Functional anatomy of the superior glenohumeral and coracohumeral ligaments and the subscapularis tendon in view of stabilization of the long head of the biceps tendon.

BACKGROUND Various findings in the lateral rotator interval to support the long head of the biceps tendon have been reported. The purpose of this study was to clarify the functional anatomy regarding the stabilization of the biceps tendon. MATERIAL AND METHODS Twenty embalmed shoulders were used for anatomic study, and 5 specimens of the anterosuperior part of the glenohumeral joint were histologically studied. RESULTS Anatomically, the most superior part of the subscapularis tendon was attached to the upper margin of the lesser tuberosity and extended as a thin tendinous slip to the fovea capitis of the humerus. The superior glenohumeral ligament ran spirally along the biceps tendon. Histologically, the superior glenohumeral ligament was attached to the tendinous slip. There was no clear boundary between the superior glenohumeral and coracohumeral ligament. CONCLUSION To keep the biceps tendon in place and stabilized, tension in the superior glenohumeral ligament and the buttress support of the most superior insertion point of the subscapularis from behind the ligament may be necessary. LEVEL OF EVIDENCE Basic Science.