A torn meniscus often does not require surgery

September 18, 2008

     As it turns out it is a common finding to discover damage to the meniscus when an MRI is performed on a middle-aged or elderly person. However, although there may also be knee pain, frequently the damage to the meniscus is not the cause (or at least not yet a contributor). The problem is the physician will often order arthroscopic surgery for the patient without searching for other causes for their pain; the blame is placed on the meniscus damage and a needless procedure is performed.
      The meniscus refers to two shock-absorbing wedges of cartilage directly below each knee. In most cases there is no symptom caused by the tear in the meniscus the researchers’ report (however a different recent study demonstrates that once there is substantial damage to the meniscus it is not very long afterwards before arthritis appears in the corresponding knee). Understand that arthroscopic surgery is a surgical procedure and involves risks. These risks include infection, blood clots, problems with anesthesia, etc, just like any other surgery..
     According to an accompanying editorial, meniscal tears and knee pain can often coexist but the meniscal tear may not be the cause of the pain and doctors should look for other causes of the pain, often caused by arthritis, before contemplating surgery to address the tear.
     To determine the frequency of meniscal damage and its association with knee pain and stiffness, Dr. Martin Englund, at the Boston University School of Medicine studied MRI scans of the right knee of 991 randomly selected, ambulatory adults, between ages 50 and 90, living in Framingham, Massachusetts. The MRI scans revealed meniscal damage in 35 percent of subjects. Damage to the meniscus was more common among men than women, and increased with age, affecting more than 50 percent of subjects over the age of 69. Often the meniscal tears were in people who experienced no knee pain or stiffness in the previous month, the authors report.
     Knee X-rays were performed for 963 of the subjects to look for arthritis. The authors found that up to 63 percent of subjects with arthritis had meniscal tears compared with no more than 32 percent of subjects without arthritis so there was a strong connection. They determined that although a meniscal tear may signal early arthritis, Englund's team points out, "other structures or processes...may be causing the pain," such as joint inflammation or bone marrow lesions. Surgical removal of the meniscus, a common procedure, is unlikely to have much effect on symptoms in patients with arthritis, they add.
     "Identifying a tear in a person with knee pain does not mean that the tear is the cause of the pain," Dr. Robert G. Marx, from Weill Medical College of Cornell University in New York, emphasizes in a Journal editorial. There are about 1,000,000 of these surgeries performed yearly in the US and according to this study many of these procedures are performed needlessly. "Although arthroscopic surgery has been widely used for osteoarthritis of the knee, scientific evidence to support its efficacy is lacking," Dr. Robert B. Litchfield, from the University of Western Ontario in London, and colleagues note (not to mention the procedure costs about $ 7000.00). The study is published in the September 11, 2008 issue of the New England Journal of Medicine.

Note: Arthroscopic surgery is done by making small incisions in the knee so an instrument called an arthroscope can be inserted. A small camera is attached to the tip of the pencil-size arthroscope to transmit images to a monitor to visualize the inside of the knee. The surgeon can then insert surgical instruments through the small incisions to repair or remove damaged tissue.