Arthroscopic repair of Bankart lesions is part of the arsenal available to the shoulder surgeon to manage chronic anterior instability of the shoulder. Despite improvements in technique, rates of recurrence remain high. Some factors relate to the patients and their lesions, others to technique. The hypothesis that insufficient repair may be the cause of failure in Bankart arthroscopy was investigated in an anatomic and biomechanical study. Bankart lesions were made on 12 cadaver shoulders and repaired using two suture techniques. The aim was to investigate whether there was any biomechanical interest in reinforcing the labrum and capsule suture by a complementary inferior gleno-humeral ligament (IGHL) suture to double the labral repair. No significant difference in overall resistance was found between the two techniques. Failure generally started from the superior suture, and the present findings suggest that special attention should be paid to superior reinsertion. In the present model, complementary IGHL fixation did not alter the biomechanics of repair. Failure of repair can be traced to the superior suture. Level of evidence: IV, biomechanical study. (C) 2010 Published by Elsevier Masson SAS.