The Radiologic Evaluation and Clinical Significance of Glenohumeral Bone Loss in Anterior Shoulder Instability

Glenoid and humeral bone loss is associated with a high incidence of recurrent shoulder instability and failure of arthroscopic stabilization procedures. However, the radiographic evaluation of bony Bankart and Hill-Sachs injuries continues to pose a diagnostic challenge, and a universally accepted optimal method of measurement is lacking. The purpose of this review is to summarize the advantages and disadvantages of various techniques and imaging modalities available for measuring glenoid bone loss in shoulder instability, including conventional roentgenography, 2-dimensional and 3-dimensional computed tomography (CT), and magnetic resonance imaging (MRI). We also review the concepts of engaging "on-track" and "off-track" Hill-Sachs lesions. Finally, we highlight the clinical importance of obtaining accurate determinations of bone loss by the various methods available, as it can affect surgical decision making and the appropriate procedure required to ensure shoulder stability is adequately restored.