A Series Of Repair Methods For Augmenting Rotator Cuff Tendon-bone Healing

Objective Rotator cuff is ofen re-torn after repairing rotator cuff injury,and the poor healing ability of rotator cuff tendon-bone is the main reason.In order to improve the quality of rotator cuff tendon-bone healing,a series of animal models for rotator cuff injury were used.To explore whether preservation of rotator cuff insertion can better integrate rotator cuff insertion;to evaluate whether absorbable sutures can form better structure with more mature and stronger rotator cuff insertion;to understand whether nano-fibrous membrane can promote rotator cuff tendon-bone integration by utilizing its osteogenic characteristics.Method 1.Acute rotator cuff injury model with stump was established in rabbits.One shoulder side was repaired with preservation of stump and the other side was repaired with removal of stump.Histological and biomechanical changes were observed at different time after operation.2.A rabbit model of rotator cuff injury was established.The rotator cuff was repaired with absorbable,patial-absorbable and non-absorbable sutures.Samples were taken at different time after operation,and the result was analyzed from the perspective of histology and biomechanics.3.Electrospun nanofiber membranes were used to observe the effects of cell proliferation and osteogenic differentiation in vitro,and then implanted into rabbit models.The effects of nanofiber membranes in vivo were observed by micro-CT,histology and biomechanics.Result 1.Preserving stump of rotator cuff had more fibrocartilage and collagen fibers at tendon-bone junction than removing the insertion during repairing rotator cuff,and improved the mechanical properties of rotator cuff tendon-humerus junction.2.In the model of acute rotator cuff injury in rabbits,the use of absorbable sutures to repair rotator cuff promoted the regeneration of fibrocartilage,forming more collagen type I,and had stronger mechanical properties of rotator cuff tendon-bone connection.3.The GO-PLGA nanofiber membrane prepared by electrospinning technology made the PLGA nanofibers and GO uniformly combine,promoted the proliferation of bone marrow mesenchymal stem cells,and enhanced the osteogenic differentiation of bone marrow mesenchymal stem cells in vitro.In the model of rotator cuff repair in rabbits,GO-PLGA fibrous membrane increased the formation of new bone and fibrocartilage,improved collagen orgnization,enhanced the biomechanical properties of tendon-bone junction and promoted tendon-bone healing.Conclusion 1.For acute rotator cuff injury with rotator cuff insertion stump,preservation of rotator cuff insertion stump functionally integrated the original rotator cuff insertion compared with removal of the insertion after repair of rotator cuff injury.2.In the model of acute rotator cuff injury in rabbits,repairing rotator cuff with absorpable suture promoted the regeneration of rotator cuff tendon insertion and improved the maturity of rotator cuff insertion.3.GO-PLGA nanofiber membrane not only promoted bone differentiation of bone marrow mesenchymal stem cells in vitro,but also promoted tendon-bone healing in rabbit rotator cuff repair model.