Evaluation of acromial spur using ultrasonography

Abstract

Background: The presence of an acromial spur implies a rotator cuff disorder due to impingement between the acromial spur and the rotator cuff. The purpose of the study was to observe acromial spurs using ultrasonography and to compare measurements between plain radiographs and sonograms.

Methods: We retrospectively enrolled 51 consecutive patients with acromial spurs, which were interpreted on preoperative plain radiographs (supraspinatus outlet view and 30° caudal tilt) and preoperative sonograms. The ultrasonography transducer was held vertically and continuously moved laterally, which corresponded to the long axis of the long head of the biceps. The distance from the most distal margin of the original acromion to the most projected point of the acromial spur was measured.

Results: No significant difference was found between the plain radiograph and ultrasonography measurements (p=0.186). A moderate to strong correlation was detected between the ultrasonography and supraspinatus outlet-view measurements (r=0.776, p=0.000).

Conclusions: Anteriorly projected acromial spurs were well-visualized by ultrasonography. No discrepancy in acromial spur length was detected between the use of plain radiography (supraspinatus outlet view and 30° caudal-tilt view) and ultrasonography. The correlation coefficients between the plain radiography and ultrasonography measurements exceeded 0.7.

Keywords: Acromial spur; Ultrasonography; Shoulder.

Fig. 1.

Right shoulder of a 59-year-old woman. (A) The length (arrow) from the anterior acromion (yellow dotted line) to the most projected point of the acromial spur was measured on supraspinatus outlet-view radiographs. (B) The length (arrow) from the most distal margin of the original acromion (yellow dotted line) to the most projected point of the acromial spur was measured on 30° caudal-tilt view radiographs. (C) Length of the acromial spur (arrow) measured on a sonogram.

Fig. 2.

The transducer was held vertically during ultrasonography and continuously moved laterally to medially, which corresponded to a scan of the long axis of the long head of the biceps to the short axis of the subscapularis.

Fig. 3.

Scattered plot showing a moderate correlation between plain radiography and ultrasonography measurements. (A) Supraspinatus outlet view and 30° caudal-tilt view. (B) Supraspinatus outlet view and ultrasonography. (C) Thirty-degree caudal-tilt view and ultrasonography.