title: Low-level laser therapy improves early healing of medial collateral ligament injuries in rats.
abstract: OBJECTIVE
  This study sought to investigate whether or not low-level laser therapy (LLLT) with a helium-neon laser increased biomechanical parameters of transected medial collateral ligament (MCL) in rats.
  
  
  BACKGROUND
  It has been reported that LLLT can enhance tendon healing.
  
  
  METHODS
  Thirty rats received surgical transection to their right MCL, and five were assigned as the control group. After surgery, the rats were divided into three groups: group 1 (n = 10) received LLLT with 0.01 J/cm(2) energy density per day, group 2 (n = 10) received LLLT with 1.2 J/cm(2) energy density per day, and group 3 (sham = exposed group; n = 10) received daily placebo laser with shut-down laser equipment, while the control group received neither surgery nor LLLT. Biomechanical tests were performed at 12 and 21 days after surgery. The data were analyzed by one-way analysis of variance.
  
  
  RESULTS
  The ultimate tensile strength (UTS) of group 2 on day 12 was significantly higher than that of groups 1 and 3. Furthermore, the UTS and energy absorption of the control (uninjured) group were significantly higher than those of the other groups.
  
  
  CONCLUSIONS
  LLLT with a helium-neon laser is effective for the early improvement of the ultimate tensile strength of medial collateral ligament injuries.
authors.affiliation: Cell and Molecular Biology Research Center, Medical School, Shaheed Beheshti University of Medical Sciences, Tehran, Iran. bayat_m@cyahoo.com
authors.forename: Mohammad
authors.initials: M
authors.lastname: Bayat
authors.forename: Ali
authors.initials: A
authors.lastname: Delbari
authors.forename: Mohammad Ali
authors.initials: MA
authors.lastname: Almaseyeh
authors.forename: Yousef
authors.initials: Y
authors.lastname: Sadeghi
authors.forename: Maryam
authors.initials: M
authors.lastname: Bayat
authors.forename: Fatemesadat
authors.initials: F
authors.lastname: Reziae
mesh_terms: D000818:Animals; D004307:Dose-Response Relationship, Radiation; D028022:Low-Level Light Therapy / Q000379:methods*; D008297:Male; D017888:Medial Collateral Ligament, Knee / Q000293:injuries*; D051381:Rats; D017208:Rats, Wistar; D013718:Tensile Strength; D014945:Wound Healing