A detailed morphometry of the Hill-Sachs lesion and quantification of its volume was studied in 71 patients with traumatic anterior shoulder instability with radiographs and computerized arthrotomography. The accuracy of the conventional radiographs and Bernageau view to visualize the humeral and the glenoid lesion was also assessed. This study also analysed the depth of the Hill-Sachs lesion (D) and the humeral head radius (R) from conventional radiograph and its location from the computerized arthrotomography. All the findings were analysed and correlated with the outcome of the arthroscopic stabilization procedure. Sensitivity for demonstrating the Hill-Sachs lesion for the 45A degrees internal rotation anteroposterior radiograph was 84%, whereas sensitivity for demonstrating the glenoid lesion for the comparative Bernageau view was 68%. The mean D/R ratio, the lateralization angle and the volume of the Hill-Sachs lesion were 16.2%, 188A degrees and 1,019 mmA(3), respectively. The mean Hill-Sachs lesion volume represented 2.28% of the total humeral head volume. The D/R ratio, the lateralization angle and the volume of the Hill-Sachs lesion were significantly high in the recurrent dislocation group, whereas the D/R ratio and the lesion volume were also significantly high in the group that did not perform well following the stabilization procedure. The recurrence rate in this study was 16.6%, majority being from the recurrent dislocation group. This study confirms the interest as risk factor for a simple and reproducible radiographic quantitative measure of the Hill-Sachs lesion: D/R. II.
