Knee Joint Meniscus Tears
What is the Meniscus?
The knee joint works by bones gliding smoothly across each other even when there is load going through them. Bones can’t perform that function without some shock absorption and lubrication which is provided by the cartilage and the joint fluid. There are two types of cartilage in the knee: the cartilage that covers the ends of the bones (‘articular cartilage’) and two extra wedges of cartilage (one on each side of the knee) called the meniscus.
What Causes a Meniscus Tear?
The meniscus cartilage peaks in its strength and durability at roughly the age of 23. Before that age, it usually takes pretty high levels of trauma to cause a meniscus tear. Everyone is different but, the further we get from that age the more the meniscus can get injured with quite innocuous movements. Sometimes simply getting out of a chair at just the wrong angle can tear a meniscus in anyone middle-aged or above.
Some people have a slightly higher risk based on the inherited shape of their meniscus, alignment of their knee joint or the way their cartilages age.
What are the Symptoms of a Meniscus Tear?
Symptoms from meniscus tears can be very variable. Some people recall the exact moment the injury happened and describe a catching type of pain. Other have no pain at the onset but progressively develop pain.
Not everyone with a meniscus tear gets pain but most who do experience pain describe sharp pain on one side of the knee that occurs with certain positions or movements but is ok at rest.
How Can I tell if my Meniscus is Torn?
Your doctor will firstly thoroughly assess you to decide on the likelihood of a meniscus tear. Although confirmation isn’t always necessary for treatment, the only way to completely confirm a meniscus tear is by a scan. An MRI scan is preferred over a CT arthrogram as it is more sensitive, non-invasive and does not involve radiation. Ultrasounds are not sensitive enough at visualising the entire meniscus and are therefore not recommended.
What is the Treatment for a Meniscus Tear?
In decades past, we had a low threshold for performing keyhole surgery to ‘clean out’ meniscus tears. This is a procedure that cuts away at the meniscus to restore its smooth edge. The problem with this approach is that it results in less shock-absorbing meniscus which can have long-term implications and accelerate further wear and tear. Sometimes this can be unavoidable, but we now have a much higher threshold for surgery and give most tears the opportunity to improve with more conservative means. Often this can involve rest, bracing, load-modification and various types of anti-inflammatory treatment including corticosteroid injections where required.
Is Surgery Required for a Meniscus Tear?
Many (perhaps most) meniscus tears do not require surgery but some are large and unstable and will keep catching inside the knee joint unless they are trimmed (or repaired) with keyhole surgery. A specialist Sport and Exercise Physician can take an unbiased approach to help you find the best approach for your knee.
Can a Meniscus Tear Heal?
It has previously been accepted that meniscus tears in adults usually don’t heal on their own. That concept is starting to be challenged. Firstly, unstable meniscus tears can certainly stabilise by developing scar tissue that keeps them from causing any functional problems. There is increasing evidence now showing that, if left alone, some meniscus tears will also repair.