Age-related bone loss and osteoporosis in archaeological bone : a study of two London collections, Redcross Way and Farringdon Street
This thesis examines the ways in which age- and sex-related bone loss in archaeological bone can be assessed, with a view to providing criteria by which osteoporosis should be diagnosed. Sample material for this investigation came from two London collections of skeletal material dated 1700-1850 (Redcross Way and Farringdon Street). A comparative study using a wide range of techniques for the detection of bone loss was carried out on the samples from Redcross Way. Sample numbers were then increased through the inclusion of the material from Farringdon Street in order to provide sufficient data to examine changes seen in relation to age and sex. Current research into bone biology and knowledge of osteoporosis in the present day population was reviewed in the context of possible observations that can be made on archaeological bone. There is a large body of historical literature available relating to the period covered by this study (AD 1700-1850). A review was made of material relating to population demographics and medical literature relating to fractures. This work showed that it is valid to study osteoporosis in populations of this period, as a significant number of individuals reached an age at which today they could be considered at risk of sustaining an osteoporotic fracture. Literature relating to fractures contained significant numbers of reports of cases of fracture which, from knowledge of such fracture in the present population, fit the criteria of osteoporotic fractures. Archaeological bone was examined using non-invasive investigative techniques many of which are in current clinical use for the determination of osteoporosis. These were: dual energy x-ray absorptiometry; low angle x-ray scattering; and optical densitometry. Optical densitometry was also applied to bone slices. Cortical bone was assessed through calculation of its area, and thickness. The cortical index were calculated from radiographs. Trabecular bone loss was assessed from femoral radiographs using the Singh index, and stereometric measurements made using close range photogrammetry. The possibility of the archaeological bone material having undergone post-mortem (diagenetic) changes, which can adversely affect results obtained from non-invasive investigations, was briefly addressed. Mineral deposition was found to have occurred in some of the sample material examined. It was found that the direct examination and measurement of the three dimensional trabecular architecture through stereometric analysis provided the best indication of bone loss and, possibly osteoporosis. Where sample material cannot be sectioned and non-invasive investigative techniques have to be applied, low angle x-ray scattering, which produces quantitative and qualitative measurements of trabecular bone, produced the most reliable results. Both these techniques overcame the problems associated with diagenetic change in archaeological material. The results from the investigation of the Redcross way and Farrmgdon Street skeletal material showed that age- and sex-related bone loss was taking place, with loss occurring at an earlier age and being more severe in females than males. The conclusion is made that patterns of loss observed in the archaeological bone broadly mirror those seen in the present day population.