Dong-Ri Li

The cranial stress distribution and morphological characteristics of cranial fractures in adult heads run over by motor vehicle were investigated. Cases of adults’ heads run over by motor vehicles were collected. The skull fracture degrees are categorized into no skull fracture, multiple skull fractures, and skull fractures with brain tissue overflow. According to China’s road traffic management system, vehicles in traffic accidents are categorized as heavy vehicles (weight ≥ 12 t), medium vehicles (4.5 t ≤weight < 12 t), light vehicles (1.8 t <weight < 4.5 t), and light minicars (weight ≤ 1.8 t). Finite element simulations were used to analyze the relationship between cranial fracture morphology and vehicle weight as well as cranial stress response. A total of 41 cases of heads run over by motor vehicles were collected. In seven cases of multiple skull fractures caused by medium vehicles, there were skull fractures on both the ground side and the tyre side, and the degree of skull fracture was more serious on the ground side than on the tyre side. Finite element simulations showed that the cranial stress in was more concentrated on the ground side than on the tyre side. Light vehicles and light minicars running over a head usually do not fracture the skull. Head injuries caused by medium vehicles are mainly characterized by multiple skull fractures, and the degree of skull fracture is more serious on the ground side than on the tyre side.

A 56-year-old man with a long history of alcoholism and a palpable raised mass about 23 cm × 12 cm in size on his neck was diagnosed with Madelung’s disease (MD); the patient also had hyperuricemia. On day 1, he underwent neck lipoma tissue resection and suddenly had dyspnea 9 h after the operation, which was followed by cardiac arrest. After heart rate resuscitation, he developed a heartbeat, but he remained in a coma and died 9 days after the operation. No obvious pathological tracheal compression from a hematoma was observed while evaluating the patient’s neck on autopsy. On microscopy, the patient had an extensive pulmonary fat embolism, partial alveolar septal rupture and hemorrhage, and fat particles, and there was extensive infiltration of macrophages, which had phagocytosed fat particles, in the alveolar cavity. There was also evidence of pulmonary infection and hypoxic-ischemic encephalopathy. The cause of death was postoperative pulmonary fat embolism resulting in pneumonia and central nervous system injury. This is the first report of a patient with MD who died of a fatal pulmonary fat embolism after neck lipoma tissue resection. Medicolegal experts and clinicians should pay sufficient attention to this case.

Introduction There are many migrant workers in China’s first-tier cities, but little is known about road safety. This paper systematically analysed road traffic injuries and risk factors among migrant workers in Guangzhou, China. Methods Road traffic crash data from 2017 to 2021 were obtained from the Guangzhou Public Security Traffic Management Integrated System. We plotted the crash network of road users in road traffic crashes and used logistic regression to analyse the risk factors for migrant workers of motorcycle and four-wheeled vehicle crashes. Moreover, the roles of migrant workers and control individuals as perpetrators in road traffic crashes were also analysed. Results Between 2017 and 2021, 76% of road traffic injuries were migrant workers in Guangzhou. Migrant workers who were motorcyclist drivers most commonly experienced road traffic injuries. Crashes between motorcyclists and car occupants were the most common. The illegal behaviours of migrant worker motorcyclists were closely related to casualties, with driving without a licence only and driving without a licence and drunk driving accounting for the greatest number. Migrant workers were responsible for many injuries of other road users. Motorcycle drivers have a higher proportion of drunk driving. Discussion Migrant workers play an important role in road traffic safety. They were both the leading source of road traffic injuries and the main perpetrators of road traffic crashes. Measures such as strict requirements for migrant workers to drive motorcycles with licences, prohibit drunk driving, greater publicity of road safety regulations, and combining compulsory education with punishment for illegal behaviours.

Liver injury is one of the most severe traffic trauma. The development of accurate liver finite element model is beneficial for improving the biofidelity and validity in crash simulations, aiming to analyze the injury in accidents. 12 human liver finite element models in the current research were constructed from high resolution CT data of a Chinese male 50th percentile human subject, including the main structures like left lobe, right lobe, capsule, parenchyma and falciform ligament. The simulations based on Nava et al. experiment were conducted to validate the models and make comparisons of modeling method accuracy. The results demonstrated that the larger deviation happened to the tetra models due to the stiffer algorithm compared to the hex models, which were more sensitive to element size. The existence of capsule had significant effects on the liver mechanical responses, reducing the liver tissue pressure. Shell elements were more suitable for modeling the capsule.

Background: So far, there have been more than 761 million confirmed cases of SARS-CoV-2 worldwide, with more than 6.8 million deaths. The most common direct causes of death for COVID-19 are diffuse alveolar injury and acute respiratory distress syndrome. Autopsy results have shown that 80-100% of COVID-19 patients have microthrombi which is 9 times higher than in patients with influenza. There are reported cases of fat embolism associated with Covid-19, but relevant epidemiological investigations and fatal cases of pulmonary fat embolism are lacking. In this report, we describe the first COVID-19 patient to die from pulmonary fat embolism. Case presentation: A 54-year-old woman suddenly felt unwell while at work. She had difficulty breathing for 40 min and lost consciousness for 20 min before being taken to the hospital. On admission, her temperature was 36 ℃, but her respiration, heart rate, and blood pressure were undetectable. Laboratory examination revealed C-reactive protein, 26.55 mg/L; D-dimer, 11,400 µg/L; and procalcitonin, 0.21 ng/mL. She was declared clinically dead 2 h after admission due to ineffective rescue efforts. At autopsy, both lungs were highly oedematous with partial alveolar haemorrhage. The presence of microthrombi and pulmonary fat embolism in small interstitial pulmonary vessels was confirmed by phosphotungstic acid haematoxylin staining and oil red O staining. The immunohistochemical results of spike protein and nucleocapsid protein in laryngeal epithelial cells confirmed SARS-CoV-2 infection. Conclusions: Pulmonary fat embolism may be another fatal complication of COVID-19 infection, and clinicians should pay more attention to it.

Objective In this study, the hemopericardium volume and pathological characteristics associated with cardiac ruptures caused by blunt violence, AMI, aortic dissection and CPR have been analyzed. The findings might provide reference and data support for deciphering the cause of heart rupture in forensic pathology. Method Pericardial water-injection tests were conducted in 22 noncardiac death subjects. Other study groups included 9 cases of myocardial infarction, 20 cases of aortic dissection rupture, 11 cases of cardiac rupture caused by trauma and 4 cases of cardiac rupture by CPR. The volume of hemopericardium and the pathological features were analyzed for each group. Result The hemopericardium volume in myocardial infarction and dissecting aneurysm rupture were significantly higher than the pericardial injection test in noncardiac subjects (p-value < 0.01). The traumatic cardiac rupture cases had a large range in hemopericardium volume and no significant difference was observed with respect to non-cardiac death cases (p-value > 0.05). The volume of hemopericardium in CPR-induced cardiac rupture had no difference with non-cardiac rupture and it was significantly lower than the pericardial injection test (p-value < 0.01). Conclusion Differences in the volume of hemopericardium induced by different causes of cardiac rupture were observed. It may be related to the state of the cardiac systolic functions during an event of a rupture. The volume of hemopericardium can be used as reference data to determine the mechanism of the rupture. This could also be beneficial in cases of cardiac rupture with similar morphological and pathological features such as severe blunt chest injury and CPR.

A 40-year-old woman underwent vaginoplasty with intramural injection of fillers from an illegal medical practitioner. Approximately 2 h after the injection, she developed lower abdominal pain. The patient was taken to the hospital approximately 5 h later due to worsening pain. When the patient was admitted for physical examination, she suddenly experienced cardiac and respiratory arrest. She was resuscitated but remained in a coma. Unfortunately, the patient died approximately 12 h after being admitted to the hospital. The forensic autopsy revealed extensive amorphous basophilic emboli in the small interstitial vascular lumen of both lungs, and a large amount of the same type of substances were also found in the vaginal wall. Hyaluronidase digestion and Alcian blue staining confirmed that most components of the injection were hyaluronic acid (HA). HA is widely used as a cosmetic filler in the field of plastic surgery and is generally considered to have few adverse effects. This paper reports the first anatomical case of fatal pulmonary embolism caused by vaginal injection of HA. Level of Evidence V This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.