Low-Intensity Pulsed Ultrasound Accelerates Healing in Rat Calcaneus Tendon Injuries

• Autor(a) principal: Jeremias Junior, Sergio Luiz
• Data de Publicação: 2011
• Outros Autores: Camanho, Gilberto Luis [UNIFESP], Bassit, Ana Cristina Ferreira, Forgas, Andrea, Ingham, Sheila Jean McNeill [UNIFESP], Abdalla, Rene Jorge [UNIFESP]
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNIFESP
• Texto Completo: http://dx.doi.org/10.2519/jospt.2011.3468; http://repositorio.unifesp.br/handle/11600/33837
• topic: biomechanical testing; physical agents; therapeutic ultrasound

STUDY DESIGN: Controlled laboratory study.OBJECTIVE: To evaluate the effect of low-intensity therapeutic ultrasound on the murine calcaneus tendon healing process.BACKGROUND: Therapeutic ultrasound promotes formation and maturation of scar tissue.METHODS: Calcaneus tendon tenotomy and tenorrhaphy was performed on 28 Wistar rats. After the procedure, the animals were randomly divided into 2 groups. the animals in the experimental group received a 5-minute ultrasound application, once a day, at a frequency of 1 MHz, a spatial average temporal average intensity of 0.1 W/cm(2), and a spatial average intensity of 0.52 W/cm(2) at a 16-Hz frequency pulse mode (duty cycle, 20%). Data for the injured side were normalized in relation to the data from the contralateral healthy calcaneus tendon (relative values). the animals in the control group received sham treatment. After a 28-day treatment period, the animals were sacrificed and their tendons surgically removed and subjected to mechanical stress testing. the parameters analyzed were cross-sectional area (mm(2)), ultimate load (N), tensile strength (MPa), and energy absorption (mJ).RESULTS: A significant difference between groups was found for the relative values of ultimate load and tensile strength. the mean +/- SD ultimate load of the control group was -3.5% +/- 32.2% compared to 33.3% +/- 26.8% for the experimental group (P = .005). the mean tensile strength of the control group was -47.7% +/- 19.5% compared to -28.1% +/- 24.1% for the experimental group (P = .019). No significant difference was found in cross-sectional area and energy absorption.CONCLUSION: Low-intensity pulsed ultrasound produced by a conventional therapeutic ultrasound unit can positively influence the calcaneus tendon healing process in rats. J Ort hop Sports Phys Ther 2011;41(7):526-531, Epub 2 February 2011. doi:10.2519/jospt.2011.3468