The Effects Of Extracorporeal Shock Wave On Bone Structure,Metabolism And Function Of Cartilage And Subchondral Bone In Osteoarthritis Model With Osteoporosis

Objective:To prepare the model of osteoporosis and osteoarthritis in rats.Methods:8 female SD rats were divided into 4 groups: A group(the group without OP),B group(OP group),C group(the group without OA),D group(OA group).In the A group and the B group,the BMD of the lumbar spine and femur was measured by dual energy X-ray absorptiometry at 12 weeks and the biomechanical properties of the femur were observed by three point bending test in order to validate the model of osteoporosis in rats.For D group and C group at 4 weeks,the model was validated by the general changes of joint and the changes of tissue sections.Results:For A group and B group: 12 weeks after surgery,compared with the A group,the BMD of the lumbar spine and femur were significantly lower in the B group(P <0.05);the maximum stress in B group were significantly decreased.For C group and D group: 4weeks after surgery,the general changes of joint showed the articular cartilage of group D was significantly degenerated compared with the C group;HE staining also showed the articular cartilage of D group was severe and the Mankin score was significantly higherthan C group(P <0.05).Conclusion:It is an effective method for the preparation of rat OP model by removing bilateral ovaries for 12 weeks and the early osteoarthritis model can be successfully prepared by ACL+MM method for 4 weeks.Objective:To study of Effects of extracorporeal shock wave on bone structure,metabolism and function of cartilage and subchondral bone in osteoarthritis model with osteoporosis.Methods:Thirty-six eight-week-female SD rats were divided into three groups: Sham group,OPOA group,and OPOA+ESWT group.The OPOA group and ESWT group were both castrated.After 12 weeks,the model of osteoarthritis was established by modified Hulth method.After 1 week of the modified Hulth method,ESW intervention(the energy is1.6bar,the number is 1000 times,the frequency is 5HZ)was given in the subchondral bone site,one time a week and a total of 4 times.After 4 weeks of intervention,the changes of articular cartilage were observed by histology and biomechanics;the changes of subchondral bone microstructure were observed by immunohistochemistry and Micro-CT;the functional changes of rats were observed by gait analysis.Results:Compared with Sham group,the articular cartilage of OPOA group had obvious degeneration,and the scores of mankin and toluidine blue were significantly increased.The score of ESWT group was significantly lower than that of OPOA group.Comparedwith Sham group,the stress-strain curves and creep of OPOA group increased significantly.After 4 weeks of ESW intervention,the stress-strain curves and creep(except 0.02N)of OPOA group decreased significantly.The results of Micro-CT showed that the BV/TV,Tb.N and Tb.Th of the OPOA group decreased significantly compared with the Sham group,while the Tb.Sp increased significantly.After 4 weeks of ESW,the BV/TV,Tb.N and Tb.Th of the ESWT group increased significantly compared with the OPOA group,while the Tb.Sp decreased significantly.Compared with Sham group,the expression of BMP-2 and Osterix in the OPOA group decreased significantly.After 4 weeks of ESW intervention,the expression of BMP-2 and Osterix of the ESWT group increased significantly compared with the OPOA group.The results of gait analysis showed: in OPOA group,the stance phase,swing speed,single stance phase were significantly shorter than sham group.After four weeks of ESWT,in ESWT group,the stance phase,swing speed,single stance phase were significantly longer than OPOA group,meanwhile,the swing phase was significantly shorter than OPOA group.Conclusion:ESW can not only delay and prevent the further degeneration of articular cartilage in OPOA rats,but also improve the motor function of the rats.