Digital Rehabilitation Following Ultrasound-Guided Injection for Chronic Rotator Cuff Injury: Randomized Controlled Trial.

Background: Chronic rotator cuff injuries (CRCIs) often lead to shoulder pain and dysfunction. Although ultrasound-guided injections provide rapid pain relief, subsequent rehabilitation efficacy is often compromised by poor exercise adherence and inaccurate movement execution. Digital therapeutics may enhance patient engagement and movement accuracy, potentially improving outcomes. Objective: This study compared the effects of ultrasound-guided corticosteroid plus local anesthetic injection combined with the Digital Rehabilitation System training versus traditional exercise on pain intensity and shoulder function in patients with CRCIs. Methods: This was a single-center, parallel-group, superiority randomized controlled trial with a blinded outcome assessor, injection physician, and data analyst. Sixty eligible participants were randomized to either the conventional treatment group (group C, n=30) or the digital treatment group (group D, n=30) for a 3-month intervention. Following pain-alleviating ultrasound-guided injections, group C performed prescribed exercises, while group D used the intelligent system for self-corrective adaptive training. Primary outcome was the Constant-Murley Score. Secondary outcomes included the University of California Los Angeles Shoulder Scale, Numerical Rating Scale for pain, range of motion (ROM), and system proficiency scores. Assessments occurred at baseline (T1), 1-week (T2), 1-month (T3), and 3-month (T4) follow-ups. Results: No significant between-group differences existed in baseline characteristics or outcome measures (all P>.05). No group × time interactions were observed for any outcomes. At T4, group D demonstrated significantly greater improvements in Constant-Murley Score (Hodges-Lehmann estimator [HLE] -6, 95% CI -10 to -2; P=.007), University of California Los Angeles Shoulder Scale score (HLE -2, 95% CI -4 to -1; P=.001), and Numerical Rating Scale score (HLE 1, 95% CI 0-2; P=.002), and their improvement values (Δ) all exceeded the corresponding minimal clinically important differences. ROM also showed significant intergroup differences in all planes. Compared with T1, ROM was significantly improved in both groups at T4, with the greatest improvement in abduction (Δ group C=20.7 and Δ group D=30.5). Subgroup analysis revealed better enhanced shoulder function and ROM in participants with no or mild shoulder motion restrictions using digital therapy. Conclusions: For participants with CRCIs, combining ultrasound-guided injection with subsequent Digital Rehabilitation System training achieves greater shoulder ROM and functional scores than traditional exercise after pain relief. This approach demonstrates enhanced efficacy in subgroups with no or mild shoulder mobility limitations.