Hiding the evidence: Preliminary investigation of heat-induced alterations to pre-existing saw mark trauma.

Dismemberment and subsequent burning are common methods employed in an attempt to conceal or destroy evidence. While kerf characteristics can be utilised to identify tool(s) used for dismemberment, further research is necessary to assess the effect of burning on these characteristics. In this study, a back (tenon) saw (13 teeth per inch) was used to manually inflict trauma on Ovis aries de-fleshed femur bones (n = 18). Three different cut marks (shallow false start, incomplete cut and complete transection) were made on the mid-shaft of each bone. Subsequently, the bones were burned for 20 minutes in a muffle furnace. Three burn temperatures were assessed: 400 °C, 600 °C and 800 °C. Saw mark characteristics of each cut type were assessed and compared pre- and post-burning. All pre-existing trauma was recognisable post-burning; however, metric and morphological alterations were apparent. An increase in kerf width was observed at 600 °C in false start lesions and 800 °C in incomplete cuts. Breakaway spur thickness decreased post-burning (at 400 °C and 800 °C) but length was not significantly affected. Mean inter-striation distance decreased post burning at all temperature groups. Saw marks were distinguishable from heat-related fractures across all temperature groups. One false start lesion was obliterated at 800 °C. Exit chipping, pull-out striae as well as striation regularity appeared to be more enhanced after heat exposure. These alterations indicate a temperature-dependent impact on these characteristics. Further research is necessary to assess the role of burn duration.

Traumatic cubitus valgus consequent of distal humeral fracture: Two case studies from the Holocene Later Stone Age in southern Africa.

OBJECTIVES: Distal fractures of the humerus and their complications have rarely been described or analysed in the palaeopathological literature. The objective of this study was to evaluate two cases of distal humeral fracture with associated cubitus valgus observed in two individuals from the context of the Later Stone Age (LSA) in southern Africa. MATERIALS: Skeletal remains of two individuals. A middle-aged female radiocarbon dated to c.160 BP and a middle-aged male radiocarbon dated to c.2 300 BP. METHODS: Remains were macroscopically and radiographically assessed for injury. RESULTS: Both cases presented with healed antemortem injury to the right elbow attributed to possible falls. Distal humeral fracture resulted in non-union of the lateral epicondyle with extensive morphological changes to the elbow joint including an increased carrying angle. Morphological and osteoarthritic changes suggest a survival period of several years post-injury. SIGNIFICANCE: Cubitus valgus following traumatic injury has rarely been reported amongst historic or prehistoric populations. The described injuries would have had physical and functional consequences, raising questions relating to probable care received during the healing process. The elbow injuries would have resulted in restricted motion and instability of the elbow joint, with a high likelihood of ulnar neuropathy. LIMITATIONS: The contextual information for these individuals is limited and do not permit broader population level study. SUGGESTIONS FOR FURTHER RESEARCH: Formal biomechanical analysis including cross-sectional geometry analysis will provide further information regarding complications and strengthen the diagnosis of ulnar neuropathy. Further research is necessary on the prevalence and complications of humeral fracture.

Average thickness of the bones of the human neurocranium: development of reference measurements to assist with blunt force trauma interpretations.

The accurate interpretation of a blunt force head injury relies on an understanding of the case circumstances (extrinsic variables) and anatomical details of the individual (intrinsic variables). Whilst it is often possible to account for many of these variables, the intrinsic variable of neurocranial thickness is difficult to account for as data for what constitutes 'normal' thickness is limited. The aim of this study was to investigate the effects of age, sex and ancestry on neurocranial thickness, and develop reference ranges for average neurocranial thickness in the context of those biological variables. Thickness (mm) was measured at 20 points across the frontal, left and right parietals, left and right temporals and occipital bones. Measurements were taken from post-mortem computed tomography scans of 604 individuals. Inferential statistics assessed how age, sex and ancestry affected thickness and descriptive statistics established thickness means. Mean thickness ranged from 2.11 mm (temporal squama) to 19.19 mm (petrous portion). Significant differences were noted in thickness of the frontal and temporal bones when age was considered, all bones when sex was considered and the, right parietal, left and right temporal and occipital bones when ancestry was considered. Furthermore, significant interactions in thickness were seen between age and sex in the frontal bone, ancestry and age in the temporal bone, ancestry and sex in the temporal bone, and age, sex and ancestry in the occipital bone. Given the assorted influence of the biological variables, reference measurement ranges for average thickness incorporated these variables. Such reference measurements allow forensic practitioners to identify when a neurocranial bone is of normal, or abnormal, thickness.