掌骨骨折损伤程度及法医学鉴定

探讨掌骨骨折的致伤特点及活体损伤程度的法医学鉴定。对 5 2例掌骨骨折的案例资料按不同掌骨及损伤类型进行分析。第 1～ 5掌骨分别对于掌骨头、掌骨颈、掌骨干、掌骨基底部的骨折发生率和致伤机理各有不同 ,直接暴力所致第 2掌骨头、间接暴力所致第 5掌骨颈、第 3和 4掌骨干及第 1掌骨基底部等部位的骨折最常见。分析结果表明 ,掌骨骨折损伤程度不同 ,其损伤机理不同 ,各有其特点     

Perimortem or Postmortem Bone Fractures? An Experimental Study of Fracture Patterns in Deer Femora*

The determination of perimortem trauma is important for forensic anthropologists. Characteristics of bone fractures such as sharp edges, presence of fracture lines, the shape of the broken ends, fracture surface morphology, fracture angle on the Z-axis, and butterfly fractures are said to differentiate perimortem from postmortem trauma. A Drop Weight Impact Test Machine was used to break 76 deer femora of various ages since death. The results of this study suggest that the characteristics listed above are unreliable at differentiating a perimortem fracture from a postmortem fracture in a forensic case. There are, however, statistically significant differences between fresh bones broken less than 4 days old and dry bones broken 44 days or 1 year old after death.     

A Proposed Scheme for Classifying Pediatric Rib Head Fractures Using Case Examples

Pediatric rib head fractures are typically described as “posterior” or “costovertebral,” terms lacking specificity. To resolve this issue, a scheme was developed to describe the location of rib head fractures observed in a pediatric forensic population. The scheme uses three anatomical landmarks, terminus (tip), tubercle, and costovertebral articular surface to divide the rib head into two subregions, costovertebral and costotransverse. Examples of five cases of infants with rib head fractures are presented using this scheme. Forty‐eight rib head fractures were observed in these infants with the following frequencies: 56% (three infants) at the terminus; 21% (three infants) in the costovertebral subregion; 21% (one infant) at the costovertebral articular facet; and 2% (one infant) in the costotransverse subregion. Due to the small number of cases assessed, statistical analyses could not be performed; however, the data demonstrate the variation in distribution of pediatric rib head fractures.     

Physical Matching of Metals: Grain Orientation Association at Fracture Edge

The objective of this study was to examine whether surface crystal orientation can be used to associate or differentiate metal fracture fragments. The orientations of individual crystals and crystals across the fracture plane were measured on polished steel and iron alloy surfaces using Electron Backscattered Diffraction/ Orientation Imaging Microscopy (EBSD/OIM). This investigation examined crystallographic characteristics within a metal. This study showed that for transgranular fracture, it is feasible that pieces of grains could be associated across the fracture surface with the difference in orientation between grains (misorientation) along a length sequence of grain orientations on one side of the fracture surface to associate the other side of a fracture surface. Regarding pair comparisons of crystals on fracture surfaces, it was estimated that the probability for an ordered sequence of six distinct oriented grains along a fracture surface to occur again is about 1 in 4.82 (10)³⁰ or 2.07 (10)⁻³¹.     

Classification of Pelvic Ring Fractures in Skeletonized Human Remains

Pelvic ring fractures are associated with high rates of mortality and thus can provide key information about circumstances surrounding death. These injuries can be particularly informative in skeletonized remains, yet difficult to diagnose and interpret. This study adapted a clinical system of classifying pelvic ring fractures according to their resultant degree of pelvic stability for application to gross human skeletal remains. The modified Tile criteria were applied to the skeletal remains of 22 individuals from the Cleveland Museum of Natural History and Universidad Nacional Autónoma de México that displayed evidence of pelvic injury. Because these categories are tied directly to clinical assessments concerning the severity and treatment of injuries, this approach can aid in the identification of manner and cause of death, as well as interpretations of possible mechanisms of injury, such as those typical in car-to-pedestrian and motor vehicle accidents.     

Determination of Fracture Patterns in Glass and Glassy Polymers,

The study of fractures of glass, glassy‐type materials, and plastic has long been of interest to the forensic community. The focus of this interest has been the use of glass and polymer fractures to associate items of evidence under the assumption that each fracture is different. Generally, it is well‐accepted that deviations exist; however, the emphasis has been on classifying and predicting fracture rather than determining that each fracture is different. This study documented the controlled fracture patterns of 60 glass panes, 60 glass bottles, and 60 plastic tail light lens covers using both dynamic impact and static pressure methods under closely controlled conditions. Each pattern was intercompared, and based on the limited specimens tested in this study, the results illustrate that the fracture patterns are different. Further repetitive studies, under controlled conditions, will be needed to provide more statistical significance to the theory that each fracture forms a nonreproducible fracture pattern.     

A meta-analytic review of the frequency and patterning of laryngohyoid and cervical fractures in cases of suicide by hanging

The frequency and distribution of fractures are commonly utilized to assist in interpreting the manner of death. In cases of alleged suicide by hanging, however, the evidence base for the frequency and patterning of laryngohyoid and cervical vertebrae fractures resulting from such blunt force traumatic events is limited and so fractures cannot be reliably used to assist in interpreting the manner. Using meta-analytic techniques, this study aimed to estimate frequency and distribution of fractures in the context of relevant intrinsic and extrinsic variables. A systematic review of the literature identified 20 studies with relevant data (8523 cases of suicide by hanging). Meta-analyses identified the frequency and distribution of fractures present and how fracture frequency was affected by the subgroups of age, sex, completeness of suspension, ligature knot position and study design. Results indicated that fracture frequency was variable, there was no unique patterning, and high levels of heterogeneity were present in all variable sub-groups. Age was the only subgroup to show differences. Findings suggest that neck fracture frequency is inconsistent and cannot be predicted by the chosen variables. Subsequently, neck fractures in isolation should not be given weight in medico-legal interpretations of a hanging death as suicidal.     

骨盆骨折伤残重新鉴定65例分析

目的 研究有争议的交通事故受伤人员骨盆骨折伤残等级评定案例,分析其在初次鉴定中暴露出来的问题,探讨如何正确理解与把握骨盆骨折的鉴定条款,建立科学的判定标准。方法 收集上海市司法鉴定中心2006—2013年道路交通事故致骨盆骨折伤残等级重新鉴定案例65例,对初次鉴定和重新鉴定的资料进行分析比较。结果 鉴定时机不当,鉴定材料收集不全面,鉴定人对骨盆骨折条款的理解有误及其他一系列问题是重新鉴定意见改变伤残等级的主要原因。结论 针对上述问题,应该从提高鉴定人专业技能,建立统一判定标准等方面来提高此类案件的鉴定质量。     

胸部损伤死因鉴定审查在诉讼中的应用

人身伤害案件被害人的死因鉴定,轻则涉及被告人的量刑,重则事关案件的定性。而司法实践中,经常遇到一些刑事被害人的死因鉴定意见是建立在推断的基础之上,且其推断不具有排他性,经不起推敲,往往直接影响到案件的定性与处理。针对这一问题,结合司法案例进行分析,以期提升死因鉴定的证明力和法医学鉴定意见的公信力。