Arthroscopic-Assisted Combined Superior Capsular Reconstruction and Lower Trapezius Transfer Using Dual Achilles Allografts for Irreparable Posterosuperior Rotator Cuff Tears.

Irreparable posterosuperior rotator cuff tears remain challenging, particularly in young, active patients. Superior capsular reconstruction restores static stability but is limited by graft failure and reduced external rotation, especially with infraspinatus fatty infiltration. Lower trapezius transfer restores dynamic force coupling but lacks static support. This Technical Note describes an arthroscopic-assisted mini-open technique combining superior capsular reconstruction with lower trapezius transfer using dual Achilles allografts. The graft's thickness provides durable, superior coverage, whereas a mini-open anterior portal extension simplifies graft passage and suture management. This combined approach integrates static and dynamic stabilization to improve stability and range of motion and to reduce subacromial contact pressures in patients with irreparable posterosuperior rotator cuff tears.