Inferior GHL
This ligament consists of three parts: an anterior band, posterior band and an axillary pouch. [52] Both anterior and posterior bands originate from the antero-inferior and posterior aspects of the glenoid respectively and insert onto anatomical neck of the humerus. [9] Variations in the origin of the anterior band have been described. [29,53]
Arthroscopically, the anterior band of the inferior gleno-humeral ligament can be seen originating from the anterior labrum, proximal or marginally above the glenoid notch. [6] Snyder [6] reported the origin of the anterior band might be as high as the antero-superior labrum when seen through an arthroscope
McMahon et al [54] described the anterior band of the ligament to originate from the anterior labrum but have two attachments to the glenoid. In one type, collagen fibres inserted directly into the labrum, and in the other, collagen fibres attached to the anterior portion of the glenoid neck. In a separate study, McMahon [55] reported the length, width and thickness of the anterior to be 37 ± 2 mm, 13 ± 1 mm and 3 ± 0 mm respectively.
In a cadaveric study, Steinbeck et al [40] described 87.6% of inferior gleno-humeral ligaments to arise between the 3 and 8 o’clock position and all of them to originate between the 2 and 9 o’clock position. O’Brien et al [53] described the posterior band to originate from the posterior labrum, between 7 and 9 o’clock positions on glenoid labrum.
The prevalence of the inferior gleno-humeral ligament ranges between 75% and 100% [8-9,18,16,28-29,40,46-47].
Arthroscopically, the anterior band and axillary pouch are the only parts of the inferior glenohumeral ligament to be readily visualised [1] Snyder [6] described visualisation of the anterior band to be poor in situations where the joint is distended.
From our study:
Similar to the literature, the prevalence of the anterior band of the inferior GHL was noted to be 74.2% [Table 26]. [16,22,27-28,34-35,37-39]
As with the other two gleno-humeral ligaments, the variables of degree of development, thickness and size of the inferior gleno-humeral ligament are dependent upon observer’s interpretation. The origin of the anterior band was variable and in agreement with Snyder [6], the anterior band of the inferior ligament originated as high as the antero-superior labrum. Similar to cadaveric studies, [35,41] the 3 o’clock position on the glenoid was found to be the most common position for the origin of the anterior band [Table 27]. No other study arthroscopic study has commented on the position of origin, shape and size of the inferior gleno-humeral ligament.
Table 26 – Prevalence and absence of the inferior gleno-humeral ligament
|
% Prevalence |
% Absent |
Type of study |
|
Well defined 56% Poorly defined – 19% |
25% |
Cadaveric study [27] |
|
74.2% - Anterior band |
11.4% |
Arthroscopic study |
|
75% |
|
Cadaveric study [39] |
|
Well developed – 79.6% Poorly developed – 20.4% |
|
Arthroscopic study [34] |
|
90.5% - Anterior band |
|
Cadaveric study [35] |
|
91% |
|
MR Arthrography [37] |
|
93.2% |
6.8% |
Cadaveric study [38] |
|
99% |
|
MR Arthrography [22] |
|
100% |
|
Cadaveric study [28] |
|
100% Well defined in 92% |
|
Cadaveric study [16] |
Table 27 – Variation in the origin of the anterior band of the inferior gleno-humeral ligament on the anterior labrum
|
|
% Prevalence |
|
Origin at 12 o’clock position |
0% - Arthroscopic study |
|
Origin at 1 o’clock position |
4.1% - Arthroscopic study |
|
Origin at 2 o’clock position |
14.3% - Arthroscopic study 14.5% – Cadaveric study [35] 18% – Cadaveric study [41] |
|
Origin at 3 o’clock position |
55.1% - Arthroscopic study 64.5% - Cadaveric study [35] 73% - Cadaveric study [41] |
|
Origin at 4 o’clock position |
9% - Cadaveric study [41] 14.5% - Cadaveric study [35] 16.3% - Arthroscopic study |
|
Origin at 5 o’clock position |
6.5% - Cadaveric study [35] 10.2% - Arthroscopic study |
