Ultrasonography of the annular ligament partial tear and recurrent "pulled elbow".

A 2-year-old boy had multiple episodes of radial head subluxation, recurrent "pulled elbow." On initial ultrasonography, there was subluxation of the radial head in relation to the capitellum, and the annular ligament was partially disrupted. Following brace treatment, subluxation of the radial head was corrected and annular ligament disruption healed. As shown by ultrasonography, these findings correlated well with the clinical course and can be utilized to guide treatment.