Below the Callus Surface: Applying Paleohistological Techniques to Understand the Biology of Bone Healing in Skeletonized Human Remains

Abstract

Objectives: Bone trauma is a common occurrence in human skeletal remains. Macroscopic and imaging scrutiny is the approach most currently used to analyze and describe trauma. Nevertheless, this line of inquiry may not be sufficient to accurately identify the type of traumatic lesion and the associated degree of bone healing. To test the usefulness of histology in the examination of bone healing biology, we used an integrative approach that combines gross inspection and microscopy. Materials and Methods: Six bone samples belonging to 5 adult individuals with signs of bone trauma were collected from the Human Identified Skeletal Collection from the Museu Bocage (Lisbon, Portugal). Previous to sampling, the lesions were described according to their location, morphology, and healing status. After sampling, the bone specimens were prepared for plane light and polarized light analysis. Results: The histological analysis was pivotal: (1) to differentiate between types of traumatic lesions; (2) to ascertain the posttraumatic interval, and (3) to diagnose other associated pathological conditions. Conclusion: The outer surface of a bone lesion may not give a complete picture of the biology of the tissue's response. Accordingly, microscopic analysis is essential to differentiate, characterize, and classify trauma signs.

Utility of micro-CT for dating post-cranial fractures of known post-traumatic ages through 3D measurements of the trabecular inner morphology

“…Histology is considered the most accurate method for dating fractures and the most precise in the early healing stages, when the gross examination of the outer bone surface does not give a complete picture of the biology of the tissue’s reaction 2 , 8 , 19 , 37 , 39 , 40 . Histology proved to be superior to both conventional radiology (CR) and CT scanning 10 but it is also a destructive method that requires specific training for interpretation 17 , 25 .…”

“…Traditional anthropological methods are unable to solve the issue of the accurate dating of fractures, especially in the earliest stage of healing when the bone still possesses its elastic properties at the time of the fracture, but no mineralized signs of healing can be observed macroscopically. These difficulties also characterize the last stage of healing when the outer bone surface may not give a complete picture of the biology and inner structure of the remodeled fracture 19 .…”

The macroscopic and histomorphological properties of periosteal rib lesions and its relation with disease duration: evidence from the Luis Lopes Skeletal Collection (Lisbon, Portugal)

“…The presence of erosive foci was also recorded. Afterwards, each rib sample was prepared for histological analysis by plane and polarized microscopy, following the protocol of FitzGerald & Saunders (), as already outlined in Assis & Keenleyside (). It should be noted that for each rib sample, two contiguous slices of bone were cut and prepared for analysis.…”

The various meanings and uses of bone “remodeling” in biological anthropology: A review

“…In both direct and indirect healing, the term remodeling is used: direct healing without callus formation is achieved by either lamellar bone remodeling (in the Frostian definition of the term) with BMUs traversing the fracture site (Marsell & Einhorn, 2011; Savaridas et al, 2012), or by gap healing where weaker new bone first forms in the small gap between the fractured ends and is later replaced by stronger lamellar bone (Marsell & Einhorn, 2011; McKinley, 2003). Indirect healing consists of overlapping phases: (1) inflammatory, (2) reparative, and (3) remodeling , with the latter referring to the gradual replacement of the callus by well‐structured compact bone, which restores the original shape and mechanical integrity (Assis & Keenleyside, 2016; Einhorn, 1998). An aspect of functional adaptation is also incorporated since reunion of the fractured ends is an attempt to re‐align the loading axis (Ortner, 2003).…”