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     

Skin penetration surrogate for the evaluation of less lethal kinetic energy munitions

Although the benefits of the use of less lethal kinetic energy munitions are numerous, there is a need to evaluate the munitions prior to deployment to ensure their intended effect. The objective of the current research was to validate a surrogate that could be used to predict the risk of penetration of these devices. Existing data from biomechanical testing with post-mortem human specimens (PMHS) served as the foundation for this research. Development of the surrogate involved simulating the various layers of the skin and underlying soft tissues using a combination of materials. A standardized 12-gauge impactor was used to assess each combination. The energy density that resulted in a 50% risk of penetration for the anterior thorax region (23.99 J/cm(2)) from the previous research was matched using a specific combination of layers. Twelve various combinations of materials were tested with the 50% risk of penetration determined. The final validated surrogate consisted of a Laceration Assessment Layer (LAL) of natural chamois and .6 cm of closed-cell foam over a Penetration Assessment Layer (PAL) of 20% ordnance gelatin. This surrogate predicted a 50% risk of penetration at 23.88 J/cm(2). Injury risk curves for the PMHS and surrogate development work are presented.     

Rib Variation at Multiple Locations and Implications for Histological Age Estimation*

Existing histological age estimation methods using the rib were developed mainly from the midshaft; however, in forensic practice, uncertainty of sampling location often arises due to fragmented or previously sampled ribs. The potential for error increases when sampling location is uncertain and utilizing a section beyond the midshaft (either anterior or posterior) may result in erroneous age estimates. Additionally, there is debate within the field regarding the minimum number of sections needed for accurate age estimation. The aim of this research is to determine the importance of the midshaft distinction for age-at-death assessment and the necessity of analyzing serial sections by evaluating histological variables at sampling locations along the length of the rib. Three seriated histological sections at three sampling locations (anterior, midshaft, and posterior) were obtained from sixth ribs of ten postmortem human subjects. Cortical area (Ct.Ar) and osteon population density (OPD) were collected from each section (n = 90). Significant differences were determined in Ct.Ar between sampling locations, demonstrating the variation present along the length of the rib. A comparison of OPD at sampling locations revealed significant differences, suggesting that sampling site is critical to accurate age estimates. When sampling location is uncertain, a more anterior section should be taken. Analysis of serial sections within locations revealed no significant differences in OPD or Ct.Ar, supporting the practice of collecting data from one section for age estimation. While an age estimate can be achieved through the analysis of one section, best practice suggests reading two sections to capture intraindividual variation.     

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.     

有限元法研究高坠中躯干不同部位着地的肋骨骨折机制

目的利用有限元法研究躯干不同部位着地的肋骨损伤机制,对重建高坠过程提供新技术与新方法。方法采用有限元法观察全人类安全模型THUMS4.0在躯干部不同部位着地时的肋骨损伤情况,并与实际案例进行比较,从生物力学角度分析高坠导致的肋骨骨折形成机制。结果不同部位着地所形成的应力、应变分布及肋骨骨折部位存在一定差异。躯干前侧着地时双侧均发生肋骨骨折,骨折主要位于肋骨-肋软骨交界处和腋中线区域;躯干右前侧着地时,着地一侧首先发生肋骨骨折,骨折分布于右侧腋中线至腋后线区域以及双侧肋骨-肋软骨交界处;躯干后侧着地时,骨折主要位于双侧肋骨后侧;躯干右后侧着地时,着地部位易发生多发性肋骨骨折。塑性应变多集中于骨折处,von Mises应力除集中于骨折处,也可位于其他部位。结论躯干部不同部位着地时,肋骨骨折部位及损伤机制具有一定差异。     

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.     

163处肋骨骨折的影像学分析

目的：探讨影像学检查方法在不同区段肋骨骨折法医学鉴定中的应用。方法回顾性分析56例被鉴定人共计163处肋骨骨折的骨折部位、影像学检查次数及其首次检出的影像学技术等资料。结果在损伤后早期（≤14 d）的检出率为65.6%。 X线对肋骨前段骨折的首次检出率76.2%，两次内检出率90.5%；CT首次检出率66.7%，两次内检出率80.0%。 X线对肋骨腋段骨折的首次检出率仅27.6%，两次内检出率58.6%；CT首次检出率54.3%，两次内检出率80.4%。X线对肋骨背段骨折的首次检出率63.6%，两次内检出率81.8%；CT首次检出率50.0%，两次内检出率70.0%。结论在肋骨骨折的鉴定中，应注意影像学检查的随访，综合运用不同技术手段，尤其在疑有肋骨腋段骨折的案例中，单纯X线摄片可能造成漏检，建议选择CT扫描。     

Psychopathology and weapon choice: a study of 103 perpetrators of homicide or attempted homicide

Bone marrow (BM) analysis is of forensic interest in postmortem toxicological investigation in case of limited, unavailable or unusable blood samples. However, it remains difficult to determine whether a drug BM concentration is therapeutic or represents overdose, due to the lack of studies on this alternative matrix. Given the variations in BM composition in the body, sample location was suggested to be a relevant factor in assessing BM concentration. The aim of the present study was to compare postmortem caffeine concentrations in various BM sample locations and secondly to consider the correlation between BM and blood concentrations. Six BM samples (right and left side: proximal and medial femur and 5th rib) and a blood sample were collected from 21 forensic autopsies. Gas chromatography coupled to tandem mass spectrometry was performed. Blood caffeine concentrations ranged from 60 to 7591ng/mL. Femoral and rib BM concentrations ranged from 51 to 6171ng/g and 66 to 7280ng/g, respectively. Blood concentrations were always higher than BM concentrations. As a good correlation was demonstrated between blood and rib BM and between blood and the average of the four femoral BM concentrations, blood caffeine concentrations could be correctly extrapolated from BM concentrations. BM caffeine concentration was found to depend on sample location. Rib BM caffeine concentrations appeared to be systematically greater than averaged femur values and concentrations were much more variable between the 4 femur BM samples than between the 2 ribs. From a practical point of view, for caffeine analysis, rib BM appeared more relevant than femoral BM, which requires multisampling to overcome the concentration variability problem.     

放射影像学方法测量活体女性颈椎推算身高

目的测量颈椎高度建立四川汉族女性人群的身高推算方程，为法医学个人识别提供帮助。方法应用计算机X线摄影放射学方法，在209例四川汉族女性颈椎CR片上测量C3～C7椎体高度，并准确测量身高。按年龄是否大于45岁进行分组，对各颈椎的测量数据与身高进行线性回归分析，建立颈椎推算身高的回归方程。结果共建立一元回归方程36个，多元回归方程12个，所有回归方程经线性回归模型假设检验，均有统计学意义（P〈0．05）。所建立的回归方程的复相关系数（r）在0．628～0．280范围内，回归方程的标准误在4．03～5．03cm范围内。结论本研究所建立的回归方程，可用于四川汉族女性颈椎的身高推算。     

Rib fractures in infants due to cardiopulmonary resuscitation efforts

Although it is widely known that adults may sustain fractures of the anterior and/or lateral aspects of the ribs due to cardiopulmonary resuscitation (CPR) efforts, relatively little is written about the generation of CPR-related rib fractures in the infant age range. In a series of 70 consecutive autopsies in infants ranging in age from 2 weeks to 8 months, with no history or indications of injury, the parietal pleura of the thoracic cage was stripped and the ribs carefully examined for fracture. Subtle fractures of the anterolateral aspects of the ribs were discovered in 8 (11%) of the 70 cases. In 7 of the 8 cases, multiple ribs were fractured (ranging up to 10 rib fractures), and in 5 of these cases, the rib fractures were bilateral. All of the rib fractures were subtle, had little if any associated blood extravasation, and would have been easily missed had the parietal pleura not been stripped. These anterolateral rib fractures in infants are the likely correlate of anterolateral rib fractures that are not uncommonly seen in the adult population, resulting from resuscitation efforts. The rib fractures are subtle and may not be identified unless the parietal pleura is stripped.     

Weapon identification using antemortem computed tomography with virtual 3D and rapid prototype modeling-A report in a case of blunt force head injury

This research shows the exfoliation of the anterior dentition has significant potential to aid in establishing the minimum length of the post-mortem interval. Accumulated degree days (ADD) were used to quantify the decomposition of the periodontal ligament, represented by post-mortem exfoliation of the incisors. After subjects were removed subsequent to disturbance by scavengers and time limitations on the study, the final sample size was 36 incisors from the maxillae and mandibles of seven pigs (Sus scrofa). Average daily temperature was calculated using hourly temperature data recorded using DS1921G thermochrons for the duration of the project (June 14-December 17, 2008). During this period, six teeth (16.7%) were exfoliated. ADD for these six teeth ranged from 1539.7 °C to 2006.7 °C. The average ADD required for exfoliation was 1788.0 °C (SD=198.1 °C). No differences in ADD required for exfoliation were observed between the maxillary and mandibular teeth (t=2.085; p=0.128).     

Minimum velocity necessary for nonconventional projectiles to penetrate the eye: an experimental study using pig eyes

To satisfy the Criminal Code of Canada's definition of a firearm, a barreled weapon must be capable of causing serious bodily injury or death to a person. Canadian courts have accepted the forensically established criteria of "penetration or rupture of an eye" as serious bodily injury. The minimal velocity of nonconventional ammunition required to penetrate the eye including airsoft projectiles has yet to be established. To establish minimal threshold requirements for eye penetration, empirical tests were conducted using a variety of airsoft projectiles. Using the data obtained from these tests, and previous research using "air gun" projectiles, an "energy density" parameter was calculated for the minimum penetration threshold of an eye. Airsoft guns capable of achieving velocities in excess of 99 m/s (325 ft/s) using conventional 6-mm airsoft ammunition will satisfy the forensically established criteria of "serious bodily injury." The energy density parameter for typical 6-mm plastic airsoft projectiles is 4.3 to 4.8 J/cm2. This calculation also encompasses 4.5-mm steel BBs.     

Manual and Automated Cardiopulmonary Resuscitation (CPR): A Comparison of Associated Injury Patterns,

The purpose of this study was to identify and compare patterns of trauma associated with AutoPulse^® CPR and manual CPR. Finalized autopsy records from 175 decedents brought to the Harris County Institute of Forensic Sciences were reviewed, 87 received manual‐only CPR, and 88 received AutoPulse^® CPR (in combination with manual CPR as per standard protocol). The characteristic pattern observed in manual‐only CPR use included a high frequency of anterior rib fractures, sternal fractures, and midline chest abrasions along the sternum. The characteristic pattern observed in AutoPulse^® CPR use included a high frequency of posterior rib fractures, skin abrasions located along the anterolateral chest and shoulder, vertebral fractures, and a few cases of visceral injuries including liver lacerations, splenic lacerations, and hemoperitoneum. Knowledge of the AutoPulse^® CPR injury pattern can help forensic pathologists differentiate therapeutic from inflicted injuries and therefore avoid an erroneous assessment of cause and manner of death.     

Effects of kinetic energy and firearm-to-target distance on fracture behavior in flat bones

This research implements a fractographic approach to investigate the relationships between kinetic energy, firearm-to-target distance, and various aspects of fracture behavior in gunshot trauma. Gunshot experiments were performed on pig scapulae (n = 30) using three firearms generating different muzzle (initial) kinetic energies, including a 0.32 pistol (103 J), 0.40 pistol (492 J), and 0.308 rifle (2275 J). Specimens were shot from two distances: 10 cm (n = 15) and 110 cm (n = 15). Features evaluated in fractographic analysis such as cone cracks, radiating cracks, crack branching points, and circumferential cracks could be easily identified and measured in flat bones and allowed for statistical comparison of crack propagation behavior under different impact conditions. Higher-energy bullets produced more radiating cracks, more crack branching points, and longer fracture lengths than lower-energy bullets. Distance had no significant effect on fracture morphology at the distances tested. That quantitative measures of crack propagation varied with energy affirms that kinetic energy transfer is important in determining the nature and extent of fracture in gunshot wounds and suggests it may be possible to infer relatively high- versus relatively low-energy transfer using these features. Ranges obtained with the three firearms exhibited considerable overlap, however, indicating that other variables such as bullet caliber, mass, and construction influence the efficiency of energy transfer from bullet to bone. Therefore, fracture morphology cannot be used to identify a specific firearm or to directly reconstruct the muzzle (initial) kinetic energy in forensic cases.     

The pathological features and circumstances of death of lethal crush/traumatic asphyxia in adults--a 25-year study

A 25-year retrospective study of cases of crush/traumatic asphyxia autopsied at Forensic Science SA, Adelaide, Australia from 1980 to 2004 was undertaken. A total of 79 cases of crush asphyxia was found consisting of 63 males (80%) and 16 females (20%). The age range of the males was 19-86 years (mean=41.8 years) and of the females was 19-75 years (mean=38.6 years). In 18 cases the exact circumstances of death were unclear, leaving 61 cases in which details of the fatal episode were available. Major categories included vehicle crashes (N=37), industrial accidents (N=9), farm accidents (N=6) and entrapment beneath vehicles (N=5). Forty of the 79 victims (51%) had only very minor bruises and abrasions; 28 (35%) had evidence of chest compression with rib and sternal fractures and large areas of soft tissue bruising of the chest; 7 cases (9%) had other significant injuries or findings that had contributed to death. All of these victims had signs of crush asphyxia in the form of intense purple congestion and swelling of the face and neck, and/or petechial hemorrhages of the skin of the face and/or conjunctivae. The pattern of pathological findings of crush asphyxia was not influenced by the presence or absence of concomitant serious or lethal injuries. In 4 cases (5%) where the circumstances of the lethal episode were those of crush asphyxia there were no characteristic pathological findings. This study has shown that a high percentage of crush asphyxias may be caused by vehicle accidents. It has also demonstrated that on occasion fatal crush asphyxia may have to be a diagnosis of exclusion, made only when there are characteristic death scene findings, and no evidence of lethal natural diseases or injuries at autopsy, with negative toxicological screening.     

Structural analysis of human rib fracture and implications for forensic interpretation

Patterns of rib fractures are of significant clinical and forensic interest. Linking patterns of rib fracture with specific physical events provides a foundation for understanding the nature of traumatic events that are associated with rib fracture in forensic contexts. In this study, isolated human ribs (n = 8) were end-loaded to failure to investigate: (i) local deformations (bone strain) prior to and during structural failure, (ii) location of ultimate failure, and (iii) fracture mode. Structural properties of ribs were used to calculate theoretical stresses to determine whether such calculations could be used to predict site of fracture. Ribs fractured on the sternal side of midshaft in all experiments, but mode of failure varied with transverse, buckle, spiral, and "butterfly" fractures observed. Comparison of calculated stress with observed strain values suggest that experimental, rather than theoretical, approaches will be most productive in furthering understanding rib fracture in forensic contexts.     

Assessment of histomorphological features of the sternal end of the fourth rib for age estimation in Koreans

The aim of this study was to assess the histomorphological features of the fourth rib and to develop age-predicting equations for Koreans. Sixty-four rib samples (36 males and 28 females) obtained from forensic cases were used for developing equations. Two thin sections (<100-microm thick) per sample were prepared by manual grinding. Multivariate analysis of covariance revealed statistically significant differences in age-adjusted histomorphological variables between sexes. Using stepwise regression analysis, osteon population density and average osteon area were correlated with unknown sex (r2 = 0.826), and sex plus two histomorphological variables provided the best results for an age-predicting equation given the assumption of knowing the sex of a specimen (r2 = 0.839). Average Haversian canal area had little influence on age estimation for male or female samples, and relative cortical area was not significantly related to age for any specimen.     

Chest deflection tolerance to blunt anterior loading is sensitive to age but not load distribution

Ninety-three human cadaver tests are used in the development of thoracic injury risk functions with consideration of age and restraint condition. Linear logistic regression models are developed with the set of potential predictors including the maximum chest deflection, the age of the cadaver at death, gender, and the loading condition on the anterior thorax: blunt hub (41 tests), seat belt (26 tests), air bag (12 tests), and combined belt-and-bag (14 tests). Predicted outcomes were the probability of any rib fractures (onset of injury) and the probability of greater than six rib fractures (severe injury). The analysis shows that the injury risk function was not dependent on the loading condition, but was strongly dependent on age. A significant injury risk model with good ability to discriminate injury from non-injury tests (P < 0.0001, chi-square = 21.49, area under receiver operator characteristic curve (ROC) = 0.867, Kruskal's Gamma = 0.732) is presented using only maximum chest deflection and cadaver age as predictors of injury risk. The 50% risk of any rib fractures is found to occur at 35% chest deflection for a 30-year-old, but at 13% deflection for a 70-year-old. The 50% risk of severe injury is shown to occur at 33% chest deflection for a 70-year-old, but at 43% for a 30-year-old.     

Cardiac laceration and pericardial tamponade due to cardiopulmonary resuscitation after myocardial infarction.

Complications of cardiopulmonary resuscitation (CPR), such as rib fractures and pneumothorax, are not uncommon. The authors report the case of a 69-year-old woman who underwent surgery for a perforated duodenal ulcer. Eighteen hours postoperatively she sustained a cardiac arrest; vigorous resuscitation efforts, using advanced cardiac life-support procedures, failed. At autopsy, she had 350 mL of fresh blood in her pericardial sac, which had caused cardiac tamponade. Three ribs were fractured at the left sternal border. Directly underneath the fractured ribs were a 0.4-cm laceration of the pericardium and an accompanying 0.7-cm laceration of the left ventricle. There was an acute thrombus in the left anterior descending artery. Microscopic examination of the heart showed acute infarction of the left ventricle in the vicinity of the laceration. This case demonstrates that vigorous CPR performed on an acutely infarcted heart can result in lethal cardiac laceration and tamponade.     

Analysis of age-at-death estimation through the use of pubic symphyseal data

The question of whether age parameters derived from an American population will reliably estimate age-at-death for East European skeletal populations is important since the ability to accurately estimate an individual's age-at-death hinges on what standard is used. A reference sample of identified individuals with known ages-at-death from the regions of the Former Yugoslavia (n = 861) is used to determine the age structure of victims and serves as the prior in the Bayesian analysis. Pubic symphyseal data in the manners of Todd (Am J Phys Anthropol, 3 [1920], 285; Am J Phys Anthropol, 4 [1921], 1) and Suchey-Brooks (Am J Phys Anthropol, 80 [1986], 167) were collected for n = 296 Balkan males and females and for n = 2078 American males and females. An analysis of deviance is calculated using an improvement chi-square to test for population variation in the aging processes of American and East European populations using proportional odds probit regression. When males and females are treated separately, there is a significant association among females and the population (df = 1, chi-square likelihood ratio = 15.071, p = 0.001). New age estimates for Balkan populations are provided and are based on the calculated age distribution from the Gompertz-Makeham hazard analysis and the ages-of-transition. To estimate the age-at-death for an individual, the highest posterior density regions for each symphyseal phase are provided.