Low-level laser therapy combined with platelet-rich plasma on the healing calcaneal tendon: a histological study in a rat model.

Lasers in medical science

PubMedID: 23307438

Barbosa D, de Souza RA, de Carvalho WR, Xavier M, de Carvalho PK, Cunha TC, Arisawa EÂ, Silveira L, Villaverde AB. Low-level laser therapy combined with platelet-rich plasma on the healing calcaneal tendon: a histological study in a rat model. Lasers Med Sci. 2013;.
The objective of this study was to investigate the effects of low-level laser therapy (LLLT) treatment alone (??=?660 nm and ??=?830 nm) or associated with platelet-rich plasma (PRP). We used 54 male rats divided into six groups, with nine animals each: group 1, partial tenotomy; group 2 (GII), PRP; group 3 (GIII): ?660?nm; group 4 (GIV), ?830?nm; group 5 (GV), PRP + ?660?nm; and group 6 (GVI), PRP + ?830?nm. The protocol used was power density 0.35 W/cm(2), energy 0.2 J, energy density 7.0 J/cm(2), time 20 s per irradiated point, and number of points 3. Animals in groups GII, GV, and GVI received treatment with PRP, consisting of a single dose of 0.2 mL directly into the surgical site, on top of the tenotomy. Animals were killed on the 13th day post-tenotomy and their tendons were surgically removed for a quantitative analysis using polarization microscopy. The percentages of collagen fibers of types I and III were expressed as mean ± SD. Higher values of collagen fibers type I were obtained for groups GV and GVI when compared with all other groups (p??0.05). For collagen type III, a significant difference was observed between GII and all other groups (p?