The menisci have a blood supply only in their peripheral border so that they lack the capacity to heal even if they are surgically sewn together unless the tear is this peripheral portion. When the tear is at the periphery, meniscal repair can be performed. However, most of the time, the torn portion must be removed to prevent damage to the articular cartilage. This is call meniscectomy.
If a small portion of the meniscus is removed, say one third or so, the long term prognosis is excellent. If a majority of the meniscus needs to be removed some, but not all, patients will develop damage to the articular cartilage and arthritis, as described above. This process can occur quickly or very slowly over decades. When it does we can often transplant a cadaver meniscus to alleviate pain and arrest the progress of the arthritis.
Below is a video of a menscectomy. Originally, you can see the loose and frayed material that fills the torn area. Several tools are used to remove the damaged and torn tissue. The smooth white area to the right (and behind) the meniscus are the cartilage covered tops of the bones. At the end, a U-shaped area has been removed leaving the healthy portions of the meniscus intact.
Go to our case history for patient #8 to read about a patient who had a meniscectomy performed along with other procedures.