The meniscus is essential for normal, healthy knee function. There are two in each knee, made from the same type of cartilage found in the tip of your nose, called fibrocartilage. This is why a meniscus is sometimes referred to as a “cartilage”.
The meniscus is an important shock absorber, which works with other structures (like the ACL) to stabilise the knee, and spreads nourishing joint fluid around the knee. If other structures are damaged, for instance if the ACL is torn, then the meniscus is asked to do too much and it may tear. When the meniscus is torn, there is less cushioning to protect the joint, and it is more likely to wear out early.
Differences between meniscus tears
Even though meniscus tears are common, they are not all the same. The type of tear you have, the reason for your tear, and the recommended treatment might be different to somebody else.
Tears can happen suddenly, or gradually over months or years. They can range from painless, small splits, to big tears of the whole meniscus which cause the knee to jam painfully.
Meniscal tears are often described by which part of the meniscus is torn, and what the tear looks like.
Like other parts of your body, the meniscus changes with normal ageing. It is also damaged as part of knee arthritis, which should be thought of as affecting all parts of the knee. These are some of the reasons why the meniscus of someone in their 60s is not the same as the meniscus in a teenager, and it makes sense that there are different meniscus problems and treatments which will be based on you as an individual.
Symptoms of meniscal tear
Often, someone who has a meniscus tear might twist their knee and have pain suddenly, or soon after. Sometimes it’s a small thing, such as kneeling down, which causes the problem. There is often pain and swelling, and sometimes clicking or locking of the knee.
Not all meniscus tears cause pain, and many people who have tears don’t know about it. Sometimes, an MRI scan might show a tear which is not actually causing your problem. We will expertly assess your knee, and compare this with your scans, then make sure you understand exactly what is happening.
Physical examination of the knee
It is important to thoroughly examine your knee, rather than relying on a scan to give the answer. This will include checking for swelling, the amount of movement you have, special tests for the meniscus, and a look at your function like squatting or walking.
Imaging of the meniscus
MRI scans give the most detailed information about the soft tissues in your knee, including the meniscus. While a report from the radiologist is very valuable, the best results happen when we talk with you, then carefully examine your knee, and finally look at your scans together. Looking at the images after you have told your story allows us to look for small clues which might be missed, and it also helps you better understand what is going on in your knee.
Please make sure to bring your scans with you to all your appointments.
Many meniscal tears do not need surgery, but it can be difficult to pick these tears from those that do. We will expertly assess your knee, and guide you to the best treatment for your situation. This might include rest, exercise, physiotherapy, or an injection into the knee. We take pride in recommending the best option for your injury, and surgery is not always needed.
Because the meniscus is so important to the health of your knee, if it can be repaired it is often a good idea to do so.
Repair methods and equipment have improved greatly in recent years. However, some tears are not well suited to repair. How old you are, the type of tear, and how long ago it happened will affect the chances of successful repair.
When a tear is causing problems and can't be repaired, it might be trimmed as a way to “tidy up” the knee. This is called debridement. When a meniscus is debrided, it is important to take just enough to fix the problem, but leave any healthy tissue to protect the knee. Sometimes debridement might be the simplest way to fix a problem, trimming a flap of meniscus which is irritating the joint.
In some situations, when a meniscus is not working to cushion the joint at all, it can be replaced with a donated meniscus. This is a very specialised technique which has been shown to be safe and effective for the right person, who is usually young and lost most of their meniscus due to injury.