低强度脉冲式超声对关节软骨的修复

BACKGROUND: Articular cartilage injuries can result from a variety of causes. Conventional therapy cannot obtain the optimal clinical results. Low-intensity pulsed ultrasound has been shown to promote the repair of injured articular cartilage.OBJECTIVE: To investigate the effects of low-intensity pulsed ultrasound on the repair of injured articular cartilage.METHODS: Twenty New Zealand white rabbits were used to establish knee arthritis models and equally randomized into study and control groups, respectively. Rabbits in the study group received low-intensity pulsed ultrasound treatment, and sham low-intensity pulsed ultrasound treatment was given in the control group. At 8 weeks after treatment, pathological change and histological scores in articular cartilage tissue collected from both groups were determined. Moreover, the ultrastructure and type II collagen expression of chondrocytes were determined. Matrix metalloproteinase-13 mRNA expression was detected by quantitative real-time PCR.RESULTS AND CONCLUSION: At 8 weeks after treatment, toluidine blue staining showed a disordered arrangement of cells, decreased number of cartilage cells in each layer and cluster in the control group. Light disordered arrangement of cells, decreased appearance of the superficial layer cells and the cluster phenomenon were observed in the study group. Articular cartilage tissue scores were significantly decreased in the study group compared with the control group (P < 0.05). The chondrocytes were small, enlarged intracellular mitochondria and rough endoplasmic reticulum, cytoplasmic swelling, collagen fibrils coarse, well developed Golgi apparatus, and nuclear fragmentation were observed in the control group. In addition, the normal structure of organelles disappeared and cell degeneration was observed in the control group. In the study group, the size of chondrocytes and the Golgi complex and other organelles were normal, and the protein polysaccharide granules were observed in the cytoplasm and membrane. The mRNA expression of matrix metalloproteinase-13 in the study group was significantly lower than that in the control group (P < 0.05). Type II collagen immunoreactivity in the study group was stronger than that in the control group. No incision infection, suppuration, red swelling appeared in all rabbits. Our results suggest that low-intensity pulsed ultrasound can be used for the treatment of articular cartilage injury by alleviating the degradation of collagen type II and inhibiting the expression of matrix metalloproteinase-13.中国组织工程研究杂志出版内容重点：组织构建；骨细胞；软骨细胞；细胞培养；成纤维细胞；血管内皮细胞；骨质疏松；组织工程

Effects of low-intensity pulsed ultrasound for articular cartilage repair