Pectoralis Minor Transfer for Internal Rotation Reconstruction in Brachial Plexus Birth Injuries.

Purpose: A subset of patients with brachial plexus birth injuries experiences a loss of internal rotation, resulting either from neurological paralysis, as a complication of surgical procedures intended to restore external rotation, or because of contractures of the external rotators. Although humeral internal rotation osteotomy can address this deficit, it often results in compromised external rotation. To mitigate this drawback, in supple shoulders, we investigated the pectoralis minor tendon transfer to the subscapularis footprint as an alternative.

Methods: Five patients with active internal rotation deficits, but a supple shoulder joint, secondary to brachial plexus birth injuries, underwent pectoralis minor tendon transfer to the lesser tuberosity of the humerus via a deltopectoral approach. Pre- and postoperative evaluations measured shoulder rotation with the shoulder adducted and the elbow flexed at 90°. Postoperative follow-up ranged from 9 to 14 months.

Results: All patients demonstrated improvement in internal rotation, with an average gain of 88°. After surgery, four patients were able to touch their abdominal flanks, whereas one patient, because of passive limitations, required wrist flexion to achieve this. External rotation was preserved in all cases.

Conclusions: Pectoralis minor tendon transfer presents a viable alternative for addressing internal rotation deficits while preserving external rotation. Its unique anatomy and innervation, derived from the lower roots of the brachial plexus, make it particularly well-suited for these cases.

Type of study/level of evidence: Therapeutic V.