Effectiveness of Hydrodilatation for Adhesive Capsulitis in Patients With Pre-existing Rotator Cuff Tears

Background Adhesive capsulitis (AC) is a chronic, debilitating condition characterized by pain and progressive stiffness of the shoulder joint. Hydrodilatation (HD) is a commonly used method of non-surgical management. However, its effectiveness in patients with rotator cuff pathology remains unclear. Objective The study aimed to evaluate and compare the clinical effectiveness of HD in patients with AC, with and without rotator cuff tears. A secondary objective was to assess clinical outcomes in patients with concurrent type 2 diabetes mellitus. Methods This retrospective cohort comprised 78 patients (six excluded due to loss to follow-up and two excluded due to incomplete data) who underwent HD between 2021 and 2024. Patients were stratified by rotator cuff integrity (intact n=60, partial-thickness tear n=10, full-thickness tear n=8). Pain (Visual Analog Scale (VAS)) and range of motion (ROM: abduction, flexion, and external rotation) were recorded at baseline, six weeks, three months, and six months. Change scores were analyzed using the Wilcoxon signed-rank and Kruskal-Wallis tests with Benjamini-Hochberg false discovery rate (FDR) correction. The primary endpoint was the change in abduction at three months. Results All groups demonstrated significant within-group improvements in pain and ROM (all p-values adjusted for multiple comparisons using the Benjamini-Hochberg FDR (p(FDR < 0.05), except flexion at six months in the full-thickness tear group (p(FDR) = 0.271). At three months, median abduction improvement was 80° (60-90) in the intact group vs 40° (20-75) in partial-thickness and 35° (17.5-70) in full-thickness tears (H=13.21, p(FDR)=0.005). External rotation gains were also greater in the intact group, most notably at three months (Z=3.91, p(FDR) = 0.002 vs partial-thickness). Pain reduction was observed in all groups, but reductions were greater in the intact versus full-thickness subgroup (three months: Z=-3.08, p(FDR)=0.014). Patients with diabetes demonstrated attenuated ROM recovery but similar pain improvement compared with non-diabetic patients. Conclusions HD provided meaningful pain relief across all patient subgroups in this retrospective cohort. However, rotator cuff integrity substantially influenced ROM recovery, with reduced gains in patients with partial- and full-thickness tears. Diabetic patients appeared to achieve less ROM improvement, although this subgroup was small, and findings should be interpreted cautiously. Pre-procedure imaging and individualised counselling are recommended.