Lyophilized Platelet-Rich Plasma Lysate vs Dextrose Prolotherapy for Partial Rotator Cuff Tears

The goal of this clinical trial is to learn whether lyophilized platelet-rich plasma (PRP) lysate can improve shoulder symptoms, shoulder muscle strength, and tendon tear size in adults with partial-thickness rotator cuff tears, compared with hypertonic dextrose prolotherapy. The main questions this study aims to answer are: * Does PRP lysate improve shoulder pain and function in people with partial-thickness rotator cuff tears? * Does PRP lysate improve shoulder internal and external rotation strength? * Does PRP lysate reduce the size of the rotator cuff tendon tear as measured by ultrasound? Researchers will compare PRP lysate with hypertonic dextrose prolotherapy to determine whether the changes in shoulder symptoms, muscle strength, and tendon tear size differ between the two treatments. Participants will be randomly assigned to receive either PRP lysate or hypertonic dextrose. Each participant will receive one ultrasound-guided injection into the partially torn rotator cuff tendon each month for 3 months, for a total of three injections. Participants will complete a questionnaire about shoulder symptoms and function, undergo ultrasound examination of the rotator cuff, and have their shoulder rotation strength measured before the first injection and 1 month after the final injection. Participants assigned to the PRP lysate group will also have blood collected for preparation of the PRP lysate used for their treatment.

Inclusion Criteria: * Age older than 20 years. * Shoulder pain with a partial-thickness rotator cuff tear confirmed by physical examination and ultrasonography. * Willing and able to provide written informed consent. Exclusion Criteria: * Adhesive capsulitis. * Previous shoulder surgery. * Neuromuscular disease affecting shoulder strength. * Platelet dysfunction. * Thrombocytopenia. * Hypofibrinogenemia. * Acute or chronic infectious disease. * History of chronic liver disease. * Current antiplatelet therapy. * Depression or other psychological problems. * Rheumatological disorders. * Cognitive impairment that would prevent adherence to the study protocol.