Effectiveness of high-power laser therapy on partial tears of the supraspinatus tendon: A randomized controlled trial

High-power laser therapy (HPLT) has potential in treating shoulder disorders. However, the impact of HPLT on supraspinatus partial thickness tear (SS-PTT) remains unexplored.

To evaluate the effects of HPLT on pain, function, and musculoskeletal ultrasound (MSK-US) parameters in SS-PTT.

A randomized, assessor-blinded, placebo-controlled clinical trial was conducted. Thirty-six patients with SS-PTT were randomized into the HPLT+ exercise (Exs) group or the sham+ Exs group. Eighteen age-matched healthy subjects were evaluated for MSK-US parameters as the control group. Ten treatment sessions were administered three times per week. The HPLT was used with a maximum power of 20 watts (W), 2478 joules (J), and 24.78 J/cm² for the first three sessions, followed by 4678 J and 46.78 J/cm² for the subsequent seven sessions. Musculoskeletal parameters, visual analog scale (VAS), and shoulder pain and disability index (SPADI) were measured before and 48 hours after the final treatment session.

At baseline, short-axis (SAX) thickness (p = .027, η² p = .13), echogenicity (p = .014, η² p = .16), and occupation ratio (OR) (p = .003, η² p = .2) were different between patient groups with control. All measured parameters significantly improved in the HPLT, except for echogenicity (p = .447, η² p = .02) and the disability subscale of the SPADI (p = .131, η² p = .07). After treatment, sham + Exs still showed significant differences in SAX thickness (p = .047, η² p = .11), echogenicity (p = .001, η² p = .25) and OR (p = .015, η² p = .15) with control.

High-power laser therapy was an effective modality for patients with SS-PTT. Its ability to decrease pain and improve MSK-US parameters, especially tear size, enhances its value as part of conservative treatments.