Disc-shaped meniscus

The menisci are two crescent-shaped fibrocartilaginous elastic structures, which are inserted between the articular surfaces of the femoral and tibial condyles, intended by Nature to absorb shocks.

Disc-shaped meniscus is an abnormal anatomical variation of the meniscus, which acquires a disc-shaped shape, is thickened and larger in surface area than normal. Its frequency in the population is 3-5% and in the majority of cases it concerns the lateral meniscus, while in 1 in 4 “sufferers” it also appears in the other knee.

Discoid meniscus

There are 3 types of discoid meniscus:

Type I: complete

Type II: incomplete

Type III: unstable (Wrisberg) with a more normal shape, but without peripheral adhesions, therefore more mobile and prone to ruptures and associated with mechanical symptoms or even audible sound in the knee, especially during extension.

Symptoms may appear from childhood or in young adolescents and athletes. They include pain, joint fluid, audible clicking in the knee, difficulty flexing – extending and/or episodes of “locking” of the knee.

Age, symptoms and some findings on plain radiography (e.g. widening of the interarticular space) are indications of the condition, while MRI is conclusive and the examination of choice for diagnosis.

Treatment of asymptomatic discoid menisci is simple observation. On the contrary, when they become symptomatic, arthroscopy is performed with partial meniscectomy and shaping of the meniscus to resemble the normal one. Unstable, hypermobile types of discoid meniscus should be fixed with sutures, aiming for a stable meniscus rim, while the previously applied total removal is now avoided as a highly burdensome condition for the knee joint.