Exiting the limbo of perimortem trauma: A brief review of microscopic markers of hemorrhaging and early healing signs in bone.

The assessment and interpretation of the timing of skeletal trauma can be of extreme difficulty in post-mortem specimens, especially because of post-mortem processes and taphonomic events. The chronological diagnosis of bone trauma, consisting usually in the gross distinction between antemortem, perimortem and post-mortem, is based almost uniquely on macroscopic and morphologic parameters in the anthropological field. However, both the interference of taphonomy and the scarce persistence of specific features indicating vitality (meaning etymologically "produced in life") and/or some very early bone healing reactions, make it extremely difficult. In this perspective, it is important not only to distinguish between peri and post-mortem lesions, but also to interpret perimortem lesions with respect to vitality and time elapsed since the trauma which may change the course of the investigations. And techniques of forensic pathology applied to forensic anthropology can come in extremely handy. If any traces of vital blood extravasation, haemorrhage, hematoma, inflammation, and biomarkers of early healing reaction are found in the bone tissue of a skeletal lesion (regardless the state of preservation of the body), then can they be used as a diagnostic tool or marker of vitality for that lesion? In these terms, vital reactions like bleeding or any early sign of bone healing can be the only evidence for demonstrating that a traumatic event was prior the death. Nevertheless, very little information, or research for that matter, is available in literature concerning persistence and detectability of vitality markers during the bone decomposition process. A fundamental point for properly determining the vitality of a fracture and estimating the post-traumatic time interval in skeletal lesions is the physio-pathological picture of the very initial healing process. This article attempts to provide a review of the physiopathological current knowledge available and applicable to osteology.