Arthroscopic Posterior Glenoid Bone Block Using an Adapted Anterior Glenoid Guide and Independent Cortical Button Fixation.

Recurrent posterior shoulder instability associated with posterior glenoid bone loss remains challenging. Arthroscopic bone block procedures have gained popularity due to their minimally invasive nature and their ability to restore glenoid concavity while addressing associated intra-articular pathology. We describe a fully arthroscopic posterior glenoid bone block technique using a tricortical iliac crest autograft fixed with independent cortical buttons from the Glenoid Bone Loss-Advanced Instability System (Smith & Nephew Andover, MA, USA). A commonly available anterior glenoid guide is used with an adapted posterior application. The technique emphasizes meticulous posterior capsulolabral mobilization, preparation of a bleeding posterior glenoid bone bed, direct visualization for accurate tunnel placement, progressive independent button tensioning, and posterior capsulolabral reconstruction, leaving the graft extra-articular.