Deltoid Osteomuscular Transfer Suppresses Humeral Head Translation Caused by Massive Irreparable Rotator Cuff Tears: A Cadaveric Biomechanical Study

Abstract

Background:

The optimal treatment for massive irreparable rotator cuff tears (MRCTs) remains unclear. The deltoid flap transfer has been described in the literature as an option for MRCT; however, it has a high retear rate and therefore its effectiveness is limited.

Purpose:

To describe a modification of the deltoid flap transfer, termed the deltoid osteomuscular transfer (DOT), and assess its biomechanical effectiveness in the management of irreparable MRCT in a cadaveric model.

Study Design:

Controlled laboratory study.

Methods:

Eight fresh-frozen cadaveric shoulders were tested. Segmental deltoid muscle flaps were harvested with bone from the distal clavicle (anterior harvest), lateral acromion (middle harvest), and acromial angle (posterior harvest). The segmental deltoid muscle grafts were transferred to cover the superior humeral head, with the attached bone graft fixated to the superior glenoid with partially threaded screws. Under each condition (intact cuff; MRCT; and anterior, middle, and posterior harvest DOTs), humeral head translation and functional abduction force were measured at 0°, 30°, and 60° of glenohumeral elevation. A deltoid graft force of 0 N to 30 N was applied to the deltoid muscle flaps in each condition, and the effect was evaluated.

Results:

The anterior harvest DOT significantly suppressed humeral head translation as compared to MRCT under all applied force conditions at 0° and 30° of glenohumeral elevation. Regarding the functional abduction force, significant improvements were observed only with the anterior harvest DOT as the applied force increased.

Conclusion:

The anterior harvest DOT demonstrated the greatest effectiveness at suppressing humeral head translation after irreparable MRCT.

Clinical Relevance:

The anterior harvest DOT enables bone-to-bone fixation of the transferred deltoid, preventing humeral head translation and potentially providing both static and dynamic stabilization, which may serve as a promising treatment for irreparable MRCT.