In shoulder adhesive capsulitis, ultrasound-guided anterior hydrodilatation in rotator interval is more effective than posterior approach: a randomized controlled study

Shoulder adhesive capsulitis, also called frozen shoulder, is a musculoskeletal disorder associated with pain and functional disability. This study aimed to compare the effectiveness of shoulder ultrasound-guided hydrodilatation with corticosteroid, via rotator interval (RI) anteriorly, versus posterior approach, in adhesive capsulitis patients. All patients received exercise program following injection. Patients and methods A prospective randomized controlled study among 60 consecutive adhesive capsulitis patients was randomized into two equal groups. Group I received ultrasound-guided hydrodilatation with corticosteroid, saline, and local anesthetic via posterior intra-articular approach; group II received the same ultrasound-guided hydrodilatation via anterior rotator interval approach. Both groups received guided stretching exercises for 3 months after injection. Baseline and 3 months evaluation of pain by visual analogue scale (VAS), shoulder pain and disability index (SPADI), and range of motion (ROM) had been recorded for all patients. Results Both groups showed significant improvement 3 months after hydrodilatation regarding VAS pain, external rotation, and SPADI. Only in group II (RI anterior approach) improvement was observed regarding flexion and abduction. There was no improvement regarding extension or internal rotation in either group. When comparing the improvement in both groups after hydrodilatation, group II (anterior approach) showed a statistically significant higher level of improvement regarding VAS pain ( p = 0.003), SPADI, flexion, abduction, and external rotation, compared to group I ( p < 0.001). Extension, internal rotation, and adduction were not different. Conclusions Ultrasound-guided anterior rotator interval hydrodilatation for adhesive capsulitis, followed by guided exercise, is clinically and functionally more effective than the conventional posterior approach. Key Points • Ultrasound-guided hydrodilatation (with prednisolone acetate (40 mg), 1 ml of 2% lidocaine, and 15 ml saline) for adhesive capsulitis followed by guided exercise is clinically and functionally effective. • The ultrasound-guided anterior rotator interval approach is clinically and functionally significantly more effective than the conventional intra-articular posterior approach as it targets mainly the area of pathology. • This is the first prospective study comparing the effect of the anterior rotator interval approach versus the posterior approach in ultrasound-guided hydrodilatation in adhesive capsulitis patients.