Osteoarthritis (OA) is the most common joint disease in human populations with onset and severity influenced by mechanical loading, aging effects, genetics, anatomy, and body mass. Despite major advancements in knowledge, the aetiopathogenesis of OA is complex and still poorly understood. Lack of standardization in methods to quantify skeletal OA make it difficult to study the effects of interacting explanatory variables on arthritic response, and prevents comparison of results between bioarchaeological studies. Joint changes of OA as a function of both the natural aging process and of mechanical stress can make an individual appear older than their chronological age, potentially impacting current methods to derive accurate skeletal age at death estimates, particularly in load-bearing regions. This project addressed these issues through three studies, using a large skeletal sample of modern Europeans for which sex, age, and occupation were available. The first study used principal component analysis (PCA) as a standardized procedure to compute aggregate scores for joint complexes and a systemic measure of OA in each region of the lumbar spine, pelvis, and knee. The second study analyzed the composite scores with a multiple regression model to determine the relative contribution of three predictors: age, activity, and body size, and their effect on skeletal expression of OA in each region. Body size (stature and mass) was calculated from postcranial skeletal measurements; torsional strength (J) of the femoral midshaft was calculated from three-dimensional surface models, size standardized and used as a proxy for measure of activity. The third study considered the effect of OA severity on the validity and reliability of three methods to estimate age at death from load-bearing joints of the os coxa: the pubic symphysis, auricular surface, and acetabulum. The study was designed to determine whether OA in adults acts as a potential limitation or benefit in deriving accurate skeletal age at death estimates from pelvic joint morphology that will contribute to standardized methods in establishing physiological degeneration of the skeleton due to aging. Body size and activity factors did not contribute significantly to OA pathology outside of the age-related expression in either of the lumbar vertebrae or knee regions, and only demonstrated a weak association at pelvic joints. Differences in adult patterns of age are reflected in joint arthritic changes of the os coxa and OA severity has an effect on the accuracy of age estimates from the pelvis; those with OA consistently aging faster in all three joint areas. This influence is most significant for young individuals at the auricular surface and pubic symphysis, over-aging at both. Oldest persons with little arthritic patterning at the acetabulum were under-aged, but accuracy of the age estimate improved as OA severity increased. Systemic measures of OA determined through PCA as an indicator of age, appear useful to identify the very old, but may also help to distinguish between systemic age-related stresses and localized biomechanical effects. Interpreting OA as evidence for old age, measures of habitual activity, and larger body mass should be exercised with caution in skeletal populations. / Graduate / 2018-04-18 / 0327 / 0339 / 0571 / calce.stephanie@gmail.com

The dimensions of the lumbar vertebrae are examined in order to determine if these measurements can be used to predict the age of an individual, and if the lumbar vertebrae exhibit sexual dimorphism. Various statistical techniques were utilized to analyze several dimensions of the lumbar vertebrae. Aging patterns in the lumbar elements are distinct between males and females, and females exhibit compression of the L3 element, which may be related to vertebral wedging. Some dimensions of the lumbar vertebrae are sexually dimorphic.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 4 uppsatser.

The present study evaluates two fetal individuals (B532 and B625) from the Kellis 2 cemetery (Roman period circa A.D. 50 A.D. 450), Dakhleh Oasis, Egypt, that display skeletal anomalies that may explain their death. Both individuals exhibit bowing of the long bones in addition to other skeletal deformities unique to each individual. To assess these pathologies a differential diagnosis based on the congenital occurrence of long bone bowing is developed. Long bone bowing is selected because it is the more prevalent abnormality in the paleopathological literature and the other abnormalities are not as easily identifiable in the literature. For the purposes of this study, the differential diagnosis is defined as a process of comparing the characteristics of known diseases with those shared by an archaeological specimen, in the anticipation of diagnosing the possible condition. It is expected that the differential diagnosis will assist in providing a thorough assessment of each skeleton and yield a possible diagnosis for the condition(s). Macroscopic and radiographic analyses are used to document and examine the bone abnormalities for each individual and compare the results with the developed differential diagnosis. Results suggest that the bent long bones of B532 were caused by osteogenesis imperfecta whereas the cause of the bent long bones of B625 is not clear. Further analyses of B625, including the pathologic abnormalities of its skull, suggest that the neural tube defect iniencephaly with associated encephalocele was the likely cause of the observed skeletal abnormalities. The abnormalities of the long bones complicate estimations of the age-at-death of these two individuals, thus the pars basilaris bone was used to assess age estimation. A population sample of 37 Kellis 2 fetal individuals allowed for the development of linear regression formulae of the pars basilaris measurements for long bone length estimates and a comparison of which would provide the most accurate age estimate. Finally, the diagnoses of the fetal specimens are considered in relation to the cultural aspects and disease pattern of the Kellis 2 cemetery