We report a clinically relevant anatomic variation of the tendon of the long head of biceps brachii muscle. The clinical and historically relevant data regarding an anatomic finding observed in 1 patient are reviewed. The clinical outcome of the patient's care was successful. Recognition of the described anatomic variant of the biceps tendon can aid the surgeon in focusing the treatment on the actual pathology and not on aberrant anatomy. Several anatomic variations in the origin of the long head of the biceps brachii have been observed. Some of these anomalies have been implicated as having a role in rotator cuff tendinopathy or in exposure for shoulder surgery. We are reporting the observation that the long head of the biceps tendon may have a mesotendon or be incorporated in the extra-articular side of the glenohumeral joint capsule, making arthroscopic visualization and assessment of the tendon difficult.
