Middle GHL

 This ligament courses from the anterior/superior aspect of the glenoid and passes obliquely across the subscapularis bursa to the lesser tuberosity. [1,7,9] Variations in the origin of this ligament have been described [9-10,18,27,29,45,48]. Its prevalence ranges between 63.1% and 100% [8-9,18,26-29,40,42,47].

The width and diameter of the ligament vary considerably, being reported to be an average of 18 mm (range 6-25mm) and 3.6 mm (range 2-5mm) respectively. [40] It was reported to be rudimentary in 11.5% of cases and originate between the 1 to 3 o’clock positions on the glenoid labrum in 28.8% of cadaveric specimens. [40]

The middle gleno-humeral ligament has a highly variable appearance, [1] most commonly appearing (in approximately 70% of cases) as a thickened fold in the anterior capsule. [6] The intra-articular appearance of this ligament is determined by variation in the synovial recesses found in the shoulder joint. [10]

The cord-like appearance is the most common variant, and when seen through an arthroscope, it appears to have rolled up edges [6,25-26,29,49]. It may be associated with antero-superior labral variants - Buford Complex.

Other variants of this ligament include it appearing as a few fibrous bands or a thin fibrous sheet, [6,26] a bifid structure [26-27,50-51] or being absent. [6,8,18,26-27,40]

Snyder [6] reported a thin veil or an absent middle glenohumeral ligament to occur in about 10% of shoulders and be associated with “…a very hypertrophic inferior glenohumeral ligament”. A separate arthroscopic study [26] reported a thin sheet middle gleno-humeral ligament in 70.4% of arthroscopies, and only one case of a bifid middle ligament.

From our study:
Similar to other studies, the prevalence of the middle gleno-humeral ligament in our study was noted to be 87.1% [Table 24]. [16,22,27-28,30,34-39] No other arthroscopic study has commented on the prevalence of this ligament.
 No new variations were noted with respect to the origin of the middle gleno-humeral ligament. In agreement with Snyder [6], a thickened ligament was the most common appearance. The prevalence of a cord-like middle gleno-humeral ligament as noted in this study is similar to that mentioned in the literature [Table 25]. [6,34-35,40] Three examples of a poorly described bifid middle gleno-humeral ligament were also found. No other study has commented on the shape and size of the middle gleno-humeral ligament.

Table 24 – Prevalence and absence of the middle gleno-humeral ligament

Table 25 – Prevalence of a cord-like middle glenohumeral ligament, a variant of the middle glenohumeral ligament.