The meniscus is a cartilage in the knee that serves an important role in knee stabilization and movement. Discoid meniscus is a congenital condition where the meniscus develops an abnormal shape. Normally, the meniscus is crescent shaped, but in patients with discoid meniscus it is more oval or disc-like. This abnormal shape makes the meniscus more prone to injury. Discoid meniscus is present at birth and affects 3-5% of the population.
Though it is present since birth, symptoms generally do not appear until children are around 9-11 years-old, on average but can also affect people younger or also much older adults. When children are young their bones and tissues are soft and flexible, but over time the meniscus can wear down and tear, resulting in pain and knee impairment. Common symptoms include knee pain, stiffness, knee giving way, and knee “popping” and locking. Discoid meniscus is diagnosed through imaging such as an MRI.
The meniscus does not heal well on its own due to the lack of a strong blood supply to bring in healing nutrients. Patients who have symptoms that do not resolve with non-operative care generally undergo a partial removal of the meniscus along with a “saucerization” procedure that attempts to remold the meniscus into a more normal crescent shape. In some cases, the meniscus may be fully removed, but this carries a risk for early arthritis for the child. Patients usually can go home the same day after the surgery.
Generally, only one surgery is needed as discoid meniscus does not re-develop post-surgery. A very high percentage of patients report good or excellent results with partial removal and “saucerization” procedures. Patients may even resume playing sports after surgery.