撕脱骨折与永存骨骺、籽骨、副骨的影像学鉴别

目的探讨撕脱性骨折与永存性骨骺、籽骨、副骨的影像学鉴别办法。方法回顾性分析了14个要求重新鉴定是否存在骨折的案例,观察撕脱性骨折的直接、间接征象,并结合其发生机制与永存性骨骺、籽骨及副骨的固有形态、特点等进行对照。结果所选案例中有2例永存性骨骺、3例籽骨、3例副骨均具有骨块边缘钝圆、骨皮质连续、局部软组织未见肿胀以及伤后该骨的连续摄片无明显变化等共同特征。结论正确掌握撕脱性骨折、生理性小骨骺、籽骨及解剖变异的副骨的特点,并综合运用影像学资料是鉴别撕脱性骨折的基本要素。     

Pontomedullary lacerations in falls from a height--a retrospective autopsy study

Brainstem pontomedullary laceration (PML) in falls from a height appears as isolated cases and usually in feet-first impacts with a ring fracture. The aim of this study was to determine the frequency of PML in falls from a height, as well as the frequency of concomitant head and neck injuries. Out of 261 cases, PML was present in 40. An impact to the chin, as well as a feet- or buttocks-first impact, most often led to PML owing to transmission of the impact force. Also, a lateral, frontal, or posterior head impact, with subsequent hinge fracture, as well as the frontoposterior hyperextension of the head associated with an upper spine fracture, could be possible mechanisms of PML in falls from a height. The jawbone and other facial bones act as shock absorbers, and their fracture diminishes energy transfer toward the skull and protects the brain and brainstem from injury.     

Microscopic Pattern of Bone Fractures as an Indicator of Blast Trauma: A Pilot Study

The assessment of fractures is a key issue in forensic anthropology; however, very few studies deal with the features of fractures due to explosion in comparison with other traumatic injuries. This study focuses on fractures resulting from blast trauma and two types of blunt force trauma (manual compression and running over), applied to corpses of pigs; 163 osteons were examined within forty fractures by the transmission light microscopy. Blast lesions showed a higher percentage of fracture lines through the Haversian canal, whereas in other types of trauma, the fractures went across the inner lamellae. Significant differences between samples hit by blast energy and those runover or manually compressed were observed (p < 0.05). The frequency of pattern A is significantly higher in exploded bones than in runover and compressed. Microscopic analysis of the fracture line may provide information about the type of trauma, especially for what concerns blast trauma.     

中西医结合治疗股骨颈骨折45例

目的 观察空心加压螺钉内固定术合中药治疗股骨颈骨折的疗效。方法 45例股骨颈骨折患者在持续硬膜外麻醉下接受股骨颈骨折闭合复位加空心加压螺钉内固定术,同时在中医三期辨证基础上内服中药,观察骨折愈合的效果。结果 参照Harris评分标准,骨折愈合优40例,良1例,差4例,优良率达91.11％。结论 微创空心加压螺钉内固定术创伤小,固定骨折牢靠,中药分期辨证辅助治疗股骨颈骨折能促进骨折愈合。     

骨密度测定在外伤后骨折法医临床学鉴定中的意义

目的测定外伤后骨折者的骨密度,探讨骨折鉴定中骨质疏松和外伤的关系。方法应用双能X线骨密度吸收仪进行骨密度测定,参照世界卫生组织制定的骨质疏松症诊断标准和外伤参与度评定的一般原理,对15例外伤后骨折者的临床法医学鉴定进行分析。结果15例伤者:男6例,女9例,年龄在43~85岁之间;骨密度值在0.354~1.067 g/cm2之间;7例诊断骨质疏松症,外伤参与度为50%,其中5例评定为轻微伤,2例评定为轻伤;其余8例均为骨量减少,评定为轻伤。结论骨密度测量可预测骨折危险性,有助于骨折临床法医学鉴定的伤病关系分析。     

Rolando骨折成伤机制的法医学研究

目的研究与分析第一掌骨基底部Rolando骨折成伤原因，拟为法医学解决相应类型案件提供技术帮助与科学证据。方法对49例形成原因无争议的Rolando骨折临床病历资料进行整理分析，对21例尸体双手第一掌骨不同部位进行钝性打击实验以观察骨折类型及形态，综合分析Rolando骨折成伤原因。结果临床病历资料统计分析及法医尸体打击实验均证实第一掌骨基底Rolando骨折系拇指屈曲内收时偏桡侧作用于第一掌骨头部并沿掌骨长轴传导的轴向暴力作用所致；Rolando骨折断面呈T形或Y形，骨折线通过第一掌腕关节。结论第一掌骨基底Rolando骨折系拇指屈曲内收时偏桡侧作用于第一掌骨头部并沿掌骨长轴传导的轴向间接暴力作用所致。     

Crack Propagation in Teeth: A Comparison of Perimortem and Postmortem Behavior of Dental Materials and Cracks*

Abstract: This study presents a new method for understanding postmortem heat-induced crack propagation patterns in teeth. The results demonstrate that patterns of postmortem heat-induced crack propagation differ from perimortem and antemortem trauma-induced crack propagation patterns. Dental material of the postmortem tooth undergoes dehydration leading to a shrinking and more brittle dentin material and a weaker dentin-enamel junction. Dentin intertubule tensile stresses are amplified by the presence of the pulp cavity, and initiates crack propagation from the internal dentin, through the dentin-enamel junction and lastly the enamel. In contrast, in vivo perimortem and antemortem trauma-induced crack propagation initiates cracking from the external surface of the enamel toward the dentin-enamel junction where the majority of the energy of the crack is dissipated, eliminating the crack’s progress into the dentin. These unique patterns of crack propagation can be used to differentiate postmortem taphonomy-induced damage from antemortem and perimortem trauma in teeth.     

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.     

体表损伤和颅骨骨折形态特点的力学分析

法医在实际工作中发现,在诸多死亡案例中,颅脑损伤是最常见的死亡原因之一,而颅脑损伤多伴有颅骨的骨折。通过颅骨骨折形态特点的力学分析,可以确定死亡原因、案件性质、致伤物的种类和形态等,为案件的成功侦破提供诸多线索。     

Forensic Identification of Bipartite Patella Misdiagnosed as Patella Fracture

Bipartite patella is recognized as a developmental anomaly of ossification. Most of them are asymptomatic and are discovered incidentally. Bipartite patella is sometimes misdiagnosed as a patella fracture, because the x‐ray images of both these conditions may appear very similar. In this case, the patient complained of left knee pain after x‐ray films revealed a fracture‐like line in the left patella. The patient was then diagnosed as having a patella fracture. In China, the injury degree is categorized as serious injury, minor injury, and trivial injury. As the injury degree of patellar fracture is identified as minor injury, the defendant who injured the patient will be sentenced to prison for ≤3 years. However, the defendant objected to this judgment and applied for the second evaluation of injury degree. On the basis of the site of injury, clinical manifestations, and imaging findings, we diagnosed the patient with bipartite patella which belongs to normal anatomic variant. Therefore, the injury degree of the patient was not minor injury.