A histomorphological analysis of human and non-human femora.

Histology is used to describe post-mortem bone alterations, trauma, pathology and age estimation and to separate human and non-human bones. Many scholars are however not familiar with the intricate and variable microstructure of bone, and due to the complex nature of some classification systems, bone histomorphology is often incorrectly described or identified. Little information is available on the histomorphology of non-human bones found in southern Africa, and therefore, the aim of this study was to describe the histomorphology of non-human species commonly found in southern Africa, namely, impala and monkeys, along with cat, dog, cow, sheep, equid and pig. Human femora were included for comparative purposes. The periosteal surface of femora was described and focussed only on the arrangements of vascular canals, primary osteons and secondary osteons. The results compared favourably to other studies and also added a histomorphological description of impala femora which consisted of primary vascular longitudinal bone tissue. A large degree of overlap and combinations of bone tissue types was observed, as well as evidence which allows animals from similar taxonomic orders to be grouped together. Primary vascular bone was primarily observed in artiodactyls (cow, pig, sheep and impala), while Haversian bone was recognised in carnivores (cat and dog), Perissodactyla (horses and donkeys) and primates. These differences can be used to exclude human from unknown bone fragments and also serve to caution investigators when using animal models to infer human bone tissue responses to thermal damage, ballistic trauma, etc., as bone tissue types different to that of human bone may respond differently.