Recognition of the Presence of Bone Fractures Through Physico-Chemical Changes in Diagenetic Bone

Abstract

Much research has focused on attempting to understand the drivers of bone diagenesis. However, this sensitive process is easily influenced by various factors, particularly the condition of the remains (i.e. whether they have been subjected to trauma). Previous research demonstrates that trauma can influence soft tissue decomposition, yet to date, no studies have looked at how bone fractures could affect bone diagenesis. To address this gap, two short timescale studies were conducted to investigate the influence of bone fractures on the physicochemical composition of disarticulated, partially fleshed animal remains. Disarticulated porcine bones were either fractured using blunt-force or sharp-force whilst fresh (producing perimortem damage), at 60 days PMI (producing postmortem damage) or left intact and left outside for up to 180 days post-fracture/240 days PMI. Retrieved bone sections were then analysed for physicochemical differences using non-destructive methods: Scanning Electron Microscopy – Energy Dispersive Spectroscopy and Fourier Transform Infrared Spectroscopy with attenuated total reflectance. It was hypothesised that differences would be found in the physicochemical composition between the bones with fractures and those without after undergoing diagenetic change. The bone fractures significantly affected the elemental composition of bone over time, but structural composition initially remained stable. It was also possible to distinguish between perimortem and postmortem fractures using these two analytical techniques due to physicochemical differences. This research shows bone fractures can significantly alter the physicochemical composition of the bone during the postmortem period and has the potential to facilitate more accurate PMI estimations in forensic contexts.