Ultrasound-Guided Hydrodilatation vs Intra-Articular Corticosteroid Injection for Primary Adhesive Capsulitis: A Rapid Review of Clinical Effectiveness and Implementation Considerations

Background: Primary adhesive capsulitis (frozen shoulder) causes pain and restricted range of motion (ROM). Two common injection strategies are hydrodilatation (HD) and intra-articular corticosteroid injection (IACI), yet their comparative effectiveness remains uncertain. Objective: To rapidly synthesize randomized evidence and recent reviews comparing HD versus IACI in adults with primary adhesive capsulitis, focusing on pain, ROM (especially external rotation), patient-reported outcomes (PRO), and safety. Methods: We conducted a rapid review (2018–2025) of PubMed, PubMed Central, Europe PMC, and Google Scholar. Eligible studies were randomized controlled trials (RCTs) and systematic reviews/meta-analyses (SR/MA) directly comparing HD with IACI. Primary outcomes were pain (VAS/NRS) and ROM; secondary outcomes were PRO (SPADI/ASES/DASH) and adverse events. Risk of bias was assessed using RoB 2 (RCTs) and a condensed AMSTAR-2 (SR/MA). We performed a narrative synthesis and reproduced pooled estimates reported in SR/MA. Results: Searches identified 72 records; 60 remained after deduplication; 6 full-texts were assessed and 6 studies were included (3 SR/MA; 3 RCTs). SR/MA suggested short-term advantages of HD—particularly for disability and external rotation—whereas head-to-head RCTs reported no added benefit of HD over IACI and, in one trial, better early outcomes with IACI alone. Longer-term differences (≥6 months) were not consistent. Adverse events were infrequent and mild. SR/MA credibility was moderate; RCTs were at some concerns or high risk of bias. Conclusions: Evidence is inconsistent; durable superiority of either HD or IACI is unproven. Practically, IACI plus structured rehabilitation is a reasonable first-line choice; image-guided HD may be reserved for selected patients with predominant stiffness or inadequate response. Standardized, well-powered RCTs with harmonized HD parameters and core outcomes are needed.