Knee OA – Laser Therapy

Recommendation

700-880 probes =

1.5-163 Joules (6 Joules average)
1-3 spots
Frequency = 1x per day down to 1x per week

900 probes =

6 Joules average (4 Joules WALT)
1-6 spots (1 Joule per spot)
Frequency = 1x per day down to 1x per week

LLLT has been used in many studies to treat knee OA. In a recent review article Fangel et al. 2019 found 14 articles of good enough quality to review 12 of which showed positive results in decreasing patient-reported pain. Below is the table of articles reviewed.

	Laser	P	T	THE	NP	PD	ED	EP	ET	Effect
Knee Osteoarthritis
Yurtkuran et al. 2007	As-Ga (904 nm)	4 mW pulsed	120 s	0.4 cm ²	1 (Sp9)	10 mW / cm ²	1.2 J / cm ²	0.48 J	0.48 J	No
Hegedús et al. 2009	As-Ga-Al (830 nm)	50 mW continuous	120 s	0.005 cm ²	8	10,000 mW / cm ²	1200 J / cm ²	6 J	48 J	Yes Intergroup
Zhao et al. 2010	Laser (650 nm) + CO2 laser (10.6 µm)	36 mW + 200 mW (40 Hz)	1200 s	0.0314 cm ²	1 (ST35)	1146.5 mW / cm ² + 6369.4 mW / cm ²	1375.8 J / cm ² + 3821.65 J / cm ²	43.2 J + 120 J	43.2 J + 120 J	Yes With 2 weeks
Fukuda et al. 2011	As-Ga (904 nm)	60 mW pulsed	50 s	0.5 cm ²	9	120 mW / cm ²	6 J / cm ²	3 J	27 J	Yes
Štiglić-Rogoznica et al. 2011	YAG laser (1064 nm)	3 kW	1200 s total	not supplied	not supplied	Cannot be calculated	Cannot be calculated	Cannot be calculated	Cannot be calculated	Yes
Gworys et al. 2011	Laser (810 nm)	400 mW continuous	20 s	0.63 cm ²	12	634.9 mW / cm ²	12.7 J / cm ²	8 J	96 J	Yes
Group I	Laser (810 nm)	400 mW continuous	20 s	0.63 cm ²	12	634.9 mW / cm ²	12.7 J / cm ²	8 J	96 J	Yes
Gworys et al. 2011	MSL Laser	1100 mW (2000Hz)	11.27 s	2 cm ²	12	550 mW / cm ²	6.2 J / cm ²	12.4 J	148.8 J	Yes
Group II	MSL Laser	1100 mW (2000Hz)	11.27 s	2 cm ²	12	550 mW / cm ²	6.2 J / cm ²	12.4 J	148.8 J	Yes
Gworys et al. 2011	MSL Laser	1100 mW (2000Hz)	6 s	2 cm ²	12	550 mW / cm ²	3.28 J / cm ²	6.6 J	79.2 J	Yes
Group III	MSL Laser	1100 mW (2000Hz)	6 s	2 cm ²	12	550 mW / cm ²	3.28 J / cm ²	6.6 J	79.2 J	Yes
Kedzierski et al. 2011	Laser 10 MSL M1 (808 nm) + (905 nm)	1250 mW Continuous + Pulsed	600 s	not supplied	not supplied	Cannot be calculated	Cannot be calculated	36 J	Cannot be calculated	Yes
Rayegani et al. 2012	Laser (880 nm)	50 mW continuous	120 s	0.01 cm ²	8	5000 mW / cm ²	600 J / cm ²	6 J	48 J	Yes
Alghadir et al. 2014	As-Ga (850 nm)	100 mW	60 s	0.00785 cm ²	8	12738.8 mW / cm ²	764.33 J / cm ²	6 J	48 J	Yes
Nakamura et al. 2014	Ga-Al-AS (830 nm)	1000 mW	30 sec	1.5 cm ²	4	666.67 mW / cm ²	20.1 J / cm ²	30 J	120 J	Yes
Soleimanpour et al. 2014	Laser (810 nm)	50mW (F = 3,000, peak power = 80W, Δt = 200 ns)	120 s	1 cm ²	6	50 mW / cm ²	6 J / cm ²	6 J	36 J	Yes
Laser I	Laser (810 nm)	50mW (F = 3,000, peak power = 80W, Δt = 200 ns)	120 s	1 cm ²	6	50 mW / cm ²	6 J / cm ²	6 J	36 J	Yes
Soleimanpour et al. 2014	Laser (890 nm)	30mW (F = 3,000Hz, peak power = 50W, Δt = 200 ns	588 s	1,765 cm ²	1	17 mW / cm ²	10 J / cm ²	17.6 J	53.6 J	Yes
Laser II	Laser (890 nm)	30mW (F = 3,000Hz, peak power = 50W, Δt = 200 ns	588 s	1,765 cm ²	1	17 mW / cm ²	10 J / cm ²	17.6 J	53.6 J	Yes
Hinman et al. 2014	Red Laser (not specified)	10 mW	not supplied	not supplied	Varied	Cannot be calculated	Cannot be calculated	0.2 J	Cannot be calculated	No
Nambi et al. 2017	AS-Ga (905 nm)	25 mW, (pulsed)	60 s	1 cm ²	8	25 mW / cm ²	1.5 J / cm ²	1.5 J	12 J	Yes
Nazari et al. 2019	YAG (1064 nm)	5 W, (30 Hz)	8 min	not supplied	not supplied	Cannot be calculated	60 J / cm2	Cannot be calculated	2400 J	Yes

VAS: Visual Analog Pain Scale; Al: aluminum; Ga: gallium; As: arsenide; OA: osteoarthritis; WOMAC: Western Ontario and McMaster Universities osteoarthritis index; Sp9 / ST35: acupuncture point; P: power; nm: nanometer; PD: power density; mW: milliwatts; mw / cm2: milliwatts per square centimetre; T: time; s: second; The area; cm ² : square centimetre; ED: energy density; J: joule; J / cm ² : joule per square centimetre; E: energy; Hz: hertz; W: watts; +: plus; EP: energy per point; ET: energy per treatment; MSL: multi-session semiconductor laser.

The article summarized the energy used in the table below:

	EP	ET
Knee osteoarthritis
Mean	18.94 J	218.70 J
Median	6.3 J	48 J
Mode	6 J	48 J

EP: energy per point; ET: energy per treatment; J: joule.

Two of the included studies found no significant improvement in pain. However it appears they used lower laser doses. Yurtkuran et al. 2007 applied 0.48 J per point and 0.48 J per treatment session. Hinman et al. 2014 did not report all laser application parameters but indicated that a 0.2 J per point was used. These lower doses may explain the lack of effect.

Among the studies with positive results, 10 were randomized clinical trials (eight with a double-blind design), and four were uncontrolled studies.

Dosages given varied both per point and total. Energy per point values ranged from 1.5 J to 163.2 J, most common around 6 J (five studies). Energy per treatment session values ranged from 12 J to 2400 J, most common 48 J (three studies).

The authors concluded that:

“there is evidence in favor of LLLT application for pain reduction in knee OA. Values of 6 J per point and 48 J per treatment session are advocated since they were most used in studies with positive results; however, the great variation in dosimetry across the studies should be acknowledged”

Does this translate into the ‘real world’? In a randomised study of 100 patients with knee OA Ip (2015) found that patients who had LLLT even 6 years post treatment clearly benefited from treatment with the control (exercises only) as the only knees that needed joint replacement surgery (there was 1 outlying patient in the laser group). They concluded:

‘low-level laser therapy should be incorporated into standard conservative treatment protocol for symptomatic knee arthritis’.