Upper Subscapularis Tendon

tendo musculi subscapularis — pars superior

The upper third of the subscapularis tendon is the thickest and most clinically important portion, accounting for approximately 60% of the total subscapularis tendon volume and inserting on the superior lesser tuberosity. The upper subscapularis fibres blend with the superior glenohumeral ligament and the coracohumeral ligament at the rotator interval. Partial tears of the subscapularis most commonly begin in the upper tendon adjacent to the rotator interval, and full-thickness tears typically extend from upper to lower.

Region: Shoulder

Clinical Relevance

Clinical Notes

Upper subscapularis tears are the most common subscapularis tears and are underdiagnosed on shoulder MRI due to their location near the rotator interval and coracoid. The lift-off test and belly-press test detect subscapularis weakness from full-thickness tears, while the bear-hug test is more sensitive for partial upper tears. Arthroscopic repair of the upper subscapularis restores internal rotation strength and prevents progressive tear extension into the mid and lower portions. The biceps tendon is often involved in upper subscapularis tears due to its proximity at the rotator interval.

Pathology

Common Injuries & Conditions

Upper Subscapularis Partial Tear with Biceps Instability

Partial tearing of the upper subscapularis at the rotator interval destabilises the medial biceps pulley, allowing the long head biceps tendon to sublux medially off the bicipital groove; MRI arthrogram demonstrates the partial subscapularis tear and biceps medial subluxation and arthroscopic repair addresses both the subscapularis footprint and the biceps anchor.