Research On The Effects Of Osteoking On Biomechanical Properties And Trabecular Bone Microarchitecture In An Osteoporosis Rabbit Model

Objective:To investigate the treatment effects of Osteoking on lumber、femoral and condyle trabecular bone in an osteoporosis rabbit in vivo.Methods:rabbits were ovariectomied for6months to establish osteoporosis animal model. All animals were randomized into3groups, each group of20:group A(osteoporosis model group), group B(treatment group) and group C(sham operation group). In group B every2days with Osteoking gavage for1time, A and C group using equivalent doses saline. All animals were sacrificed24or48weeks after treatment, separation lumbar、femoral and right femoral condyle.(2)Index Testing:゜one mineral density (BMD):dual X-ray absorptiometry was used to measure the rabbit systemic BMD;②bone biomechanics index: use INSTRON-5565type electronic universal test machine, measurement of lumbar spine and femur maximum load (N), maximum displacement (mm), maximum stress, maximum strain ((N/mm)%), elastic modulus (MPa) and other mechanical indexes;③the bone microstructure index:use Micro-CT scan and analysis rabbit lumbar and femoral condyle trabecular microstructure;④tissue metrology index:using three-colour staining method analysis rabbit femur condyle trabecular bone structure.Results:(1)Use ovariectomized method can successfully established postmenopausal osteoporosis (PMOP) in rabbit animal model, ovariectomized rabbits bone density was significantly lower than of sham Operation group, the difference was statistically significant (P<0.01), for future action on postmenopausal osteoporosis pathogenesis studies provide important animal model.(2) The result of BMD:The three groups of rabbits bone density to compared has not statistical significance before ovariectomized.24Weeks after ovariectomized group rabbit total bone mineral density compare:A group and B group (P>0.05), the difference was not statistically significan,C group compared with A group and B group, the difference was statistically significant,both of the general BMD in group A and B were lower than those of group C mean minus2standard deviations.(3) Biomechanical properties of bone:Osteoking after24w (group B) and48w (group B) treatment,the lumbar spine biomechanics properties compared with osteoporosis model group (group A) and sham operation group (group C) has difference,including:the maximum load (N), maximum displacement (mm), the maximum stress (N/mm), maximum strain, elastic modulus (%)(MPa), the difference was statistically significant.(4) Micro-CT three dimensional reconstruction analysis showed that:Osteoking after24w treatment (group B) and48w (group B),the three-dimensional structure of cancellous bone trabecular has difference with group A, the difference has statistical significance. In which the B group bone volume fraction (BV/TV), bone surface/bone volume (BS/BV), trabecular number (Tb.N), trabecular separation (Tb.Sp) with A group has difference,the difference was statistically significant.Compared with C group,the difference was not statistically significant.(5) Histomorphometry:Osteoking after24w treatment (group B) and48w (group B), Compared with A group the trabecular sparse,trabecular thickness decreased, micro fracture and defect forme absorption had significant improvement.Compared with C group,the difference was not statistically significant.Conclusion:Osteoking can promote osteoporosis rabbit cancellous bone trabecular remodeling, improves trabecular three-dimensional structure, can improves bone biomechanical properties of osteoporosis rabbits.