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

Background: 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.

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

Methods: 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.

Results: 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.

Conclusion: 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.