The Effectiveness of High-intensity Laser Therapy After Arthroscopic Shoulder Rotator Cuff Repair.

• High intensity laser therapy (Device): High-intensity laser therapy (HILT) will be administered using the HIRO TT device (ASA s.r.l., Italy), based on a solid-state Nd:YAG laser source with near-infrared emission at a wavelength of 1064 nm. The treatment protocol consists of 10 sessions delivered on alternate days. Each session will last 60 minutes and will include 15 minutes of laser therapy followed by 45 minutes of conventional physiotherapy. Laser therapy will be applied to two areas of 10 × 10 cm each, located at the anterolateral and posterior aspects of the shoulder. The treatment will be delivered using a pulsed emission with a frequency of 15 Hz, a total energy of 1000 J, and an energy density of 5 J/cm². The mean power will range between 6 and 10.5 W, with a peak power between 1 and 3 kW, for a total application time of 8 minutes and 30 seconds.
• Sham laser therapy (Other): The sham laser intervention will be delivered using the same HIRO TT device and identical treatment procedures as the active HILT group. The same anatomical areas (two treatment areas of 10 × 10 cm located at the anterolateral and posterior aspects of the shoulder) will be targeted, with identical session duration and patient positioning. During sham treatment, the device will remain switched on; however, no therapeutic laser emission will be delivered. This approach is intended to ensure participant blinding by replicating the visual and procedural aspects of the active intervention without providing any active therapeutic effect.

Primary outcomes

• Visual Analogue Scale [after 3 weeks]: The VAS consists of a 100-mm horizontal line anchored by two descriptors: "no pain" (0 mm) and "worst imaginable pain" (100 mm). Participants will be asked to mark a point on the line corresponding to their perceived level of pain. The score will be determined by measuring the distance in millimeters from the left end of the line to the patient's mark, with higher scores indicating greater pain intensity.

Secondary outcomes

• Visual Analogue Scale [Baseline, after 1 week, after 2 weeks, after 4 months follow-up]: The VAS consists of a 100-mm horizontal line anchored by two descriptors: "no pain" (0 mm) and "worst imaginable pain" (100 mm). Participants will be asked to mark a point on the line corresponding to their perceived level of pain. The score will be determined by measuring the distance in millimeters from the left end of the line to the patient's mark, with higher scores indicating greater pain intensity.
• Passive Range of Motion [Baseline, after 1 week, after 2 weeks, after 3 weeks, after 4 months follow-up]: Passive shoulder range of motion (ROM) will be assessed using a digital goniometer following standardized measurement procedures. Movements evaluated will include shoulder flexion, abduction, internal rotation and external rotation at 90° of abduction, and external rotation at 0° of abduction. Measurements will be performed with the patient in the supine position. For each movement, three repetitions will be recorded and the mean value will be used for analysis. Results will be expressed in degrees.
• Active Range of Motion [Baseline, after 1 week, after 2 weeks, after 3 weeks, after 4 months follow-up]: Active shoulder range of motion (ROM) will be assessed using a digital goniometer following standardized measurement procedures. Movements evaluated will include shoulder flexion, abduction, and external rotation at 0° of abduction. Measurements will be performed with the patient in a standing position. For each movement, three repetitions will be recorded and the mean value will be used for analysis. Results will be expressed in degrees.
• Muscle strength: Handheld dynamometer [after 3 weeks and after 4 months follow-up]: Shoulder muscle strength will be assessed using a handheld digital dynamometer following standardized and reproducible testing positions. Isometric strength will be measured for shoulder abduction, internal rotation, and external rotation. Internal and external rotation will be evaluated with the patient in a seated position, with the arm at 0° and 90° of abduction in the scapular plane. Shoulder abduction will be assessed with the arm positioned at 45° of abduction. For each movement, three maximal isometric contractions of 5 seconds will be performed, with 30 seconds of rest between trials. The highest value recorded will be used for analysis. Results will be expressed in kilograms.
• Function: Constant-Murley Score [Baseline, after 1 week, after 2 weeks, after 3 weeks, after 4 months follow-up]: Shoulder function will be assessed using the Constant-Murley Score (CMS), a composite scale that evaluates pain, activities of daily living, range of motion, and muscle strength. The total score ranges from 0 to 100, with higher scores indicating better shoulder function.
• Disability: Shoulder Pain Disability Index [Baseline, after 1 week, after 2 weeks, after 3 weeks, after 4 months follow-up]: Shoulder pain and disability will be assessed using the Shoulder Pain and Disability Index (SPADI), a self-administered questionnaire composed of 13 items divided into two subscales assessing pain and disability. The total score ranges from 0 to 100, with higher scores indicating greater pain and functional impairment.
• Disability: Quick Disability of the Arm, Shoulder and Hand [Baseline, after 1 week, after 2 weeks, after 3 weeks, after 4 months follow-up]: Upper limb disability will be assessed using the Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH), a self-administered questionnaire composed of 11 items rated on a Likert scale. The total score ranges from 0 to 100, with higher scores indicating greater disability.

Sex: All, ages: 30 Years to 70 Years

Inclusion Criteria:

* Arthroscopic rotator cuff repair of one shoulder for partial or full-thickness tear
* Willingness to provide written informed consent
* Age between 30 and 70 years
* Pain intensity greater than 40/100 on the Visual Analog Scale

Exclusion Criteria:

* Psychiatric disorders
* Cognitive impairment
* Rheumatic diseases or Fibromyalgia
* Vascular diseases
* Neoplastic diseases
* Infectious diseases
* Neurological disorders
* Hemophilia or bleeding diathesis
* Use of anticoagulant therapy
* Presence of a pacemaker
* History of epileptic seizures
* Pregnancy or breastfeeding
* Skin lesions or abrasions at the laser application site
* Known hypersensitivity to laser therapy or photosensitization
* Use of photosensitizing medications
* Tattoo in the treatment area
* Steroid injections in the target area within the previous 2-3 weeks
* Recent trauma or injury
* Suspected conditions in which deep tissue heating is contraindicated
* Use of analgesic or anti-inflammatory medications during the study period
* Positive status for human immunodeficiency virus infection