Patho-mechanical comparative morpho-characterization of contre-coup injuries of liver by cadaveric experimental simulation for medico-legal and forensic implications.

BACKGROUND: Liver is the most common organ to get injured in cases of blunt force trauma to the abdomen (BFTA). It is the 2nd commonest organ after brain to sustain injuries out of all the trauma related fatalities. However, the literature about contre-coup injuries to the liver due to BFTA is scarce in-spite of the high mortality rates seen out of injury to this particular organ. PURPOSE: The authors intended to systematize the characteristic morphogenesis of the contre-coup injuries of the liver on the basis of the patho-mechanics involved in various types of BFTA. METHODOLOGY: One hundred and sixty three cases of BFTA were identified, and interpretation was attempted for the contre-coup rupture of the liver seen in twenty out of all the trauma related fatalities that presented for post-mortem examination during the study period. However, the mechanics of the pattern of the rupture injuries to the liver were indiscernible. This motivated the authors to conduct the comparative characterization of injuries to the liver by experimental simulation of BFTA after necessary permission via inflicting pre-calculated forces on unclaimed cadavers. RESULTS: The patterns of contre-coup rupture/s of liver were established in all the twenty out of one sixty-three cases of BFTA. The rupture depicted patterns of injury in the situations of - 1) strong hits with a limited surface trauma, 2) very strong hits with a generalized surface trauma, 3) and collision with a solid surface resulting due to fall onto the side of the abdomen. The causative mechanism discerned was deformation of the liver, followed by its parenchymal rupture due to the shear and strain types of force/s consequent upon tissue compression. The minimum force and energy of impact required for the liver to rupture was estimated to be 2000 N and 141.5 J. CONCLUSION: This series of the simulation experiments revealed two variants of liver rupture in the contre-coup impact zone. The pattern of injury was maintained in cases, those studied at post-mortem examinations, but the relief ruptures were found to vary depending upon the overall mechanics of the traumatic forces involved in the simulation experiments performed on the cadavers. The anti-shock ruptures were formed during shock trauma, and shockproof ruptures were not seen in cases of underlying compressive forces. The morphogenetic characterization of the relief rupture surface of the liver was also delineated in relation to its surface orientation to the spine on the basis of the terms "large" and "very large" depicting the quantum of force/s delivered out of an impact or blow.

[Study of morphometric parameters of the hyoid bone]. / Issledovanie morfometricheskikh priznakov pod"yazychnoi kosti.

THE OBJECTIVE OF THE WORK: Is to study the morphological and morphometric variations of the hyoid bone in the population of the Tver region. One hundred adult hyoid bone samples were taken from 63 males and 37 females. Morphological and morphometric variations of the hyoid bone were determined. Six types of hyoid bone were identified: U-shaped - 25 bones (25%); H-shaped - 3 bones (3%); B-shaped - 48 bones (48%); D-shaped - 14 bones (14%); V-shaped - 2 bones (2%); HK-shaped - 8 bones (8%). The width, length, and the largest transverse axis were 42.44; 36.49, and 35.6 mm, respectively. Morphological differences of the hyoid bones of the Tver region population compared to other populations were found. Anatomical variations and dimensions of the hyoid bone are important for practical forensic medicine.

[Histological signs of thermal damaging by electricity]. / Gistologicheskie priznaki termicheskogo povrezhdayushchego deistviya elektricheskogo toka.

OBJECTIVE: Identification of histological signs of thermal damaging by electricity. It was studied the histological picture of the electrometric and changes in the epidermis and dermis in the area of exposure to a red-hot metal object. The same type of microscopic changes in the skin have been revealed: in the central zone of damage there were coagulation necrosis and homogenization, as well as the porous tissue structure formation; in the peripheral zone there were deformation of cells with their verticalization and the vortex figures formation. These histological signs are a manifestation of coagulation processes, hydrodynamic effects because of explosive boiling of interstitial fluid and tissue deformation that characterize the thermal damaging effect. The data obtained clarify the mechanism of the damaging effect of technical electricity on human tissue.

[General characteristics of the driver's head injury in road accidents]. / Obshchaya kharakteristika travmy golovy u voditelya pri dorozhno-transportnom proisshestvii.

We studied the characteristics of head injuries in drivers (326 cases). There was no traumatic brain injury (TBI) found in 31.6% of the cases, and no head trauma - in 12.5% of the cases. Trauma of the soft tissues of the head without the formation of TBI was detected in 18.1% of cases, non-lethal TBI - in 19.1%, and fatal TBI - in 59.9% of cases. We characterized the injuries: their types, number and localization. A predominantly left-sided localization of head injuries, as well as anteroposterior damage asymmetry associated with phases of injury was noted. Injuries that form exclusively in the first phase with localization in the anterior parts of the head were found in most of the observations in non-lethal TBI and in cases injury to the soft tissues of the head injury without TBI. In cases of fatal TBI, the formation of injuries in both phases of the car injury was found, while the severity of the injury was mainly due to the impact on the front sections of the head.

[Comparative characteristics of injuries to individual body parts of the driver and passengers inside the passenger compartment of a moving vehicle in a traffic accident]. / Sravnitel'naia kharakteristika povrezhdenii otdel'nykh chastei tela u voditelia i passazhirov vnutri salona dvizhushchegosia avtomobilia pri dorozhno-transportnom proisshestvii.

The purpose of this study was to investigate the general nature of injuries sustained in a moving passenger car during an accident. The study investigated the nature of injuries in drivers (99 cases) and passengers in the front seat (64), rear right seat (15), rear middle seat (29) and rear left seat (22) who died in an accident due to frontal collision with an obstacle. The general characteristics of the resulting damage were determined with regard to their type, quantity and localization. Drivers were found to have predominantly left-sided injuries to the head and chest, as well as right-sided abdominal and pelvic injuries, frequent neck injuries, smaller limb and permanent foot injuries. The injuries sustained by front seat passengers were characterized mainly by right-sided localization of head and neck injuries, maximum left-sided injury of the upper and lower limbs, and an absence of injuries to the feet. Passengers in the rear right seat were predominantly characterized by right-sided localization of injuries to the head, chest, stomach, pelvis and limbs, an absence of injuries to the feet and a relatively high frequency of damage to the internal organs of the thoracic and abdominal cavities. Passengers in the rear middle seat were characterized by uniform distribution of injuries on the left and right sides of the body, a relatively high frequency of injuries to the head, upper limbs, chest, abdomen and pelvis, a relatively low frequency lower limb injuries and an absence of injuries to the feet. Passengers in the left-hand rear seat were characterized by maximum left-sided localization of injuries to the head, chest and left extremities and minimum traumatization of the internal organs of the thoracic and abdominal cavities.

[Morphogenesis of central and peripheral liver ruptures in blunt-force trauma]. / Morfogenez tsentral'nykh i perifericheskikh razryvov pecheni pri travme tupymi predmetami.

The purpose of this study was an in depth investigation of the morphogenesis of central and peripheral liver ruptures in blunt trauma and to obtain additional information about their forensic medical significance. It has been established that central and peripheral ruptures are formed by shocks caused by very high forces, as well as by frontal compression of the body as a result of general deformation of the organ and rupture of parenchyma from stretching and tissue shearing. The surface relief of central ruptures was found to be independent of the type of external influence and was determined by the size of the rupture. The peripheral part of such ruptures was characterized by a relatively homogeneous surface topography formed by shear ridges, while the central part was characterized by an inhomogeneous surface topography formed by tensile zones. The surface relief of peripheral ruptures also did not depend on the type of external influence. The surface was relatively homogeneous, with ridges along the edge of the rupture, shear ridges and stretch zones directed deep into the rupture and forming the rupture surface relief in the form of alternating elevations and depressions.

[The synopsis of results of the 20 year activities of the Department of Forensic Medicine, I.M. Sechenov First Moscow State Medical University (Sechenovsky University)]. / Itogi 20-letnei raboty kafedry sudebnoi meditsiny Sechenovskogo universiteta.

The present article was designed to summarize the results of the 20 year scientific, practical, and educational activities of the Department of Forensic Medicine, I.M. Sechenov First Moscow State Medical University (Sechenovsky University). The main directions of the research work and achievements of the Department's staff are described, and the prospects for its further development are highlighted. The new approaches to and technologies for the teaching and training specialists in forensic medicine are introduced to meet the novel requirements imposed in the framework of the ongoing reform of higher medical education in accordance with the main principles of the Bologna declaration.

[The characteristic features of vertebral lesions in the victims of a road traffic accident with intrusion into the passenger car compartment]. / Kharakter povrezhdenii pozvonkov u postradavshikh v salone legkovogo avtomobilia pri DTP.

The objective of the present study was to develop the diagnostic criteria for determining the positions of the participants of a road traffic accident inside the passenger car compartment based on the analysis of the characteristic features of vertebral lesions in the victims. The archival documents of forensic medical expertises were used to analyze the specific characteristics of fractured cervical vertebra in the victims of the accident inside the passenger car compartments including the drivers (n=92), the occupants of the forward (n=43) and rear (n=37) seats of the car. Localization and mechanisms behind the formation of vertebral lesions in the cervical part of the spinal column associated with the intra-compartment injury is of primary importance for the diagnostic purposes. The character of an injury to the cervical region gives evidence of the position of the driver and the occupants of the car inside the passenger compartment at the moment of the accident. Injuries to the cervical, thoracic, and/or sacral vertebrae may be indicative of the seat (either driver's, forward or rear) occupied by the victim(s). The fractures of the sacral part of the vertebral column are of negligible value for the differential diagnostics between the positions of the driver and/or other victims because they equally frequently occur in the drivers and occupants of both the forward and rear seats. Nevertheless, the proposed criteria made it possible to construct the mathematical model in the form of the logistic regression equations and to use them for making the probabilistic predictions as regards the positions of the participants of a road traffic accident inside the passenger car compartment based on the selected combination of pathomorphological characteristics in the victims.

[The forensic medical evaluation of the injuries inflicted inside the passenger compartment of a moving car equipped with the modern personal safety systems]. / Sudebno-meditsinskaia otsenka povrezhdenii pri travme v salone dvizhushchegosia legkovogo avtomobilia, oborudovannogo sovremennymi sredstvami individual'noi bezopasnosti.

The objective of the present study was to elucidate the characteristic features of the injuries inflicted to the victims of a road traffic accident inside the passenger compartment of a moving car equipped with the modern personal safety systems. The materials available for the present work included the lesions documented in 210 drivers and 150 occupants of the car passenger compartments. Both comparative, morphometric and statistical methods were used to analyze the data obtained. The morphometric analysis included identification of the form of the injury, such as extravasation, wounds, fractures, and lesions of the internal organs (e.g. hemorrhages, ruptures, etc.), their number and localization. Special attention was given to the specific features of the injuries to the occupants of the cars equipped with the modern personal safety systems. The study has demonstrated that the form, frequency, and localization of the injuries inflicted to the victims of a road traffic accident inside the passenger car compartment (including the drivers and other occupants) can be used for determining the positions of the victims at the moment of the accident.

[The construction of the three-dimensional model of the damaged bone tissue based on its roentgenogram]. / Postroenie trekhmernoi modeli povrezhdeniia kostnoi tkani po rentgenogramme.

The objective of the present work was to develop the method for the visualization of the shape of the bone surface in the region of its traumatic damage based on the results of the analysis of a single X-ray image for the solution of the problems facing forensic medical expertise and traumatology. The three-dimensional models of the fractures of the long tubular bones constructed with the use of the visualization technique were shown to adequately reproduce the morphological picture of the injury. It allowed to enhance the potential of the forensic medical analysis and the accuracy of the diagnostic methods employed for the purposes of forensic medical expertise.

[Characteristic of the fractures of the cervical, thoracic and lumbar vertebrae in the victims of a traffic accident found in the passenger compartment of a modern motor vehicle].

The objective of the present work was to study peculiar features of the injuries to three spinal regions in the victims of a head-on car collision found in the passenger compartments of modern motor vehicles equipped with seat belts and other safety means. It was shown that most frequent fatal injuries to the driver include the fractures of the cervical, thoracic, and lumbar vertebrae. These injuries are much less frequent in the passengers occupying the front and the right back seats. The multilayer and multiple character of the fractures in different parts of the spinal column in the car drivers is attributable to more pronounced spine flexion and extension associated with injuries of this kind. The fractures of the lower cervical vertebrae in the front seat passengers occur more frequently than injuries of a different type whereas the passengers of the back seats most frequently experience fractures of the upper cervical vertebrae. The passengers of the left back seat less frequently suffer from injuries to the thoracic spine than from the fractures of the cervical and lumbar vertebrae. The passengers of the central back seat most frequently experience fractures of the thoracic part of the vertebral column and the passengers occupying the right back seat fractures of the lumbar vertebrae.

[The forensic medical evaluation of the injuries to the cervical spine in the driver and the front-seat passenger of a modern motor vehicle after the frontal crash].

The objective of the present study was to elucidate the specific features of the lesions of the cervical spine in the driver and the front-seat passenger of a modern car after the frontal crash. We made use of the archival materials of forensic medical expertises concerning the traffic accidents carried out in the city of Moscow during the period from 2005 to 2012. The study was focused on the analysis of the character of the fractures of cervical vertebrae in the drivers (n = 55) and the front-seat passengers (n = 85) of a modern motor vehicle involved in a traffic accident. It was shown that the drivers most frequently suffer bending-extension fractures of the cervical vertebrae, with the II-IV vertebrae being especially frequently subject to multiple fractures resulting in the damage to the anterior support column, sometimes to both the anterior and posterior columns, and much rarer to the posterior column. The front-seat passengers also suffer bending-extension fractures. The IV-VI vertebrae are most frequently affected in them with isolated damages to either the anterior or the posterior support column of the neck vertebrae.

[The new working classification of blood stain patterns].

The results of analysis of the existing classifications of blood stain patterns indicate that systematization of the morphological characteristics of blood stains requires that mechanisms and circumstances of the injury, properties of the surfaces receiving blood stains and the objects leaving them should be taken into consideration. The new working classification of blood stain patterns has been developed for the purposes of forensic medical expertise satisfying the above requirements. It makes it possible to pass to the next stage of research on systematization of the general and specific morphological features of blood stains depending on concrete circumstances of bodily injuries.

[The morphological characteristic of an experimental rupture of the liver for the simulation of the blunt abdominal injury].

The strength and the energy of a striking blow with a clenched fist may be as high as 300 kgf (3,000 H) and 824.4 J respectively. Pressing a human body against a hard surface leads to a deep chest deflection while the rupture of the liver is associated with a lower blow strength and energy (2,000 H and 141.5 J respectively). In such situations, the shockproof mechanisms of the injury prevail giving rise to antishock peripheral and central ruptures of the liver due to the general deformation and displacement of this organ in the direction of the blow. In the absence of barriers preventing the inertial movement of the body, even a strong strike (1950 H) with an energy of 202.5 J does not cause a damage to the liver; it occurs when the strike strength and energy amount to 2650 H and 260.1 J respectively. In such cases, the direct injury mechanism develops manifested in the formation of local liver injures. The results of the study suggest the possibility of the rupture of the liver inflicted by a clenched fist strike delivered to the abdomen.

[Forensic-medical diagnostics of an electrical mark resulting from the injury inflicted by technical electricity in the aqueous environment].

The objective of the present study was to develop the criteria for forensic-medical diagnostics of an electrical injury inflicted in the aqueous environment based on the characteristics of the electrical mark. The specific morphological features of the electrical injuries inflicted in the aqueous environment that were discovered in the materials available for the forensic medical expertise were analysed taking into consideration the results of the relevant research reported in the forensic medical literature. It was shown that an electrical injury inflicted in the aqueous environment results in the formation of an unusual mark in the form of blisters containing no watery liquid associated with electrogenic oedema in the surrounding tissues. Macroscopic and microscopic studies of the electrical mark failed to reveal the signs of grade III and IV grade thermal burning or thermally affected hair. It is concluded that the consistent characteristics of the electrical mark resulting from the injury inflicted by technical electricity in the aqueous environment include cell lengthening, blister formation inside the corneal layer, and the separation of epidermis from the skin proper.

[The morphological characteristic of hepatorrhesis in the subjects with the blunt abdominal injury].

We have elucidated certain consistent patterns of the development of hepatic lesions associated with blunt abdominal trauma including primary and secondary local and distant ruptures of the liver of different localization, e.g. in the direction of the injurious force (central and anti-shock) and apart from it (peripheral). A kick in the stomach causes local (primary and secondary) or distant ruptures of the liver. A strong impact gives rise to local secondary and distant ruptures. Compression of the body with massive objects is associated with local primary ruptures whereas falling down on the stomach results only in anti-shock ruptures. Local (primary and secondary) as well as distant (anti-shock and peripheral) ruptures of hepatic parenchyma have different morphological properties and surface relief which makes it possible to discriminate between them. The consistent patterns of hepatorrhesis provide a methodological basis for the explanation of the physical nature of liver deformation and destruction of its tissue after a blunt abdominal trauma.

[Characteristic of the hepatic tissue degradation processes underlying the development of its local and distant lesions].

The processes associated with liver disruption caused by a blunt abdominal injury have been investigated on a model of continuous media deformation. It was shown that local primary injuries to the liver result from stress-induced tissue stretching, compression, and shear in the longitudinal direction. They have a layered relief due to transverse fissures. The peripheral ruptures result from tissue extension under effect of overall liver deformation. They are not deep and have a uniform relief created by alternating low tubercles and superficial fissures oriented at the right angle to the surface. Antishock ruptures are the consequences of tissue extension or stretching/compression during local and overall deformation of the liver surface. They develop in the longitudinal direction, have a non-uniform relief created by alternating high prominences and numerous fissures differing in both the depth and the extension and oriented at the right angle to the liver surface. Central ruptures result from tissue stretching accompanying overall deformation of the organ. They are directed perpendicular to the direction of the surface force, have the longitudinal direction and non-uniform relief.

[Current concepts of the mechanisms of formation of gunshot fractures].

The mechanisms of formation of gunshot fractures in flat bones inflicted by a semispherical bullet were investigated using expert and experimental materials. The process of crack formation was considered in terms of the Hertzian contact problem and the Hill-Johnson model. It was shown that the fracture develops as a result of combination of stresses and strains in the bone tissue leading to the formation of a hydrostatic nucleus prior to tissue fragmentation. Dynamic fluctuations (waves) generated in the zone of hydrostatic compression resulting from the gunshot injury propagate with the velocity of sound from the nucleus in the direction of the bullet movement. According to the Hill-Johnson model, the waves propagate in the direction of the impact within a parabolically expanding space; this accounts for the mechanism of formation of parabolic cracks and the specific shape of the defect that the bullet produces in the flat bones. The dynamic load applied by means of an indentor forms at a higher rate than the velocity of sound in the affected material. It gives reason to consider the effect of a bullet moving with the speed of 250 m/s as quasi-static loading. The results obtained in this study make a contribution to the theory of impact effect of a bullet and provide a deeper insight into the physical nature of the direct and sideway action of a gunshot projectile. Moreover, they explain the cause behind the widening of the outlet part of the perforating fracture in the flat bones.

[Characteristics of duodenal ruptures depending on topographical and anatomical properties of this organ and circumstances of blunt abdominal trauma].

We have studied specific morphological properties of duodenal rupture depending on the topographic and anatomical features of this organ and circumstances of blunt abdominal trauma suffered in a car crash (with the victim found in the passenger compartment or involved in an automobile-pedestrian accident) and a railway crash (a train-pedestrian accident) or resulting from a blunt-force trauma, a fall from height, a fall on the stomach, and traumatic compression of the body. We took into consideration the anatomical peculiarities of the duodenal rupture, such as its circular, horseshoe, and loop-like shape. The study has demonstrated that the frequency of duodenal injury associated with a blunt abdominal trauma shows a stronger dependence on the topographical and anatomical peculiarities of duodenum than on the circumstances of the case. Specifically, the circular duodenum and especially its descending portion are more readily subjected to the damage than the organs of a different shape. The position of the break with respect to the duodenal axis is an important diagnostic signs allowing to clarify circumstances of the blunt injury. Transverse ruptures are typical of strong impacts associated with the short-term interaction between the damaging object and the affected part of the body whereas longitudinal ruptures more commonly occur as a result the long-term traumatic impact. Bile imbibition of paraduodenal and peripancreatic retroperitoneal adipose tissue may be used as an additional diagnostic sign of duodenal rupture.