Reversed double PCL sign: unusual location of a meniscal fragment of the knee observed by MR imaging.

A 36-year-old woman with tears of the anterior cruciate ligament and medial meniscus received a meniscectomy. The MR images obtained prior to the partial meniscectomy showed a bucket-handle meniscal tear with centrally displaced fragment lying anterior to the posterior cruciate ligament (PCL), representing a "double PCL sign"; however, after the meniscectomy, MR images demonstrated a fragment in the space posterior to the PCL where no structure is generally recognized except for the ligament of Wrisberg. This article reports a "reversed" double PCL sign, caused by inadequate surgical clearance of a bucket-handle tear of the medial meniscus.