Summary

This study evaluates the effectiveness of rotator interval shifting in managing massive irreparable rotator cuff tears, identifying that an acromiohumeral interval greater than 5.0 mm is a key predictor of surgical success. The findings provide clinical insights for optimizing outcomes in patients undergoing arthroscopic partial repair for improved shoulder function and reduced pain.

Abstract

Background

Massive, irreparable rotator cuff tears (RCTs) present a significant challenge in shoulder surgery, often resulting in substantial pain and functional impairment. Arthroscopic partial repair combined with rotator interval shifting has emerged as a promising surgical approach. However, the optimal indications for this technique and its predictive factors for success remain uncertain. This study aimed to elucidate the ideal scenarios for this intervention and identify the prognostic determinants of surgical outcome.

Methods

A retrospective analysis was conducted on a cohort of 45 patients (mean age 66.5 years) with massive, irreparable RCTs who underwent arthroscopic partial repair augmented by rotator interval shifting. Clinical outcomes were assessed at two-year follow-up using the American Shoulder and Elbow Surgeons (ASES) score, Constant-Murley score, and visual analog scale (VAS) for pain. Preoperative and postoperative magnetic resonance imaging (MRI) evaluations focused on the extent of supraspinatus retraction, fatty infiltration, and the acromiohumeral interval (AHI) to identify potential predictors of surgical success.

Results

Significant improvements in shoulder function were observed following surgery. Forward elevation increased from 77.7° to 156.1°, and abduction improved from 82.9° to 161.3° (p<0.001). Concomitantly, ASES and Constant scores demonstrated substantial improvement, while VAS pain scores decreased markedly from 7.1 to 1.3 (p<0.001). MRI analysis revealed that 66.7% of patients achieved full humeral head coverage postoperatively. An AHI greater than 5.0 mm was identified as a strong predictor of favorable outcomes, with patients in this group exhibiting superior functional recovery and lower rates of failure.

Conclusion

Rotator interval shifting is an effective surgical approach for managing massive, irreparable RCTs, particularly in patients with favorable preoperative conditions, such as an AHI exceeding 5.0 mm, minimal fatty degeneration, and manageable supraspinatus retraction. These findings provide valuable guidance for surgeons in selecting appropriate candidates and tailoring surgical strategies to optimize outcomes.

Clinical Implications:

Preoperative measurement of the AHI is essential for determining the suitability of rotator interval shifting for irreparable RCTs, serving as a reliable predictor of surgical success and potentially reducing the need for more invasive procedures.

Keywords:

Rotator cuff tear, arthroscopic partial repair, rotator interval shifting, acromiohumeral interval, predictive factors, shoulder surgery.