Meniscus tears occur frequently. Some meniscus tears are age-appropriate. Some are due to trauma or injury. The most common location for a meniscus tear is the posterior horn of the medial meniscus.
You’ve read your MRI report, and naturally, you’re concerned. Many Orthopedic Surgeons consider certain posterior horn meniscus tears to be a normal age-appropriate change. Wait? What? Yes, certain meniscus tears are simply part of the wear and tear process. Many posterior horn meniscus tears are found in people without knee pain. But some meniscus tears do cause pain. How do we determine which meniscus tears may need surgery and which can be treated without surgery? This post will dive deeper to answer your questions about tears of the posterior horn of the medial meniscus.
Despite being considered a common age-appropriate change, some meniscus tears can be a cause of knee pain. Many of you will recover from this episode of knee pain without surgery, yet some of you might be considered a good candidate for surgery. How do we differentiate the two?
All meniscus tears are not viewed in the same manner. All meniscus tears are not treated the same. Some of us run every day with known posterior horn tears. Therefore, certain meniscus tears can be safely ignored, yet some we may want to fix immediately? We will discuss all this in more detail.
How does the meniscus work?
The meniscus is a C-shaped cartilage disk that is found in the knee. We have two menisci in either knee. We have the medial meniscus on the inner side of the knee and the lateral meniscus on the outer side of the knee. See this post to learn more about how a meniscus functions.
The menisci serve a critical function in the knee as a shock absorber or cushion. This helps minimize the stress on another type of cartilage in the knee, which we call the articular cartilage. If you look at the image below, you see the meniscus in light blue. As the femur or thigh bone pushes down towards the tibia, the meniscus accepts a lot of the force. It deforms or pushes outward and dissipates a lot of the force from the femur before the femur contacts the tibia. This is how the meniscus protects the articular cartilage.
The articular cartilage coats the ends of our bones within a joint. If the articular cartilage wears away, arthritis will occur. By protecting the articular cartilage, the meniscus helps prevent the onset of arthritis. As you can see below, if the articular cartilage is subject to too much force or load due to a meniscus tear then the cartilage can start to degenerate.
Causes of Posterior Horn Meniscus Tears
People can develop tears of the meniscus because of trauma or sports injuries. Believe it, or not most meniscus tears do not occur due to injury in middle-aged individuals. A meniscus can tear simply because it wore out. Most of you will not recall any specific injury. Some of you might remember that you bent down to get something off the floor or from under the bed and felt a click or pop.
Either way, most posterior horn meniscus tears in adults are “complex” tears and did not occur because of an injury– they simply wore out. That is why many of us in the orthopedic community now view these as an age-appropriate change. We develop age-appropriate “tears” in other parts of our body too, not all of them cause pain and most do not require surgery.
By far, the most common location for a tear is in the back and on the inner or medial side of the knee — that is the area we call the posterior horn of the medial meniscus. The image below shows your knee region where you may feel pain from a posterior horn tear.
The posterior horn is also the most common area for degenerative meniscus tears where the meniscus tissue simply wore out. These degenerative posterior horn meniscus tears are found in many runners- and often do not need surgery.
Treatments for Posterior Horn Medial Meniscus Tears
As mentioned in my recent post, the majority of posterior horn tears are determined to be degenerative. These degenerative tears are usually managed without the need for surgery. It’s true… many of you with a degenerative meniscus tear probably had the tear long before your knee started hurting. And in most instances, you will be able to return to activities without the need for surgery.
It may take 2-6 months for the pain to go away, but this is worth waiting for. People who have surgery on these complex degenerative posterior horn tears are at higher risk of developing arthritis than those treated with surgery. Again… truth. Having the meniscus removed, a procedure we call a partial menisectomy will increase your risk of developing arthritis. Were you told that these tears will increase your risk of developing osteoarthritis and that surgery will prevent that? Well, that’s just not what the research shows.
The onset of knee pain is multi-factorial. That means it is due to many different things. Sometimes our knees just get cranky or upset. Synovitis or inflammation of the inside of the knee develops. This will subside in time… but if you rush to your doctor and they order an MRI, they might find a meniscus tear. Now you might find yourself fast-tracked to surgery. Besides… you cannot unsee your MRI report.
As with most forms of knee pain in a middle-aged adult, focusing on strength, balance, and muscle mass will help most of you get through this episode of pain without needing surgery. This post talks about the importance of balance training and strengthening- it contains a few videos to guide you too.
Walking, jogging, cycling, etc., will not cause harm. When you are comfortable, you should return to those activities.
Muscle mass.. or larger muscles are associated with longevity and better health. Yes, our muscles contribute enormously to our overall well-being by aiding in our metabolism and glucose control. The stronger your legs are, the less likely they are to bother you.
Many of you who have posterior horn tears might also have some evidence of osteoarthritis. This is not a terminal diagnosis! Physical activity should not be avoided because there is very little chance that most exercises will make your tear or arthritis worse. You don’t want your risk of heart disease, stroke, and dementia to increase because you stopped exercising, thinking that you are protecting the knee. This post goes into considerable detail about managing a knee with arthritis and a complex or degenerative meniscus tear.
The majority of you who have a degenerative meniscus tear will do very well without surgical management. Again, it may take 2-6 months. If it’s two weeks out from the onset of pain and you are told to consider surgery, it is often in your best interest to wait. The body heals far more slowly than we think.
Many of you will see improvement in your pain with the use of a compression knee sleeve. Just because something is torn doesn’t always mean that it needs to be “fixed.” Surgery for meniscus tears is not always necessary. Cold/ice compression can help when the pain is awful. This is particularly true for a “degenerative” posterior horn medial meniscus tear.
On the other hand, “Flap tears,” “bucket-handle tears,” and other larger tears of the meniscus are more than likely to lead to surgery because of the persistent pain and mechanical symptoms such as popping locking and instability.
Posterior horn medial meniscus tears in children tend to lead to a recommendation to consider surgery since these tears are usually repairable. That means that we can suture the tear back together. In addition, children have much more regenerative or healing potential. If a meniscus tear is repaired (sutured back together), then the risk of developing arthritis later in life drops significantly.
Generally speaking, the treatment options for meniscus tears include:
- physical therapy,
- activity modification, and
- occasionally a surgery we refer to as an arthroscopy.
An arthroscopy involves placing a small fiber-optic camera into the knee through a 1/4 inch incision. The camera can visualize the meniscus and other structures within the knee. During an arthroscopy, we have the choice of either repairing the meniscus tear or removing the torn piece.
Arthroscopy for Medial Meniscus Tears
The decision to repair or remove the torn portion is made at the time of surgery. We need to see whether or not the meniscus is repairable based on its quality, location, and size. Preference is given to repair posterior horn medial meniscus tears, if possible, to help preserve the meniscus and minimize the risk of developing arthritis.