Low-level laser therapy in ankle sprains: a randomized clinical trial.

OBJECTIVE To test the efficacy of low-level laser therapy on lateral ankle sprains as an addition to a standardized treatment regimen, a trial was conducted in which high-dose laser (5J/cm2), low-dose laser (0.5J/cm2), and placebo laser therapy (0J/cm2) at skin level were compared. DESIGN Randomized, double-blind, controlled clinical trial with a follow-up of 1 year. Patients, therapists, assessors, and analysts were blinded to the assigned treatment. SETTING An ambulatory care setting. PATIENTS After informed consent and verification of exclusion criteria, 217 patients with acute lateral ankle sprains were randomized to three groups from September 1, 1993, through December 31, 1995. INTERVENTIONS Twelve treatments of 904nm laser therapy in 4 weeks as an adjunct to a standardized treatment regimen of 4 weeks of brace therapy combined with standardized home exercises and advice. The laser therapy device used was a 904nm Ga-As laser, with 25-watt peak power and 5,000 or 500Hz frequency, a pulse duration of 200nsec, and an irradiated area of 1cm2. PRIMARY OUTCOME MEASURES Pain and function as reported by the patient. RESULTS Intention-to-treat analysis of the short-term results showed no statistically significant difference on the primary outcome measure, pain (p = .41), although the placebo group showed slightly less pain. Function was significantly better in the placebo group at 10 days (p = .01) and 14 days (p = .03) after randomization. The placebo group also performed significantly better on days of sick leave (p = .02) and at some points for hindrance in activities in daily life and pressure pain, as well as subjective recovery (p = .05). Intention-to-treat analysis showed that total days of absenteeism from work and sports were remarkably lower in the placebo group than in the laser groups, ranging from 3.7 to 5.3 and 6 to 8 days, respectively. The total number of relapses at 1 year in the low-dose laser group (n = 22) was significantly higher (p = .04) than in the other two groups (high laser, n = 13; placebo, n = 13). Subgroup analysis to correct for possible confounders did not alter these findings. CONCLUSIONS Neither high- nor low-dose laser therapy is effective in the treatment of lateral ankle sprains.