Low level laser therapy for osteoarthritis
Clinical bottom line:
Based on little data there is no evidence that low level laser therapy (LLLT) is more effective than placebo in reducing osteoarthritis pain. There were few trials of disparate design and quality and overall produced negative results for most outcome measures.
Low level laser therapy (LLLT) uses a light source that is thought to generate photochemical reactions in the cells and is used as a non-invasive treatment for osteoarthritis (OA).
Brosseau L; Welch V; Wells G; Debie R; gam A; Harman K; Morin M; Shea B; Tugwell P. Low level laser therapy (classes I, II and III) for the treatment of osteoarthritis (Cochrane Review). In: The Cochrane Library, Issue 2, 2000. Oxford: Update Software.
Date review completed : January 2000
Number of trials included : 4 randomised controlled trials and 1 controlled clinical trial
Number of patients : 112 in active laser groups and 85 in placebo laser groups
Control group : placebo
Main outcomes : pain, physical function, global assessment, joint imaging
Inclusion criteria were randomised controlled trials (RCTs) or controlled clinical trials (CCTs); clinical and/or radiological confirmation of the diagnosis of OA; adults; all types of LLLT; placebo and active controls; pain or functional outcomes.
Reviewers conducted a comprehensive search strategy including the main databases and references of retrieved reports. Experts in the field were contacted for additional and unpublished data. Methodological quality of trials assessed using Oxford rating scale, maximum score is five (Jadad et al., 1996). A quantitative analysis on sub-sets of trials were performed. Reviewers calculated a standard mean difference (SMD), or an odds ratio (OR) for sub-sets of trials based on methodological quality of trials, duration and dose of treatment and site of OA involvement.
Four of the included trials were RCTs, one was a non-randomised controlled trial and is not commented on further here. Of the 4 RCTs, only one was cited as being double-blind, the blinding status of the other three was unclear but they were probably patient blind. All compared laser therapy with placebo. Trials varied in the number of laser treatments given, type of laser and wavelength used and outcome measures. Treatment sessions varied from twice daily for 10 days to two to three a week for three to four weeks.
Two of three trials found no significant difference between laser and placebo for the primary outcome of pain, overall there was no significant difference with standard mean difference of -0.23 (95% CI: -1.0 to 0.57). For two trials that measured patient assessed global disease activity there was no difference between laser and placebo OR 0.96 (0.44 to 2.1). There were no significant differences between laser and placebo for functional status, swelling, muscle strength or joint tenderness.
No adverse effects were reported and no evidence of harm was found.
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Gan AN; Thorsen H; Lonnberg F. The effect of low-level laser therapy on musculoskeletal pain: a meta-analysis. Pain. 1993; 52: 63-66