Effect of low-level laser therapy on bone repair: a randomized controlled experimental study
The aim of this study was to investigate the effect of low-level laser therapy (LLLT) on bone repair in femoral fractures. Sixty adult Wistar rats were randomly assigned into one of two groups: group A (ostectomy + LLLT) or group B (ostectomy + sham laser). An experimental model of complete bone fracture was surgically created by removing a 2-mm fragment from the middle third of the femoral shaft. Data were analyzed on days 8, 13, and 18 after the fracture (subgroups 1, 2, and 3). Samples were assessed for changes in inflammatory infiltration; trabecular bone matrix, periosteal, and new bone formations; and changes in the expression of particular osteogenic-related proteins (osteocalcin, osteopontin, and osteonectin). Microscopic analysis revealed a significant decrease in inflammatory infiltration, intense trabecular bone matrix and periosteal formation, and an increase in newly formed bone after laser irradiation. We also found an increase in the expression of bone matrix proteins with LLLT, with a significant difference measured for osteocalcin in the LLLT group at day 8 (p = 0.007). We show that LLLT plays an important role in augmenting bone tissue formation, which is relevant to fracture healing. LLLT may therefore be indicated as an adjunct therapeutic tool in clinical practice for the treatment or recovery of nonunion injuries.
KeywordsBone remodeling Femoral fracture Low-level laser therapy
Animal manipulation was performed in accordance with the animal testing guide (in agreement with the Brazilian Legislation no. 11.794/2008 for Procedures for the Scientific Use of Animals). This randomized controlled experimental study was previously approved by the Research Ethics Committee of Federal University of São Paulo under no. 1101/09.
Conflict of interest
All authors have no conflicts of interest.
- 4.Haal BK (2005) Bones and cartilage: developmental and evolutionary skeletal biology. Academic, San Diego, CAGoogle Scholar
- 10.Marchesano L (2005) Comportamento de marcadores séricos de formação e reabsorção óssea após enxerto autógeno em fissure alveolar congênita: sem e com plasma rico em plaquetas. Doctoral, Universidade Estadual Paulista “Júlio de Mesquita Filho”, AraraquaraGoogle Scholar
- 11.Santa Cruz Biotechnology I (2010) osteocalcin (FL-100): sc-30044Google Scholar
- 12.Santa Cruz Biotechnology I (2010) Osteopontin (LFMb-14): sc-73631Google Scholar
- 13.Santa Cruz Biotechnology I (2010) SPARC (AON-5031): sc-73472 instructions guideGoogle Scholar
- 14.Suvinil catalog - brick (2014)Google Scholar
- 16.Pham N, Morrison A, Schwock J, Aviel-Ronen S, Iakovlev V, Tsao M, Ho J, DW Hedley (2007) Quantitative image analysis of immunohistochemical stains using a CMYK color model. Diagn Pathol:2–8Google Scholar
- 18.Drosse I, Volkmer E, Seitz S, Seitz H, Penzkofer R, Zahn K, Matis U, Mutschler W, Augat P, Schieker M (2008) Validation of a femoral critical size defect model for orthotopic evaluation of bone healing: a biomechanical, veterinary and trauma surgical perspective. Tissue Eng Part C Methods 14(1):79–88. doi: 10.1089/tec.2007.0234 CrossRefPubMedGoogle Scholar
- 19.Huang Y-Y, Chen AC-H, Hamblin M (2009) Low-level laser therapy: an emerging clinical paradigm.3. doi: 10.1117/2.1200906.1669
- 25.Favaro-Pipi E, Ribeiro DA, Ribeiro JU, Bossini P, Oliveira P, Parizotto NA, Tim C, de Araujo HS, Renno AC (2011) Low-level laser therapy induces differential expression of osteogenic genes during bone repair in rats. Photomed Laser Surg 29(5):311–317. doi: 10.1089/pho.2010.2841 CrossRefPubMedGoogle Scholar
- 28.Guimarães KB (2006) Fotoengenharia do processo de reparo ósseo induzido pela laserterapia de baixa potência (GaAlAs): estudo em fêmures de ratos. Faculdade de Odontologia, PUCRS, Porto AlegreGoogle Scholar
- 29.Giordano V, Knackfuss IG, Gomes RC, Giordano M, Mendonça RG, Coutynho F (2001) Influência do Laser de baixa energia no processo de consolidação da fratura de tibia: estudo experimental em ratos (Influency of low-level laser on healing process of tibial fracture: experimental study in rats). Rev Bras Ortop 36(5):174–178Google Scholar
- 30.Noda M, Denhardt D (2008) Osteopontin. In: AP I (ed) Principles of bone biology, 3rd edn, pp 351–366Google Scholar
- 33.Irie K, Zalzal S, Ozawa H, McKee MD, Nanci A (1998) Morphological and immunocytochemical characterization of primary osteogenic cell cultures derived from fetal rat cranial tissue. Anat Rec 252(4):554–567. doi: 10.1002/(SICI)1097-0185(199812)252:4<554::AID-AR6>3.0.CO;2-2 CrossRefPubMedGoogle Scholar