Sagittal T1 weighted MRI of the knee through the intercondylar notch reveals a fragment of torn meniscus, which appears as a low-signal intensity, longitudinally oriented band lying beneath and parallel to the PCL, creating a double cruciate configuration. This is referred to as the double PCL sign. This sign of a bucket-handle tear on MRI relates to the peripheral (bucket) portion of the meniscus and the displaced inner fragment (handle) portion. The inner fragment can be displaced for a variable distance over the tibial plateau surface. If displaced as far as the intercondylar notch, in the case of the medial meniscus, the inner fragment can come to lie between the PCL and the underlying tibia.
Reference
Weiss KL, Morehouse HT, Levy IM: Sagittal MR images of the knee: a low-signal band parallel to the posterior cruciate ligament caused by a displaced bucket-handle tear. AJR Am J Roentgenol 1991 Jan;156(1):117-9.
Ruff C, Weingardt JP, Russ PD, Kilcoyne RF: MR imaging patterns of displaced meniscus injuries of the knee. AJR Am J Roentgenol 1998 Jan;170(1):63-7.
