The Glenohumeral Ligaments of the Anterior Aspect of the Shoulder: Anatomical Patterning and Morphometry

Abstract The glenohumeral ligaments are key stabilizers of the glenohumeral joint. Three distinct fascicles are usually described from the anterior surface of the shoulder joint: a superior glenohumeral ligament (SGHL); a middle glenohumeral ligament (MGHL) and an anteroinferior glenohumeral ligament (AIGHL). A remarkable interindividual variation has been reported, and there is a lack of consensus regarding terminology and quantitative measures of ligament attachments. A recent study provided a much-needed insight into the quantitative details of the glenohumeral ligament insertions. However, there is a lack of studies describing linear measurements (closer to real-life surgical anatomy) of glenohumeral ligamentous insertions according to their pattern. Hereby, we present a Thiel-based anatomical study describing proximal (glenoid) insertions of glenohumeral ligaments in 39 specimens. Only 43,5% of cases showed a canonical pattern of SGHL, MGHL, and AIGHL, with scapular insertions ranging from 0,28 to 1,58 cm for SGHL, 0,1–3,6 cm for MGHL, and 0,45 − 2,05 cm for AIGHL, frequently mixed between the labrum and the bony edge of the glenoid surface. Most cases show a single glenohumeral ligament inserted, usually in the labrum. A wide range of patterns regarding the number of insertions and their labral or bony nature is present in our sample. Overall, there are three different patterns of glenohumeral ligaments in the anterior aspect of the shoulder joint, with the canonical pattern (three ligaments) represented in less than half of the cases. The morphometric study of the glenohumeral ligaments should consider their pattern of distribution. Also, insertions vary between the labrum and the scapular bony articular surface..