorphological signs of fracture of long tubular bones in normal distribution and transformation of deforming forces are presented. Fractographic signs of bone for each destructive stage, signs of repeated trauma are singled out. Interrelationship between bone microstructure and conditions of its destruction is stated.     

The use of SEM/EDS analysis to distinguish dental and osseus tissue from other materials

With increasing frequency, relatively small, fragmentary evidence thought to be osseous or dental tissue of human origin is submitted to the forensic laboratory for DNA analysis with the request for positive identification. Prior to performing DNA analysis, however, it is prudent to first perform a presumptive test or "screen" to determine whether the questioned material may be eliminated from further consideration. When material is shown not to be consistent with bone/teeth, DNA testing is not performed. When such determinations cannot be made from gross morphological features, elemental analysis can be indicative. This presumptive test is made possible by applying scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS) in conjunction with an X-ray spectral database recently developed by the FBI laboratory. This database includes spectra for many different materials including known examples of bone and tooth from many different contexts and representing the full range of taphonomic conditions. Results of SEM/EDS analysis of evidence can be compared to these standards to determine if they are consistent with bone and/or tooth and, if not, then what the material might represent. Analysis suggests that although the proportions and amounts of calcium and phosphorus are particularly important in differentiating bone and tooth from other materials, other minor differences in spectral profile can also provide significant discrimination. Analysis enables bone and tooth to be successfully distinguished from other materials in most cases. Exceptions appear to be ivory, mineral apatite, and perhaps some types of corals.     

Bone weathering patterns of metatarsal v. femur and the postmortem interval in Southern Ontario

Twenty-five defleshed pig femora and 25 metatarsals were placed outdoors and observed over 291 days to establish: (1) bone weathering patterns for use in estimating time since death in Southern Ontario and (2) whether larger (femora) or smaller (metatarsals) bones provide a better indicator of time since death. Pig hind limbs were observed to determine a timeline for decomposition of soft tissues during the fall and winter. Ambient air temperature, humidity, precipitation, sunlight, soil pH, and freezing and thawing were considered as factors affecting the breakdown of bone. Weathering patterns were observed based on the extent of bleaching, amount of periosteum and soft tissues present, as well as the appearance of greasiness, cracking and flaking of cortical bone. Both entomological activity and climatic conditions affected soft tissue decomposition. Animal activity affected both the process of bone weathering and soft tissue decomposition, causing variability in sample decomposition and bone breakdown. The variation in microenvironment, partially caused by soil composition, introduced variability in bone weathering rates. Four bone weathering stages were established based on patterns observed. Femora proved to be more resilient and showed more degrees of change due to weathering, thus proving to be a better indicator of time since death than metatarsals.     

Analysis of elemental composition of bone tissue by the method of laser mass spectrometry to diagnose of human medico-biological characteristics

The results of analysis of elemental composition of human bone tissue by the method of laser mass spectrometry are published for the first time. This method makes it possible to detect about 20 elements of bone tissue at once. Quantitative analysis of 1 microgram/gram of an element contained in bone tissue is sufficient to diagnose of human medico-biological characteristics by this method.     

Chronic Alcohol Abuse Leads to Low Bone Mass with No General Loss of Bone Structure or Bone Mechanical Strength,

Chronic alcohol abuse (CAA) has deleterious effects on skeletal health. This study examined the impact of CAA on bone with regard to bone density, structure, and strength. Bone specimens from 42 individuals with CAA and 42 individuals without alcohol abuse were obtained at autopsy. Dual‐energy X‐ray absorptiometry (DEXA), compression testing, ashing, and bone histomorphometry were performed. Individuals with CAA had significantly lower bone mineral density (BMD) in the femoral neck and significantly lower bone volume demonstrated by thinner trabeculae, decreased extent of osteoid surfaces, and lower mean wall thickness of trabecular osteons compared to individuals without alcohol abuse. No significant difference was found for bone strength and structure. Conclusion: CAA leads to low bone mass due to a decrease in bone formation but with no destruction of bone architecture nor a decrease in bone strength. It is questionable whether this per se increases fracture risk.     

Gun-shot fractures of the flat bones: mechanisms of development

We studied experimental gun-shot fractures in the flat bones due to slow-speed bullets. We have found common features information of gun-shot fractures. Fragmentation of the bone tissue occurs within a Herz cone surrounded by ring-shape fissures as a result of crossing over of subsurface and median fissures. Invasion of the bullet into the bone thickness is accompanied with shift abruption of bone fragments, their parallel transfer, rotation and radial movement. In the injury with slow-speed blunt-pointed bullets the fragments move, as a rule, by parallel transfer and rotation. In the injury with sharp-pointed bullets, of a key importance is radial movement of the fragments changing characteristics of the gun-shot fracture.     

Brain injury after survived gunshot to the head: reactive alterations at sites remote from the missile track

Gunshot wounds to the brain usually lead to acute respiratory arrest or death after a brief survival period, even in cases involving only slight direct tissue damage. It can be assumed therefore that the damage extends beyond the zone of recognizable destruction and hemorrhages. To determine the true extent of the tissue injury resulting from gunshot wounds to the brain, we carried out microscopic investigations for reactive changes (emigration of leukocytes and macrophages, axonal expression of beta-amyloid precursor protein (beta-APP) in 10 cases of gunshot wound to the narrow channel of the brain with survival times >2h. Demonstration of leukocytes expressing naphthol AS-D chloroacetate esterase activity in the brain tissue at the border of the missile track established the vitality of the gunshot effect. The presence of macrophages (CD68-epitope) allowed demarcation of a 1-2mm wide necrotic zone around the permanent cavity. Within this zone and beyond, beta-APP showed an initial increase followed by a decline in the number of injured axons. Three types of beta-APP positive staining could be differentiated. In the immediate vicinity of the missile track beta-APP positive neurons were present at a distance of 2-4mm from the margin of the permanent cavity (type 1) as a result of primary injured neuronal tissue by the gunshot itself. At longer distances from the narrow channel and the permanent cavity single beta-APP positive axons or axon fragments and two additional types were found; type 2 shows a parallel, wave-like arrangement of the damaged fibers, which suggests that the injury was produced by mechanical acceleration of the brain tissue created by the energy the projectile expended within the brain; irregular aggregation of beta-APP positive axons or axon fragments within a local edema represents type 3, which may be attributed to secondary ischemia or edema.     

An Analysis of Systematic Elemental Changes in Decomposing Bone

The aim of this pilot study was to investigate compositional changes in bone during decomposition. Elemental concentrations of barium, calcium, iron, potassium, magnesium, zinc and phosphorus in porcine bone (as an experimental analog for human bone) were analyzed by inductively coupled plasma optical emission spectroscopy (ICP‐OES). The samples were taken from porcine bone subjected to shallow burial and surface depositions at 28‐day intervals for a period of 140 days. Results indicated that ICP‐OES elemental profiling has potential to be developed as a forensic test for determining whether a bone sample originates from the early stages of soft tissue putrefaction. Significant changes in iron, sodium and potassium concentrations were found over 140 days. These elements are known to be primarily associated with proteins and/or tissue fluids within the bone. Changes in their respective concentrations may therefore be linked to dehydration over time and in turn may be indicative of time since deposition.