If you have experienced any type of injury to your knee, you may have a torn meniscus. Of course, to most of us that means absolutely nothing. So let’s break down exactly what it means to have a torn meniscus, as well as what a torn Meniscus MRI can do to help:
What is a Torn Meniscus?
A torn meniscus is a common type of injury to the knee. The meniscus is a rubbery disc, formed in the shape of a ‘C’. It is a piece of cartilage that provides cushioning to the thighbone and shinbone (or femur and tibia). Each knee has two menisci. One meniscus is on the inner edge of the knee, and the other is on the outer edge. Menisci play a large role in helping to balance our weight. If any one of your menisci has a tear, the knee may not work properly.
How can you get a torn Meniscus?
Before we jump into more information on torn meniscus MRI scans, let’s talk a little about what could cause such an injury. Meniscus tears are usually caused by twisting or turning too quickly. While they are most commonly related to sporting accidents and heavy lifting, they can also be caused by any activity that puts pressure on, or requires rotation of, the knee joint.
As you age, your meniscus starts to wear. In return, your risk of a tearing a meniscus increases as you get older. If you have weak menisci, even simple things like squatting and stepping can result in tears. Those with osteoarthritis are also at greater risk of meniscus tears.
What does a torn meniscus feel like?
The feeling of a torn meniscus will vary depending on its severity. Tears can range from minor to severe. In a minor case, slight pain and swelling may persist for up to 2-3 weeks. After this, it should begin to subside.
If you have pain at the side or in the center of your knee, and swelling gets worse over a few days, you may have a moderate meniscus tear. Most people can usually still walk with moderate tears, but you may experience stiffness of the knee and have difficulty bending it. Squatting and twisting may result in sharp pains. Moderate meniscus pains are often intermittent, residing for one or two weeks before again returning. If untreated, pain can last for years.
In a severe meniscus tear, you may lose all ability to straighten your knee. In such cases, pieces of the meniscus move into the joint space. This can lead to catching, popping, and locking of the knee. Walking can be very difficult with severe meniscus tears, and your knee may give out without any warning. Stiffness and swelling are common.
Does a Doctor use a Torn Meniscus MRI to diagnose severity?
In many cases, yes. But there are some other tests that the doctor may order first. The first test a doctor usually performs to determine if you have a torn meniscus is the McMurray test. This is a simple physical exam where the doctor will ask you to straighten, bend, and rotate your knee.
Based on the results of your McMurray test, a doctor may order an X-ray, an MRI, or both. X-rays themselves do not diagnose meniscus tears. They can, however, help to determine if there are any other causes of your knee pain. If the X-ray does not show anything, the doctor will almost certainly order an MRI.
What exactly is an MRI?
An MRI produces a 3D image of the internal structures of your knee. It does so by taking a series of photos using a magnetic field. Unlike other forms of scans, MRIs can provide more detailed photos, allowing doctors to see the cartilage and ligaments within the knee. In return, they can better determine if a meniscus tear is the cause of your pain.
Unfortunately, MRIs are not 100% accurate at diagnosing meniscus repairs. While they come close at 77% accuracy, there is a 23% chance that they will not be able to determine the cause of the pain. This is because meniscus tears can often resemble degenerate/age related changes in MRI photos. In such a case, other alternatives like ultrasounds or arthroscopy can help to further examine the cause of pain.
What happens during a torn meniscus MRI?
During an MRI, you will lay on a small table controlled by a technician. They will move your body in an out of the MRI machine (a thin, tunnel like machine) that will produce a 3D image of the inside of your knee. MRIs are painless, though they may be uncomfortable for those with claustrophobia. Given that they use strong magnetic fields, they are not suitable for those with metals in their body, or those using pacemakers. If you fall into this category, your physician will recommend a safer alternative.
In terms of safety, there are no known risks of MRI machines on their own. Having said that, physicians sometimes use contrast dyes to help distinguish some internal structures from others. In such a case, allergic reaction is a possibility. In most cases, reactions are minor and easily treated with medications.
The process of receiving an MRI generally takes between 30 minutes to 1 hour.
What happens if the MRI shows a meniscus tear?
If your doctor has determined that you do, in fact, have a meniscus tear, there are several different treatments they may prescribe. In terms of minor tears, rest, ice, compression, and elevation are usually the recommended course of treatment. Doctors may also suggest that you take an over the counter pain killer to help reduce pain and swelling.
In more moderate tears, your doctor may suggest physical therapy to help increase mobility and stability. Massage can also help to reduce swelling and stiffness. If your torn meniscus MRI shows more severe tears that are not responding to above treatments, surgery may be necessary.