Lower trapezius transfer with semitendinosus tendon augmentation: Indication, technique, results.

Background: Lower trapezius transfer can restore external rotation in brachial plexus palsies. In some cuff tear arthropathies, there is lack of active external rotation with a preservation of forward elevation. We evaluated the clinical outcomes of a lower trapezius transfer extended with a semitendinosus tendon and fixed to the insertion of the infraspinatus via arthroscopy.

Methods: Between 2013 and 2016, we operated on 14 patients (8 men, 6 women; mean age of 62 years, range: 50-70) to reconstruct irreparable posterosuperior rotator cuff tear. A vertical incision of 6 cm following the medial border of the spine was made to harvest the lower trapezius in extension with the semitendinosus tendon. The extension band of the lower trapezius was fixed laterally via arthroscopy on the great tuberosity at the level of the insertion of the infraspinatus. The proximal stump of this extension band was then fixed medially into the muscle of the lower trapezius with the arm in maximum external rotation. Outcomes were evaluated with the Constant-Murley score, simple shoulder test (SST), and subjective shoulder value (SSV).

Results: Over a mean follow-up of 24 months (range: 12-36 months), the gain in external rotation with the arm at the side was 24° and 40° in 90° of abduction. The Constant-Murley score improved from 35 to 60 points, the SST from 3.5 to 7.5, the SSV from 30 to 60%, and the pain decreased from 7 to 2 (visual analogue scale, 0-10). Both the lag sign and hornblower sign were negative after this transfer. There were two cases of hematomas, and one was revised because of infection.

Conclusion: Lower trapezius transfer is a therapeutic option for irreparable posterosuperior cuff tears with a lack of active external rotation and a good subscapularis. Patients can expect improvements in pain and in active external rotation without any loss of active anterior elevation.