The effect of a local application of fibroblast growth factor-2 on tendon-to-bone remodeling in rats with acute injury and repair of the supraspinatus tendon

Methods: We investigated the effect of application of fibroblast growth factor (FGF)-2 on the tendon-to-bone remodeling of repaired supraspinatus tendon in rats subjected to bilateral detachment. FGF-2 (100 mg/kg) in a fibrin sealant or sealant alone was applied on the right and left shoulders, respectively. Twelve animals each at 2, 4, and 6 weeks after sur.-cry were sacrificed for histological analysis (n = 5) and biomechanical Q1 testing (n = 7). Results: Histologically, at 2 weeks, FGF-treated specimens had significantly higher tendon-to-bone insertion maturing scores then untreated specimens (P < .002). At 4 and 6 weeks, the scores of FGF-treated and untreated specimens were similar (P > .05). Biomechanically, FGF-treated specimens were stronger at 2 weeks (P = .001); at 4 and 6 weeks, both specimens exhibited similar strength (P > .05). Conclusions: The initial tendon-to-bone remodeling was accelerated by a local application of FGF-2. This may represent a clinically important improvement in rotator cuff repair. Level. of evidence: Basic science study. (C) 2009 Journal of Shoulder and Elbow Surgery Board of Trustees.