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

PURPOSE: To assess the Value of ultrasonography (US) in the preoperative ev aluation 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 approach es: two frontal and one axillary. The anterior labrum, the anterior ligamen tal-capsular complex, and the presence of humeral head and glenoid rim frac tures 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 glen oid 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 com plex was correctly evaluated in 14 patients. The use of multiple approaches helped to prevent misinterpretation, but there were no substantial differe nces among the approaches in the depiction of the anterior shoulder structu res. CONCLUSION: The high accuracy in the depiction of labral tears and associat ed fractures indicates that US can provide useful preoperative information in patients with anterior shoulder instability.