Pseudodefect of capitellum

Radiopaedia • CC-by-nc-sa 3.0 • de

Pseudodefect of capitellum refers to an abrupt contour change of the posterolateral margin of capitellum on coronal sections and is a potential MRI imaging pitfall giving rise to misinterpretations. It occurs because the width of the articular surface of the capitellum is non-uniform and gradually tapers posteroinferiorly.

Differential diagnosis

osteochondral defect
- occurs most commonly on the anterolateral aspect, not on the posterolateral aspect like pseudodefect
- can have other pathological features like marrow edema or fluid-filled cysts