The knee is the largest joint in the body. It is a specialised hinge joint made up of four main things: bone, cartilage, ligaments and tendons. The main movement that occurs in the knee joint is flexion and extension. It does however allow for a small amount of rotation and gliding on the surfaces. Each of the bone surfaces in the knee joint are covered with articular cartilage which creates a smooth surface for the bones to glide seamlessly over, and to cushion, the joint on weight bearing.
The knee also contains two rubbery discs of cartilage, one on either side of the knee, between the femur and the tibia. These cartilages are called the meniscus. They provide additional shock absorption and stability to the knee.
Meniscus injuries occur from an injury to the knee. In younger people meniscus tears are generally the result of sporting injuries that involve twisting the knee or by direct blows to the knee that can occur during tackles. These injuries may also result in damage to other structures in the knee.
When the initial injury occurs a popping sound is often heard. It is often still possible to weight bear on a leg with a torn meniscus however, swelling and stiffness will appear over the next few days. Symptoms can include:
- Stiffness and swelling
- Catching of the joint
- Knee feels it will give way
- Limited range of motion
Your doctor will ask you questions to get information on the nature of your injury, the activity you were undertaking when it occurred and the symptoms.
Your doctor will examine your knee to look for any swelling, tenderness or clicking which can be seen with meniscal injuries.
Although x-rays will not show a meniscus tear, they may be required to show damage to other structures within the knee that may have occurred in addition to the meniscus injury. X-rays are also useful to determine if there is arthritis in the knee, which is often associated with degeneration of the meniscus.
An MRI (magnetic resonance imaging) is often needed to show soft tissue injuries like meniscus tears.
Initial treatment should include:
- Rest – take a break from playing sport to give your knee time to heal
- Ice – ice the affected knee for 20 minutes at a time, taking care not to apply ice directly to skin
- Compression – light compression of the knee will provide support and help reduce the swelling
- Elevation – will help reduce the swelling
You may also require pain and anti-inflammatory medication to assist with the pain and inflammation.
How your meniscus tear is treated will depend on the location and nature of the tear. Some parts of the meniscus receive good blood supply and tears will heal. Other parts of the meniscus will not heal however may not require surgery where the tear is small and your symptoms subside.
When surgery is recommended it will arthroscopic surgery. An arthroscopy (link to arthroscopy page) is a minimally invasive surgical procedure in which a small fiber-optic camera (arthroscope) and special surgical instruments are inserted into the joint through small incisions. The camera is attached to a monitoring screen that allows your surgeon to view and access any damage to the structures in the knee and to make repairs as necessary.
During an arthroscopy, your surgeon is able to repair or remove (part of) the damaged meniscus as necessary.
Other structs inside of your knee can also be addressed at the same time.
Arthroscopic meniscal surgery is usually performed as a day surgery procedure. You will have a bulky bandage around your knee after surgery but will usually not require a brace or crutches. You will be able to put all you weight through the operated knee. Rest and ice are the most important ways you can control post-operative swelling and discomfort, as well as pain relief which you will be given on discharge from hospital. Physiotherapy will help strengthen the muscles and stabilise the knee. Following full recovery, most people are able to return to sport and physical activity.