What is a meniscus? -by Vic Goradia, M.D.

A type of 'rubbery' cartilage that acts as a shock absorber in the knee. There are two in each knee- one on the inside (medial meniscus) and one on the outside (lateral meniscus). They are located between the thigh bone (femur) and the leg bone (tibia).

Where is the meniscus?

How does a meniscus tear?

Most meniscus tears occur when a twisting type of torque is applied to the knee joint. Menisci are often torn when a major ligament is injured e.g. the anterior cruciate ligament (ACL). However, in most cases meniscal tears are isolated. As one ages, the meniscus loses water content and becomes less “rubbery” and can tear with little effort.

Will the meniscus tear heal?

Most meniscus tears do not heal without surgical treatment. However, some small meniscus tears or incomplete tears may stop hurting and not require surgery in the short-term. Repeat injury could cause the tear to become larger and ultimately require surgery.

What type of surgery is needed for a meniscus tear?

Meniscal tears can be treated with arthroscopic surgery through two small skin punctures. Most tears are in the inner 2/3 of the meniscus- they have no blood supply and thus no potential for healing. These tears require excision of the torn segment. Tears in the outer 1/3 have healing potential and can be repaired.

Will all of my symptoms go away?

If you have an isolated meniscal tear, the arthroscopic procedure should relieve your symptoms. The advantage of arthroscopy is that everything else in the knee can also be examined. If there is damage to the articular cartilage, the symptoms associated with this damage may improve after surgery but will not go away completely.

What is articular cartilage?

It is the white, hard, shiny material at the ends of bones. Along with the menisci, articular cartilage also protects the joint. With injury, normal aging or rheumatalogical diseases, the cartilage can be worn away leaving bone on bone within the joint.

Can you tell if the articular cartilage is damaged before surgery?

If there is severe damage (i.e. arthritis), the x-rays will show it. However, you can have significant amounts of cartilage degeneration that will not be seen on x-rays.

What about an MRI? An MRI can identify meniscus tears and cartilage damage but only arthroscopy can accurately determine the extent of damage and simultaneously provide treatment.