The knee consists of three bones: the shinbone (tibia), the thighbone (femur) and the knee cap (patella). The knee joint is supported by ligaments, tendons and muscles which maintain stability of the joint and allow movement. 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.
Damage to the meniscus discs can be the result of deterioration over time or from repetitive injury or arthritis or degeneration of the knee joint. 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 injuires.
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.
Following an sporting injury to the knee, initial treatment should include:
- Rest – your doctor may recommend you avoid weigh bearing
- Ice – applied in 20-minute intervals. Ice should not be applied directly to the skin.
- Compression – will provide support and help reduce the swelling
- Elevation – will help reduce the swelling
You may also require pain and anti-inflammatory medication to help settle your symptoms.
How your meniscus tear is treated will depend on the location and nature of the tear and your symptom.
Some tears will settle with conservative treatment including rest and modifying activity levels. Some tears will not settle on their own and will require arthroscopic surgery. During an arthroscopy, your surgeon may repair the meniscal tear with sutures, or remove the damaged or torn piece of meniscus disc. Your surgeon will also deal with any loose fragments of bone or cartilage or ligament injuries that may also be causing your symptoms.