Fractures of the arches of the atlas: a study of their causation

The autopsy findings in 32 accidental deaths which showed fracture(s) of the arches of the atlas have been correlated to reconstructions of the course of events in the accidents. Flexion of the head causing fracture(s) of the neural arch or odontoid process of the axis also resulted in fracture(s) of the posterior arch due to downward traction. Extension of the head causing fracture of the odontoid process of the axis gave rise to fractures of the posterior arch due to pressure from below. Tilting of the head caused marginal fractures of the anterior arch due to oblique traction. Tilting of the head also caused fracture(s) of the anterior and/or posterior arch due to transverse extension of the atlas ring and/or superior dislocation of one lateral mass in relation to the other. Oblique flexion or extension of the head resulted in similar fractures. Flexion of the head with some rotation combined with compression of the neck can cause the anterior margin of one upper joint surface of the axis to act as a wedge separating the anterior arch of the atlas from below. Extension of the head with some rotation combined with compression of the neck can lead to a fracture running through one lateral mass due to its tilting-dislocation in posterior direction. It is striking that there was no fracture of the atlas which could be ascribed to a simple and symmetric compression of the neck (classical Jefferson's 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.     

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.     

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。     

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.     

Case report: Forensic anthropological assessment in a suspected case of child abuse from South Africa

Not many case reports of suspected child abuse as assessed solely on skeletal remains are available. Forensic anthropologists have intimate knowledge of normal skeletal anatomy, bone trauma and processes of healing of bone and may therefore be of help in suspected cases of child abuse. Patterns of trauma in juvenile skeletal remains which are suggestive of abuse include fractures in different phases of healing, multiple fractures, typical fractures on ribs and long bones and severe, complicated cranial fractures. The aim of this paper is to report on the findings of the analysis of the skeletal remains of a 3.5 years old boy. Forensic pathological examination indicated that the boy had died from a massive cranial fracture, with multiple injuries present to the rest of the body. After the body had been buried for some time, it was exhumed and we were requested to look for signs of chronic, long-term abuse. Findings included a massive cranial fracture, another fracture in the roof of the orbit, two areas of non-specific subperiosteal bone growth and several untreated carious teeth. No clear healed fracture could be found, except for a possible healed cranial base fracture which stretched transversely across the petrosal bone. This area showed signs of recent bone activity. The court decided that this was not enough evidence of chronic abuse and found the accused guilty of murder but not of chronic child abuse. This case illustrates the difficulty to obtain clear signs of chronic injury on juvenile remains.     

146例上颌骨额突骨折法医学鉴定分析

目的探讨上颌骨额突（PFM）骨折的特点及损伤程度的评定。方法从鼻外伤的法医鉴定案例中，选取CT扫描诊断为PFM骨折的146例鉴定资料进行回顾性分析。结果在146例中，PFM骨折伴移位成角134例，其中左侧PFM骨折（82例）多于右侧（49例），复合骨折多于单纯骨折。PFM复合骨折多为PFM骨折伴发鼻骨骨折（88例），伴发2个骨骨折26例，伴发3个骨骨折2例。结论PFM骨折极易出现移位成角，多伴有鼻骨、眶骨骨折。单纯PFM骨折，应评定为轻微伤，伴有合并骨折时应评定为轻伤。     

The occurrence of cervical fractures in victims of judicial hanging.

Cervical vertebrae from 34 victims of judicial hanging were examined. In only six cases was there a fracture of the axis and only one other fracture was seen in the series. The fractures were of two types. Three were the traditional 'Hangman's fracture' whilst three were of a type previously unreported. The incidence of fracture was unassociated with drop, date age or hangman. The results of the post mortems on these subjects were reviewed and found to be grossly inaccurate with regard to fractures. The results indicate that the traditional hangman's fracture occurred in only a small proportion of cases of judicial hanging. The cause of fractures and cause of death in judicial hanging are discussed with a brief history of judicial hanging in this country.     

鼻骨骨折螺旋CT3D成像与X线片对比研究

目的 评价螺旋CT扫描三维重建成像与X线摄片对比对鼻骨骨折法医学鉴定的价值。方法 使用SOMATOM BALANCE 1s螺旋CT机，对32例复杂鼻部外伤者2mm／2mm扫描，常规进行最大密度投影法(MIP)、多平面重建(MPR)、表面覆盖法(SSD)、容积成像(VR)方式。全貌显示受伤鼻骨骨折影像，并与常规鼻骨摄片比较。结果 螺旋CT三维成像纠正3例X线照片的假阳性和6例诊断骨折类型不准确。结论 螺旋CT三维重建对诊断复杂鼻骨骨折块数目、移位，以及骨折类型优于X线摄片。     

Understanding rib fracture patterns: incomplete and buckle fractures

Reconstructing traumatic thoracic events, especially when soft tissues are absent, requires an advanced understanding of ribcage fracture patterns. The morphology and orientation of ribs complicate the fracture pattern, as a single blow often causes multiple fractures at various locations. Furthermore, fracture types observed in ribs are not explained easily by current bone biomechanic literature. Using evidential skeletal material archived at the Regional Forensic Center, Memphis, the ribs of 43 blunt force trauma cases were analyzed. A total of 195 incomplete fractures and 63 buckle fractures were noted. Incomplete fractures, previously thought to be common in children but rare in adults, were found among individuals ranging in age from 21-76 years. A buckle fracture, failure resulting from compressive instability, has been undefined previously in bone trauma literature but was repeatedly observed in this sample. This study elucidates recognizable rib fracture patterns while emphasizing gross bone examination for force and mechanical factors.     

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.     

Analysis of the incidence of pelvic trauma in fatal automobile accidents

Pelvic fractures are frequent complications of motor vehicle accidents, and motor vehicle accidents are the most common cause of pelvic fracture. Although pelvic fractures are associated with considerable morbidity and mortality, there has traditionally been no attempt to grade or classify pelvic fractures during postmortem examination. The authors performed a retrospective study of cases examined at the Jefferson County Coroner/Medical Examiner Office from 1994 to 1996, reviewing investigative reports and autopsy findings. Radiographs were examined for the presence and Tile type of pelvic fracture. Pelvic fractures were identified in 88 of 392 cases (23%). In most (89%), the pelvic fracture was readily classified according to Tile type on the basis of radiographs and the inferred mechanism of injury. This study indicates that current estimates of the mortality of pelvic fractures are low because of the exclusion of individuals who do not survive to hospitalization. Furthermore, pelvic fractures in rapidly fatal motor vehicle accidents tend to be more severe than fractures in individuals who have a significant interval of survival. The presence and classification of pelvic fractures may be readily determined by radiographs in most cases. The Tile classification scheme is easy to apply and has important implications in the comparison of study groups.     

The determination of the type of external exposure by rib fractures

The paper deals with differential diagnosis of an external exposure (blow, compression) from rib fractures in chest trauma. New informative parameters of bone microdestruction in fracture zones which may serve as expert criteria for conditions of their formation are proposed. Registration of microfissures in thickness of rib compact plates and spongy substance on both sides of the basic fracture, their character, direction and original mosaic makes it possible to determine the type of an external exposure blow, compression) with high accuracy.     

The diagnosis of the mechanisms of bone tissue destruction from the surface of the break]

Data on bone tissue fractography are summarized and systematized. Possibilities of a microscopic fractography method in analysis of skeletal bone fractures in order to determine conditions of traumatic exposure were shown. Destruction of bone tissue is considered from the point of view of fragile and tough destruction using as a model solid body with crack at the top of which deformations of detachment, lateral and longitudinal shifts are acting. Morphologic features for different types of destruction were singled out. Use of these features may help to determine character and type of deformation at concrete areas of fracture during all destruction process.     

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.     

81例外伤性鼻部骨折的特点及其法医学鉴定分析

研究鼻部损伤后骨折的特点、确诊的方法及法医学鉴定的相关问题。 81例以鼻部外伤为主诉 ,经鼻骨拍摄X线侧位片 ( 62例加做鼻部CT扫描 )检见有鼻骨骨折的患者 ,进行法医临床学鉴定分析。单纯性线性骨折 19例 ,骨折移位者 11例 ,粉碎性、多发性骨折 4 0例 ,鼻骨骨折伴上颌骨额突骨折或 (及 )伴眶骨骨折 11例 ;轻伤 58例 ( 72 % ) ,未构成轻伤 2 3例 ( 2 8% )。多数鼻骨骨折为粉碎性、多发性 ,且可伴有其它部位骨折。鼻骨X线侧位片只能明确部分粉碎性骨折及部分移位明显的骨折 ,CT扫描能确定鼻部骨折形态。     

颅骨骨折断面细微结构的观察研究

作者利用扫描电子显微镜,对颅骨骨折断面上微细结构的形态学特征进行了观察与研究,发现在颅骨骨折断面上有微细的骨折裂线,向断面深部的骨质中延伸,其宽度为5至100um不等,主要分布在颅骨外板内,或外板与板障的交界处.分布于板障内的微细裂线可造成骨小梁横行、纵行和螺旋形骨折.骨折时,骨基质中的胶原纤维束可被分离或断裂,各胶原纤维层可分开.骨内血管可被骨折裂线横断或纵形撕裂,损伤的血管可被从哈佛氏管中拉出.生前骨折时,在微细裂线的深方可清楚见到纤维蛋白网和红细胞相互粘集,死后骨折则未见到此现象.本文还探讨了颅骨骨折发生的机理和推断生前骨折的可能性.     

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.     

对冲性眶壁骨折的法医学鉴定

目的 探讨对冲性眶壁骨折在眼眶骨折中的分类及其发生机制以及法医学鉴定要点。方法 对42例对冲性眶壁骨折的法医学鉴定案例进行回顾性研究,全部资料有明确的致伤原因,均进行临床常规检查及双眼影像学检查。结果 对冲性眶壁骨折在眶壁骨折中占6.2％,致伤同侧42眼均表现为眼球钝挫伤,其中视网膜震荡18眼,重影症15眼,CT扫描显示眶壁无骨折。对侧42眼均无眼球钝挫伤及视网膜震荡表现,其中重影症10眼,CT扫描显示均为眶内壁骨折。双侧84眼全部出现视物模糊及视力下降。结论 致伤同侧眼表现为眼球钝挫伤以及对侧眼CT扫描显示眶内壁骨折为诊断对冲性眶壁骨折的主要指标,损伤程度评定为轻伤。