2024, Vol. 28 ›› Issue (23): 3636-3641

Biomechanical analysis of the bones in a rat model of osteoporosis based on the combination of disease and syndrome

Lin Chubin1, He Xingpeng2, Qiu Yuhui1, Wu Wenjin1, Chang Yu1, Ye Tao3, Li Pengfei4, 5, Yang Jian1   

Abstract: BACKGROUND: Kidney deficiency is the main pathogenesis of osteoporosis. To study the relationship between the two major syndrome types of kidney deficiency, Kidney-Yang deficiency and Kidney-Yin deficiency, is beneficial for the development of clinical diagnosis and treatments based on the combination of disease and syndrome.
OBJECTIVE: To evaluate the biomechanical differences of the rat femurs with Kidney-Yang deficiency and Kidney-Yin deficiency caused by Yougui pills, and to demonstrate the scientific efficacy of medication based on the combination of disease and syndrome in osteoporosis from a biomechanical perspective.
METHODS: The bilateral ovaries of 60 female Sprague-Dawley rats were surgically removed to establish an ovariectomized osteoporosis model. At 10 weeks after modeling, all the rats were randomly divided into a Kidney-Yang deficiency group (n=30) and a Kidney-Yin deficiency group (n=30). Rats with Kidney-Yang deficiency were given gluteal intramuscular injection of hydrocortisone, while rats with Kidney-Yin deficiency were orally administered with thyroid tablet suspension, once a day, for 14 consecutive days. After successful modeling, 20 rats in each group were given a suspension of Yougui pills by gavage once a day for 12 consecutive weeks and the remaining 10 rats were used as the control group without intervention. After gavage, the microstructural parameters of the bone were measured using Micro-CT scanning. Three-point bending, finite element simulation, femoral head compression, and surface indentation distribution experiments of the femurs were performed on a mechanical testing machine.
RESULTS AND CONCLUSION: Micro-CT revealed that the femoral bone density, bone volume fraction, bone surface density, trabecular number, and trabecular separation were improved in the Kidney-Yin deficiency+Yougui pills group compared with the Kidney-Yin deficiency group (P < 0.05); the femoral bone volume fraction, bone surface density, trabecular number, and trabecular thickness were improved in the Kidney-Yang deficiency+Yougui pills group compared with the Kidney-Yang deficiency group (P < 0.05). The three-point bending experiment showed that the femur elastic modulus, maximum bending strength and bending fracture strength were decreased (P < 0.05) and toughness was increased (P < 0.05) in the Kidney-Yang deficiency+Yougui pills group compared with the Kidney-Yang deficiency group. Finite element simulation showed that Yougui pills could significantly improve the bending resistance of the femurs in the Kidney-Yang deficiency group, but had no significant effect on the Kidney-Yin deficiency group. The femoral head compression experiments showed that Yougui pills could enhance the ability of the femoral head to resist deformation in the Kidney-Yang deficiency group, but there was no significant difference in the effect of Yougui pills on the surface properties of the femoral head in the Kidney-Yin deficiency group and the Kidney-Yang deficiency group. To conclude, Yougui pills can significantly enhance the biomechanical properties of the osteoporotic bones with Kidney-Yang deficiency, but have no significant effect on the osteoporotic bone with Kidney-Yin deficiency.

Key words: the combination of disease and syndrome, osteoporosis, Yougui pills, Kidney-Yang deficiency, Kidney-Yin deficiency, biomechanics