Fractures of the axis caused by hanging

Prerequisities for fractures of the neural arch of the axis in the region of the isthmus (hangman's fracture) during hanging are considered to be a long drop and a submental knot. A case is presented showing that hangman's fracture arising in hanging can result from stretching of the neck combined with anteroflexion of the head.     

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.     

Forms of fractures of the occipital condyles

In contrast to the large fracture system of the base of the skull, little attention has so far been paid to fractures of the occipital condyles. The mechanics of these fractures have mostly been described in the form of case reports. Here an attempt is made to classify fractures of the occipital condyle based on the literature and our own material. Fractures of the condyles in the sense of bursting or the injuries themselves are classified under the following forms of strain: 1. Axial compression (Jefferson type) condylar impression; 2. Axial traction (hangman's type) condylar retraction; 3. Rotation with axial strain condylar retraction; 4. Oblique compression (bursting fracture of the abutment) frontal condylar fracture; contralateral; 5. Oblique traction (horizontal thrust); a tearing at the base of the skull as in a contralateral condylar horizontal fracture; 6. Transverse thrust (longitudinal fracture of the base of the skull) partial condylar avulsion The functional connection between a longitudinal clivus and condylar fracture is illustrated by typical examples. Furthermore, the elliptical deformation model for a burst fracture at the base of the skull in the longitudinal axis is extended by the deeper transverse thrust stabilization of the condyles.     

Neck injuries: II. Atlantoaxial dislocation--a pathologic study of 14 traffic fatalities.

C1-C2 vertebral dislocations have not been commonly recognized at autopsy. Among 66 subjects with neck injuries, drawn from a series of 155 traffic fatalities, were 14 with injuries at the level of the atlantoaxial motion segment, ranging in age from 8 months to 93 years. Thirteen had sprains or lacerations of the atlantoaxial facet joints, and one had a healed C1 fracture. Six of the 14 had odontoid fractures. None had transverse ligament lacerations. Injuries of the alar ligaments and the tectorial membrane were frequent. Only 3 subjects had subaxial cervical injury. All 14 had evidence of impact to the head or neck. Four had fractures of the mandible or facial bones, and 5 had skull fractures. Subdural and subarachnoid hemorrhages were found in 7 and 6, respectively. Brainstem lacerations were not uncommon, but only one had a pontomedullary laceration. Spinomedullary cord injuries occurred in 5. Acute neurogenic shock was the major mechanism of death in 9 of the 14, including 5 with major cardiovascular lacerations. Delayed effects of craniocerebral trauma accounted for the majority of the remainder. The biomechanical mechanisms are discussed.     

Upper cervical trauma in motor vehicle collisions

Motor vehicle collisions can cause a variety of injuries in pedestrians and vehicle occupants. Fatal and nonfatal trauma to the upper cervical spine, that is, atlanto-occipital junction, atlas and axis, can be part of this spectrum. Certain distinctive injuries (for example, "hangman's fracture") which occur result from the unique anatomic structure of this area and the various disruptive forces such as extension, distraction (tension), compression (axial loading), shear, and inertia generated during collision. Correlation of autopsy findings or radiological information of these cervical injuries or both with scene investigation can be informative not only in the determination of morbidity and mortality, but also in the assessment of injury mechanisms and improvements in occupant protection.     

道路交通事故致足弓结构破坏伤残评定

足弓由横弓、内侧纵弓、外侧纵弓组成。足弓测量包括内弓角、外弓角、前弓角、后弓角和跟距角五个角度的测量。《道路交通事故受伤人员伤残评定》（GB18667—2002）标准将足弓结构破坏分为破坏1／3以上和完全破坏两种情形。前者是指足三弓（内侧纵弓、外侧纵弓、横弓）的任一弓结构破坏。后者是指一足三弓结构均有损害。当伤侧内弓角或外弓角测量值超过健侧10％时，提示内侧纵弓或外侧纵弓损坏；当伤侧前弓角或后弓角测量值小于健侧3％时，提示前弓或后弓破坏。在全面了解案情、严格审查送检材料，对被鉴定人进行体格检查和影像学检查后，可以做出最终判定。     

Homicide by manual occipitoatlantal dislocation

Occipitoatlantal dislocation is usually seen as a fatal injury in traffic accidents and has rarely been reported as a consequence of a homicide. The authors report the case of a women presenting a fatal occipitoatlantal dislocation, the circumstances of which pointed to a homicidal origin. Blood extravasation surrounding the muscles of the posterior part of the neck as well as abnormal mobility of the cranio-cervical joint was noted during autopsy; thus a complete dissection of this region was performed. This led to the finding of a fracture of the left occipital condyle and of the left superior articular facet of the atlas. This case clearly demonstrates the need to perform a large, systematic, posterior approach to the upper cervical spine, completed by the opening of the skull around the posterior fossa, when injury to the cranio-cervical junction is suspected. In these cases, the classic anterior approach give poor information and poor dissection possibilities.     

Artifactual injuries of the larynx produced by resuscitative intubation

Over a period of 9 months we examined a series of 50 deaths due to natural and unnatural causes in which there had been endotracheal intubation and chest compression during resuscitation at the scene or in the emergency department shortly before death. In 37 of 50 cases (74%) there were airway injuries directly resulting from the intubation procedure which we documented using a standardized protocol and photography. Specific airway injuries, ranging from petechiae to contusions, included oral injury (28%), posterior pharyngeal injury (16%), epiglottic injury (22%), piriform recess injury (12%), laryngeal and tracheal mucosa injury (64%), strap muscle hemorrhage (14%), and cutaneous injury of the neck (4%). In addition, we recorded the presence of facial (6%) and conjunctival petechiae (21%) and attributed these changes to resuscitative chest compression. No cases had associated fractures of the hyoid or thyroid cartilage. Based on our findings, we conclude that resuscitative intubation can cause artifactual injury that may mimic inflicted injuries caused by neck compression, including strangulation and neck holds.     

376例肋骨骨折的X线诊断分析

探讨肋骨骨折的X线诊断。对 480例胸部闭合性创伤患者的X线图像及临床资料进行回顾性分析。在 480例中 ,376例 (78 3% )出现肋骨骨折。其中 335例 (89 1% )为多根肋骨骨折 ;348例 (92 6 % )骨折发生在一侧。376例共有 941根肋骨骨折 ,其中 90 3根 (96 0 % )为单根肋骨骨折 ,6 2 3根 (6 6 2 % )骨折发生在腋中线前后。在376例中 ,有 46例在伤后首次后前位胸片中出现部分或全部漏诊 ,占 12 2 %。肋骨骨折患者在摄取后前位胸片的同时应加拍患侧后前斜位 (加用滤线器 )胸片及在伤后 1～ 4周时复查摄片     

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.     

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.     

Injuries of the Head from Backface Deformation of Ballistic Protective Helmets Under Ballistic Impact

Modern ballistic helmets defeat penetrating bullets by energy transfer from the projectile to the helmet, producing helmet deformation. This deformation may cause severe injuries without completely perforating the helmet, termed “behind armor blunt trauma” (BABT). As helmets become lighter, the likelihood of larger helmet backface deformation under ballistic impact increases. To characterize the potential for BABT, seven postmortem human head/neck specimens wearing a ballistic protective helmet were exposed to nonperforating impact, using a 9 mm, full metal jacket, 124 grain bullet with velocities of 400–460 m/s. An increasing trend of injury severity was observed, ranging from simple linear fractures to combinations of linear and depressed fractures. Overall, the ability to identify skull fractures resulting from BABT can be used in forensic investigations. Our results demonstrate a high risk of skull fracture due to BABT and necessitate the prevention of BABT as a design factor in future generations of protective gear.     

Analysis of neck injuries in hanging

Retrospective study of suicidal hangings was made on 175 cases (133 male victims, 42 female victims) for a 5-year period. The mean age was 47.33 +/- 17.51 years. The sample was divided in 4 groups according to the position of the ligature knot (anterior, right, left, and posterior hanging). The authors analyzed all visible injuries of soft tissues and bones and cartilage of the neck, and in 150 cases (85.7%), we established that there was at least one injury of these structures (hematoma or fracture for example). The most frequent injury was to sternocleidomastoid muscles. Fracture of throat skeleton was detected in 119 cases (68%). The proportion of fractures increases with age of the deceased. There was no clear correlation between frequency of neck injuries and type of hanging.     

Abusive Pediatric Thoracolumbar Fracture Due to Forced Hyperextension: Case Report,Biomechanical Considerations,and Review of the Literature

Pediatric thoracolumbar fractures are rare due to the physiological differences which afford greater resilience to the immature spine. Most pediatric thoracolumbar fractures occur as the result of high energy trauma, such as motor vehicle accidents, and modes of reasonable accidental injuries are limited by age and developmental capabilities of the child. These fractures can occur as the result of inflicted blunt force trauma and child abuse, and in most cases, the mechanism of injury to the spine is not known. We report the death of a 29-month-old man due to blunt force trauma to the back and forced hyperextension of the thoracolumbar spine causing fracture of the fourth lumbar (L4) vertebral body. A complete forensic examination revealed a previous healing fracture of the anterior aspect of the L4 vertebral body, with acute disruption of the anterior longitudinal ligament overlying the fracture site, complete fracture of the vertebral body, and fatal retroperitoneal hemorrhage. We present a review of the biomechanical considerations of the pediatric spine, a survey of pediatric spinal fractures, and a review of the literature on pediatric abusive thoracolumbar fractures. In this case, there was never a provided explanation for how the injury occurred; however, understanding the biomechanics of the pediatric spine allowed for the determination of the mechanism, force required to produce this specific pattern of abusive spinal injury, and the manner of death.     

Biomechanism of intracranial and spinal trauma of child born in occipitoanterior presentation as used in forensic examination

The new conception of mechanism and sequence of damages typical for labor trauma is presented: injury of ligaments of atlas and axis and anterior atlanto-occipital membrane, ruptures of synchondrosises of cranial bones because of vertebral column pressing on occipital bone; tears of dura mater of brain upon basilar impression in the area of focal spot; subarachnoid hemorrhage and intracerebral bleeding in case of cerebral compression by bone borders where they overly override; ruptures of ligaments of cervico-occipital and intervertebral joints in case of excess flexion and overextension of head. Authors show that damage of sutures, bones of calvarium and partition parts of dura materialize later than injury of synchondrosises of base and they are absent if sinchondrosises are not damaged. Also iatrogenic damages of fetal in labor and the mechanism of their formation are described.     

Laryngohyoid fractures after agonal falls: not always a certain sign of strangulation

Haemorrhagic fractures of the thyroid cartilage and hyoid bone are frequently observed in cases of strangulation and often regarded as evidence for an assault against the neck. In contrast, two cases of laryngohyoid fractures after agonal falls in prone position are presented to draw attention to alternative causes of these injuries with special regard to practical medicolegal casework. A 45-year-old man collapsed at a fairground and died after unsuccessful resuscitation. He showed excoriations at his elbows and right knee, a crush injury at the mentum and his mandibular front teeth were knocked out. The upper parts of the chest and the head showed blue discolouration as a marked sign of congestion due to heart failure. The right coronary artery (RCA) was completely obturated by a 5 cm long post-stenotic thrombus with subsequent myocardial infarction of the lateral part of the left ventricle. Both superior horns of the thyroid cartilage were fractured with surrounding haemorrhage, the skin and muscles of the neck uninjured. In the second case, a 63-year-old woman with a mobility handicap had fallen from a 2m high lifting platform and was found in prone position with her wheelchair on her. Resuscitation efforts were not successful. Autopsy showed signs of blunt external force against head, neck, chest and limbs. Examination of the neck revealed haemorrhage of the right sternocleidomastoid muscle, both superior horns of the thyroid cartilage were fractured, as well as the hyoid bone, with slight haemorrhage of the surrounding soft tissue and mucosa. On the same level, the fifth intervertebral disk was ruptured, without any injury of the spinal cord. These cases demonstrate that laryngohyoid fractures should not be overestimated as unequivocal indication of neck compression and may well be caused by falls, even at ground level.     

掌骨骨折致伤方式法医学鉴定附27例分析

目的探讨掌骨骨折的形成机制,为掌骨骨折致伤方式的法医学推断提供参考。方法通过对27例致伤方式明确的掌骨骨折案例进行回顾性分析．对不同部位、性质的掌骨骨折结合其致伤方式进行损伤机制分析,并分类统计。结果诸掌骨中以第5掌骨骨折最为常见。就部位而言,又以基底部骨折最为常见,多见于间接暴力传导作用所致;其次为掌骨颈骨折．往往为纵向暴力作用所致。常见于攻击伤、撞击伤;掌骨头骨折常见于握拳时暴力直接打击所致;掌骨体横行或粉碎性骨折为直接暴力作用所致．斜形或螺旋形骨折多为旋转暴力作用所致。结论根据掌骨骨折的部位、性质,通过分析其骨折的形成机制,可以推断其致伤方式,从而为司法鉴定提供有力证据。     

Histologic appearance of fractured thyroid cartilage and surrounding tissues

Histological appearances of the fractured superior horns (SH) of the thyroid cartilage and their surrounding tissues were reviewed, with particular reference to signs of vital origin of the fracture. Twenty-nine autopsies with either histories or findings indicating asphyxial neck compression, with a total of 39 fractured SHs, and three autopsies with history of suicidal jump from height with a total of two SH fractures, were examined. Fifteen autopsies with finding of 19 artefactually fractured SHs while removing neck organs at autopsy were used as controls. In the cases of neck compression and victims of jump from height haemorrhages, retraction of fractured SH fragments with invagination or squeezing of the perichondrium, contraction bands, contraction band necrosis and 'opaque fibres', in the adjacent muscle fibres could be seen. Fibrin deposition and/or leucocytic reaction were noted in cases where circumstances of death indicated prolonged death struggle (as in incomplete hanging, resuscitation or homicidal neck compression). However, retraction of fractured fragments and invagination of perichondrium between artefactually fractured SH fragments were observed in both control cases and cases with antemortem trauma to the larynx. Many of these histological findings, including haemorrhages and fractures had not been evident at gross examination. We conclude that histological examination of SHs may not only uncover macroscopically overlooked injuries but also may facilitate the clarification of an injury's vital origin.     

Novel Classification System of Rib Fractures Observed in Infants

Rib fractures are considered highly suspicious for nonaccidental injury in the pediatric clinical literature; however, a rib fracture classification system has not been developed. As an aid and impetus for rib fracture research, we developed a concise schema for classifying rib fracture types and fracture location that is applicable to infants. The system defined four fracture types (sternal end, buckle, transverse, and oblique) and four regions of the rib (posterior, posterolateral, anterolateral, and anterior). It was applied to all rib fractures observed during 85 consecutive infant autopsies. Rib fractures were found in 24 (28%) of the cases. A total of 158 rib fractures were identified. The proposed schema was adequate to classify 153 (97%) of the observed fractures. The results indicate that the classification system is sufficiently robust to classify rib fractures typically observed in infants and should be used by researchers investigating infant rib fractures.