Effects Of Water Exercise On Knee Cartilage In Rats With Traumatic Osteoarthritis

Purpose:The pathological changes,MMP-13 and TNF-α of knee joint cartilage were observed by aquatic exercise in rat model of traumatic knee arthritis,and the effect of aquatic exerciseon knee joint cartilage in rat model was investigated.Methods:After adaptive feeding for one week,24 SD rats were randomly divided into3 groups:sham operation group(group A),osteoarthritis model group(group B),osteoarthritis model+aquatic exercise group(group C),8 rats.Group A rats only opened the joint cavity,and then sutured the wound.Rats in group B and group C underwent knee arthritis modeling(anterior cruciate ligament amputation),and the wound was sutured after confirmation of successful modeling.After cage feeding for2 w under the same feeding conditions,rats in groups A and B continued normal feeding,and rats in group C underwent 6w aquatic exercise(adaptive swimming exercise in the first week,and then aquatic exercise for 20 min every day and 5d every week).Six weeks later,the rats in the three groups were weighed and killed,knee samples were collected and prepared,and the pathological changes of the samples were observed by HE staining and serine-solid green staining.The samples were stained with immunohistochemical staining and analyzed quantitatively to observe the content change of MMP-13.The expression of MMP-13 and TNF-α in the samples was determined by real-time fluorescence quantitative PCR.Results:1.Knee cartilage in the osteoarthritis model group showed many pathological changes,such as chondrocyte injury and extensive death,uneven matrix distribution,degradation,fuzzy tide line and so on.After 6 weeks of aquatic exercise,the local chondrocyte loss and bone spur formation in the knee joint of rats decreased significantly.2.The staining intensity and density of MMP-13 in knee cartilage of the osteoarthritis model group were the highest among the three groups;The content of MMP-13 was higher than that of sham operation group and arthritis model+aquatic exercise group(P<0.05).After 6 weeks of aquatic exercise,the staining intensity and density of MMP-13 in knee cartilage of rats were significantly decreased,and the content of MMP-13 was significantly decreased(P<0.05).3.The expressions of MMP-13 and TNF-α in the knee cartilage of the OA model group were the highest among the three groups(P<0.05).After 6 weeks of aquatic exercise,the expressions of MMP-13 and TNF-α in knee cartilage of rats were significantly lower than those of the OA model group(P<0.05).Conclusion:The expressions of TNF-α and MMP-13 in the knee cartilage of rats were increased after modeling,Aquatic exercise can reduce the content of MMP-13 and the expression of TNF-α and MMP-13 in the knee joint of rats with traumatic knee arthritis,slow down the degradation of cartilage matrix,improve the degree of injury of knee joint cartilage in rats,and have a certain protective effect on the knee joint cartilage of rats...