Restoring deficient glenoid bone stock is indicated and integral in the treatment of anterior shoulder instability with critical glenoid bone loss. The amount of glenoid bone loss at which this critical threshold is reached, however, has been debated over time.^{1, 2 and 3} Historically, bone loss greater than 20% to 30% was considered critical.^{1, 2 and 3} However, recently, it has been shown that anterior glenoid bone loss as small as 13.5% may portend poor outcomes if an exclusively soft tissue procedure is performed.⁴

While the importance of bony augmentation in the setting of significant glenoid bone loss has been well established, a validated algorithm to guide surgical treatment has not been determined. Until now, many surgical techniques capable of augmenting glenoid bone stock have been described.⁵ Broadly, these techniques fall into the categories of coracoid transfer procedures or free bone block procedures. Coracoid transfer procedures include the Latarjet procedure, which involves the transfer of the coracoid base to the glenoid, along with the conjoined tendon and the coracoacromial ligament, and the Bristow procedure, which, instead, involves the transfer of only the coracoid tip.⁶ Within the category of free bone block procedures, variation exists, both in surgical approach and bone block source.⁵ Bone block procedures can be performed via arthroscopic, open, or combined approaches.⁵ Furthermore, the bone block can be obtained from a variety of sources, including iliac crest autograft, distal tibial allograft (DTA), scapular spine autograft, and distal clavicle autograft.^{5,7, 8, 9 and 10} Recently, arthroscopic anatomic glenoid reconstruction using distal tibial allograft has been described and is gaining popularity.^5,11

Given the lack of a codified treatment algorithm for treating anterior shoulder instability in the setting of critical glenoid bone loss, the choice of surgical technique is affected by the consideration of the various advantages and disadvantages of the different surgical options, as well as the surgeon’s experience with certain techniques. To that end, arthroscopic DTA has been found to have several notable advantages. Arthroscopic management may facilitate faster recovery, decrease patient morbidity, and facilitate a more effective intra-operative examination of the shoulder.^12,13 Additionally, the use of a distal tibial allograft, specifically, has several advantages when compared to other bone block sources. Most importantly, the use of an allograft source eliminates donor site morbidity in autograft procedures.^5,14 Furthermore, a distal tibial allograft bone block, which possesses a cartilaginous articular surface that articulates with the humeral head, may produce a more anatomic and long-lasting reconstruction.^14,15