Outcome of Arthroscopically Assisted Lower Trapezius Transfer to Reconstruct Massive Irreparable Posterior-Superior Rotator Cuff Tears

Abstract

The purpose of this study is to report the outcome of arthroscopically assisted lower trapezius transfer to reconstruct irreparable posterior-superior rotator cuff tear. Reasonable outcomes has been reported with indirect open lower trapezius transfer extended with an Achilles tendon allograft to reconstruct irreparable posterior-superior rotator cuff tears. Techniques have been developed to perform this procedure arthroscopically. However, the outcome of arthroscopically assisted lower trapezius transfer is largely unknown. Forty-one consecutive patients with irreparable posterior-superior rotator cuff tears who underwent an arthroscopically assisted transfer of the lower trapezius transfer were included in this study. There was an associated repairable tear of the subscapularis tendon in 25 shoulders. The average age of the patients was 52 (range, 37-71) years and average follow-up was 13 months (range, 6-17 months). Nineteen patients had true pseudoparalysis of the shoulder on preoperative examination. Outcome measures included visual pain analogue score (VAS), range of motion (ROM), subjective shoulder value (SSV), and Disabilities of the Arm, Shoulder and Hand (DASH) score. Thirty-seven patients had significant improvement of all outcome scores: VAS, SSV and DASH. At most recent follow-up, range of motion averaged: 133o flexion, 95o abduction, and 47o external rotation. Outcome was not affected by the presence of a subscapularis tear. However, three patients who had preoperative arthritic changes of the shoulder, 2 with Hamada 2 and one Hamada 3, had persistent pain and limited range of motion of the shoulder after surgery, and 2 of them underwent reverse shoulder arthroplasty. One patient had significant improvement of pain but with no improvement of motion, and elected not to have further surgery. Two additional patients had a traumatic rupture of the transfer as result of fall (at 5 and 8 months post op). One underwent revision arthroscopic repair and did well after surgery, and the other had good pain relief but recurrent weakness and limited range of motion, and elected not to have a revision surgery. Arthroscopic assisted lower trapezius transfer may lead to a good outcome in patients with massive irreparable posterior-superior rotator cuff tears, including patients with pseudoparalysis. The presence of an associated reparable subscapularis tear did not affect the outcome. However, the presence of radiographic degenerative changes did lead to a worse outcome and the need for revision to reverse shoulder arthroplasty.