Sonography of the rotator cuff: analysis of interobserver variability

Abstract

Objective: The purpose of our study was to determine the interobserver variability in the sonographic evaluation of the rotator cuff.

Subjects and methods: Two radiologists independently scanned 61 patients with shoulder pain. Each radiologist categorized the rotator cuff as normal, partially torn, or fully torn. When a tear was present, the tendons involved were specified. All diagnoses were made prospectively without knowledge of the findings of the other radiologist.

Results: The radiologists were in full agreement in the categorization of 92% (56/61) of the patients. In four of the five discrepant cases, the disagreement was whether there was a full-thickness or a partial-thickness tear. The radiologists were in agreement concerning which tendons were involved in 80% (41/51) of the patients in whom a tear was detected by both observers. In all 10 discrepant cases, the disagreement was whether a tear involved both the supraspinatus and infraspinatus tendons or was isolated to one or the other of these tendons.

Conclusion: The level of interobserver variability in the sonographic detection and characterization of rotator cuff tears is low.