Magnetic resonance imaging appearance of a double anterior cruciate ligament associated with a displaced tear of the lateral meniscus.

The aim of this study is to report a novel description of a displaced tear of the lateral meniscus as a curvilinear low signal intensity band parallel and posteroinferior to the anterior cruciate ligament (ACL) on midline oblique sagittal magnetic resonance (MR) images, resulting in the appearance of a "double ACL." The appearance of a double ACL may potentially be a specific indicator for a lateral meniscal displaced tear. Increased awareness of this characteristic MR finding may increase accuracy in the diagnosis of displaced tears of the lateral meniscus.