Inferiorly Displaced Flap Tear of the Medial Meniscus Sonographic Diagnosis

Meniscal tears may result from acute trauma or repetitive trauma leading to progressive degeneration. Acute tears often occur after a single traumatic event in younger, physically active patients. Chronic repetitive trauma is common in middle-aged and older patients, either athletes or nonathletes, with the patients often unaware of when the tear occurs. The medial meniscus is much more frequently involved than the lateral meniscus.(1) Magnetic resonance imaging (MRI) is considered the reference standard for noninvasive assessment of meniscal tears. Assessment of menisci with sonography has been more limited and is presumably not ideal. Nevertheless, the sonographic features of meniscal tears have to be known because these lesions may be encountered during evaluation of knee pain. The aim of this report is to describe the sonographic findings of a meniscal flap tear inferiorly displaced in the medial meniscotibial recess. To the best of our knowledge, such a description has never been reported. This sonographic feature is all the more interesting because it was not clinically suspected.