Glenoid bone loss is a significant risk factor in surgery for anterior glenohumeral instability. We formulated a new radiographic technique which enables us to observe the glenoid morphology without the fluoroscopy. The purpose of this study is to assess the effectiveness of the new radiographic technique in a series of patients with anterior glenohumeral instability. Ninety five patients with recurrent anterior glenohumeral instability were included in this study. The X-ray was applied from 15-20 degrees cranially in lateral decubitus position. The glenoid views were classified into three groups including a fragment type, an attritional type and a normal type using contra-lateral control by three blinded observers. The results were verified by 3DCT. The fragment types and attritional types were classified to three subtypes, including small, medium, large and mild, moderate, severe respectively. The diagnostic rate in each type and subtype were obtained and a sensitivity and specificity were calculated. According to 3DCT, there were 33 fragment types (16 small, 17 medium to large), 55 attritional types (30 mild, 25 moderate to severe) and 7 normal types. The diagnostic rates using the radiographs were 62.6% in fragment type (small 64.6, medium to large 58.8), 76.2% in the attritional type (mild 55.6, moderate to severe 86.7) and 69.7 in the normal type. Sensitivity/specificity in each group was as follows, fragment: 62.6/94.1%, attritional: 62.4/70.8% and normal: 76.1/82.6%. Our new method diagnosed the glenoid morphology with the rate 63 to 76%. The better diagnostic rate was obtained in the moderate to severe attritional type compared to the mild attritional type. The modest sensitivities were found in each type and the higher specificity was observed in fragment type. We concluded that our new method can be valuable for the screening of glenoid morphology in patients with glenohumeral instability.
