Systematic review on the incidence, operative treatments, and outcomes of deltoid ruptures.

Background: A deltoid rupture can result in significant losses of shoulder function, and in the setting of a rotator cuff tear, the deltoid serves as the sole abductor of the shoulder. Deltoid ruptures can be secondary to trauma, a consequence of massive rotator cuff tears, or a result of postoperative complications. There is a paucity of literature on the management of deltoid ruptures. In this systematic review, we aim to report on the incidence of deltoid ruptures, the surgical treatment options, and the outcomes following operative treatment. Methods: A literature search was conducted on February 1, 2023 on MEDLINE and Google Scholar. Titles and abstracts were screened and the full text versions of articles that met criteria were reviewed. Criteria for inclusion included peer-reviewed studies evaluating the outcomes following surgical treatment of deltoid ruptures (direct repair, mobilization, reconstruction, and pedicled pectoralis transfer, with or without a reverse total shoulder arthroplasty). Secondary outcomes included incidence and causes of deltoid ruptures. Results: A total of 101 studies were retrieved. After review and additional studies identified from reference lists, a total of 14 studies were included in the review. The incidence of deltoid ruptures ranged from 0.3% to 7%, and large, full-thickness rotator cuff tears were found to be a significant risk factor. Surgical treatment options for deltoid ruptures include direct repair, rotationplasty, and pedicelled muscle-tendon transfers; and when indicated, these procedures can be paired with a reverse total shoulder replacement. Postoperatively, the operative extremity should be immobilized in the position of least tension (forward flexion and abduction, 30°-70°) for 4-8 weeks. Most patients in this systematic review who underwent surgical treatment of their deltoid rupture had significant improvements in pain and mean postoperative forward elevation and abduction above 90°. Discussion: The current available literature demonstrates that direct deltoid repair, rotationplasty, or reconstruction (muscle tendon transfer) with or without a concomitant reverse total shoulder arthroplasty can be an acceptable treatment option in patients with deltoid defects and massive rotator cuff tear. The average shoulder flexion and abduction increased postoperatively with improvements in pain.