Skull fractures in forensic putrefied/skeletonised cases: The challenge of estimating the post-traumatic interval

Ante- and Post-Mortem Fracture Identification Protocol Based on Low- and High-Level Fusion Using Fourier Transform Infrared Spectroscopy and Raman Spectroscopy Association

In this study, the application of low-level fusion (LLF) and high-level fusion (HLF) strategies using a combination of Fourier transform infrared spectroscopy (FT-IR) and Raman spectroscopy in the identification of antemortem and postmortem fracture at different postmortem intervals (PMIs) was investigated. On a technical level, the same hard tissue sample can be detected using a mix of FT-IR and Raman techniques. At the method level, two cutting-edge chemometrics approaches (LLF and HLF) combining FT-IR and Raman spectroscopic data are explored. The models were ranked in accordance with their parametric quality as follows: HLF and LLF + HLF models > LLF single model > Raman single model > FT-IR single model. The LLF model performed marginally better than the Raman model, however, when compared to other models, the HLF model performed considerably better. The HLF model achieved the best performance, with both cross-validation accuracy and test data set accuracy of 0.88. The importance of the feature wavelengths in the model construction process was subsequently evaluated by intersection fusion, and it was found that the absorbance bands of amide I, PO43- ν1 ν3, and CH2 in FT-IR and phenylalanine, CO32- ν1- PO43- ν3, and amide III in Raman have outstanding contributions to the construction of antemortem and postmortem fractures identification models. Overall, the combination of FT-IR and Raman with the HLF strategy is a novel and promising approach for developing antemortem and postmortem fracture identification models at different PMIs.

Autopsy-Based Comparative Study of Gross and Histopathological Findings at Bone Fracture Surfaces Before and After Death

ABSTRACT

Fractures of bones are commonly encountered in traumatic injuries, and distinguishing between antemortem (AM) and postmortem (PM) bone fractures is crucial for estimating the time since injury and has important medicolegal implications. Correct differentiation enables understanding the dynamics of the injury and, in some cases, the cause of death. The present study aims to evaluate the gross morphological and histopathological characteristics of bony fracture surfaces to determine whether they occurred before or after an individual's death.Fifty-seven sets of bone samples, including both antemortem and artificially created postmortem fractures, were collected from cadavers during medicolegal autopsies, meeting the inclusion criteria. Gross morphological and histopathological features were examined after staining the bony fracture edges with hematoxylin and eosin stain. The study revealed distinct morphological characteristics at fracture surfaces for both antemortem and artificially created postmortem fractures. In addition, signs of vital reaction were observed exclusively in antemortem fracture cases.In conclusion, the findings emphasize the importance of meticulous morphological and histopathological examination of bony fracture surfaces to differentiate between antemortem fractures and artificially created postmortem artifacts. This differentiation holds significant value in forensic investigations and medicolegal cases.

The various meanings and uses of bone "remodeling" in biological anthropology: A review

OBJECTIVES

In modern bone biology, the term "remodeling" generally refers to internal bone turnover that creates secondary osteons. However, it is also widely used by skeletal biologists, including biological anthropologists as a catch-all term to refer to different skeletal changes. In this review, we investigated how "remodeling" is used across topics on skeletal biology in biological anthropology to demonstrate potential problems with such pervasive use of a generalized term.

METHODS

Using PubMed and Google Scholar, we selected and reviewed 205 articles that use the term remodeling to describe skeletal processes and have anthropological implications. Nine edited volumes were also reviewed as examples of collaborative work by different experts to demonstrate the diverse and extensive use of the term remodeling.

RESULTS

Four general meanings of bone "remodeling" were identified, namely, internal turnover, functional adaptation, fracture repair, and growth remodeling. Additionally, remodeling is also used to refer to a broad array of pathological skeletal changes.

DISCUSSION

Although we initially identified four general meanings of bone remodeling, they are not mutually exclusive and often occur in combination. The term "remodeling" has become an extensively used catch-all term to refer to different processes and outcomes of skeletal changes, which inevitably lead to misunderstanding and a loss of information. Such ambiguity and confusion are potentially problematic as the field of biological anthropology becomes increasingly multidisciplinary. Therefore, we advocate for precise, context-specific definitions and explanations of bone remodeling as it continues to be used across disciplines within and beyond biological anthropology.

Forensic applications of micro-computed tomography: a systematic review

Purpose

The aim of this systematic review was to provide a comprehensive overview of micro-CT current applications in forensic pathology, anthropology, odontology, and neonatology.

Methods

A bibliographic research on the electronic databases Pubmed and Scopus was conducted in the time frame 01/01/2001–31/12/2021 without any language restrictions and applying the following free-text search strategy: “(micro-computed tomography OR micro-CT) AND (forensic OR legal)”. The following inclusion criteria were used: (A) English language; (B) Application of micro-CT to biological and/or non-biological materials to address at least one forensic issue (e.g., age estimation, identification of post-mortem interval). The papers selected by three independent investigators have been then classified according to the investigated materials.

Results

The bibliographic search provided 651 records, duplicates excluded. After screening for title and/or abstracts, according to criteria A and B, 157 full-text papers were evaluated for eligibility. Ninety-three papers, mostly (64) published between 2017 and 2021, were included; considering that two papers investigated several materials, an overall amount of 99 classifiable items was counted when referring to the materials investigated. It emerged that bones and cartilages (54.55%), followed by teeth (13.13%), were the most frequently analyzed materials. Moreover, micro-CT allowed the collection of structural, qualitative and/or quantitative information also for soft tissues, fetuses, insects, and foreign materials.

Conclusion

Forensic applications of micro-CT progressively increased in the last 5 years with very promising results. According to this evidence, we might expect in the near future a shift of its use from research purposes to clinical forensic cases.

A method for the development of cranial fracture histology slides

Cranial vault fractures are of medicolegal interest as they have long-term impacts to someone's health and may contribute to an individual's death. The ability to distinguish antemortem from perimortem fractures and to assess the age of the injury is increasingly dependent on histology. Despite the increasing role of histology in assessing the microanatomy of osseous fractures, there are no methods currently available which account for the nuances and difficulties in creating high-quality histologic slides of cranial vault fractures that allow visualization of cellular features associated with healing bone. The authors present a modified method specific to slide development of human cranial vault fractures derived from the trial-and-error process of creating 730 such slides over a 3-year period which are suitable for the evaluation of the tissues, cells, and nuclei involved in fracture healing. This method adapts and troubleshoots typical histological procedures including sample excision, fixation, decalcification, dehydrating, clearing, embedding, microtomy, and staining, and introduces new procedures including preprocessing photography and cassette placement. By implementing these modifications, the number of poor-quality slides that required a new section to be sent to the histology laboratory was greatly reduced. Proactively implementing this new method into cranial fracture histologic slide development significantly reduces the number of slide rejections due to common issues like folding, chatter, or insufficient staining, saving both time and financial resources for forensic practitioners, researchers, and histotechnologists.

Utility of micro-CT for dating post-cranial fractures of known post-traumatic ages through 3D measurements of the trabecular inner morphology

Fracture dating is an issue at the forefront of forensic sciences. While dating fracture is crucial to understanding and verifying the chronology of events in cases of abuse and violent death, its application is the subject of considerable discussion in the scientific community, filled with limitations and difficulties. Current methods for fracture dating are mainly based on a qualitative assessment through macroscopy, microscopy, and imaging and subject to variations depending on the experience of the observer. In this paper, we investigated the potential of quantifiable micro-CT analysis for fracture dating. Five histomorphometric parameters commonly used for the study of the 3D bone trabecular microarchitecture with micro-CT were calculated based on nine fractures of known post-traumatic ages, including the degree of anisotropy, connectivity density, bone volume fraction, trabecular thickness, and trabecular separation. As a result, trends in the evolution of the microarchitecture of the bone relative to age of the callus could be identified, in particular concerning anisotropy, trabecular separation and connectivity density, consistent with the healing bone process. The findings obtained in this pilot study encourage further research in quantifiable parameters of the bone microarchitecture as they could represent useful features for the construction of objective models for fracture dating.

The Repository of Antemortem Injury Response (REPAIR): an online database for skeletal injuries of known ages

An accurate assessment of time since fracture is an essential component of abuse and death investigations; however, little evidence-based research exists on dating fractures, especially those of the cranial vault. This is primarily due to difficulties in procuring human fracture specimens of known posttraumatic survival times. The aim of this article is to introduce a new database through which limitations imposed by sample procurement may be mitigated. The Repository of Antemortem Injury Response (REPAIR) is a digitally accessible database of cranial vault fractures of known ages with extensive contextual information and visual documentation in the form of photography, radiography, and histological photomicrographs. This repository is a multifunctional tool that serves as a case submission portal for cranial fractures of known posttraumatic survival time, a sample database for research on fracture healing and rates of repair, a resource for comparative assessments of cranial fractures in forensic casework, and an educational tool for healing fracture histomorphology.

Forensic Application of Monoclonal Anti-Human Glycophorin A Antibody in Samples from Decomposed Bodies to Establish Vitality of the Injuries. A Preliminary Experimental Study

Glycophorins are an important group of red blood cell (RBC) transmembrane proteins. Monoclonal antibodies against GPA are employed in immunohistochemical staining during post-mortem examination: Through this method, it is possible to point out the RBC presence in tissues. This experimental study aims to investigate anti-GPA immunohistochemical staining in order to evaluate the vitality of the lesion from corpses in different decomposition state. Six cases were selected, analyzing autopsies’ documentation performed by the Institute of Legal Medicine of Rome in 2010–2018: four samples of fractured bones and three samples of soft tissues. For the control case, the fracture region of the femur was sampled. The results of the present study confirm the preliminary results of other studies, remarking the importance of the GPA immunohistochemical staining to highlight signs of survival. Moreover, this study suggests that the use of this technique should be routinely applied in cases of corpses with advanced putrefaction phenomena, even when the radiological investigation is performed, the macroscopic investigation is inconclusive, the H&E staining is not reliable. This experimental application demonstrated that the use of monoclonal antibody anti-human GPA on bone fractures and soft tissues could be important to verify whether the lesion is vital or not.

An evaluation of the differences in paediatric skeletal trauma between fatal simple short falls and physical abuse blunt impact loads: An international multicentre pilot study

In cases where a deceased child exhibits trauma as a result of a physical abuse blunt impact load, a parent/caregiver may provide a simple short fall (SSF) as the justification for that trauma. The skeletal fractures remain difficult to differentiate between a SSF and physical abuse however, as both are the result of a blunt impact load, and are therefore biomechanically alike, and the rare nature of these fatalities means only anecdotal research has been available to validate such claims. The aim of this pilot study was to investigate if there may be differences in the skeletal fracture patterns and types resulting from SSFs compared with those resulting from physical abuse blunt impacts. Paediatric (<10 years) cases of fatal SSFs (≤1.5 m) and physical abuse were collected from the Victorian Institute of Forensic Medicine (Australia), Institut Médico-Légal de Paris (France), University of Pretoria (South Africa) and Great Ormond Street Hospital (England). For each case the intrinsic and extrinsic variables were recorded from medico-legal reports and skeletal trauma was documented using post-mortem computed tomography scans and/or skeletal surveys. Three SSFs and 18 physical abuse cases were identified. Of the SSF cases, two exhibited fractures; both of which were simple linear neurocranial fractures. Comparatively, 12 of the physical abuse cases exhibited fractures and these were distributed across the skeleton; 58% located only in the skull, 17% only in the post-cranial and 25% located in both. Skull fracture types were single linear, multiple linear and comminuted. This pilot study suggests, anecdotally, there may be differences in the fracture patterns and types between blunt impact loads resulting from a SSF and physical abuse. This data will form the foundation of the Registry of Paediatric Fatal Fractures (RPFF) which, with further multicentre contributions, would allow this finding to be validated.

The potential of micro-CT for dating post-cranial bone fractures: a macroscopic, radiographic, and microtomography study of fractures of known post-traumatic ages

The estimation of the post-traumatic survival time (PTST) in case of bone injuries remains a tricky issue in the forensic field, especially when dealing with dry bones. Newer high-resolution imaging, and in particular microcomputed tomography (micro-CT), has the potential to significantly improve our abilities to interpret antemortem and perimortem lesions and accurately date fractures in a less destructive analysis. In this paper, nine costal fractures of known post-traumatic ages were analyzed through gross examination, conventional radiography, and microcomputed tomography, in order to test the potential of microcomputed tomography for dating fractures. As a result, microcomputed tomography provided images of high quality and definition and allowed the observation of the internal microarchitecture of the fractures and calluses. While microcomputed tomography cannot substitute histological examination for the estimation of the post-traumatic survival time, it constitutes a potent and helpful complementary tool for the analysis of bone trauma.