Role of us in the preoperative evaluation of patients with anterior shoulder instability

PURPOSE: To assess the value of ultrasonography (US) in the preoperative evaluation of patients with anterior shoulder instability. MATERIALS AND METHODS: Twenty-two patients with one-sided anterior shoulder instability were examined with US by using three dynamic scanning approaches: two frontal and one axillary. The anterior labrum, the anterior ligamental-capsular complex, and the presence of humeral head and glenoid rim fractures were evaluated. Arthroscopy or arthrotomy was subsequently performed in all patients and was considered the standard. RESULTS: US correctly depicted the presence (n = 20) or absence (n = 1) of humeral head fractures and the presence (n = 10) or absence (n = 9) of glenoid rim fractures. All 22 patients had anterior labral tears; 21 tears were correctly depicted with US. The labral tear was seen as a hypoechoic zone larger than 2 mm (n = 15), labral movement (n = 10), a degenerated labrum (n = 6), or a vacuum phenomenon (n = 3). The anterior ligamental-capsular complex was correctly evaluated in 14 patients. The use of multiple approaches helped to prevent misinterpretation, but there were no substantial differences among the approaches in the depiction of the anterior shoulder structures. CONCLUSION: The high accuracy in the depiction of labral tears and associated fractures indicates that US can provide useful preoperative information in patients with anterior shoulder instability.