ABSTRACT
Abstract Purpose: To evaluate the effect of transforming growth factor β1 (TGF-β1) on tendon-to-bone reconstruction of rotator cuff tears. Methods: Seventy-two rat supraspinatus tendons were transected and reconstructed in situ. At 8 and 16 weeks, specimens of three groups; that is control, L-dose (low dose), and H-dose (high dose) were harvested and underwent a biomechanical test to evaluate the maximum load and stiffness values. Histology sections of the tendon-to-bone interface were identified by hematoxylin-eosin or Masson trichrome stain. Collagen type III was observed by picric acid sirius red staining under polarized light. The level of insulin-like growth factor 1 (IGF-1) and vascular endothelial growth factor (VEGF) was measured by the enzyme-linked immunosorbent assay (ELISA) method. Results: Collagen type III of the H-dose group had a significant difference in histology structure compared with the L-dose group (P<0.05). The maximum load and stiffness decreased significantly in the control group compared with the values of the L-dose and H-dose groups. The stiffness among the three groups differed significantly at the same postoperative time (P<0.05). Interestingly, progressive reestablishment of collagen type III affected tendon-to-bone healing significantly in the later stages. Conclusion: The H-dose was associated with an increased collagen type III morphology stimulated by TGF-β1.
Subject(s)
Animals , Male , Rats , Tendon Injuries/drug therapy , Wound Healing/physiology , Rotator Cuff/surgery , Vascular Endothelial Growth Factors/metabolism , Transforming Growth Factor beta1/metabolism , Rotator Cuff Injuries/surgery , Tendon Injuries/metabolism , Tensile Strength/physiology , Wound Healing/drug effects , Biomechanical Phenomena , Enzyme-Linked Immunosorbent Assay , Rotator Cuff/metabolism , Rats, Sprague-Dawley , Collagen Type III/metabolism , Disease Models, Animal , Elasticity/physiology , Transforming Growth Factor beta1/pharmacology , Muscle Strength/physiology , Fibroblasts/drug effects , Fibroblasts/physiology , Rotator Cuff Injuries/metabolismABSTRACT
Este trabalho investiga o efeito do traumatismo e infiltraçao de xilocaína com corticóide, traumatismo e infiltraçao de xilocaína e traumatismo apenas, no peritendao da unidade musculotendínea do tríceps sural em 20 ratos adultos machos. Foram obtidos o estudo histológico e o teste de resistência da unidade musculotendínea em cinco séries. As três primeiras séries foram de infiltraçao após trauma inicial com intervalos semanais (24 horas, uma e duas semanas). As duas últimas séries (três e quatro semanas) tiveram o descontínuo do uso de infiltraçoes, tendo sido realizado apenas estudo histológico e biomecânico. Observou-se o efeito deletério nos aspectos anatomopatológico e biomecânico na unidade músculo-tendao dos animais experimentais em que a associaçao de infiltraçao de xilocaína com corticóide foi utilizada.