Pre-operative departmental ultrasound of the rotator cuff: sensitivity and specificity in a regional specialist orthopaedic centre.

BACKGROUND: The present study aimed to assess the accuracy of radiology department ultrasound scans in identifying rotator cuff tears at our institution, a regional specialist orthopaedic centre.
METHODS: Pre-operative ultrasound scan reports were obtained from 64 consecutive patients who subsequently underwent arthroscopic subacromial decompression and/or rotator cuff repair. The ultrasound reports were compared with the arthroscopic findings as a reference standard.
RESULTS: If both full- and partial-thickness tears are counted as true positives, ultrasound has a sensitivity of 70%, a specificity of 67% and a positive predictive value of 81%. If only partial tears are counted as true positives, sensitivity decreases to 8% and positive predictive value to 10%. The mean time lag from scan to surgery was 44 weeks.
CONCLUSIONS: A positive pre-operative ultrasound scan at our institution predicts an actual rotator cuff tear in 70% of cases. However, it is not accurate with respect to identifying partial-thickness tears or distinguishing them from full-thickness defects. Ultrasound scanning is highly operator dependent and, in addition, its accuracy may be affected by the lengthy time period from scanning to surgery. Clinicians should be cautious in proceeding to surgery based on the ultrasound findings.