Orthopedics · Medical Literature
Efficacy and safety of invasive laser acupuncture (650 and 830 nm) on knee osteoarthritis: A pilot randomized clinical trial.
Abstract
This pilot study explored the safety and efficacy of invasive laser acupuncture (ILA) using two wavelengths (650 and 830 nm) compared with a sham laser in patients with knee osteoarthritis (KOA). This randomized, parallel-arm, patient- and outcome assessor-blinded, placebo-controlled, single-center clinical trial was designed with three groups (control, 650, and 830 nm), and 45 participants were randomly allocated in a ratio of 1:1:1. All participants were treated with ILA on the more affected side at SP9, SP10, ST34, ST35, EX-LE2, EX-LE4, and GB34 for 10 minutes per session, twice weekly, for a total of 12 sessions over 6 weeks. The primary outcome was the change in pain visual analog scale (VAS) score at rest and during activity at baseline (Visit 1) versus 1 week after intervention completion (Visit 13). Secondary outcomes included VAS scores after six treatments (Visit 7) and 6 weeks after intervention completion (Visit 14), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores, European Quality of Life Five Dimension Five Level Scale (EQ-5D-5L), patient's global assessment, rescue medication dosage, and responder rate. Changes in the VAS scores at rest (p = 0.0044, Visit 13; p = 0.0001, Visit 14) and during activity (p = 0.0038, Visit 13; p < 0.0001, Visit 14) were significantly different among the three groups. Significant differences were also observed in WOMAC total (p = 0.0278, Visit 7; p = 0.0485, Visit 13; p = 0.0051, Visit 14), pain (p = 0.0073, Visit 7; p = 0.0210, Visit 13; p = 0.0038, Visit 14), function subscale (p = 0.0055, Visit 14), and EQ-5D-5L scores (p = 0.0131, Visit 14). No ILA-related adverse events or significant changes in vital signs or laboratory results were observed during the study. ILA at 650 and 830 nm showed preliminary signals of short-term pain reduction. However, these preliminary findings should be confirmed in larger, rigorously designed clinical trials. CRIS registration number: KCT0008860; registered on 10/11/2023 (https://cris.nih.go.kr/cris/search/detailSearch.do/25506).
Clinical relevance
Knee osteoarthritis (KOA) is a highly prevalent, disabling condition for which non-pharmacological analgesic adjuncts are increasingly sought to reduce reliance on rescue medications and NSAIDs. This pilot RCT addresses the evidence gap surrounding invasive laser acupuncture (ILA) — a minimally invasive variant of photobiomodulation delivered at acupuncture points — for which rigorous placebo-controlled data have been largely absent. Given the growing interest in integrative, low-risk pain interventions for KOA, these preliminary findings are timely and clinically relevant for orthopedic and pain management practitioners.
Key findings
1. Among 45 patients randomized 1:1:1 to sham control, 650 nm ILA, or 830 nm ILA, both active wavelengths demonstrated statistically significant inter-group differences in VAS pain scores at rest at Visit 13 (1 week post-intervention, p = 0.0044) and at Visit 14 (6 weeks post-intervention, p = 0.0001), suggesting durable short-term benefit. 2. VAS scores during activity were likewise significantly different across groups at Visit 13 (p = 0.0038) and Visit 14 (p < 0.0001), indicating functional pain relief extending beyond the active treatment period. 3. WOMAC total scores showed significant inter-group differences at Visit 7 (mid-treatment, p = 0.0278), Visit 13 (p = 0.0485), and Visit 14 (p = 0.0051), reflecting meaningful improvements in composite pain, stiffness, and physical function. 4. WOMAC pain subscale differences were significant at all three follow-up time points: Visit 7 (p = 0.0073), Visit 13 (p = 0.0210), and Visit 14 (p = 0.0038), corroborating the VAS findings across multiple validated instruments. 5. WOMAC physical function subscale and EQ-5D-5L quality-of-life scores reached statistical significance at Visit 14 (p = 0.0055 and p = 0.0131, respectively), suggesting that benefits extended to functional capacity and patient-perceived health-related quality of life at 6-week post-treatment follow-up. 6. No ILA-related adverse events were recorded, and no clinically significant changes in vital signs or laboratory parameters were observed across all 12 treatment sessions, supporting an acceptable short-term safety profile. Note: Individual effect sizes, confidence intervals, NNT, and NNH were not reported in the available abstract; quantitative between-group magnitude data should be sought in the full publication.
Practice implications
ILA at 650 nm or 830 nm, administered twice weekly for 6 weeks (12 sessions, 10 minutes each) at standardized KOA acupuncture points (SP9, SP10, ST34, ST35, EX-LE2, EX-LE4, GB34), may serve as a safe adjunctive analgesic strategy in patients with KOA who are poor candidates for or wish to minimize pharmacological therapy, though it should not yet replace guideline-based care given the pilot design and small sample size (n = 15 per arm). Clinicians considering referral for ILA should note that pain and functional benefits appeared to persist at 6 weeks post-treatment, suggesting a potential carry-over photobiomodulatory effect warranting structured follow-up assessment. Larger, adequately powered, multi-center RCTs with standardized outcome reporting (effect sizes, CIs, NNT) and active comparator arms (e.g., conventional acupuncture or exercise) are needed before ILA can be incorporated into routine orthopedic or integrative pain management protocols.