Anterior Shoulder Dislocation Mechanisms and Implications

Anatomical Vulnerability

The rotator cuff provides less muscular support anteriorly, with the subscapularis being the only anterior rotator cuff muscle compared to multiple posterior stabilizers 1

Posterior dislocations are frequently missed on initial evaluation (over 60% misdiagnosed) because they can appear normal on standard AP radiographs alone, requiring axillary or scapula-Y views for proper diagnosis 2, 3
Always obtain axillary or scapula-Y views in addition to AP views, as glenohumeral dislocations can be misclassified on AP views alone 2, 3
Associated injuries differ by direction: anterior dislocations typically cause Hill-Sachs deformities (posterolateral humeral head compression fractures) and bony Bankart lesions (anterior glenoid rim fractures), while posterior dislocations have different fracture patterns 2, 3

Younger patients (<35 years) with anterior dislocations have higher recurrence rates due to labroligamentous injury and persistent instability 3