Medial displacement of the biceps brachii tendon: evaluation with dynamic sonography during maximal external shoulder rotation.

PURPOSE: To determine the value of the sonographic subluxation test--dynamic scanning of a shoulder during maximal external rotation--in the evaluation of medial displacement of the biceps tendon. MATERIALS AND METHODS: The subluxation test was performed during shoulder sonography in 1,210 patients, 284 of whom subsequently underwent surgery (152 men and 132 women aged 24-77 years [mean, 52 years]). Subluxation or displacement of the biceps tendon was surgically confirmed in 21 of the 284 patients (16 men and five women aged 35-57 years [mean, 48 years]). The sonographic and surgical findings in these 21 patients were analyzed. RESULTS: The subluxation test helped detect 12 of 14 (86%) cases of subluxation. Static scanning (without the subluxation test) depicted six of seven (86%) cases of dislocation. The test failed or could not be performed in 18 of the 284 (6%) patients; however, no false-positive findings occurred. CONCLUSION: The subluxation test is reliable in the diagnosis of subluxation of the biceps tendon and should be performed during shoulder sonography.