Meniscal Root Tear Overview
The meniscus is a very important piece of cartilage in the knee. It is shaped like a “C” and it serves to cushion and stabilize the knee. In recent years the importance of the meniscus “root” has become more apparent.
The meniscus has 3 main zones, the 1) posterior horn, the 2) body, and the 3) anterior horn. Each horn is anchored to the bone at the meniscus root (anterior and posterior). When you put weight on your leg, it is the meniscal roots that transfer the axial loading forces of the knee into hoop stress in the meniscus. This hoop stress is resisted by fibers that run circumferentially through the meniscus.
When a tear of the meniscal root, or even a tear near the root, occurs, the meniscus can no longer convert axial loading forces into hoop stresses. Thus, the entire weight of the body is transmitted through the femur into the cartilage of the knee. This results in premature arthritis and cartilage damage in the knee.
For this reasons, it is crucial to identifiy and treat meniscal root tears in a timely manner. Unlike some meniscus tears which can be observed or treated conservatively, most meniscus root tears need surgery. Fortunately, this is usually done arthroscopically and with good results.
Treatment of Meniscal Root Tears
The most common method to fix meniscus root tears is through a tibial bone tunnel. Sutures are passed through the meniscus, and then pulled down into a bone tunnel located at the same site as the root attachment before it tore. This allows the meniscus to heal back to the bone. Studies have demonstrated that this type of repair technique restores similar shock-absorbing and cushioning function as normal meniscus before it tore. Proper fixation of the meniscal root can prevent or slow down the development of arthritis in that area of the knee.
Signs and Symptoms of a Meniscus Root Tear
A torn meniscus can result in either sudden or gradual onset of pain. There is often swelling of the knee and severe pain with walking, running, twisting, or moving the knee. The pain is usually located one the sides or front of the knee, although it can occasionally be located in the back of the knee. Some patients may experience catching, clicking, or locking of their knee.
Treatment of a Meniscus Tear
Many meniscus tears can be treated successfully without surgery. The RICE (rest, ice, compression, elevation) principle can be useful in the first several days after a meniscus tear to help reduce inflammation, swelling, and pain. Physical therapy exercises can help to improve muscle strength, knee range of motion, and decrease sensitivity to the pain.
Most patients with meniscal root tears will ultimately need surgical fixation of the root. MRI is used to look more closely at the meniscus and determine if it is something that needs surgical treatment, although not all meniscus root tears show up on MRI.
What Should You Do if You Think You Have a Torn Meniscus?
If you think you may have a meniscus tear, it is recommended that you see a sports medicine physician as soon as possible. Many tears have better outcomes if they are treated early. A sports medicine specialist will examine your knee and any relevant imaging to determine which treatment you should start with first. Identifying and properly treating meniscus tears (with or without surgery) will lead to the most rapid reduction in your symptoms and is crucial to optimize the long term health of your knee.
Additional Resources About Meniscus Tears
- Meniscal Ramp Lesions. Arner, J.W., Herbst, E., Burnham, J.M. et al. Knee Surg Sports Traumatol Arthrosc (2017) 25: 3955. https://doi.org/10.1007/s00167-017-4523
Meniscal Root Repair Article. Malempati C, Burnham JM, Johnson DL. 2017