A meniscus is a cartilage structure that provides shock absorption and cushioning in the knee joint. There are two menisci. They are located in between the thigh bone (femur) and the shin bone (tibia). Meniscus tears are very common among tennis players. They are often the result of a twisting injury.
When a patient has a torn meniscus, he or she usually complains about sharp pain in the knee. A torn meniscus is similar to a hangnail. The same way that a hangnail can catch and cause discomfort, a torn meniscus can catch and get pinched between the bones in the knee during regular activities causing pain. Torn menisci can occur as a result of a singular traumatic event, such as an abrupt twist of the knee, or as the result of many years of wear and tear.
To diagnose a meniscus tear, a doctor will take a history and perform a physical examination. X-rays and an MRI are usually ordered. X-rays show the bones of the knee but do not show the meniscus. The MRI shows the meniscus and any possible tears. Other causes of knee pain in addition to meniscus tears include ligament tears, such as a torn ACL, sprains and arthritis. These are elucidated by the X-rays, exam and MRI, and are treated differently than meniscus tears.
The majority of meniscus tears do not heal on their own. Therefore, surgery is often recommended. Surgery for a torn meniscus is performed arthroscopically. Arthroscopic surgery uses small incisions and small tools, about the size of a pencil, to perform the procedure. All the work is visualized with a small camera, the arthroscope. The surgeon sees inside the knee with the arthroscope and its images are projected on a video screen.
The torn meniscus fragment is removed and the remaining meniscus is trimmed. Occasionally, the meniscus is torn in such a way that it can be sewn back in place and will heal if stitches are placed across the tear. However, the majority of meniscus tears are treated by removing the torn fragment.
Even though a portion of the meniscus is removed in these procedures, a significant portion of a normal intact meniscus is left behind. While it does not function in the way that it did prior to the injury, a significant amount of its function is still retained.
Recovery after meniscus surgery depends upon whether a repair or a partial meniscus removal was performed. If a partial meniscus removal is performed, then a patient can usually resume his or her normal activities within several weeks of surgery. If a repair is performed, weight-bearing restrictions may apply and crutches may be needed. Additionally, the patient may be restricted from returning to sports until appropriate healing has taken place. Rehabilitation with physical therapy may be necessary, and if so, it will be prescribed by the surgeon.