Arthroscopic Congruent-Arc Distal Tibial Allograft Bone Augmentation With Cerclage Fixation for Anterior Shoulder Instability With Bone Loss.

Glenoid bone loss is a common sequela of recurrent anterior shoulder instability. When treated surgically, a bone augmentation procedure is more likely to provide a good outcome with a lower risk of recurrent instability compared with a soft-tissue repair alone. There are several bone augmentation options to address glenoid bone loss, including coracoid transfer, iliac crest autograft, and distal tibial allograft (DTA). Both open and arthroscopic DTA techniques have been described using the lateral one-third of the distal tibia oriented with the anterior aspect placed superiorly on the anterior glenoid. This graft orientation places its concavity in the superior-to-inferior direction. It may be preferred to have this concavity maximized toward the anterior direction so that it can further resist anterior displacement. The posterior one-third of the distal tibia may provide a more optimal arc of resistance. However, no previous technique has used the posterior one-third of the distal tibia to reconstruct the "half-pipe" concavity of the anterior glenoid. We describe an all-arthroscopic technique for a posterior third DTA oriented with the posterior tibial edge placed anteriorly on the glenoid, termed the "congruent-arc DTA," to address anterior shoulder instability with bone loss.