Study and Prediction of Bone Strength of Rats with Different Intensity of Swimming Therapy Based on Synchrotron Radiation

The most serious health consequence of osteoporosis is a fracture, which is life-threaten and causes a large economic and social burden. However, as the gold standard for clinical diagnosis, bone mineral density (BMD) has significant limitations in fracture risk assessment. Therefore, the purpose of this study is to explore new evaluation criteria for osteoporotic bone quality to better predict bone strength and prevent the occurrence of osteoporotic fractures. In this study, we evaluated the bone strength of rats osteoporotic model with different intensity of swimming therapy based on the synchrotron radiation X-ray imaging. By quantitatively comparing changes of bone microstructural parameters in lumbar vertebra and femur, it was found that swimming therapy has effects on both lumbar and femur, in which the femur are more sensitive. It suggests that femur may be more suitable for the diagnosis and efficacy evaluation of osteoporosis than the lumbar vertebra. By analyzing the correlations between bone microstructure and bone strength, we found that bone volume fraction (BV/TV) and structure model index (SMI) are proper predictors of bone strength than BMD. Selecting a suitable diagnosis site and predictors that more representative of bone strength can provide the basis for fracture risk assessment and efficacy evaluation.