The latissimus dorsi tendon is a flat, broad tendon that inserts on the floor of the intertubercular groove (bicipital groove) of the humerus, immediately inferior and slightly posterior to the tendon of the teres major. The two tendons run together through the posterior axilla and have a characteristic twist: the latissimus dorsi fibres that originate posteriorly at the iliac crest insert anteriorly on the humerus. The tendon wraps around the teres major to reach its insertion, so the two tendons' anterior and posterior relationships are reversed at their humeral insertions compared to their origins.
The latissimus dorsi tendon is the primary transfer tendon for reconstruction of posterosuperior rotator cuff tears with intact subscapularis. The L'Episcopo and subsequent modified procedures reroute the tendon to the greater tuberosity posteriorly to restore external rotation and abduction in massive irreparable tears. In biomechanical testing, the transferred latissimus functions as an external rotator when repaired posteriorly, converting a powerful internal rotator into a functional external rotator. The tendon is also transferred in brachial plexus palsy reconstruction and for elbow extension restoration in tetraplegic patients.
A rare injury in throwing athletes and water polo players producing acute posterior axillary and medial arm pain during a forceful pulling or throwing motion; MRI reveals the tear at or near the humeral insertion with associated muscle oedema, managed conservatively for partial tears and surgically for complete tears in high-demand athletes.
Following transfer to the greater tuberosity for posterosuperior cuff reconstruction, the tendon can elongate or re-tear if sutured under insufficient tension or loaded prematurely, producing recurrent external rotation weakness and requiring revision surgery.
