Meniscus injuries are exceedingly common and can occur in anyone, from junior high athletes to the senior population.
The meniscus is a cushion that evenly distributes the weight you put on your knee. There’s two in each knee: one on the inside of the knee and one on the outside. Without the meniscus, you’re putting all your weight in a small section of bone, which causes accelerated breakdown of the smooth articular cartilage on the end of the bone. If you lose part of your meniscus, you’re going to have an increased risk of arthritic progression in the part of the knee where you lost the meniscus from. The meniscus distributes about 50% of the weight when your leg is straight and about 85% when your leg is bent.
The second job of the meniscus is to be a knee stabilizer. The collateral ligaments, ACL and PCL, are the primary stabilizers, but the meniscus is a secondary stabilizer. If a knee doesn’t have an ACL, chronic meniscus tears may develop, especially on the inside part of the knee.
The meniscus is shaped like a C, and the points of the C are attached to the bone. It is made up of stacked layers of fibers. One type of fibers, called longitudinal fibers, help absorb the energy and weight-bearing. Another type of fibers, called radial fibers, are also part of the meniscus. As you get older, the layers may not be as closely bound together as they used to be and the meniscus may get degenerative tears. Tears can also occur from an acute injury, especially twisting and falling injuries.
Types of Meniscus Tear
- Degenerative tear: fibers making up the meniscus aren’t bound together well anymore, and the meniscus tears like the hem on an old pair of favorite jeans
- Vertical tear: tears in line with the meniscus
- Radial tear: tears through the meniscus
- Root tear: the meniscus detaches from the bone
- Flap tear: a flap comes off the meniscus and can get stuck under or in the joint
- Bucket-handle tear: a piece of meniscus tears off, flips over the joint, and gets stuck
- Horizontal tear: tear between layers of the meniscus
Symptoms of a Meniscal Tear
Pain along the joint line is a common symptom. People may have pain or trouble moving, especially squatting or twisting. The symptoms are the same with a tear in the inside or outside meniscus; the difference is where the symptoms are. If you have a bucket handle tear, it might become difficult to move your leg if the tear makes your knee get stuck in place.
On a physical exam, your doctor is looking to see if you have pain on the joint line when they’re pushing on it. If the doctor twists your knee to pinch the meniscus, does it hurt? Is it uncomfortable?
Treatment of a Meniscal Tear
Amount of Blood Supply
The meniscus has different amounts of blood supplied to different parts. If a tear occurs in an area with ample blood supply, it may qualify for a repair. If a tear occurs in an area without ample blood supply, a repair may not be possible because there won’t be enough blood going to the area for it to heal well.
Meniscus Tears and Arthritis
Many people in their forties, fifties and sixties will have some degenerative tearing of their meniscus on their MRI. Instead of trimming it, it’s better to keep it to continue to provide a cushion in your knee. While results were about the same after six weeks between people who had a meniscectomy (removed meniscus) and people who did physical therapy, after a few years the people who did physical therapy and kept their meniscus did better.
If the meniscus can be repaired, we prefer to save it. The meniscus will be sutured together or will be sutured to the bone, as needed, so it will be held in place as it heals.
Repairability depends on the quality of the tissue. If the meniscus is too tattered and cannot hold a suture, it cannot be repaired and that portion must be removed.
Rehabilitation after a Meniscus Tear
After a meniscectomy, you can typically put weight on the knee and bend it right away since you’re not waiting for anything to heal. After a meniscus repair, you’ll have physical therapy, a brace, and must wait to put your full weight on your knee.
Frequently asked questions
Is an MRI necessary for diagnosing a meniscus tear?
It’s very helpful. If a physical exam, patient history and x-rays are suspicious, we’ll order an MRI to confirm.
Does icing help with pain from a meniscus tear?
Icing is the most helpful right after an injury. Icing weeks after an injury may not provide pain relief since much of the acute swelling is gone. However, there are not many downsides to icing if it makes you more comfortable.
Is an artificial meniscus available?
No, there is not an artificial meniscus available at this point. There are some products starting to come on the market as an augment to fill in where a partial meniscectomy was done, but they are rare.
Can a meniscus be torn more than once?
Theoretically, yes. It is relatively uncommon to have a meniscectomy and then develop another tear since you’ve removed most of what could be torn. After a meniscectomy you’re more likely to have a progression of arthritis after that contributing to your symptoms. While it is also relatively uncommon, it’s still possible to retear your meniscus if you’ve had a meniscus repair.
Is it ever too late to perform surgery on a meniscus?
It depends on the specifics. If you’re having symptoms and you have an appropriate meniscus, where you can have quality sutures in an area with blood supply, you may be able to have a meniscal repair. I would rather try to save it and repair it than cut it out.
Is there a way to prevent a meniscus tear?
There’s not a direct way to prevent it, but the better strength and conditioning you have the more resilient you are to almost all injuries.
If you’ve had a meniscus tear in one knee, are you more likely to have a tear in the other knee as well?
Not necessarily. If you have a degenerative tear in one knee, you’re more likely to have a degenerative tear in the other knee. If you have an acute traumatic tear, there’s probably not a direct correlation with an acute injury in the other meniscus.
What is the recovery like after a meniscus repair surgery?
The worst-case scenario, particularly with a radial tear or a root repair, is non-weight-bearing for six weeks and using a brace. Physical therapy will be started during that time to work on range of motion. On more stable repairs, you will still have a brace for six weeks but you may be able to start putting weight on it earlier. It will be about four months before you’re able to do sports.
Is surgery always needed after a meniscus tear?
No, not always, especially the more degenerative tears. There is a huge portion of people who can do well and not need surgery for a meniscus tear if they do physical therapy and non-surgical treatments such as injections and anti-inflammatories.