A meniscus is one of the most important structures inside your knee. It’s the true unsung hero of your knee! Unfortunately, a meniscus is also very fragile, and a torn meniscus is very common. The best treatment for a meniscal tear varies hugely between one patient and the next. Treatment depends upon your age, the type of meniscal tear you have, your health history, and whether or not you also have arthritis within your knee.
What is a Meniscus?
A meniscus is a horse-shoe shaped structure that sits in between the articular cartilage of the thigh and shin bone. There are two of these inside your knee, one on the inner side called the medial meniscus, and one on the outer side, called the lateral meniscus.
Meniscus is made from a rubbery type of cartilage called ‘fibrocartilage’. Unlike the articular cartilage that is firmly attached to the thigh and shin bone, a meniscus is a lot more mobile within your joint.
Incredibly, a meniscus absorbs 70-90% of the force that goes through your knee joint. It also plays an important role in knee stability. Without a meniscus, the articular cartilage is exposed to more shock than it can cope with, and it becomes arthritic. A meniscus really is the best friend of articular cartilage.
I think I have a Torn Meniscus
You should make an appointment with your GP or sports doctor promptly. Your doctor may start with an x-ray, and sometimes even a trial of observation if they don’t suspect a meniscal tear. If they are suspicious of a meniscal tear, or you don’t improve with time, it is likely they will consider ordering an MRI scan. A meniscal tear, and other ligament injuries, will not show on an x-ray or ultrasound.
Types of Meniscus Tears
There are two, main types of meniscal injuries; acute meniscal tears that occur in younger patients with an otherwise healthy knee, and degenerative meniscal tears that occur in older patients with some knee arthritis.
Acute Meniscus Tears
Acute meniscal tears can occur in patients of any age group, but they are most common in younger patients. They can occur with a significant sporting injury, or even quite innocuously, like twisting your knee when getting out of a chair.
Symptoms of Acute Meniscus Tear
Symptoms of an acute meniscal tear include sudden pain, swelling and also a feeling of catching within the joint. If the meniscal tear is severe it can displace. This is sometimes called a ‘bucket handle tear’ on an MRI report. This can lock your knee, stopping it from bending and straightening fully.
A meniscal tear is repaired with a key-hole surgery to your knee joint, called an arthroscopy. We make two, small incisions, about 5mm in size, at the front of your knee joint.
We then place a camera and some special tools inside the knee and repair the meniscus back together with sutures. This stabilises the meniscus and helps it to heal; the same way that putting a broken bone into a cast keeps the bones stable so healing can occur. This is usually a day surgery procedure and you are able to walk on your knee immediately. Some patients may need to wear a knee brace for 6 weeks.
If a meniscal tear does not heal, you may require the torn component removed from your knee joint with an arthroscopy. Otherwise, it will continue to cause pain and mechanical symptoms.
Surgery for Acute Meniscus Tear
A meniscus has a poor blood supply, and therefore has a very limited healing potential after being torn. The very high majority of meniscal tears will never heal unless they are surgically repaired.
Younger patients with a diagnosed, acute meniscal tear should seek an opinion from an orthopaedic surgeon as soon as possible. The sooner a meniscal tear is repaired, the more likely it is the meniscus will heal. If a meniscal tear is left more than 6-12 weeks, it is much less likely it will heal, even if repaired.
Degenerative Meniscus Tear
Degenerative meniscal tears are a very different kettle of fish than acute meniscal tears. These usually occur in more elderly patients, whose knees are beginning to become arthritic. Think of an old rug that gets walked on all the time. Eventually, the threads begin to show, and it wears out. A degenerative meniscus is the same, and it’s prone to tearing quite easily. You don’t even need a specific injury for this to occur.
Symptoms of Degenerative Meniscus Tear
Symptoms of a degenerative meniscal tear include pain and swelling, but they can also cause clicking, catching or locking within your knee. We call these mechanical symptoms, because something is mechanically catching within the knee joint, like a loose screw in a clock. These are caused by the torn meniscus grinding and grating between the knee bones. Symptoms may start suddenly after quite an innocuous incident, like getting up from kneeling in the garden, or they can also develop slowly over time.
Surgery for Degenerative Meniscus Tears
Unlike an acute meniscal tear, a degenerative meniscal tear can never heal, even with surgical repair. The torn meniscus fragments will remain in your knee joint for the rest of your life.
A key-hole operation, or knee arthroscopy, can remove the torn fragments of meniscus from the inside the knee joint. This is done through two, small incisions, about 5mm in size, at the front of your knee joint. We can also remove loose pieces of articular cartilage that may have peeled off the bone due to arthritis and are also causing mechanical symptoms.
This is usually done as a day surgery procedure, and you can walk out of hospital the same day without crutches. The average patient needs 1 week off work, and you can usually drive a car 24 hours after.
However, it is very important that patients understand that an arthroscopy cannot cure arthritis. If your surgeon tells you this, then considering seeking a second opinion. But it can help with reducing the discomfort associated with mechanical symptoms of clicking, catching and locking.
An analogy I often use with my patients is this. Imagine you are walking in an old, worn-out pair of hiking boots. The tread has worn off the sole and your feet are sore. You also have a few pebbles inside the boots that are irritating. We can put a camera and some tools into your boots and remove those loose pebbles. Yes, this will make your walk more comfortable and take away some of the irritation as you move. But, you are still walking around in the same pair of old boots. You’re may not feel perfect, and over time the boots will continue to wear out. The only way of permanently fixing the problems is to change to a new pair of boots.