Investigations on the Cellular and Morphologic Characteristics of Cranial Vault Fracture: Research and Development of a Time Since Fracture Protocol and Database

As submitted by the proposer: Determining time since injury of cranial fractures is important in many medicolegal investigations -- especially those involving child abuse and abusive homicide. Forensic practitioners are often asked whether age of the injury corroborates the history provided to determine whether the death should be classified as an accident or homicide. Furthermore, the presence of multiple injuries at different stages of healing establishes a pattern and history of abuse. Thus, an accurate interpretation of injury timing is paramount to thorough death investigations. Unfortunately, there is minimal evidence-based research on human fracture repair rates. The majority of studies focus on radiological techniques to make these interpretations, however these studies are often based on the author’s experience, performed on small sample sizes with unknown time since injury, and not independently validated. Furthermore, as cranial fractures are difficult to visualize radiographically, there is a paucity of research on the sequence and timing of fracture healing in the cranium. As a consequence, forensic practitioners use inappropriate comparative information to estimate time since fracture, and there is no standard procedure for making these interpretations. To address this significant gap in forensic science, this research will focus on the following objectives: a) create a database of decedents with cranial vault fractures of known injury dates with associated information on fracture cause, co-morbidities and photographic, radiologic, and histological documentation of injury; b) histologically evaluate cranial fracture healing to determine the cellular and tissue progression at different anatomic zones within the fracture site; and c) establish stages of cranial fracture healing with specific tissue and cellular characteristics. To ensure a robust and diverse sample is obtained, we will partner with other medical examiner offices and forensic anthropologists to collect samples on cases in which the mechanism and date of previous injuries are known. Each fracture sample submitted will be sectioned and treated with five different histochemical stains, including standard hematoxylin and eosin, alcian blue hematoxylin/orange G, Masson’s trichrome, Perl’s Prussian blue, and tartrate-resistant acid phosphatase to optimize the visibility of the cellular and tissue healing response. The products of this project will include a universal method to sample, analyze, and evaluate healing cranial fractures, and a database of known-age cranial fractures with supporting documentation. The Fracture Healing Database will be made available as a reference series for other anthropologists and pathologists, and will be an invaluable research tool incorporating macroscopic, radiographic, and histologic data for investigating time since cranial fracture. Note: This project contains a research and/or development component, as defined in applicable law, and complies with Part 200 Uniform Requirements - 2 CFR 200.210(a)(14). ca/ncf