Outcomes of arthroscopic-assisted middle trapezius tendon transfer for isolated irreparable supraspinatus tendon tears: minimum 2-year follow-up

Introduction Middle trapezius tendon (MTT) transfer has been proposed as a feasible option for managing isolated irreparable supraspinatus tears (IISTTs). However, no clinical study has been attempted. This study aimed to evaluate clinical and radiologic outcomes of arthroscopic-assisted MTT transfer in patients with IISTTs. Methods This retrospective study included patients who underwent arthroscopic-assisted MTT transfer using fascia lata autograft for IISTTs. Clinical outcomes, including pain visual analog scale (VAS), Constant, American Shoulder and Elbow Society (ASES), University of California Los Angeles (UCLA) shoulder scores and active range of motion (aROM), were assessed. Radiographic analyses included the acromiohumeral distance (AHD), Hamada grade, and transferred tendon integrity at the final follow-up. Results Twenty-two patients (mean age: 63.3 +/- 6.8 [51-74] years; mean follow-up period: 28.9 +/- 4.9 [24-44] months) met the study criteria. The mean VAS, Constant, ASES, and UCLA scores improved postoperatively at the final follow-up (p < 0.001). The mean aROMs for forward flexion and abduction were significantly increased postoperatively. No significant changes of AHD (p = 0.105) and Hamada grade (p = 0.815) were observed postoperatively. One patient had a re-tear of the transferred tendon at the footprint site at the final follow-up. Conclusion In this minimum 2-year follow-up study of the novel aMTT transfer using fascia lata autograft, we found significant improvement in pain relief, clinical scores, and active forward flexion and abduction. Additionally, no significant progression of cuff tear arthropathy was observed at the final follow-up. Therefore, aMTT transfer could be a promising treatment option for patients with IISTTs. However, further multicenter and long-term trials are needed to verify its effectiveness.