Arthroscopic anatomy of the middle glenohumeral ligament

PurposeThe middle glenohumeral ligament (MGHL) has seldom been studied and its function is unknown. The aim of this study was to describe its anatomical presentations.MethodsA prospective study was conducted of MGHL anatomy in 107 arthroscopies, with a description of its shape and superior and inferior insertion in the articular surface of the subscapularis tendon. The MGHL was investigated dynamically during internal rotation of the glenohumeral joint.ResultsSixty-three percent (68/107) of the MGHLs were found to be leaf-like, and 27% (28/107) cord-like, 5.5% (6/107) vestigial, and 2% (2/107) had several strands. The MGHL was absent for 2% of patients (2/107). The inferior insertion point of the MGHL was lateral, masked by the humeral head, in 34% of cases (36/105), intermediate, in front of the glenohumeral joint line, in 57% of cases (60/105), and medial, in front of the labrum, in 9% of cases (9/105). During internal rotation, 46% (48/105) of the MGHLs were observed to retract medially, the subscapularis tendon moving away from the anterior glenoid rim, while 54% (57/105) remained visible in front of the glenohumeral joint and came into contact with the articular surface of the subscapularis tendon.ConclusionsThe MGHL has many anatomical variations.