Joint conditions in post-Medieval England: A comparative assessment of modern risk factors and historic lifestyles

Pathological conditions of the joints are commonplace and incurable, affecting millions of living individuals and yet, surprisingly, there is a great deal that is still unknown about them, including the role and interactions of a variety of risk factors which underpin their development. Much can be learned about joint conditions in the past by marrying clinical and palaeopathological research and by examining patterns of prevalence for joint conditions amongst the living and the trends of the past, the risk factors can be better understood. This thesis aims to utilize palaeopathological evidence of specific joint conditions from past populations in an effort to critically evaluate and analyze the potential risk factors as researched in the clinical literature. This body of research assessed the joint conditions osteoarthritis, ankylosing spondylitis, sacroiliitis and degenerative disc disease in a sample of skeletal remains from sites across England dating to the 18th-19th centuries. Mature individuals, both male and female, (18+ years) were included. This allowed for the determination and insight into how the lifestyles of each site category affect the development of the joint conditions. A series of palaeopathological assessments were undertaken to generate a novel dataset that provided skeletal proxies for clinically identified risk factors of the joint diseases to determine whether any relationships/associations existed between the risk factors and joint conditions. Osteological assessments were conducted to create demographic profiles using the pertinent variables (age at death and biological sex), pathologies and the risk factors. These risk factors consisted of body mass (via skeletal height/weight estimation) and activity (via non-imaging cross-sectional geography and entheseal changes), which consisted of five variables, four of which were produced using a method of non-imaging cross-sectional geometry, with the fifth being the scoring of pertinent entheses. The prevalence rates of the joint conditions fell within the upper ranges of similar sites of post-medieval England and followed sex and age trends also seen in clinical research. These trends showed that the rates increased with age, however statistical testing did not display significance. Body mass and activity did not correspond with joint conditions in the archaeological sample in the same fashion reported in the clinical trials, resulting in a discussion that raised questions about the (1) accuracy and efficacy of currently available osteological methods used to create proxies for these variables from skeletal data, (2) the extent iii | Mc A f e e IM: J o i n t C o n d i t i o n s i n P o s t -Me d i e v a l E n g l a n d to which clinical and osteological methods of detecting joint condition offer comparable data and (3) the level which would cause changes to joint function cause a joint condition. However, the body mass of the samples used within this thesis may simply have been too low to have caused sufficient impairment/degradation to the joint, explaining the lack of correlation/association found compared to clinical studies. The variables used as proxies for activity levels did display a significance association with the joint conditions when tested individually. The final binomial logistical regressions found that only a small number of these activity variables were significant factors in the prediction of each joint condition, when all the variables were used in the test. Ankylosing spondylitis was not found to be present in any of the samples used and sacroiliitis was present in only a small percentage of samples and so were unable to be further tested. Further tests on a larger sample size to test the validity of the results found within this thesis, such as the body mass and activity findings, will need to be conducted. This will help to check the validity of the current data as well as to expand it further so new assumptions/conclusions can be made. The joint conditions conformed to the clinical trends concerning age and sex but differed concerning BMI and activity, offering insights into further avenues to explore. For the spondyloarthropathies, a greater sample size would help to accurately study ankylosing spondylitis and sacroiliitis by increasing the level at which inferential analyses can be made. This research, while concluded in its present form, provides a list of future directions to continue to explore the questions and limitations that have arisen throughout.