Review Question - QID 4514

The labeled structure is the middle glenohumeral ligament (MGHL) of the shoulder. The primary function of the MGHL is to prevent anterior translation of the humeral head with the arm in 45-60 degrees of abduction.

This structure originates from the glenoid labrum and inserts medial to the lesser tuberosity running obliquely across the subscapularis. The size of the structure may be variable and there are recognized normal anatomic variants (including a cord like MGHL in the Buford complex). It is important to be able to recognize the MGHL and differentiate this from the subscapularis, IGHL, SGHL, and other intraarticular structures in the shoulder to be able to perform effective and precise arthroscopic procedures.

Burkhart et al. describe the function of the glenohumeral ligaments in anterior shoulder instability, noting that the MGHL provides a restraint to anterior translation with the arm in 45-60 degrees of abduction.

Wang et al. discuss microdamage to the inferior glenohumeral ligament from a basic science perspective, indicating that over time it may stretch and compromise it's function in restraining humeral translation.

Figure A is an arthroscopic image of the intraarticular structures of the shoulder with an asterisk on the MGHL.

Incorrect Answers (these are labeled on Illustration A, with the exception of the subscapularis which is difficult to visualize):
Answer 1: Describes the superior glenohumeral ligament (1: Illustration A)
Answer 2: Describes the subscapularis (2: Illustration A)
Answer 4: Describes the inferior glenohumeral ligament (4: Illustration A)
Answer 5: Describes the biceps tendon (5: Illustration A)