Evaluation of the effect of internal rotation of the shoulder on the coracohumeral and acromial range with three-dimensional tomography

Purpose: The aim of this study was to assess whether the coracohumeral and acromiohumeral distances were really decreasing with the passive internal rotation of the shoulder. Materials and Methods: The patients who underwent computerized tomography arthrography with the prediagnosis of rotator cuff tear between May 2016 and October 2016 were enrolled in the study. The computerized tomography arthrography imagings were performed in two positions of the shoulder, the neutral position and the internal rotation of the arm, and then the 3 dimensional reconstructions of the images were constituted. The coracohumeral and acromiohumeral distance measurements were made on 3 dimensional reconstructions of these two computerized tomography examinations. Results: Seventeen patients with the mean age of 64.06 +/- 9.06 were involved in the study. The coracohumeral and acromiohumeral distance measurements in neutral and internally rotated arms were also statistically similar between patients with full-thickness rotator cuff tears and those without. Between the male and female patients, there was no statistically significant difference in any of measurements. Conclusion: The coraohumeral distance narrows significantly with the internal rotation of the arm. The measurements made on three dimensional computerized tomography may provide us more reliable data about the several parameters of the coracoid process.