Collateral Ligaments.

The collateral ligaments of the elbow are responsible for stability in response to varus and valgus stress. Injury to the collateral ligaments can be acute, but it is usually due to repetitive microtrauma. In the general population, collateral ligament injury is rare, but in the appropriate individual with the proper forces applied to the elbow, this type of abnormality is not uncommon. The elbow is the second most commonly injured joint because of overuse. Magnetic resonance imaging (MRI) is the best technique available for visualization of the ligaments. Contrast injection further enhances identification of these structures and helps to define pathological conditions affecting them. This article demonstrates some normal anatomy and shows examples of collateral ligament pathology in unenhanced and enhanced MR images.