Knee injuries bring a huge amount of people into our physio clinic every year. You can be affected by a wide range of different knee injuries which can affect different structures around your knee. One type of common knee injury is a meniscus tear. This can be an extremely painful injury for you to sustain. It commonly occurs through playing sport. However, meniscus tears don’t always require a high level of force or trauma to occur. Indeed, they can often occur after kneeling, bending or twisting.
What is the Meniscus?
The meniscus is a type of cartilage which sits inside your knee joint. It sits between your thigh bone (the femur) and your shinbone (the tibia). If you compare it to the filling in a sandwich, the meniscus is essentially the filling between these two bones. There are in fact two meniscus in each of your knees. Both menisci are crescent-shaped. One sits on the outer aspect of your knee joint, known as the ‘lateral meniscus’. The second sits on the inner aspect of your knee joint and is called the ‘medial meniscus’.
What Does the Meniscus Do?
Both menisci act as shock absorbers, enabling you to absorb force and load through your knee joint (Englund et al, 2009). Essentially, this means they help to protect your knee joint when you are walking, running, jumping and landing. The menisci also help to stabilise your knee joint. This is because, the top of the shinbone is flatter than the more rounded surface of the thigh bone. As the menisci are slightly wedge shaped, they help to overcome the slight mismatch in the joint surfaces of the two bones. This ensures a snug fit within your knee joint (Matar et al, 2019).
How Do Meniscus Tears Happen?
Typically, a meniscus tear will occur when there is an excessive or forceful twisting of the knee joint. This often occurs whilst the foot is planted on the ground. This can occur in football for example, if you’re tackled from the side. This causes impact through your knee whilst your foot remains steady on the ground. A meniscus tear can also occur after jumping and landing awkwardly. Injuries tend to occur when the force applied to the soft tissue is too much for it to withstand. This means, that if a high force is applied to your meniscus, it will tear if it is unable to cope with it.
In clinical practice, the inner or medial meniscus is more commonly torn than the outer or lateral meniscus. This is because the medial meniscus attaches to other structures inside the knee joint. This leaves it less mobile to forces acting on it, compared to its lateral counterpart.
Signs and Symptoms of a Meniscus Tear:
80% of meniscus tears occur in men, rather than women (Bhan, 2020). Depending on who you are and how you sustain a meniscus tear, the injury can lead to a very varied degree of symptoms. If you are older, your meniscus is more likely to show signs of degenerative change within the cartilage. This means, a high force is not always required to cause a meniscus tear. Due to the degenerative change, less forceful activities such as squatting or kneeling may give rise to a meniscus injury. This could for example, include a day of gardening. Here, you are likely to have repeatedly squatted and kneeled throughout the day. This can give rise to a degree of pain which you may only feel 24-48 hours later. This means, your knee pain doesn’t always start suddenly.
This is in contrast to a young footballer. Here, higher forces will be required to tear your cartilage. This is because, if you are younger, your cartilage is not degenerative and is therefore stronger. If your meniscus becomes damaged, you will likely feel a much higher level of sudden pain. It will also often occur with significant and somewhat immediate swelling and knee restriction. It’s likely in this instance that if you tear the meniscus, you’ll also likely sustain an injury to the surrounding knee ligaments as well. This typically includes the MCL, ACL or PCL (Bhan, 2020).
The Main Symptoms of a Meniscus Tear:
Overall, typical signs and symptoms of a meniscus tear include the following:
- Pain when walking, kneeling, squatting or jumping. Your knee pain will often feel sharp in nature
- Swelling can be extremely common
- Your knee may feel stiff and restricted
- Knee joint locking. When locking occurs, you will feel unable to fully bend or straighten your knee without it locking into position
- A popping or clicking sensation (often following an episode of locking). The popping sensation may be painful
- A feeling that the knee feels weak and may give way from underneath you
- Tenderness around the line of the knee joint where the tear has occurred. For example, on the inner aspect of your knee if your medial meniscus is torn. Or, on the outer aspect of your knee if your lateral meniscus is torn
Diagnosing a Meniscus Tear:
The most important thing to do if you sustain a knee injury, is to book in for an assessment with a physiotherapist. Do this, as soon as possible. Any pain, swelling, inflammation and restriction in your knee are clear signs that your knee is injured. Therefore, establishing what you’ve damaged is important. Through questioning, a physio assessment will take into account various factors. This includes, the mechanism of injury, including how your injury happened. It will also focus on what you were doing at the time and how your knee pain started. A physical assessment of your knee can also be a great indication of whether or not you have a meniscus tear. Your physiotherapist will go through specific clinical tests to establish this.
Is the Size of the Tear Important?
As a meniscus tear can vary in size, a small tear is likely to be less problematic than a large tear. A meniscus tear can cause considerable, ongoing pain, together with knee locking, giving way or restriction. In this instance, an MRI scan can be performed to discover the severity of the tear. In many cases, even if an MRI scan detects a tear, it does not always change your treatment plan. However, in some cases, your meniscus tear may require surgical intervention.
How is a Meniscus Tear Treated?
If you attend physio and a meniscus tear is suspected, a variety of different treatment techniques can be used. Firstly, your knee can be extremely painful, and you may be unable to walk or weight-bear. This requires crutches or a knee brace to help offload your knee. If your knee is swollen, applying ice regularly over the knee can help. Elevating your leg can also be beneficial in helping to reduce the amount of swelling you have. Taking anti-inflammatories can also help to reduce the level of pain and inflammation in your knee.
Physiotherapy Treatments:
Physiotherapy treatments can include ultrasound to reduce any swelling and pain. It can also include soft tissue therapy, joint mobilisation, knee strapping and taping. When able to, a gradual, progressive exercise programme will be introduced. It is notable, that in the early stages of a meniscus tear, your knee can feel quite painful. As the meniscus is a relatively avascular structure it has an extremely limited blood supply (Bhan, 2020). This means, that when it’s injured, it can take a long time for it to heal. However, over time, as it begins to heal, your initial pain should begin to reduce. At this point, you should start to see signs of improvement. As the pain reduces in your knee, rehab will be focussed on establishing knee strength and movement. This will help to restore your knee back to full function.
Surgery:
If you sustain a large meniscus tear or your knee pain continues with a high degree of catching, popping and weakness, surgery can be an excellent option. Surgery is normally performed via a keyhole or arthroscopic technique. It will either aim to stitch the torn meniscus back together or will remove the torn part of the meniscus all together. Surgery tends to have a good outcome for the majority of meniscus tears.
Overall Treatment Aims:
Irrespective of whether a torn meniscus requires surgery or not, the treatment aims will remain the same. The aim will be to:
- Reduce any knee pain
- Restore full range of motion in your knee joint
- Improve the strength of your surrounding muscles including your quads, hamstrings, calves and other knee and hip related muscles
- Return you to the sports you enjoy, or your normal activities, as soon as possible without risking further injury
As a meniscus tear can be an extremely painful knee injury, it is extremely important to see a physiotherapist if you develop any knee pain. Good hands-on treatment together with a progressive knee rehabilitation programme is critical to help your knee heal and recover. Generally, with time and rehab, meniscus tears should improve well, so that you can get back to doing what you enjoy.
