Split Latissimus Dorsi Tendon Transfer for External Rotation in Obstetrical Brachial Plexus Injury

The intramuscular neurovascular branching pattern of the latissimus dorsi muscle provides 2 parts with independent neurovascular supply. The medial and lateral branches arising from the thoracodorsal pedicle run parallel to the muscle fibers and, therefore, 2 independent motor flaps can be harvested. We propose a modification to the latissimus dorsi tendon transfer for external rotation based on these 2 muscular parts. The medial (transverse) part is transferred to the rotator cuff insertion to dynamically enhance external rotation, and the lateral part acts as a stabilizer of the humeral head during rotation. A retrospective review of the patients who underwent this procedure was performed, and active and passive ranges of motion for external rotation and Mallet scores were analyzed, with special attention to complications and limitations to internal rotation. The average shoulder abduction aROM after the procedure was 140 degrees (range: 90 to 180 degrees). The external rotation aROM showed a significant postoperative increase both in abduction (from a mean value of 3 to 78 degrees) and in adduction (from a mean value of 1 to 37 degrees). A significant improvement of the Mallet scores for global abduction, global external rotation, hand to neck and hand to mouth motions was registered, with no significant change in hand on spine score. The proposed technique proved to be a good option to optimize the reconstruction of external rotation without limiting internal rotation. It takes advantage of the anatomy of the latissimus dorsi to perform a double transfer with one donor muscle, limiting morbidity. Level of Evidence: Therapeutic IV.