Sonography as a tool for identifying engaging Hill-Sachs lesions: preliminary experience.

Engaging Hill-Sachs lesions can be a factor predictive of recurrent anterior shoulder instability, yet no method has been recognized as an effective means to predict engagement. We evaluated the ability of sonography to identify engaging Hill-Sachs lesions by using a transaxillary approach and dynamic scanning. In patients with engaging lesions, there was an abrupt change in the contour of the humeral head when the shoulder was in 90° of abduction and 90° of external rotation. Sonography therefore has the potential to be a useful preoperative tool in determining which patients may benefit from a surgical repair that also addresses Hill-Sachs lesions.