Anatomic variants and pitfalls of the labrum, glenoid cartilage, and glenohumeral ligaments.

Magnetic resonance (MR) imaging is the primary diagnostic imaging modality for the evaluation of patients with suspected internal derangement of the shoulder joint. Awareness and understanding of the complex anatomy of the shoulder articulation and the ability to recognize normal anatomic variants and potential imaging pitfalls are critical to accurate interpretation of conventional and arthrographic MR imaging studies. This review discusses the normal anatomy and anatomic variants of the glenoid labrum, articular cartilage, and glenohumeral ligaments. An improved understanding of normal anatomy, biomechanics, and variants will help to avoid potential pitfalls in the interpretation of noncontrast and arthrographic shoulder MR imaging examinations.