The double flipped meniscus sign: Unusual MRI findings in bucket-handle tear of the lateral meniscus

Abstract

Bucket-handle meniscal tears are either longitudinal, vertical, or oblique in direction with an attached tear fragment displaced from the meniscus. Magnetic resonance imaging (MRI) signs are widely used in the diagnosis of these tears, including the 'fragment within the intercondylar notch sign', 'flipped meniscus sign', 'double anterior horn sign', 'absence of the bow tie sign', 'double posterior cruciate ligament (PCL) sign', 'posterior double PCL sign', and 'triple PCL sign'. We report an unusual case, not yet described in previous studies, of a bucket-handle tear presenting as a double longitudinal tear of the lateral meniscus (LM). Two longitudinal tears were observed in the white-white zone and the red-white zone of the LM, where both fragments were shown to be displaced and locked within the intercondylar notch. Partial menisectomy was performed for the central fragment and a repair with modified all-inside sutures was performed for the peripheral fragment.

Spontaneous Healing of a Displaced Bucket-Handle Tear of the Lateral Meniscus in a Child

“…There is various nomenclature that describes this characteristic, such as recurrent subluxation of the lateral meniscus, popliteo-meniscal fascicle tear, hypermobile posterior horn of the lateral meniscus, and MRI negative bucket handle tear of the lateral meniscus3,4).…”

“…However, the lateral meniscus is relatively loosely attached to the capsule that is interrupted by the popliteal hiatus, which allows it to be quite mobile. Therefore, the posterior horn of the lateral meniscus is susceptible to subluxation resulting in a displaced bucket handle tear3,4). We report a rare case of a child with a displaced bucket-handle tear of the lateral meniscus in the stable knee that healed spontaneously without any surgical procedures.…”

Common Mistakes and Pitfalls in Magnetic Resonance Imaging of the Knee

“…MRI signs on sagittal images include the double posterior cruciate ligament (PCL) sign [ 19 ] and absent bow tie sign [ 20 21 ]. MRI signs on coronal images include the fragment-in-notch sign [ 22 ], the flipped meniscus sign [ 23 ] or a centrally located meniscus fragment.…”

Self-Reduction of Displaced Bucket-Handle Medial Meniscal Tear in a 71-Year-Old Patient

“… 3 – 7 Bucket-handle tears occur more commonly in the medial meniscus than in the lateral meniscus. 3 , 5 , 7 , 8 …”