2001 年 25 巻 3 号 p. 453-457
The purpose of this study is to introduce a simple method of evaluating the shape and quantity of osseous defect of the glenoid rim using three-dimensional computed tomography (3DCT). Glenoid morphology of 84 consecutive shoulders in traumatic anterior glenohumeral instability, including 6 acute glenoid rim fractures, was evaluated through the use of 3DCT, comparing with 13 normal shoulders. Humeral head was deleted during the process of creating reconstructed 3D images. A ratio of osseous defect (fragment) against the outer fitting circle of the lower part of the glenoid contour (from 3o'clock to 9 o'clock) was obtained by images viewed from the perpendicular direction to the glenoid surface.
Forty-one out of 78 chronic cases (52.6%) had an osseous defect. Average ratio of the osseous defect was 7.9 (range,1.3-26.9) % in chronic cases and 24.3 (range,11.5-34.5) % in acute cases. Morphologic abnormality was seen even in 30 out of 37 no defect glenoids(38.5%). The unique imaging technique of this study enables precise morphologic and quantitative evaluation of glenoid and would be a great asset in the preoperative decision making of the surgeons.