Laser Acupuncture for Patients with Knee Osteoarthritis: A Systematic Review and Meta-Analysis of Randomized Placebo-Controlled Trials

OBJECTIVES: To provide updated evidence from randomized controlled trials (RCTs) on the effectiveness of laser acupuncture for patients with knee osteoarthritis (KOA). METHODS: A literature search in 9 databases was conducted from their inception through February 2019. Randomized controlled trials (RCTs) written in English that compared active laser acupuncture with placebo in KOA patients were included. Two authors independently extracted data from these trials. Meta-analysis software was used to analyze the data. Included studies were assessed in terms of the follow-up period, the methodological quality, and appropriateness of their technical features. RESULTS: Of 357 studies, seven RCTs (totaling 395 patients) met the inclusion criteria. The short-term outcomes showed that laser acupuncture offered significant pain relief over placebo when assessed by the 100 mm visual analog scale (VAS) pain score (p = 0.02), while there was no significant difference between laser acupuncture and placebo based on Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain score (p = 0.25). For subgroup analysis, laser acupuncture had superiority over placebo in terms of both VAS and WOMAC pain scores in the appropriate technical features subgroup and the excellent methodological quality subgroup. But the effect of laser acupuncture on pain relief was not maintained in terms of either VAS (p = 0.19) or WOMAC pain score (p = 0.60). The pooled effect showed no significant difference between laser acupuncture and placebo at either time point according to WOMAC function scale, WOMAC stiffness scale, and quality of life outcome. CONCLUSIONS: Our findings indicate that laser acupuncture can effectively reduce knee pain for patients with KOA at short term when appropriate technical features are applied, but the effect likely fades away during the subsequent follow-up period.