Osteoarthritis (OA) is the most common joint disease and skeletal disorder related to aging. Hip OA is a common chronic degenerative joint disorder that causes pain, stiffness and physical disability in the elderly population. The cause of this disease is still unclear. However, it is estimated that the risk of fracture would increase with the development of hip OA. There is a lack of understanding regarding the effect of hip OA on bone quality. The aim of this thesis was therefore to study bone quality of hip OA in terms of both microstructure and material properties.

To assess cortical and trabecular bone microstructure, High-Resolution Peripheral Quantitative Computed Tomography (HR- pQCT) was used to analyze aged human proximal femora with OA compared to non-OA (control). It was found that OA group had a lower number of trabeculae and higher trabecular spacing than the control group at the femoral head and head-neck junction regions. Within the femoral neck region, OA group showed thicker cortex but higher porosity.

Bone mineralization was qualitatively observed by using backscattered electron (BSE) and Optical microscopy (OM). Regions of hypermineralization were found in the cortical bone of the OA femoral neck. It had similar morphological features to the hypermineralization found in control samples. It can thus be concluded that hypermineralization was not a result of OA, but may be related to age.

This thesis provided better understudying of bone quality in OA patients, specifically the microstructural changes in both cortical and trabecular regions. The findings provided a new clue in terms of the similarity of hypermineralization between OA and control group. Further research along this direction may lead to development of new diagnosis techniques and better ways of hip repairing and reconstruction.