Accuracy of measurement of Hill-Sachs lesions with computed tomography

作者:Kodali Pradeep; Jones Morgan H; Polster Josh; Miniaci Anthony; Fening Stephen D*
来源:Journal of Shoulder and Elbow Surgery, 2011, 20(8): 1328-1334.
DOI:10.1016/j.jse.2011.01.030

摘要

Background: Bone defects play a role in recurrent instability. There is no universal method to quantify humeral head defects. The purpose of this study is to assess the accuracy of 2-dimensional computed tomography (CT) scan measurements of Hill-Sachs lesions.
Materials and methods: Six Hill-Sachs defects were created in anatomically shaped bone substitutes. The samples were scanned with a 3-dimensional laser scanner. Maximum width and depth were measured and used as the true measurement. The samples underwent routine CT scanning, and 5 physicians measured maximum width and depth on each plane independently. The intraclass correlation coefficient (ICC) was used to assess agreement. Percent error and paired t test were used for statistical analysis (P < .05 denoted significance).
Results: The ICC between observers was 0.879 (95% confidence interval, 0.780-0.946) and 0.721 (95% confidence interval, 0.543-0.865) for the depth and width measurement, respectively. The ICC was good between individual observers and the true measurement (range, 0.765-0.956). Individual observers were more accurate in depth rather than width measurements. The mean overall percent error of the depth and width measurements for the 6 defects was calculated: coronal, 19.2% +/- 13.6%; sagittal, 11.8% +/- 8.2%; and axial, 13.6% +/- 8.4%.
Conclusions: The depth of Hill-Sachs lesions can be reliably assessed using CT scan. Observers consistently underestimated width in all imaging planes. Overall, sagittal- and axial-plane measurements are more accurate for evaluation of these defects than the coronal plane. Future studies using 3-dimensional CT may be helpful to further quantitatively assess the size of the Hill-Sachs lesion, including width and volume.
Level of evidence: Anatomic Study, Imaging of Instability Model.