Arthroscopic alphabet soup: recognition of normal, normal variants, and pathology.

The capsule, labrum, glenohumeral ligaments, and rotator cuff represent the static and dynamic stabilizers of the glenohumeral joint. Various injuries can occur to one or more of these structures during traumatic shoulder dislocation, predisposing the patient to recurrent instability. Improved understanding of shoulder anatomy and biomechanics, and advancements in arthroscopic technique led to the recognition of various pathologic lesions that may contribute to instability. The ability to identify and address these lesions during arthroscopy will allow the surgeon to more fully tailor operative treatments for each individual patient suffering from shoulder instability. Furthermore, the ability to differentiate pathologic lesions from normal anatomic variants is critical to avoid inadvertent repair that will lead to loss of normal function and worsening symptoms.