The seriousness of a meniscus tear depends on which one in injured and the location, type, and shape of the tear. When a meniscus tear occurs, is it usually the medial rather than the lateral meniscus that is damaged. This is because the lateral meniscus, unlike the medial meniscus, has a section that is not attached to the wall of the knee joint. This makes it more likely to move rather than tear when abnormal force hits it. Therefore, the medial meniscus takes most of the impact and is more likely to tear.
Because a good blood supply is critical in healing, location of the tear impacts its ability to heal. A meniscus tear on the outer part of the meniscus and knee joint will receive a good supply of blood, which greatly enhances the ability of the tear to heal. A tear that occurs between the outer and middle part of the meniscus, which includes the outside rim and center of the meniscus, heals less quickly because the blood supply to the inner part of the tear is less ample. People who experience a meniscus tear in the middle and inner part of the meniscus can expect poor healing, as little blood reaches this area.
There are three main types of meniscus tears.
- Partial meniscus tear is one in which the meniscus is still connected to the front and back of the knee. Because this type of meniscus tear does not move freely, it sometimes heals well on its own.
- Complete meniscus tear is one in which the tissue separates from the meniscus and can move in the joint. This type of meniscus tear is usually larger than a partial tear and can result in further damage if not treated.
- Degenerative meniscus tear has frayed edges on the inner rim, which may tear in many directions and result in a completely degenerated meniscus.