| Background: In our clinical treatment, it is common that the articular cartilage defects caused by trauma and kinds of disease. The articular cartilage hasn't blood vessel, nerves and lymph, and the cells can't execute caryocinesis. So the self-repairing capability is extremely limited for the articular cartilage cells once defected. It has become a hot spot and difficult question for the department of orthopaedics and related domain in the foundation and clinical research to repair the articular cartilage defects in recently years. The traditional restorative procedures for the articular cartilage defects mainly include two methods. The first is to stimulus the articular cartilage cells to repair by themselves including articular cleaning, articular cavity irrigation, plane and erasion, drilling of subchondral bone, micro-fracture, osteotomy, exposured to radiation and magnetic field. And the second is to repair by tissue and cell graft which includes self or xenoma cartilage transplantation, periosteum and cartilaginous membrane transplantation, cartilage cell and marrow mesenchymal cell transplantation, and so on. People have tried to therapy the articular cartilage defecets by using the gene engineering and tissue engineering recently. But there was not a method to therapy the articular cartilage defects thoroughly.The study indicates that the joint's cataplasia will accelerate after the cartilage defected, and it will lead to the generation of osteoarthritis. Many growth factors play an important role in the repairing of articular cartilage defects and the joint's cataplasia,including insulin-like growth factor-1, fibroblast growth factor,transforming growth factor-β,hepatocyte growth factor, platelet-derived growth factor,bone morphogenetic protein,and so on. The insulin-like growth factor-1 is one of the strongest factors for the cartilage cell multiplication and differentiation. It can stimulate the typeⅡcollogen and proteoglycan synthesized, inhibit the degradation of the cartilage stroma and accelerate the caryokinesis of the cartilage cells. It also can stimulate the colony forming. Generally speaking, the cartilage cells can secrete the IGF-1 by themselves. It needs a further study and research for the expression level of IGF-1 and IGF-1R around the damaged cartilage after the articular cartilage defects. Besides, the effect of repairing after the articular cartilage defects by Intra-articular injection of IGF-1 is still not clear.Objectives: To observe the effect of intra-articular injection of IGF-1 on repairing of articular cartilage defects. To investigate the expression of IGF-1 and IGF-1R in cartilage cells around the defects. To provide some theory and experiment evidences on repairing of articular cartilage defects,delaying the cataplasia of articular cartilage and preventing the generation of osteoarthritis.Materials and methods: Twenty-one white New Zealand rabbits were divided into four groups randomly. That is, group A,B and C were operation groups and each group had five rabbits. Group D was normal group and had six rabbits. The cartilage damage model was established by drilling on the knee joint trochlea zone with group A, B and C. On the right knee, 0.1ml IGF-1(1mg/ml) was injected into the knee cavity after the operation immediately and once a week after that, while on the left knee the defect was left as a control and 0.1 ml normal saline was injected at the same time. Nothing was done with the group D. The rabbits of group A,B and C were killed respectively at 1,4,8 week after operation, and two rabbits of group D were killed each time when the group A,B and C were killed. Then the macroscopic examination was performed, to observe the repair tissue in the area of articular cartilage defects in operation groups. It included the state of filling,the color ,the luster, and so on. The wakitani's histology scores of the repair tissue were performed with the light microscope after the hematoxylin and eosin stain,and the score standard included the cell shape,matrix metachromatism,superficial regulation,cartilage thickness and the binding with the surround cartilage. To observe the cataplasia of articular cartilage around the defects, the improved mankin's scores which contained the structure,cell proliferation,matrix staining,and the integrity of tidemark were performed with the light microscope after the safranin- O stain. IGF-1 and IGF-1R immunohistochemical examination were performed in order to investigate the expression of IGF-1 and IGF-1R in articular cartilage around the defects. The masculine cells of the experiment side and control side in each operation group were compared with the normal group separately in order to observe the change between them.Results: The hematoxylin and eosin stain showed that the regeneration tissue of the experiment side was better than the control side in group B and C,but there was no difference in group A. there was a significant statistical difference (P﹤0.01) between the experiment side and the control side in group B and C by Wakitani score. The Safranin-O stain showed that there was not cataplasia around the defected articular cartilage on the experiment side, but different degrees cataplasia were found around the defected articular cartilage on the control side in group B and C. There was a significant statistical difference (P﹤0.01) between group B and C by Mankin score. There wasn't statistical difference (P﹥0.05) between the experiment side and the normal group with the expression of IGF-1, but there was a significant statistical difference (P﹤0.01) between the control side and the normal group in group B and C. The expression of IGF-1R hasn't statistical significant (P﹥0.05) compared the experiment and control side with the normal group.Conclusion:The intra-articular injection of IGF-1 could accelerate the repair of the articular cartilage defects effectively after the articular cartilage defects,delay the cataplasia of articular cartilage around the defects and prevent the generation of osteoarthritis which caused by the defects of articular cartilage. |
PDF Full Text Request