Abstract
Osteoporosis and osteoarthritis (OA) are two common age-related skeletal disorders, which are associated with substantial morbidity and disability, particularly among elderly women. The present study was performed to investigate the trabecular bone deterioration of proximal tibiae and lumbar vertebrae in postmenopausal women with OA. The results demonstrated that the histomorphometric section of trabecular bone below the growth plate was markedly different between the healthy control and OA group. However, the loss of trabecular bone underneath the growth plate in the healthy control group was significantly worse than that of the OA group. Hematoxylin and eosin staining demonstrated the increased disconnection and separation of the trabecular bone network as well as the reduction of trabecular bone mass of primary and secondary spongiosa throughout the proximal metaphysis of tibia in the healthy control compared to the OA group; similar results were found when the same experiment was repeated on the lumbar vertebrae of healthy control subjects and OA patients from postmenopausal women. The biological properties of trabecular bone in the proximal tibia and lumbar vertebrae were measured in postmenopausal women with OA. Spearman's rank correlation analysis revealed that the bone volume fraction was both positively correlated with radiographic severity and Western Ontario McMaster University Osteoarthritis Index scores in in the proximal tibia and lumbar vertebrae from postmenopausal women with OA. In conclusion, the structural properties of the proximal tibia and lumbar vertebrae supported that an inverse correlation existed between postmenopausal women with OA and healthy controls. Moreover, there is an important protective mechanism of OA on trabecular microstructure in proximal tibiae and lumbar vertebrae from postmenopausal women.