Abnormality of the crus of the helix Horizontal crus of helix 2009-04-30T10:34:52Z Horizontal orientation of the crus of helix Horizontal orientation of the ear crus HP:0009897 Railroad track ears The term 'railroad track sign' has been used to describe prominent horizontal crus of the helix in combination with prominent and parallel inferior crus of the antihelix. It is preferable to simply describe each component separately. Helix, crus, horizontal Railroad track sign An abnormal horizontal axis orientation of the crus of the helix. That is, the main axis of the crus of the helix is perpendicular to the medial longitudinal axis of the ear, instead of sloping inferoposteriorly. UMLS:C4021379