Restoration of active internal rotation following reverse shoulder arthroplasty: anterior latissimus dorsi and teres major combined transfer.

BACKGROUND:
Reverse total shoulder arthroplasty (RSA) for Irreparable massive rotator cuff tear (mRCT) and cuff tear arthropathy (CTA) demonstrate satisfactory clinical outcomes. However, many studies reported no significant improvements in internal and external rotation. To our knowledge, there have been no studies on new attempts to restore active internal rotation following RSA. The purpose of this study was to compare RSA alone and RSA with anterior latissimus dorsi and teres major (aLDTM) tendon transfer in patients with CTA and mRCT with combined loss of active elevation and internal rotation (CLEIR).

METHODS:
This retrospective cohort study included patients who underwent lateralized designed RSA for patients who had CLEIR between 2014 and 2019. Two groups were classified; patients who underwent RSA alone (group R, n=36) and RSA with aLDTM tendon transfer (group T, n=24). Clinical outcomes, including VAS, Constant, ASES, active range of motion (aROM), activities of daily living requiring internal rotation (ADLIR) scores, and toileting activity were compared. Moreover, radiological outcomes and complications were compared.

RESULTS:
The mean follow-up was 36.8 ± 11.6 (24-67) months. Both group R and group T showed significant improvements in clinical scores and aROM pre-and postoperatively. In the group T, Constant (65.2 ± 7.5 vs. 58.1 ± 12.3, p=0.008), ADLIR score (26.1 ± 3.1 vs. 20.3 ± 5.0, p< .001), internal rotation with the arm behind the back (p< .001) and subscapularis-specific physical examinations (p< .001) were significantly better than group R. However, no significant difference in ASES, forward flexion, external rotation at 0° and 90° abduction were found at final follow-up. Two patients with transient axillary nerve palsy were found in group T. However, both groups showed no significant differences in complication rates.

CONCLUSION:
Lateralized RSA with aLDTM tendon transfer for patients with CTA and mRCT with combined loss of active elevation and internal rotation restored shoulder function and improved clinical outcomes, especially in ability to activities of daily living requiring internal rotation and toileting activity.