| Part one Histological analysis of extracorporeal shock wave promoting the bone-to-tendon healing after the rat supraspinatus tendon insertion reconstructionObjective To observe the effects of extracorporeal shock waves therapy (ESWT) on tendon-bone healing after the rat supraspinatus tendon reconstruction.Method 35 SD rats (365.6±20.5g) were randomly classified into 2 groups: ESW group (n=16), model group (n=16) and the other 3(reserved for use in case of death and wound infection). The ESW group and model group were used to establish the rat supraspinatus tendon reconstruction models. The ESW group was given extracorporeal shock wave therapy on the 2nd day after the operation, with a frequency of once a day for 7 days on end. The energy flux density was 0.16 mJ/mm2 and the impact of volume 500 (5Hz, 2kPa)) and the model group was not given ESWT. 4 animals from ESW group and the other 4 from model group were sacrificed at 1,2,4 and 8 weeks after operation for general and histological examinations. The specimens were stained with hematoxylin-eosin to investigate pathological change of the tendon-bone healing tissue.Result The histological examination revealed that at 1 and 2 weeks after operation, within the model group and ESW group, tendon-bone interface was observed to be comparatively loose and filled with granulation cells,inflammatory cells,fibroblasts and angiogenesis etc, and the content of chondrocytes and collagen fibers was obviously not enough. At 4 weeks after reconstruction, the number of inflammatory cells decreased. Instead, more fibroblasts and chondrocytes, the content of collagen fibers were increased and the fiber arrangement more regular than before. The ESW group, the fiber arranged more regular and the number of inflammatory cells reduced rapidly. At 8 weeks after operation, the healing tissue at the bone-tendon interface had developed into dense connective tissue and the collagen fibers were formed in abundance and the perpendicular collagen fibers were regularly and longitudinally arranged. As for the ESW group, a change of these issues occurred in the transition zones of collagen fibers, fibrocartilage and bone (a structure like a direct ligamentous insertion). On the whole, the histological observations showed that the tissue healing at tendon-bone interface of the ESW group were quicker than those of the control group(about 2-4weeks).Conclusion 1.SD rat is the ideal choice for establishing animal model of rotator cuff injury. 2. The treatment of ESW can significantly enhance the tendon-bone healing in the early stage after reconstruction of the rat supraspinatus tendon.The mechanism of extracorporeal shock wave promoting the bone-to-tendon healing after the rat supraspinatus tendon insertion reconstructionObjective To investigate the mechanism of tendon-bone healing of SD Rats supraspinatus muscle that ESWT promates after the rat supraspinatus tendon reconstruction.Method 70 SD rats (383.6±22.75g) were randomly classified into 2 groups: ESW group (n=32), model group (n=32) and the other 6 (spared). The ESW group and model group were used to establish the rat supraspinatus tendon reconstruction models. A half of the 8 specimens was used to evaluate VEGF,vWF,OC(BGP) and Collagen-ⅡmRNA expression of the tendon-bone healing tissue by real-time PCR method; another half of the 8 specimens was used to investigate vWF,OC(BGP) and Collagen-Ⅱprotein expression of the tendon-bone healing tissue by immunohistochemisty..Result Real time PCR data showed that the expression levels of VEGF in the model group went up at 1 week after the operation, and reached to the highest level at 2 weeks after the operation, then gradually dropped after 8 weeks, it recovered to the pre-injury level. The expression levels of VEGF in the ESW group seemed better than that of model group.vWF of ESW group went up rapidly at 2 weeks, and reached its peak at 4 weeks, then dropped gradually to the same level as that was at 2 weeks after the operation. The ESW group had similar results as the model group, the expression levels of vWF in the ESW group seemed better than that of model group at 4 and 8 weeks. The expression level of Collagen-Ⅱincreased rapidaly at 2 weeks after the operation and reached to the peak at 4 weeks and continued with a steady growth until 8 weeks, the expression levels of Collagen-Ⅱin the ESW group seemed better than that of model group at 2,4 and 8 weeks. At 4 and 8 weeks, the expression levels of BGP in ESW group were higher than that of model group. There were significant differences between the model and ESW groups in this experiment. Immunohistochemistry results: The detection index expression gradually increased over time. vWF, Collagen-Ⅱand BGP all increased substantially 4 and 8 weeks after surgery and compared with model group, the difference was statistically significant.Conclusion The treatment of ESW can enhance the tendon-bone healing in the early stage after reconstruction of the rat supraspinatus tendon by regulating the VEGF, vWF, BGP and typeⅡcollagen expression, promoting angiogenesis, cartilage regeneration and bone formation. |
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