Introduction: Excellent outcomes of arthroscopic rotator cuff repair for small and medium tears have been recently reported. However, re-tears after surgery have been a common complication after surgical repair of large and massive rotator cuff tears andoften occur in early postoperative phase. It was previously reported that basic fibroblastgrowth factor and platelet-rich plasma enhanced rotator cuff tear healing. Wehypothesized that this combined therapy could enhance rotator cuff healing after rotatorcuff repair in a rat model. This study aimed to evaluate the efficacy of combined therapyof platelet-rich plasma and basic fibroblast growth factor with gelatin-hydrogel sheet.
Methods: To create a rotator cuff defect, the infraspinatus tendon of Sprague Dawley ratwas resected from the greater tuberosity. The infraspinatus tendons were repaired andcovered with gelatin-hydrogel sheet impregnated with PBS (control group), basicfibroblast growth factor (bFGF group), platelet-rich plasma (PRP group), or both basicfibroblast growth factor and platelet-rich plasma (combined group). Histologicalexaminations were conducted using hematoxylin and eosin, safranin O, andimmunofluorescence staining such as Isolectin B4, type II collagen. For mechanicalanalysis, ultimate failure load of the tendon-humeral head complex was evaluated at41 weeks postoperatively.
Results: In the hematoxylin and eosin staining, the tendon maturing score of the combined group was higher than that of the control group postoperativeat 2 weeks. Inthe safranin O staining, stronger proteoglycan staining was observed in the combinedgroup compared with the other groups at postoperative 2 weeks. Vascular staining withisolectin B4 in 3 treatment groups was significantly higher than that in the control group.Type II collagen expression in the combined group was significantly higher than those inthe other groups. The ultimate failure load of the combined group was significantly higherthan that of the control group.
Conclusion: Combined therapy of basic fibroblast growth factor and platelet-rich plasmapromoted angiogenesis; tendon maturing and fibrocartilage regeneration at the enthesis,which could be enhance the mechanical strength. It was suggested that basic fibroblastgrowth factor and platelet-rich plasma enhance both tendon and bone-tendon junctionhealing, and basic fibroblast growth factor and platelet-rich plasma were synergistic.