Combined arthroscopic release with corticosteroid hydrodilatation versus corticosteroid hydrodilatation only in treating freezing-phase primary frozen shoulder: a randomized clinical trial

BACKGROUND: There has been no ideal treatment for freezing-phase frozen shoulder to rapidly relieve pain and improve joint mobility. No any other team directly compared the effectiveness of combination of arthroscopic release and corticosteroid hydrodilatation with corticosteroid hydrodilatation only in treatment of freezing-phase frozen shoulder. METHODS: Seventy-two patients with freezing-phase frozen shoulder were randomly assigned to combined arthroscopic release with corticosteroid hydrodilatation (group A) or corticosteroid hydrodilatation only (group B). Clinical states were examined at baseline and periodically (Weeks 1, 4, 12, 24 and 1 year) after intervention by passive ROM; visual analog scale (VAS); UCLA and Disabilities of the Arm, Shoulder, and Hand (DASH) score. RESULTS: The passive ROM, VAS, UCLA and DASH scores always improved along the time points (all p < 0.01). The passive abduction (pAB), passive forward flexion (pFL), passive external rotation (pER), passive internal rotation (pIR) were better in group A than in group B at Week 1, 4, 12, 24 (all p < 0.01). At 1 year post-operation, the pFL and pIR were better in group A than in group B (all p < 0.01). VAS scores of group A were similar with those of group B (all p > 0.01), the differences between group A and group B were all lower than minimal clinically important difference (MCID). At Week 12, the UCLA sores and DASH scores were 26.8 ± 3.8, 14.2 ± 2.0 in group A versus 22.3 ± 3.4, 22.5 ± 3.1 in group B (all p < 0.01). At Week 24 post-operation, there were 32.7 ± 2.0, 9.8 ± 1.5 in group A versus 26.3 ± 3.6, 17.5 ± 3.5 in group B (all p < 0.01). At 1 year post-operation, there were 34.5 ± 0.8, 1.7 ± 1.5 in group A versus 32.1 ± 2.3, 8.8 ± 2.8 in group B (all p < 0.01), the differences of UCLA scores between group A and group B at Week 24 was higher than the MCID. There were no complications such as infection, nerve or vascular injury. CONCLUSIONS: Combined arthroscopic release with corticosteroid hydrodilatation would yield better results in passive ROM and function than corticosteroid hydrodilatation only. TRIAL REGISTRATION: ChiCTR1900024235, July 2, 2019 (Retrospectively registered). SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12891-022-06065-3.