The meniscus is a C-shaped piece of fibrocartilage located in the knee. It acts as a shock absorber between the shin bone and the thigh bone. There are two (2) menisci within each knee. The meniscus on the inside part of the knee is known as the medial meniscus and the meniscus located on the outside of the knee is referred to as the lateral meniscus. A meniscus tear may be the result of an activity that forcefully twists or rotates the knee such as while playing sports or a traumatic fall. The meniscus tear can also occur without any type of traumatic event. This typically occurs in an older patient population given the fact that the meniscal tissue degenerates with age and therefore tearing can occur as part of the aging process. These degenerative type meniscus tears typically are associated with osteoarthritis of the knee.
Symptoms of a Meniscus Tear
Meniscus tears can result in pain and swelling in the knee. If the torn meniscus tissue is mobile, it may cause popping, clicking, catching, or even locking (when the knee is stuck in a position). If the meniscal tear occurs related to trauma, the patient’s knee becomes swollen and stiff within a few days. Patients may also have difficulty with bending their knee or with weight-bearing. The most common symptoms of meniscal tears include:
- Joint line pain
- Catching, clicking and locking
- Difficulty with flexing or straightening the knee
- Pain with weight-bearing
Diagnosis of a Meniscus Tear
A meniscus tear is typically diagnosed after a complete evaluation by taking a thorough history and performing a physical examination. Findings on examination include:
- Tenderness over the affected joint line
- Pain with flexing and rotating the knee (Mcmurray maneuver)
- Re-creates the catching of the torn meniscus
- Limited ability to straighten the knee
- Swelling in the knee joint (a.k.a. effusion)
Diagnostic testing includes plain x-rays to assess for osteoarthritis of the knee as well as any other conditions that could be causing pain in the knee such as a fracture or tumor. If a torn meniscus is suspected, then an MRI is ordered to determine if meniscus is torn.
Treatment for a Meniscus Tear
Treatment depends on the severity of the patient’s symptoms, physical exam findings, and finding on imaging studies. If the meniscus tear is not causing restriction of motion or significant mechanical type symptoms such as catching or locking, than typically a meniscus tear can be treated conservatively at first. This conservative treatment includes rest, ice, oral anti-inflammatory medication, cortisone injection and a home exercise program/physical therapy. If symptoms continue despite these conservative measures, surgery may be necessary. In the case of surgery, the meniscal tissue may be removed via arthroscopy (small poke hole incisions where a camera assists in the surgery) or it may be amenable to repair with stitches depending on the location of the tear, size of the tear and quality of the tissue. Meniscal repair is performed if it is felt that the meniscus has the ability to heal. Many meniscal tears occur in an area that has no ability to heal and therefore requires removal. This can be done based on the MRI image but sometimes the decision is made at the time of arthroscopy when the meniscus is viewed directly. A special case is when a patient has significant arthritis in association with a meniscus tear. Typically, surgical treatment in this case has been found to be uncertain in regards to outcome if done solely for pain. Surgery is generally reserved for patients with significant arthritis and a meniscus tear when they are experiencing mechanical type symptoms such as catching and locking.
Following arthroscopy, patients are allowed to weight-bear as tolerated. In the case of meniscal repair, they will require the use of a brace for about six (6) weeks. In the case of meniscal tissue removal only, then no brace is necessary. Patients can start a home exercise program or physical therapy right after the surgery. Rehabilitation and improvement can occur over the course of several weeks.