Effectiveness of low-level laser therapy in patients with knee osteoarthritis: a systematic review and meta-analysis

Abstract

Objective To investigate the efficacy of low-level laser therapy (LLLT) treatment of knee osteoarthritis (KOA) by a systematic literature search with meta-analyses on selected studies. Design MEDLINE, EMBASE, ISI Web of Science and Cochrane Library were systematically searched from January 2000 to November 2014. Included studies were randomized controlled trials (RCTs) written in English that compared LLLT (at least eight treatment sessions) with sham laser in KOA patients. The efficacy effective size was estimated by the standardized mean difference (SMD). Standard fixed or random-effects meta-analysis was used, and inconsistency was evaluated by the I-squared index (I2). Results Of 612 studies, nine RCTs (seven double-blind, two single-blind, totaling 518 patients) met the criteria for inclusion. Based on seven studies, the SMD in visual analog scale (VAS) pain score right after therapy (RAT) (within 2 weeks after the therapy) was not significantly different between LLLT and control (SMD = −0.28 [95% CI = −0.66, 0.10], I2 = 66%). No significant difference was identified in studies conforming to the World Association of Laser Therapy (WALT) recommendations (four studies) or on the basis of OA severity. There was no significant difference in the delayed response (12 weeks after end of therapy) between LLLT and control in VAS pain (five studies). Similarly, there was no evidence of LLLT effectiveness based on Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain, stiffness or function outcomes (five and three studies had outcome data right after and 12 weeks after therapy respectively). Conclusion Our findings indicate that the best available current evidence does not support the effectiveness of LLLT as a therapy for patients with KOA.

Safety and Effectiveness of Low-Level Laser Therapy in Patients With Knee Osteoarthritis: A Systematic Review and Meta-analysis

“…Huang meta-analysis also showed no significant differences between two groups in WOMAC stiffness and WOMAC functional outcomes, while our metaanalysis indicated a significant improvement in patients who received LLLT. The results of our meta-analysis were similar to Huang and colleagues' study 10 concerning WOMAC pain and range of knee motion outcomes in which there were no significant differences between two groups. Since there was a significant heterogeneity in results of outcome meta-analysis, it cannot be said with certainty that the LLLT impacts in reducing pain and improving function in patients with KOA.…”

“…Reduced sample size may lead to biased results in these trials. The last systematic study in this area in recent years belongs to Huang et al 10 However, the study neither encompasses some related articles, nor considers follow-up period of outcomes in the analysis, it also does not analyze consequences such as pain at rest, pain during activities and quality of life. The most important limitation of this study is, of course, high heterogeneity between studies that is the reason for using random model for meta-analysis.…”

“…On the other hand, there are few systematic and meta-analyses studies that clarify the efficacy and safety of LLLT in these patients. The last systematic study that has been conducted in this area in recent years belongs to Huang et al 10 However, the study does not encompass some related articles, does not consider follow-up period of outcomes in the analysis and does not analyze consequences such as pain at rest, pain during activities and quality of life. Accordingly, we aimed to alleviate some of these limitations, to have a more comprehensive analysis of the safety and effectiveness of low power laser in people with KOA and ultimately contribute to an evidence-based decision making and policy on the use of this technology in this group of patients.…”

Effect of High-Intensity Laser Treatments on Chronic Pain Related to Osteoarthritis in Former Professional Athletes: A Case Series

“…Previous studies suggested that LLLT was of limited benefit in patients with knee OA [9] and non-specific low back pain [10,13,14]. However, for patients with chronic joint and back pain not responding to non-opioid analgesics, HILT may represent a simple, non-invasive, and more cost-effective alternative to other non-invasive physiotherapy and electrostimulation modalities.…”

“…These investigators concluded that LLLP should be incorporated into standard conservative treatment protocol for symptomatic OA involving the knee. However, a recent systemic review and meta-analysis by Huang et al [9] concluded that "current evidence did not support the effectiveness of LLLT" in patients with knee OA.…”