Function of the 3 portions of the inferior glenohumeral ligament: a cadaveric study.

The stabilizing function of the inferior glenohumeral ligament of the anterior band and posterior band has been investigated, but little is known about the function of the axillary pouch. The strain of the 3 portions of the inferior glenohumeral ligament in 17 fresh-frozen cadaveric shoulders was measured with use of linear transducers. The measurements were performed under the following conditions: 0 degrees, 30 degrees, 45 degrees, and 60 degrees of glenohumeral elevation in the coronal, scapular, and sagittal planes and internal to external rotations in 10 degrees increments. The anterior band and axillary pouch showed significant strain increases when the arm was elevated and externally rotated in the coronal and scapular planes but no increase in the sagittal plane. The posterior band showed no strain in the coronal and scapular planes, but a significant strain increase with the arm elevated and internally rotated in the sagittal plane. We conclude that the anterior band and axillary pouch, which showed the greatest strain in abduction and external rotation, are anterior stabilizers, whereas the posterior band, which showed the greatest strain in flexion and internal rotation, is a posterior stabilizer. We recommend that the 6 o'clock position be firmly repaired during the Bankart procedure.