Study On The Relationship Between Stress And Knee Cartilage Degeneration

This study aims to the relationship between stress and knee cartilage degeneration,observe the changes in cartilage tissue components(chondrocytes,type I collagen,type II collagen,IL-1,IL-6,etc.)under pressure,and whether the articular cartilage can be regenerated and repaired after the pressure is reduced or normal.The causes of knee cartilage degeneration,changes in the molecular biology of related factors,and the correlation between pressure and cartilage damage or degenerative factors,provide new theoretical basis for the treatment of osteoarthropathy,alleviating joint pain and promoting articular cartilage repair and direction.Methods:Using 24 adult rabbits,weighing about 3kg,according to the principle of random grouping,they were divided into 4 groups,each with 6 rabbits.Group I:One knee joint was used as the control group and kept still,and the contralateral knee joint was used as the test group.The pressure was 0.6kg(1/5 of the rabbit’s body weight),and the test period was 8 weeks;Group I was the same,but the experimental knee joint applied pressure 1.5kg(1/2 of the rabbit’s body weight),and the test period was 8 weeks;the third group control group was the same as the first group,and the experimental knee joint applied pressure 3kg(the rabbit’s weight).1 times),the test period is 8 weeks;the control group of group IV is the same as the group I,the knee joint of the experimental side exerts pressure of 3kg(1 times the rabbit’s body weight),the test period is 8 weeks,and the external fixation frame is removed after the expiry And springs,flexion and extension of the knee joint on the experimental side,the test period is 8 weeks.After the expiration of the experiment,the knee joint was dissected under anesthesia,and the articular surfaces of the medial femur and the medial tibial plateau were cut out,and the specimens were fixed according to the routine requirements of morphological examination.The specimens were divided into three groups.The first group was stained with hematoxylin-eosin(HE)to observe the flatness of cartilage surface and the arrangement of cartilage cells;the second group was used to observe type I collagen and type II collagen by immunohistochemistry,IL-1,IL-6 expression level;the third group used light microscope and electron microscope to observe the morphological changes of cartilage surface.Results:1.Preparation of rabbit pathological sections and determination of morphological damage(hematoxylin-eosin staining method)Statistical research results show that the Mankin scores of the control knee joints of the four groups of experimental rabbits are significantly different from those of the model knee joints(P<0.05).The cartilage cells of the control knees of the four groups of experimental rabbits are in good condition and the surface is smooth and tidy.,There are no cracks,and the shape and size of the tube cells are not abnormal,the hematoxylin-eosin staining is uniform,and the tide line is complete.The structure is clear.When a pressure of 0.6 kg was applied to the knee joint on the test side of the rabbit in the first group,the Mankin score was 4.11,which was 1.06 on the control side.There was a significant difference.The number,structure,staining and tidal line of chondrocytes changed,indicating that the pressure effect Next,the cartilage cell morphology of the knee joint changes.As the experimental rabbit knee joint pressure gradually increased to 1.5kg,3.9kg,the number of cells was significantly reduced,clustered into clusters,staining became lighter or disappeared,and the tide lines were multiple,indicating that the pressure and knee cartilage degradation are related.When elevated,the cartilage of the knee joint degenerates significantly.Perform knee rehabilitation exercises on the knee joints that have been cartilage degenerated(group IV),that is,remove the pressure on the knee joints,and repeatedly flex and extend the knee joints until the 8th week.The cartilage cell condition can be significantly improved,but the state of damaged cartilage in the knee joint cannot be recovered.It shows that moderate exercise is conducive to changes in knee cartilage degradation.2.Immunohistochemical observation of the expression levels of type I collagen,type II collagen,IL-1 and IL-6The results of the statistical study showed that the expression levels of type I collagen,type II collagen,IL-1 and IL-6 of the test knee joint chondrocytes were significantly higher than those of the control knee joint chondrocytes.When 0.6kg and 1.5kg were applied to the knee joint of the experimental rabbit,the content of type I collagen and type II collagen of the knee joint chondrocytes increased significantly,and the greater the pressure,the higher the collagen content;The pressure of the joint increased to 3.0kg,and the type I collagen and type II collagen began to decrease;after the knee joint under the pressure of 3.0 kg was subjected to flexion and extension rehabilitation exercises,the expression of type I collagen and type II collagen in the knee joint cartilage cells The level is higher than that of a knee joint with only 3.0kg pressure.The expression levels of IL-1 and IL-6 in the cartilage cells of the experimental rabbit’s knee joint increased significantly with the increase of pressure;after performing flexion and extension rehabilitation exercises on the knee joint with a pressure of 3.0 kg,IL-1 in the knee joint chondrocytes,The expression level of IL-6 decreased.It shows that after the pressure increases,the chondrocyte inflammation reaction is obvious,and the knee joint flexion and extension rehabilitation exercise is beneficial to alleviate the osteoarthritis.3.Observe the morphological changes of cartilage surface with light microscope and electron microscopeWhen the knee joint is under pressure,the morphology of chondrocytes changes,the cells are disordered,the number of layers is not obvious,the cells are clustered into clumps,and the furrow-like structure is not obvious,but the surface of collagen fibers is not damaged.With the gradual increase of pressure,the cell shape Different,the degree of disorder increases,the tide lines are multiple and the cracks are enlarged,the cartilage ridge-like structure becomes flat or disappears,and there are some blood vessels and cells in the cartilage cells,and the collagen fibers are exposed and broken with different thickness.After performing flexion and extension rehabilitation exercises on injured knee joints,chondrocytes are disordered and the number of layers is reduced.The number of clustered cells is less than that of knee joints that have not undergone flexion and extension rehabilitation exercises.Some cartilage furrow-like structures disappear,and there are a small amount of blood vessels and cartilage cells.Cells and collagen fibers are partially exposed,indicating that the flexion and extension rehabilitation exercise relieved the cartilage damage of the knee joint,but could not completely restore the cartilage cell state.Conclusion:Compared with the control side where no pressure was applied,the Mankin score,the morphology and structure of chondrocytes and the expression of type I collagen,type II collagen,IL-1,and IL-6 of the experimental rabbit knee joints after different pressures were applied The degrees are significantly different.Pressure makes the morphology of knee joint cartilage cells disordered,with different sizes,inconspicuous or disappearing ridge-like structures,multiple damp lines,uneven HE staining,enlarged cell gaps,exposed and broken collagen fibers,type I collagen,type II collagen The expression levels of protein,IL-1 and IL-6 are all significantly increased;with the gradual increase in pressure,the damage of chondrocytes is significantly increased,the disorder of chondrocytes is intensified,and the ridge-like structure disappears and increases.IL-1 The expression levels of IL-6 and IL-6 were significantly increased,and type I collagen and type II collagen were decreased,indicating that pressure is related to knee cartilage degeneration.When pressure increases,knee cartilage degeneration is significantly intensified.Perform flexion and extension rehabilitation exercises on the knee joints(group IV)that have cartilage degeneration,that is,remove the pressure on the knee joint,and repeatedly and gently flex and extend the knee joint,which can significantly improve the properties and structure of cartilage cells,type I collagen and type II collagen The expression of protein increased,and the expression of IL-1 and IL-6 decreased slightly,indicating that moderate exercise is conducive to changes in knee cartilage degradation,but it cannot restore knee cartilage cells to a normal state.