Inferiorly displaced flap tears of the medial meniscus: MR appearance and clinical significance.

OBJECTIVE: We describe the MR imaging features of medial meniscus flap tears in which the fragment becomes located inferomedial to the tibial plateau and deep in relation to the medial collateral ligament.

CONCLUSION: Inferior flap tears of the medial meniscus can be inconspicuous and overlooked by both radiologists and orthopedic surgeons. Inferiorly displaced meniscal fragments may escape detection during arthroscopic surgery unless the fragment is sought with a probing hook. Recognition of this meniscal abnormality on MR imaging is important for preoperative planning.