Sonographic assessment of ulno‐humeral joint instability.

The ulnar collateral ligament (UCL) of the elbow plays a crucial role in elbow stability, specifically as a valgus and rotational constraint. Injuries to the UCL are common in overhead‐throwing athletes resulting in elbow instability. A timely diagnosis of early ulno‐humeral joint space widening in the overhead‐throwing athlete is required, to inform patient management and return to play. Sonographic assessment and measurement of the ulno‐humeral joint space with and without stress, and comparison to the contralateral uninjured side provides a quantitative assessment of instability. A systematic sonographic technique for single operator stress ultrasound is outlined to improve consistency of assessment and reporting of findings. [ABSTRACT FROM AUTHOR]