Sistema FMUSP-HC: Faculdade de Medicina da Universidade de São Paulo (FMUSP) e Hospital das Clínicas da FMUSPFARCIC, Thiago SaikaliBALDAN, Cristiano SchiavinatoMACHADO, Aline Fernanda PerezCAFFARO, Leonardo Affonso MassabkiMASSON, Igor Fagioli BordelloCASAROTTO, Raquel Aparecida2018-05-082018-05-082018ADVANCES IN WOUND CARE, v.7, n.4, p.114-120, 20182162-1918https://observatorio.fm.usp.br/handle/OPI/26311Objective: The aim of this study was to evaluate the organization of collagen fibers in the healing process of rat Achilles tendon rupture using different times of ultrasound therapy (TUS). Approach: Forty Wistar rats were selected. Among these, 32 were submitted to total tenotomy of the calcaneous tendon and divided into 5 groups: control group (CG, n = 8), without tenotomy or any treatment; tenotomy group (n = 8), with tenotomy and without treatment; TUS groups-TUS3 (n = 8), TUS4 (n = 8), and TUS5 (n = 8)-submitted to tenotomy and treated with TUS for 3, 4, and 5 min per effective radiating area (ERA), respectively. The animals were sacrificed on the 12th postoperative day. The tendons were surgically removed for analysis of the collagen fiber organization using the birefringence technique (OR, optical retardation). Results: The collagen fibers exhibited better aggregation and organization in the UST3, TUS4, and TUS5 groups compared with CG (p < 0.05). The TUS5 group had better response rates in intergroup comparison. Innovation: The dose response of therapeutic TUS is influenced by many variables. The scientific evidence to support the dosimetry is insufficient. The application time is an important variable to be considered in TUS. In this study, the longer the application time, the better for organization and aggregation of collagen fibers in the rat tendon. Conclusion: TUS applied for 5min per ERA presented higher dose response to the organization of collagen fibers in the healing process of rat Achilles tendon rupture.engrestrictedAccessbirefringencedosimetrywound healingAchilles tendonultrasonic therapytendon injuriestissue-repairmorphologyintensityarticleCopyright MARY ANN LIEBERT, INC10.1089/wound.2017.0748Dermatology2162-1934