Interobserver reliability of acromial morphology classification: an anatomic study.

One hundred ten acromial anatomic specimens were classified by three shoulder surgeons with the classification system described by Bigliani et al. to determine the interobserver reliability. These results demonstrated a fair to poor level of interobserver reliability. Given this relatively low level of agreement, the diagnosis of impingement and rotator cuff tears should be based on clinical findings supplemented, when indicated, by rotatory cuff imaging with less diagnostic reliance placed on the assessment of acromial morphology.