Determining Fracture Timing from Microscopic Characteristics of Cortical Bone

• NCJ Number: 309742
• Author(s): Natalie R. Langley
• Date Published: 2024
• Length: 25 pages
• Grant Number(s): 2020-75-CX-0015
• Agencies: NIJ-Sponsored
• Publication Type: Report (Study/Research)

Annotation

This study explores an innovative, experimental approach to determining fracture timing from microscopic characteristics of the cortical bone.

Abstract

In this study, researchers leverage the multidisciplinary expertise of three academic research centers (Mayo Rochester, Mayo Arizona, Arizona State University) to employ an innovative, controlled experimental design and derive baseline data on the microscopic characteristics of perimortem and postmortem fractures. The researchers found that scanning electron microscopy (SEM) is an effective means of assessing microscopic surface characteristics of experimentally induced fractures in human bone at various postmortem intervals (PMIs). Microscopic fracture characteristics, including delamination, osteon pullout, and microfractures, differ as bone's material properties (e.g., elasticity and toughness) change throughout the PMI, elucidating perimortem and postmortem events more reliably than macroscopic analyses. Microscopic analysis of fracture surfaces is more reliable and sensitive for detecting biomechanical effects of decreased elasticity than macroscopic analysis. These factors make SEM analysis of bone fracture surfaces a promising avenue for refining fracture timing assessments. Determining if an injury occurred before death (antemortem), around the time of death (perimortem) or after death (postmortem) is typically straightforward if the soft tissues are present but becomes more challenging as remains skeletonize. Bone may maintain elasticity for days, weeks, even months after death depending on environmental circumstances. Numerous studies have demonstrated that the current practice of examining macroscopic fracture characteristics is limited and unreliable for determining fracture timing with scientific certainty, particularly during the transitional period between elastic and brittle bone. The inability to make this distinction may mean cause and/or manner of death are undetermined, and families are denied justice and closure for the untimely loss of their loved ones.