Anatomical Variants of the Shoulder: Pitfalls and Clinical Significance

Variants of the shoulder are commonly encountered and may occasionally be confused with pathological conditions. Our goal is to provide an overview of common normal variants of the shoulder's anatomical structures as well as any associated clinical or surgical relevance.

Following a literature search of common variants of the shoulder and supporting structures, this review provides a summary of variants related to the scapular body, acromion, glenoid, coracoid, labrum, long head biceps tendon, glenohumeral ligamentous complex, and rotator cuff.

The shoulder is composed of the glenohumeral, acromioclavicular, sternoclavicular, and scapulothoracic joints and their associated osseous, ligamentous, cartilaginous, and musculotendinous stabilizers. Anatomic variants about the shoulder, especially in the adolescent and young adult populations, are frequently encountered. An awareness of associated pathological conditions and an understanding of when variants might be clinically significant is important in interpreting radiological exams.

· Normal variants of the shoulder are commonly encountered when interpreting imaging exams, especially in the adolescent and young adult population. We describe some of the more clinically relevant variants of the glenohumeral joint.. · Meso-acromion os acromiale is the by far the most common type followed by the pre-acromion type.. · While an os acromiale is commonly asymptomatic; acromial apophysiolysis is typically symptomatic and may result in future development of an os acromiale.. · The glenoid bare area is typically small and near the center of the glenoid, which helps differentiate it from a pathological cartilaginous lesion.. · The middle glenohumeral ligament has the most variability, and it is absent in nearly 40% of patients..

· Haug LP, Shah AS, Shrestha R et al. Anatomical Variants of the Shoulder: Pitfalls and Clinical Significance. Rofo 2026; DOI 10.1055/a-2805-0742.