Fixed superior humeral migration in the setting of a chronic rotator cuff tear is a difficult problem to manage. A reverse total shoulder arthroplasty can restore shoulder function, but the degree of humeral lengthening caused by the procedure places considerable tension on the deltoid and the surrounding neurovascular structures. This can result in neurological compromise, poor joint function, and acromial fracture. The authors present a reverse total shoulder arthroplasty combined with humeral shortening osteotomy. This technique allows independent control of the correction of the joint center of rotation and the tension in the deltoid, rotator cuff remnants, and surrounding neurovascular structures.