Classification of Anterosuperior Glenoid Labrum Variants and Their Association With Shoulder Pathology

Abstract

This prospective study of 367 consecutive shoulder arthroscopies assessed variants of the anterosuperior glenoid labrum and associated shoulder pathology. Thirty-three shoulders were excluded because of prior surgery, septic arthritis, or adhesive capsulitis. Anterosuperior glenoid variants were classified as: type I, cordlike middle glenohumeral ligament without sublabral foramen; type II, sublabral foramen without a cordlike middle glenohumeral ligament; type III, sublabral foramen with a cordlike middle glenohumeral ligament; and type IV, absent anterosuperior labrum with the anterior aspect of the superior labrum continuous with a cordlike middle glenohumeral ligament. The presence of these variants was correlated with the incidence of shoulder pathology found on arthroscopic inspection. Of 334 shoulders, 118 (35.3%) had variants of the anterosuperior glenoid labrum. Of these, 32 (27.1%) were type I, 27 (22.9%) were type II, 34 (28.8%) were type III, and 25 (21.2%) were type IV. The incidence of advanced superior labrum anterior-posterior lesions in the 86 shoulders displaying a type II, III, or IV variant was significantly higher than in shoulders with no anterosuperior variant (48.8% versus 23.6%, P<.001). Other pathologic findings were not significantly increased in shoulders with variants compared to those without. Level 1.