Acromial spurs reportedly relate to the impingement syndrome and rotator cuff tears. We classified the morphologic characteristics
of the acromion (shape and thickness) and acromial spurs and determined whether they correlated with rotator cuff tears. We
measured acromial shape and thickness using simple radiography and MR arthrography or CT arthrography in 106 patients with
full-thickness rotator cuff tears and in 102 patients without tears. Acromial spurs could be classified morphologically into
six types: heel, lateral/anterior traction, lateral/anterior bird beak, and medial. We found acromial spurs in 142 of the
208 patients (68%), and their incidence increased with age. The acromial spur was more common in the cuff tear group. The
heel type was most common and detected in 59 patients (56%) in the cuff tear group and in 36 patients (35%) in the control
group. The flat acromion was more common (60%) than curved and hooked acromion; however, there was no major difference between
acromial shape and cuff tear. The mean acromial thickness was 8.0 mm, and the cuff tear group had thicker acromion. These
data suggest acromial spurs can be classified according to the distinct morphology, and the most common heel-type spur might
be a risk factor for full-thickness rotator cuff tears.
Level of Evidence: Level IV, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.
Each author certifies that he or she has no commercial associations (eg, consultancies, stock ownership, equity interest,
patent/licensing arrangements, etc) that might pose a conflict of interest in connection with the submitted article.
Each author certifies that his or her institution has approved the human protocol for this investigation and that all investigations
were conducted in conformity with ethical principles of research.
This work was performed at Seoul National University College of Medicine, Seoul, Korea.