Discoid Meniscus

Excerpt

The menisci are 2 crescent-shaped structures in the knee that act as shock absorbers between the femur and tibia, dissipating stress and dispersing compressive loads. They are fibrocartilaginous structures, mainly composed of type I collagen, whose functions include force transmission, increased joint congruency, and secondary stabilization of the knee. The medial meniscus is typically C-shaped and intimately in contact with the surrounding capsule. The lateral meniscus is more circular in shape and has increased mobility due to fewer capsular attachments.

A discoid meniscus is an anatomical variant of the normal crescent-shaped meniscus. It is often thicker and is disc- or saucer-shaped. These variants are more commonly susceptible to injury compared with a normally shaped meniscus. When these variants are present and symptomatic, they can often lead to pain and a popping sensation within the knee, commonly referred to as “popping knee syndrome." Three types of discoid menisci have been well described in the literature based on the pattern of the meniscus: complete, incomplete, and Wrisberg variant. Management consists of observation versus arthroscopic saucerization with or without meniscal repair based on the morphology and patient presentation.