Determination of a new computed tomography method for measuring the glenoid version and comparing with a reference method. Radio-anatomical and retrospective study

Purpose In the literature, there are several techniques for measuring the glenoidal version of the scapula. The superiority of the scannographic measurement over the standard radiologic measures seems evident. The main problems are the evaluation and the reproducibility of these methods, which are dependent on the quality of the CT scan and the orientation of its sections. We pinpoint a simple method of the ``scapular triangle'', the reliability of which deserves special consideration. The aim of this study is to report a simple and reproducible computed tomography method to measure the glenoidal version. Methods Thrity-one shoulder CT scans, performed on patients attending the emergency department of the University Hospital of Dijon between January 2012 and April 2013 for shoulder trauma, were evaluated retrospectively. The CT scan must include the entire body of scapula to allow measurements to be made with both methods: the conventional method of Friedman and our new method of the ``scapular triangle''. Two independent operators performed inter-observer and intra-observer reproducibility. We compared both techniques with Pearson's test. Result Pearson's test showed a trend line according to a linear correlation between the two methods with a p value of 7.791(-10) and a correlation coefficient of 0.85 with the 95 % confidence interval (0.7213; 0.929). Conclusion The method of the ``scapular triangle'' is easily applicable on most sections of the CT scan of scapula whether or not it takes the whole body. It is more reliable and reproducible and could be used by any radiologist.