Fact-sheet: Meniscal tear
Updated on 08/25/2020 at 5:01 PM
View all RADEOS cases associated with this fact-sheet
Definition
Discontinuity within a meniscus.
Meniscal tears are classified according to the orientation of the tear and its location:
- Vertical tear
- Complex tear (visible cleavage plane, combination of two tear patterns)
- Oblique tear
- Horizontal tear
- Radial tear
Ultrasound
Ultrasound visualization of the menisci remains challenging.
- Hyperechoic line, more echogenic than the meniscus itself.
- Hypo- to anechoic area due to fluid effusion tracking into the meniscal tear.
Parameniscal cysts may however be observed, appearing as an anechoic cystic formation adjacent to the meniscus, and meniscal extrusion should be looked for
MRI
Tears appear as a linear area of hyperintensity on T2-weighted or T1-weighted sequences after intra-articular gadolinium injection (MR arthrography)
- A vertical tear is parallel to the meniscal periphery. It may be complete -i.e. extending from the superior to the inferior surface- or partial if it involves only one articular surface.
- A bucket-handle tear is an unstable vertical tear whose inner fragment may displace into the intercondylar notch
- A horizontal tear is parallel to the articular surfaces. Most often degenerative in origin, the articular surface it communicates with should be specified
- An oblique tear is an oblique linear area within the meniscus
- A radial tear is a vertical tear perpendicular to the free edge of the meniscus, which may be partial or extend completely to the meniscal periphery
- A meniscocapsular separation is a peripheral tear with disruption of the peripheral meniscal attachments to the capsule
Differential diagnosis
Normal variants:
- Superior recess at the posterior horn of the medial meniscus
- Popliteal hiatus
- Transverse ligament
- Meniscofemoral ligaments of Wrisberg and Humphrey
- Soft tissue between the capsule and the medial meniscus
Meniscectomy
Grade I or II degenerative meniscal lesion
Discoid meniscus