This study investigated whether changes in hardness of human trabecular bone are associated with osteoarthritis.
Twenty femoral heads extracted from subjects without musculoskeletal diseases (subject age: 49–83 years) and twenty femoral heads extracted from osteoarthritic subjects (subject age: 42–85 years) were tested. Sixty indentations were performed along the main trabecular direction of each sample at a fixed relative distance. Two microstructures were found on the indenting locations: packs of parallel-lamellae (PL) and secondary osteons (SO). A 25 gf load was applied for 15 s and the Vickers Hardness (HV) was assessed.
Trabecular tissue extracted from osteoarthritic subjects was found to be about 13% less hard compared to tissue extracted from non-pathologic subjects. However, tissue hardness was not significantly affected by gender or age. The SO was 10% less hard than the PL for both pathologic and non-pathologic tissues. A hardness of 34.1 HV for PL and 30.8 HV for SO was found for the non-pathologic tissue. For osteoarthritic tissue, the hardness was 30.2 HV for PL and 27.1 HV for SO. In the bone tissue extracted from osteoarthritic subjects the occurrence of indenting a SO (28%) was higher than that observed in the non-pathological tissue (15%).
Osteoarthritis is associated with reduced tissue hardness and alterations in microstructure of the trabecular bone tissue. Gender does not significantly affect trabecular bone hardness either in non-pathological or osteoarthritic subjects. A similar conclusion can be drawn for age, although a larger donor sample size would be necessary to definitively exclude the existence of a slight effect.