Red Light Therapy for Broken Bones: Scientific Evidence

Researchers in South Korea tested LED-based low-level laser therapy (LLLT) on swelling in patients with broken facial bones, in a 2017 observational study. 40 patients admitted to a single hospital were split into 2 groups of 20, treated with either real or sham light from flat LED panels giving amber light at 590 nm and near-infrared light at 830 nm, twice a day from day 1 to day 5 after injury, with face volume measured after each session. Swelling fell by 16.5% in the treated group compared with 7.3% in the sham group, and the difference was statistically significant. Light treatment appeared to reduce swelling after a facial fracture faster than sham light did.

When researchers added laser treatment at acupuncture points to standard rehabilitation exercises, a 2017 randomized controlled trial tested whether recovery from a wrist fracture improved. All patients had a break at the wrist end of the forearm bone, set without opening the skin and held with pins and a short cast for 6 weeks, and all followed the same active exercise program. The treated group received 980 nm near-infrared light for 30 seconds at each of 9 acupuncture points at 50 mW and 8000 Hz across 10 sessions given 3 times per week, while the control group followed the identical routine with the laser switched off. Pain fell by 44% and wrist function improved by 33% in the treated group compared with the control group. According to the study, laser treatment at acupuncture points combined with active exercises benefits recovery from this fracture.

50 patients with a broken wrist or hand, where the bone had not pierced the skin, took part in a 2014 randomized controlled trial of low-level laser therapy (LLLT). Patients were randomly assigned to LLLT or a sham laser, with the treated group receiving 830 nm near-infrared light at an average power of 60 mW and a peak of 8 W, pulsed at 10 Hz for 10 minutes and delivering 9.7 J/cm² to each fracture site, 5 times per week over 14 days, and none of them had surgery. Pain, difficulty using the hand, grip strength, and signs of bone healing all improved in the laser group compared with their starting levels, and the differences between the 2 groups were statistically significant at the end of treatment and again 2 weeks later. Adding LLLT to standard care appeared to improve both symptoms and healing in these fractures.

A 2021 randomized controlled trial tested photobiomodulation therapy (PBMT) given while a broken wrist was still in a cast. 53 patients with a break at the wrist end of the forearm bone were randomly assigned to 9 treatments of either PBMT or a placebo, delivered through openings cut in the cast using 904 nm near-infrared light at 60 mW and 6.6 J, and were assessed at the start and at 4, 8, 12, and 26 weeks after the injury. Scores on a questionnaire covering wrist pain and difficulty showed no difference between the groups, while grip strength, pinch strength, and how far the wrist could move were better with PBMT at week 4. The trial found fewer patients reporting night pain at week 3 in the PBMT group, but concluded that these physical gains did not carry through to what patients actually felt.

Across 106 participants pooled from 2 randomized controlled trials, a 2020 meta-analysis assessed photobiomodulation (PBM) using low-level laser therapy (LLLT) for healing broken bones in the arms and legs. The review searched in October 2018 and included only trials comparing PBM against another treatment in adults, looking at pain, healing seen in the bone, and unwanted effects. No difference appeared in bone healing, whether judged by the fracture line closing or by new bone forming, and although pain was lower with PBM, the size of that difference was too small to matter clinically. 1 trial of 50 patients did show a meaningful improvement in physical function. The study concluded that the certainty of the evidence was low to very low and that new trials are needed before PBM can be recommended in practice.

Comparing low-level laser therapy (LLLT) against a placebo, a 2006 randomized controlled trial tested treatment for stress fractures in the shin bone. 68 patients were split evenly, with 34 receiving LLLT at 830 nm and doses of 8 and 16 J/cm² over 21 days, and 34 receiving the placebo. Treatment in both groups continued until pain and tenderness had fully settled and the patient could walk without pain. The laser group reached that point sooner than the placebo group and had fewer recurrences. The trial found LLLT beneficial but described the work as preliminary and called for a larger study across several centers.