Comparative Efficacy of Isolated Hydrodilatation and Hydrodilatation with Adjuvant Interventions for Frozen Shoulder

OBJECTIVE: This study aimed to compare hydrodilatation (HD)-based interventions for pain relief and range of motion (ROM) improvement in frozen shoulder. METHODS: PubMed, Embase, Cochrane Library, and Web of Science were searched through September 2025 for randomized controlled trials (RCTs). Outcomes included visual analogue scale (VAS) pain scores and ROM. Effect sizes were standardized mean differences (SMDs) or mean differences (MDs) with 95% credible intervals (CrIs). Interventions were ranked by the surface under the cumulative ranking curve (SUCRA). RESULTS: Twenty RCTs (n=1,410) were included. Anterior rotator interval corticosteroid hydrodilatation (ARICHD) reduced pain (SMD=-1.30, 95% CrI -1.80 to -0.78; SUCRA=97.2%), whereas anterior shoulder joint hydrodilatation (ASJHD) increased pain (SMD=0.97, 95% CrI 0.30 to 1.60). For ROM, anterior intra-articular corticosteroid hydrodilatation combined with additional intra-articular corticosteroid injection (AIACHD + IACI) improved forward flexion (MD=23, 95% CrI 12 to 33; SUCRA=97.7%) and abduction (MD=33, 95% CrI 23 to 43; SUCRA=98.8%), while ARICHD improved external rotation (MD=21, 95% CrI 14 to 28; SUCRA=97.8%). Isolated suprascapular nerve block (SSNB) may reduce internal rotation (MD=-17, 95% CrI -34 to -0.13). CONCLUSIONS: HD-based interventions differ in efficacy. ARICHD is associated with pain relief and improved external rotation, whereas AIACHD + IACI is associated with greater ROM improvement.