Sagittal MR images of the knee: a low-signal band parallel to the posterior cruciate ligament caused by a displaced bucket-handle tear.

A low-signal band parallel and anterior to the posterior cruciate ligament has been noted on sagittal MR images of the knee in some patients with other evidence for medial meniscal tears. It was hypothesized that this low-signal band represented the mesially displaced fragment of a bucket-handle tear. To verify this, we retrospectively reviewed MR and arthroscopic findings in 54 consecutive patients. Arthroscopy showed a bucket-handle tear of the medial meniscus in seven patients and was considered diagnostic. Sagittal MR images were reviewed without knowledge of the arthroscopic results. The presence of a curvilinear low-signal band above the tibial cortex anterior, inferior, and parallel to the posterior cruciate ligament was identified on MR images in all seven of the patients in whom the presence of a bucket-handle medial meniscal tear was confirmed by arthroscopy. Our findings suggest that a low-signal band anterior and parallel to the posterior cruciate ligament on sagittal MR images of the knee is caused by a mesially displaced bucket-handle tear of the medial meniscus.