Ultrasonographic evaluation of the rotator cuff after shoulder arthroplasty

Objective: Ultrasonography of the rotator cuff tendons is a standard imaging technique. Although increasing numbers of shoulder arthroplasty are performed, there is no available data concerning the use of ultrasound after shoulder replacement. Our experimental study was performed to analyse the value of ultrasonography after shoulder arthroplasty a) in an ex-vivo-setting and b) in a retrospective analysis of our patients after shoulder hemiprothesis.

Methods: After defrosting, anatomic modular humeral head replacement was performed in four fresh-frozen specimens with intact rotator cuffs. The supraspinatus and subscapularis tendons of each specimen were either detached to simulate a cuff defect or reattached anatomically (four times per specimen). Two experienced examiners then performed ultrasonography to evaluate the two tendons to be either intact or deficient. In a retrospective study, 22 patients with 25 hemiprotheses of the shoulder underwent clinical and sonographic examination. For documentation of the clinical findings, the Constant score was used.

Results: In the cadaver study, the reliability of the method was slightly higher for the subscapularis tendon (13 correct, 3 false results) than for the supraspinatus tendon (12 correct, 4 false results). In our patients, rotator cuff defects and effusions around the biceps tendon and in the subdeltoid bursa could be detected. Normal sonograms correlated with good clinical results.

Conclusions: In the cadaver study, we found a good reproducibility of in-vivo conditions. We believe that ultrasonography is beneficial in follow-up evaluation after shoulder arthroplasty.