Surgical procedure to restore shoulder external rotation in post-traumatic brachial plexus lesions in adults

The lack of active external rotation following a brachial plexus injury in adults is very disabling and very challenging to solve. If direct nerve surgery or nerve transfer fails or if the patient is seen too late, palliative surgery is the last resort. Shoulder fusion can stabilize the joint to increase strength at the elbow, but the patient loses all external rotation. A metaphyseal humeral osteotomy shifts the sector of mobility to push out the arm from the chest but does not restore any active external rotation. Latissimus dorsi and teres major transfers are not indicated in traumatic brachial plexus injuries. Lower trapezius (inferior fibers of the trapezius) transfer detached from the medial angle of the scapula and fixed to the infraspinatus tendon is the main option in paralyzed shoulders. It can restore 90° external rotation on average. This tendon transfer is an agonist, with the same direction but with less excursion and strength. If this muscle is paralyzed (nerve lesion), one can harvest and transfer the contralateral lower trapezius instead. The goals of this paper are to describe the surgical technique for these two tendons transfer, their indications and results.