Glenoid exposure in total shoulder arthroplasty

Glenoid exposure is agreed to be a difficult step, but is also a key step in total shoulder arthroplasty, both anatomic and reverse. It conditions unhindered use of the ancillary instrumentation and thus correct glenoid component positioning. The main stages comprise arthrotomy, by opening the rotator cuff, humeral head cut, and inferior glenohumeral release, enabling shifting of the humerus and good exposure of the glenoid cavity. The two main approaches are deltopectoral and anterosuperior transdeltoid. Using the deltopectoral approach, arthrotomy is performed through the subscapularis muscle, by various techniques. This approach enables extensive inferior glenohumeral release and thus an approach to the inferior apex of the glenoid cavity, which is a key area for glenoid implant positioning. The main drawbacks are postoperative shoulder instability and limited access to the posterior part of the glenoid in case of significant retroversion. Moreover, subscapularis healing is uncertain, which can impair the clinical outcomes, with risk of glenoid component loosening. Advantages, on the other hand, include the fact that it can be implemented in all cases, even the most difficult ones, and that the deltoid muscle is respected. The transdeltoid approach has the advantage of being simple, providing direct exposure of the glenoid cavity through a rotator cuff tear after passing through the deltoid. It is therefore especially indicated for reverse prosthesis in case of rotator cuff tear, and in traumatology. However, the approach to the inferior part of the glenoid cavity can be restricted, with insufficient exposure and a risk of glenoid component malpositioning (superior tilt). The preoperative assessment is essential, to detect at-risk situations such as severe stiffness and anticipate difficulties in glenoid exposure.