Six Types of Meniscus Tears
Meniscus tears are a common cause of knee pain and many people end up with arthroscopic knee surgery for their condition. But is surgery always necessary? Are all meniscus tears treated the same?
In practice, a variety of factors are used to determine the ideal treatment of a meniscus tear. Some of these factors include the age of the patient, results of nonsurgical treatment, and if there is other damage than just a torn meniscus. In addition, the specific type of meniscus tear can determine the most appropriate treatment. Described here are six common types of meniscus tears.
- Intrasubstance/Incomplete Tear: An intrasubstance tear is a common finding on an MRI report. Seen in the upper left corner of the image, an intrasubstance tear typically looks normal at the time of surgery. Often these are a sign of early degenerative changes of the meniscus tissue, but seldom are they the sign of a problem. Incomplete and intrasubstance tears of the meniscus are stable injuries, and they generally do not require any surgical treatment. By the time people are in their 20s or 30s, intrasubstances changes of the meniscus tissue are very commonly seen on an MRI.
- Radial Tear: Radial tears of the meniscus, pictured in the middle of the top row on the image, are the most common type of meniscus tear. These tears are within the avascular zone of the meniscus, where there is no blood supply, and therefore there is little capacity for these tears to heal. Therefore, when these tears come to requiring surgical treatment, typically the only option is to trim out the damaged portion of the meniscus.
- Horizontal Tear: A horizontal tear is a tear that is most commonly amenable to meniscus repair. Seen in the upper right corner of the image, a horizontal tear runs along the circumferential fibers of the meniscus. Rather than removing the damaged portion of the meniscus, a horizontal tear may be able to be sewn together. The key to determining the treatment of these tears is their location. If located within the vascular portion of the meniscus (near the outer edge) then there is healing potential, and thus repair. When located more centrally, these tears will not heal, even if repaired.
- Flap Tear: A flap tear of the meniscus, pictured in the bottom left corner of the image, is an unusual pattern of the tear. In circumstances where the flap is causing symptoms of catching in the knee, usually, the flap of the meniscus can simply be removed without removing much tissue at all.
- Complex Tear: A complex tear means there is a combination of tear patterns. Shown in the middle image on the bottom row, a complex tear often involves both radial and horizontal tear patterns. Typically complex tears are not treated with meniscus repair because of the complex nature of the tear. In some unusual circumstances, some of the torn meniscus can be removed, while other portions can be repaired.
- Bucket-Handle Tear: A bucket-handle tear is a large type of horizontal tear of the meniscus. These tears often cause the knee to become stuck by causing the torn portion of the meniscus to block normal knee motion. Bucket-handle tears often require more urgent surgical treatment in order to allow the knee to start bending again.
Location of the Tear
In addition to describing the type of tear, most MRI and surgical reports will describe the location of the tear. Anterior horn tears are less common and located in the front of the meniscus. Posterior horn tears are much more common and located in the back of the meniscus. Central tears are located on the inner side of the meniscus. This is a part of the meniscus without vascular blood supply and therefore not amenable to repair. Peripheral tear s are located further on the outside of the meniscus, and these are the types of tears that can sometimes be repaired.