Hyaluronic Acid Injection Combined With Rehabilitation for Frozen Shoulder (HA - AC)

Adhesive capsulitis is a common musculoskeletal disorder characterized by progressive pain and restricted range of motion of the shoulder joint, leading to significant functional impairment. Although rehabilitation remains the cornerstone of treatment, the additional benefit of intra-articular hyaluronic acid injection remains controversial.

This randomized controlled trial aimed to evaluate the clinical efficacy of ultrasound-guided intra-articular injection of non-cross-linked hyaluronic acid combined with a structured rehabilitation program in patients with adhesive capsulitis.

Participants were randomly assigned to two groups: an injection plus rehabilitation group and a rehabilitation-only group. The injection group received ultrasound-guided intra-articular hyaluronic acid injections once weekly for three consecutive weeks. Both groups underwent a standardized rehabilitation program twice weekly for six weeks, including range of motion exercises, stretching, and strengthening under the supervision of a physical therapist.

Clinical outcomes were assessed at multiple time points, including baseline, 4, 6, 8, and 12 weeks. The primary outcome measure was the change in the Shoulder Pain and Disability Index (SPADI) total score over time. Secondary outcomes included SPADI pain and disability subscales, as well as shoulder external rotation range of motion.

The trial was registered retrospectively at ClinicalTrials.gov (NCT07570095) after study completion due to administrative oversight.

The study was conducted in accordance with the protocol approved by the Tri-Service General Hospital Institutional Review Board (approval no. C202205160) prior to enrollment. The IRB-approved protocol specified the eligibility criteria and outcome measures reported in this record; discrepancies in the initial registry entry have been corrected in this amendment.