A Novel Ultrasound-Guided Injection Strategy for Rapid Functional Recovery in Frozen Shoulder: A Multicenter Randomized Trial

Abstract

Background:

Current frozen shoulder (FS) therapies present a clinical dilemma: although intra-articular corticosteroids with home exercise provide proven medium-term (3-month) benefits, they lack short-term (<4-week) efficacy for rapid recovery; conversely, manipulative treatments achieve faster outcomes but carry invasiveness risks. These limitations highlight the urgent need for developing and validating novel noninvasive approaches with prompt therapeutic effects.

Purpose:

To compare the efficacy and safety of ultrasound-guided tendon surface (UGTS) injection versus manipulation under local anesthesia (MULA) and blind tender point (BTP) injection, all combined with intra-articular injection and home exercise.

Study Design:

Randomized controlled trial; Level of evidence, 1.

Methods:

The authors first developed a novel ultrasound-based strategy, which they named “ultrasound-guided tendon surface.” Then they conducted a multicenter randomized controlled trial (2019-2022). The primary outcome was 4-week shoulder function assessed by the Beijing Friendship Hospital Scale (BFHS), a modified version of the Constant-Murley Score adapted for Chinese populations with demonstrated validity. Secondary outcomes included (1) short-term (1-month) pain (visual analog scale [VAS]) score, active range of motion (ROM), Evaluation Scale of the Shoulder under Ultrasound (ESSU) score, pain relief, treatment sessions, and cartilage thickness; and (2) long-term (2-year) complete remission rates (tele-follow-up).

Results:

Among 365 screened patients, 139 were enrolled and randomized to receive UGTS (n = 49), MULA (n = 43), and BTP (n = 47). At the 1-week follow-up visit, the UGTS group showed rapid improvement in BFHS scores compared to both the MULA and BTP groups. These early functional advantages were also indicated by the VAS score, ROM, ESSU score, and pain relief. UGTS achieved faster complete remission (1 month: 59.2% vs 31.0% and 34.9% for BTP and MULA, respectively; 3-month: 79.6% vs 53.2% and 69.8% for BTP and MULA, respectively; P < .05), with remission rates converging by 24 months (P = .216), yet retained early rapid response as its key clinical advantage. UGTS showed no significant impact on articular cartilage thickness. Serial ultrasound monitoring demonstrated no rotator cuff injuries attributable to either the UGTS procedure or prescribed exercises.

Conclusion:

UGTS combined with intra-articular injection and exercise promotes faster recovery without safety concerns, representing an effective noninvasive first-line option for rapid relief in FS.

Registration:

ChiCTR1900025874 (Chinese Clinical Trial Registry number).