椎弓崩裂与外伤伤病关系法医学鉴定26例分析

目的阐述椎弓崩裂与外伤之间伤病关系的法医学鉴定要点。方法收集26例椎弓崩裂案例,从年龄、伴随症状、治疗方式、致伤方式等方面讨论此类病例的特点。结果认定外伤与损伤后果之间存在一定因果关系的2例被鉴定人年龄均在50岁以下,致伤方式均为高能量损伤,且均伴有合并伤,2例患者均接受了手术治疗。结论应关注50岁以下中青年外伤后椎弓崩裂与外伤之间的伤病关系分析。对于选择手术治疗者,更需分析两者之间的伤病关系。     

无骨折脱位型颈脊髓损伤法医学鉴定25例分析

目的 探讨无骨折脱位型颈脊髓损伤案例中外伤与损害后果因果关系法医学鉴定的要点.方法 收集25例无骨折脱位型颈脊髓损伤的法医学鉴定案例资料,总结被鉴定人的年龄、致伤方式、影像学检查结果、自身颈椎退变情况、临床表现、主要诊疗情况、预后情况等,按照损伤与损害后果相关程度分为直接原因、主要原因、同等原因、次要原因、无原因进行伤...     

An unusual case of sudden unexpected death: postmortem investigation and biomechanical analysis of the cervical spine

A naked man died under peculiar circumstances and the postmortem examination revealed unexpected lesions in the cervical spine. Investigations of the cervical spine (computed tomography, magnetic resonance imaging, and histological examination) showed that a piece of bone was torn of the anterior part of vertebra C6 and that there was fresh bleeding in the surrounding tissue. The cause of death remained unclear but was most likely cardiac arrhythmia initiated by beta-2 agonist inhalation due to an acute asthmatic attack. Data from biomechanical investigation using finite element analysis supported the conclusion that the cervical spine injury was secondary to impact during falling as a consequence of the cardiac arrhythmia.     

Do bone elasticity and postmortem interval affect forensic fractographic analyses?

Forensic fractographic features of bone reliably establish crack propagation in perimortem injuries. We investigated if similar fracture surface features characterize postmortem fractures. Experimentally induced peri- and postmortem fractures were used to assess if fractographic features vary as bone elasticity decreases during the postmortem interval (PMI). Thirty-seven unembalmed, defleshed human femoral shafts from males and females aged 33–81 years were fractured at varying PMIs with a drop test frame using a three-point bending setup and recorded with a high-speed camera. Vital statistics, cause of death, PMI length, temperature, humidity, collagen percentage, water loss, fracture energy, and fractography scores were recorded for each sample. Results showed that fractographic features associated with perimortem fractures were expressed in PMIs up to 40,600 accumulated degree hours (ADH), or 60 warm weather days. Hackle was the most consistently expressed feature, occurring in all fractures regardless of ADH. The most variable characteristics were wake features (78.4%) and arrest ridges (70.3%). Collagen percentage did not correlate strongly with ADH (r = −0.04, p = 0.81); however, there was a strong significant correlation between ADH and water loss (r = 0.74, p < 0.001). Multinomial logistic regression showed no association between fractographic feature expression and ADH or collagen percentage. In conclusion, forensic fractographic features reliably determine initiation and directionality of crack propagation in experimentally induced PMIs up to 40,600 ADH, demonstrating the utility of this method into the recent postmortem interval. This expression of reliable fractographic features throughout the early PMI intimates these characteristics may not be useful standalone features for discerning peri- versus postmortem fractures.     

Discrimination of Falls and Blows in Blunt Head Trauma: A Multi‐Criteria Approach

Abstract: In the discrimination of falls versus blows, the hat brim line (HBL) rule is mentioned in several textbooks as the most useful single criterion. Recent studies, however, have found that the HBL rule is only moderately valid and that its use on its own is not recommended. The purpose of this 6‐year retrospective study was to find additional individually useful criteria in the distinction of falls from blows. Overall, the following criteria were found to point toward blows: more than three lacerations, laceration length of 7 cm or more, comminuted or depressed calvarial fractures, lacerations or fractures located above the HBL, left‐side lateralization of lacerations or fractures, more than four facial contusions or lacerations, presence of ear lacerations, presence of facial fractures, and presence of postcranial osseous and/or visceral trauma. Based on the most discriminating criteria, a decision tree was constructed to be potentially applicable to future cases.     

Are Peripapillary Intrascleral Hemorrhages Pathognomonic for Abusive Head Trauma?*

Abstract: The American Academy of Pediatrics’ Committee on Child Abuse and Neglect, Section on Ophthalmology, acknowledges that searching for retinal hemorrhages (RHs) in infants only in cases of suspected of abuse creates selection bias. However, they also recommend that postmortem eye removal might not be indicated “in children who have clearly died from witnessed severe accidental head trauma or otherwise readily diagnosed systemic medical conditions.” Although infrequently described in the child abuse literature, peripapillary intrascleral hemorrhages (bleeding in the sclera at the optic nerve insertion)—putatively from severe repetitive acceleration/deceleration forces with or without blunt head trauma—have been considered essentially pathognomonic for abusive head trauma (shaken baby syndrome). We present two neonates who sustained accidental, severe in utero head injuries and had associated extensive RHs and optic nerve sheath hemorrhages with peripapillary intrascleral hemorrhages detected at autopsy. Neither neonate had a documented clinical fundal examination in the intensive care unit.     

Interpreting Injury Mechanisms of Blunt Force Trauma from Butterfly Fracture Formation

According to biomechanics of fracture production during blunt impact, tubular bones are subject to compressive (impact site) and tensile (opposite impact site) forces; this causes bones to break in tension before compression, producing Y-shaped fracture patterns with breakaway (butterfly) fragments. In current forensic models, the side of the bone exhibiting the breakaway fragment is designated the impact side, with initial breakage occurring opposite. Fracture production and patterning of blunt impacts to 255 sheep femora were analyzed. Contra the existing model, only 60% of complete butterfly fractures exhibited impact side breakaway fragments. Although fractures initiated on the tension, nonimpact side, butterfly fragments formed on either compression or tension sides. Using newly defined breakaway fragment shape criteria, impact side was estimated with 98% accuracy for both complete and partial butterfly fractures. Furthermore, the results suggest that the impact site is the located on one of the Y-fracture's arms, not the butterfly fragment's center, as previously modeled.     

Postmortem Skeletal Survey Practice in Pediatric Forensic Autopsies: A National Survey*

Abstract: Recommendations for the evaluation of an unexplained death in infancy include a postmortem skeletal survey (PMSS) to exclude skeletal trauma. Objectives of this study were to assess adherence to these recommendations in forensic autopsies in children equal to or less than 36 months of age, and what factors influence the use or nonuse of the PMSS. We surveyed pathologists who were members of the American Academy of Forensic Sciences. The survey included practice characteristics about where, when, and how PMSS were done. Nearly all respondents (99.6%) indicated they performed PMSS at least some of the time; however, almost a third did not use PMSS for all suspected Sudden Infant Death Syndrome (SIDS), abuse, unsafe sleep, or undetermined causes of death. Despite evidence that “babygrams” are inappropriate in a SIDS workup, 30% of pathologists use them preferentially. Despite SIDS being a diagnosis of exclusion that requires a PMSS, almost 10% of pathologists do not order a PMSS. Future research is necessary to reduce barriers to this important component of the pediatric forensic autopsy.