Low-Level Laser Therapy on Tissue Repair of Partially Injured Achilles Tendon in Rats

Author(s)

de Jesus, Julio Fernandes ^[1] ; Spadacci-Morena, Diva Denelle ^[2] ; dos Anjos Rabelo, Nayra Deise ^[3] ; Pinfildi, Carlos Eduardo ^[4] ; Fukuda, Thiago Yukio ^[5] ; Plapler, Helio ^[6]

Affiliation

^[1] Univ Fed Sao Paulo UNIFESP, Interdisciplinary Surg Sci Program, BR-04021001 Sao Paulo - Brazil

^[2] Inst Butantan, Lab Physiopathol, Sao Paulo - Brazil

^[3] Univ Nove Julho UNINOVE, Rehabil Sci Program, Sao Paulo - Brazil

^[4] Univ Fed Sao Paulo UNIFESP, Dept Plast Surg, Sao Paulo - Brazil

^[5] ISCMSP, Phys Therapy Sect, Sao Paulo - Brazil

^[6] Univ Fed Sao Paulo UNIFESP, Dept Surg, Sao Paulo - Brazil

• Document type: Journal article
• Source: Photomedicine and Laser Surgery; v. 32, n. 6, p. 345-350, JUN 2014.
• Web of Science Citations: 5

Abstract

Objective: The aim of this study was to assess the alignment and type of collagen (I and III) in partially injured Achilles tendons of rats treated with low-level laser therapy (LLLT). Background: Achilles tendons present high indices of injury and their regeneration process may take a long time. LLLT has been used to accelerate and enhance injured Achilles tendon repair. Methods: Sixty-five male Wistar rats were distributed into seven groups: LASER 1, 3, and 7 (the rat's Achilles tendons were partially injured and submitted to treatment for 1, 3, or 7 days, respectively); a Sham group 1, 3, and 7 for each of LASER group (same injury, but the LLLT was only simulated), and five remaining animals were allocated to the control group (no procedures were performed). The 780 nm LLLT was applied once a day, with 70 mW of mean power, fluence of 17.5 J/cm(2) for 10 sec. After the rats were euthanized, the tendons were surgically removed and assessed by birefringence technique (collagen alignment) and picrosirius red (collagen I and III). Results: Sham versus LASER analysis did not show differences (p > 0.05) for collagen alignment. The collagen composition (median) was significantly different (p < 0.05) for LASER 3 (I: 16.5; III: 83.5) versus Sham 3 (I: 12.5; III: 87.5) and LASER 7 (I: 20.2; III: 79.8) versus Sham 7 (I: 10.2; III: 89.8). LASER groups exhibited a higher percentage of type I collagen and a lower percentage of type III collagen. Conclusions: LLLT stimulated collagen I proliferation, improving the injured Achilles tendons' healing process. (AU)

• FAPESP's process: 11/00979-1 - Low level laser influence in the modulation of inflammation and tissue repair of rat Achilles tendon after partial injury
• Grantee: Helio Plapler
• Support Opportunities: Regular Research Grants