No interferences were noticed between portals and the cephalic vein anteriorly. The center of the graft was located in a subequatorial position. The contact surface between the anterior part of the glenoid and the bone graft was 80% of the surface area of the bone block in the first 2 cases and 90% in the other 4 cases. No evidence was found of soft tissue interposition between the bone graft and the glenoid. All the grafts were positioned 1 mm more medial with respect to the articular surface. No interference was found between graft tunneling and the anchor side for the subscapularis tenodesis. There was a good covering of the graft by the tendon and a good position of its fixation on the glenoid neck. At the end of bone block procedure the shoulder was not easily dislocable as before the procedure in presence of a glenoid bone defect of about 25%. After ASA procedure the humeral head resulted recentered and shifted posteriorly under arthroscopic view. There was no vascular damage to the anterior and posterior vessels. No interference with the axillary nerve anteriorly and the suprascapular nerve posteriorly was noted. The axillary nerve was located 35 mm to 55 mm (average 40.3 mm) from the inferior gleno-humeral portal. The suprascapular nerve was located 8 mm to 15 mm (average 11 mm) from the two glenoid holes (Fig. 10). The musculocutaneous nerve was located 33 mm to 50 mm (average 38 mm) from the insertion of the coraco-biceps tendon (Fig. 11).Fig. 10Posterior side of the scapular neck: absence of interference of the upper graft fixation button with suprascapular nerve (arrow)Fig. 11Anterior aspect of muscolo-cutaneus nerve (arrow) showing the distance from the antero-inferior portal enlarged from seven mm to fiftheen (CP: coracoid process)