Effects of Osteoporosis on Bone Morphometry and Material Properties of Individual Human Trabeculae in the Femoral Head

Abstract

Osteoporosis is the most common bone disease and is conventionally classified as a decrease of total bone mass. Current diagnosis of osteoporosis is based on clinical risk factors and dual energy X‐ray absorptiometry (DEXA) scans, but changes in bone quantity (bone mass) and quality (trabecular structure, material properties, and tissue composition) are not distinguished. Yet, osteoporosis is known to cause a deterioration of the trabecular network, which might be related to changes at the tissue scale—the material properties. The goal of the current study was to use a previously established test method to perform a thorough characterization of the material properties of individual human trabeculae from femoral heads in cyclic tensile tests in a close to physiologic, wet environment. A previously developed rheological model was used to extract elastic, viscous, and plastic aspects of material behavior. Bone morphometry and tissue mineralization were determined with a density calibrated micro‐computed tomography (μCT) set‐up. Osteoporotic trabeculae neither showed a significantly changed material or mechanical behavior nor changes in tissue mineralization, compared with age‐matched healthy controls. However, donors with osteopenia indicated significantly reduced apparent yield strain and elastic work with respect to osteoporosis, suggesting possible initial differences at disease onset. Bone morphometry indicated a lower bone volume to total volume for osteoporotic donors, caused by a smaller trabecular number and a larger trabecular separation. A correlation of age with tissue properties and bone morphometry revealed a similar behavior as in osteoporotic bone. In the range studied, age does affect morphometry but not material properties, except for moderately increased tissue strength in healthy donors and moderately increased hardening exponent in osteoporotic donors. Taken together, the distinct changes of trabecular bone quality in the femoral head caused by osteoporosis and aging could not be linked to suspected relevant changes in material properties or tissue mineralization. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

The role of microscopic properties on cortical bone strength of femoral neck

“…In our survey, the mineral matrix ratio of femoral neck cortical bone decreased gradually from normal bone mass to severe osteoporosis. These suggest that the bone loss of femoral neck may be associated with the imbalance in the ratio between bone collagen and mineral, which may also affect bone strength in femoral neck [ 32 ]. Correlation analysis revealed that there is a significant relationship between the mineral matrix ratio and the L max of the femoral neck cortical bone, which further illustrated that the imbalance in the ratio between bone collagen and mineral lead to the changes of femoral neck macroscopic mechanical properties.…”

Osteodystrophy in the conditions of experimental aluminum intoxication as a result of violation in the digestive tract of rats

“…Достатньо виражені та різноманітні біохімічні прояви інтоксикації алюмінієм [9,12]. Токсичність алюмінію багато в чому пов'язана з його антагонізмом щодо кальцію, магнію, фосфору, цинку та міді, а також зі здатністю утворювати сполуки з білками, накопичуватися в нирках [12], кістковій [7,10,14] і нервовій тканинах [6,11]. У травному тракті виявлено різні алюмінієві депо, на які суттєво впливають зміни рН у просвіті кишок, що забезпечує можливість його абсорбції, накопичення у тканинах або слизових оболонках і виведення з калом [9].…”