Synergetic effects of shock waves with polydeoxyribonucleotides on rotator cuff tendon tear in a rabbit model

This work aimed to investigate the synergetic therapeutic effects of polydeoxyribonucleotides(PDRN)combined with extracorporeal shock waves therapy(ESWT)and the effects of the therapy according to ESWT sequences on a chronic traumatic full-thickness rotator cuff tear(RCT)in rabbit models.For this purpose,thirty-two rabbits were randomly allocated into 4 groups.An excision was made to create a 5-mm sized full-thickness RCT right proximal to the insertion site on the supraspinatus.After 6 weeks,4 different procedures(normal saline,Group 1;PDRN injection,Group 2;PDRN injection before ESWT,Group 3;PDRN injection after ESWT,Group 4)were performed.PDRN injection and radial type ESWT were each performed 4 times per week.Gross morphology,Immunohistochemistry,and motion analysis were performed at 4 weeks after treatments.All parameters including tear size,Masson’s trichrome(MT)staining,anti-collagen 1 monoclonal antibody immunostaining(COL-1),proliferating cell nuclear antigen(PCNA),vascular endothelial growth factor(VEGF),anti-platelet endothelial cell adhesion molecule-1 polyclonal antibody(PECAM-1),and motion analysis,were significantly greater in Group 2,Group 3,and Group 4 than in Group 1.In Group 4,all parameters were significantly greater than in Group 2,and parameters including MT staining,COL-1,PCNA,PECAM-1,and fast walking time were significantly greater than Group 3.There were no significant differences between Group 2 and Group 3.This study demonstrated that PDRN injection alone and combined with ESWT were more effective than control treatment and applying ESWT before PDRN injection was also shown to yield better outcomes in parameters including angiogenesis,cell proliferation,and fast walking time in a rabbit model with chronic traumatic full-thickness RCT.Therefore,the application of ESWT before PDRN injection could be recommended for optimal outcomes of the conservative treatments when the patients with full-thickness RCT are not suitable in surgical treatment.