Attachment of the anteroinferior glenohumeral ligament-labrum complex to the glenoid: An anatomic study

Purpose: To determine the morphology of the attachment of the anteroinferior glenohumeral ligament-labrum complex (AIGHL-LC) to the anterior rim of the glenoid. Methods: Sixty-six cadaveric shoulders with a mean age of 81 years were studied. The length of the AIGHL-LC attachment in the superoinferior direction and its depth in the mediolateral direction at the 2-, 3-, 4-, and 5-o'clock positions were measured. The radial histologic sections from the center of the glenoid at the 2- and 4-o'clock positions were used for histologic examinations. Results: The mean length of the AIGHL-LC attachment was 11.7 mm. The mean depth was 4.7 mm (1.6 mm on the articular cartilage and 3.0 mm on the glenoid neck) at the 2-o'clock position, 6.7 mm (2.4 mm and 4.3 mm, respectively) at the 3-o'clock position, 8.4 mm (3.0 mm and 5.4 mm, respectively) at the 4-o'clock position, and 6.8 mm (2.5 mm and 4.3 mm, respectively) at the 5-o'clock position. The depth of the AIGHL-LC attachment was the greatest at the 4-o'clock position (P <.01) and the smallest at the 2-o'clock position (P <.05). Histologically, the AIGHL-LC attached to both the cartilage and bone in 52 shoulders (86.7%) at the 2-o'clock position and in 53 shoulders (88.3%) at the 4-o'clock position. Conclusions: The depth of the AIGHL-LC attachment was the greatest at the 4-o'clock position and the smallest at the 2-o'clock position. At the 4-o'clock position, the AIGHL-LC attaches to both the articular cartilage and bone in 88% of shoulders whereas it attaches only to bone in 12%. Clinical Relevance: This study provides fundamental information on the AIGHL-LC attachment. Because healing of the AIGHL-LC to the articular cartilage cannot be expected, the same attachment area as to the bone and cartilage observed in normal shoulders needs to be created on the glenoid neck during Bankart repair to obtain the physiological strength of the AIGHL-LC.