Mid-term outcomes of arthroscopically assisted lower trapezius tendon transfer using Achilles allograft in treatment of posterior-superior irreparable rotator cuff tear.

ABSTRACT

BACKGROUND: Arthroscopically assisted lower trapezius tendon (aLTT) transfer is one of the treatment options for posterior-superior irreparable rotator cuff tears (PSIRCTs). Although short-term clinical outcomes have shown promising results, there are currently no reported clinical outcomes over a longer follow-up period. This study evaluated the mid-term outcomes of aLTT transfer in patients with a diagnosis of PSIRCT. METHODS: This retrospective case-series study included patients who underwent aLTT transfer between May 2017 and May 2019. The clinical outcome assessment included the visual analog scale (VAS) pain score, Constant score, American Shoulder and Elbow Surgeons score, University of California-Los Angeles score, Activities of Daily Living Requiring Active External Rotation (ADLER) score, active range of motion, Single Assessment Numeric Evaluation score, and return-to-work rate. The radiographic analysis included the acromiohumeral distance, Hamada grade, and integrity of the transferred tendon at final follow-up. Subgroup analyses were performed based on the integrity of the transferred tendon and the trophicity of the teres minor (Tm). RESULTS: This study enrolled 36 patients with a mean age of 63.4 years who met the inclusion criteria and were followed up for a mean of 58.2 ± 5.3 months. At final follow-up, the patients showed significant improvement in mean VAS score, Constant score, American Shoulder and Elbow Surgeons score, University of California-Los Angeles score, ADLER score, and active range of motion in all directions except internal rotation. A decrease in the acromiohumeral distance and an increase in the Hamada grade were observed at final follow-up (P = .040 and P = .006, respectively). Retears of the transferred tendon occurred in 7 patients, and postoperative infections developed in 2 individuals. An interesting finding was that the retear group still demonstrated improvement in the VAS score but did not show improvement in external rotation at the side by the final follow-up. Compared with the Tm non-hypertrophy group, the Tm hypertrophy group showed significantly better improvement in external rotation at 90° of abduction and at the side, as well as the ADLER score. Of the study patients, 30 (83.3%) were able to successfully resume their previous work. CONCLUSION: In this study, aLTT transfer in patients with PSIRCTs demonstrated significant improvements in clinical and radiologic outcomes by the final follow-up. These findings provide support for the mid-term safety and effectiveness of aLTT transfer as a viable joint-preserving treatment option for PSIRCTs. However, larger and longer-term studies are still needed to further validate these findings.