Wet bone characteristics persist in buried bone after 10 weeks: implications for forensic anthropology

Abstract

Background: Assessing the timing of skeletal trauma significantly impacts the reconstruction of events surrounding death and deposition in forensic cases. However, there are no absolute time frames in which the characteristics of wet bone (perimortem) fractures transition to dry (post-mortem) fractures. Objective: Identify a point within the post-mortem interval in which the characteristics of bone change from wet to dry bone properties. Method: 32 deer ribs were placed in a laboratory burial environment and three fractured with blunt force trauma every week in a period of ten weeks. A complementary set-2 of 32 deer ribs paired to set-1 were left to dry quickly exposed (not buried) so as to provide an insightful point of reference with regard to the drying out process. All samples and the inflicted trauma effects were documented and analysed by macroscopic observation, SEM analysis, thermal analysis, biomechanical analysis, and ATR-FTIR. Results: No significant difference was found in the macroscopic, microscopic, thermal, and biomechanical analyses over the 10 week period. A significant difference was only found in the carbonate-to-phosphate ratio in analytical chemistry. Conclusion: To differentiate between the timing of trauma (perimortem vs postmortem) in forensic anthropology within the first ten weeks of the post-mortem interval of buried bones is challenging as bone still retains its wet properties.