Which types of the discoid meniscus are more common – medial or lateral?
Lateral discoid meniscus.
What is the most common tear pattern in discoid meniscus?
A degenerative horizontal cleavage tear, they comprise > 58% of tears in symptomatic discoid menisci.
Findings:
Small knee joint effusion.
Intercondylar region:
- unremarkable anterior and posterior cruciate ligaments
Medial compartment:
- unremarkable cartilage and medial meniscus
- normal medial supporting structures and ligaments
Lateral compartment:
- small discoid lateral meniscus with horizontal cleavage tear and anterior shift
- anteroinferior meniscopopliteal ligament not readily definable
- posterosuperior meniscopopliteal ligament visible but ill-defined
- very thin meniscofemoral ligament of Wrisberg
Patellofemoral compartment:
- unremarkable retro-patellar and trochlear cartilage
Impression:
Discoid lateral meniscus with horizontal cleavage tear, anterior shift and suspected meniscocapsular detachment.