Purpose:
To compare the diagnostic performance of a standardized ultrasound (US) to 3.0T-MRI before endoprosthetic joint replacement.
Materials and Methods:
MRI and US were performed in 45 consecutive patients before shoulder prosthesis implantation. Key evaluation criteria included the integrity of the rotator cuff, the biceps tendon and the presence of a joint effusion. The results were presented in multi-field tables, MRI was regarded as the gold standard.
Results:
The supraspinatus tendon (intact, partial rupture, complete rupture) was sonographically correctly assessed in 41/45 cases (accuracy 91.1%, kappa = 0.85, p = 0.26), no complete ruptures were missed. With regard to the infraspinatus tendon there was correspondence between US and MRI in 38/45 cases (accuracy 84.4%; kappa = 0.71, p = 0.39). No full-thickness tear of the infraspinatus tendon was missed in US. Both imaging modalities showed the condition of the subscapularis tendon consistently in 35/45 patients (accuracy 77.78%, kappa = 0.57, p = 0.88). US identified 2/4 full-thickness tears which were detected by MRI, the other two were underestimated as partial-thickness tears. With regard to the long biceps tendon (intact, tendovaginitis, rupture, dislocation) the ultrasound corresponded in 38/45 cases with the MRI diagnosis (kappa = 0.75, p = 0.32).
Conclusion:
In the present study, we could demonstrate that with US the detection of rotator cuff and biceps tendon integrity and damage is comparable to MRI before shoulder joint replacement. US is especially advantageous in revision cases where MRI quality is often reduced due to metallic implants. Furthermore, in particular patients with claustrophobia, pacemakers or other MRI exclusion criteria benefit from US diagnosis of the rotator cuff. For all patients with limited ROM especially external rotation US is just as valid as MRI for the preoperative assessment of the supraspinatus, infraspinatus and the long biceps tendon.
