Adhesive capsulitis is a common and disabling shoulder condition characterized by pain and progressive limitation of range of motion. Capsular distension and intra-articular corticosteroid injection are commonly used therapeutic options, often combined with rehabilitation, but their comparative effectiveness remains debated.

The objective of this randomized controlled trial is to compare the efficacy and tolerance of ultrasound-guided capsular distension combined with rehabilitation versus intra-articular corticosteroid injection combined with rehabilitation in patients with adhesive capsulitis.

Outcomes will include shoulder pain, range of motion, functional disability, patient satisfaction, and procedure-related complications, assessed at short, mid, and long-term follow-up.

Inclusion Criteria:

• Age between 18 and 80 years
• Ability to provide informed consent
• Shoulder pain with Visual Analog Scale (VAS) ≥ 40/100
• Limitation of external rotation < 45° or < 50% compared to the contralateral side
• Clinically diagnosed adhesive capsulitis with normal shoulder radiography

Exclusion Criteria:

• Rotator cuff tear
• Previous shoulder surgery
• Cervico-brachial neuralgia
• Pregnancy or breastfeeding
• Poorly controlled diabetes
• Coagulation disorders or anticoagulant therapy with INR > 3
• Allergy to lidocaine
• Inflammatory rheumatic diseases
• Severe cardiovascular or hematological diseases
• Active infection or immunodeficiency
• Severe psychiatric disorders
• Recent shoulder rehabilitation (within 1 week)
• Intra-articular corticosteroid injection or hyaluronic acid injection within the last 6 months
• Refusal to sign informed consent

The IPD collected in this study will not be shared publicly. Data will be used exclusively by the study investigators for the purposes of this research.