The meniscus is a vital part of the knee. They are semi-circular shaped specialised cartilage structures. They act as a shock absorber between the femur (thigh bone) and tibia (shin bone). They help spread the load when an impact or force goes through the knee. There are 2 menisci on each side of the knee. The medial and the lateral meniscus. They have several important roles:
- They act as shock absorbers
- They share load within the knee
- They are secondary stabilisers, of particular importance in the ACL-deficient knee
- They probably contribute to proprioception (sensory feedback and reflexes) within the knee
- They probably have a role lubrication of the joint, and they may play a part in nutrition of the articular cartilage.
Meniscal tears are the most common injury of the knee presenting to an Orthopaedic Surgeon. The meniscus is commonly injured in sports. The classic injury is for a twist (rotate) to occur to the knee while the foot is still on the ground. The meniscus may tear fully or partially. How serious the injury is depends on how much is torn and the exact site of the tear.
Meniscal tears may also occur without a sudden severe injury. With age, the menisci degenerate and become less elastic, more friable and more liable to tearing. In some cases a tear develops due to repeated small injuries to the cartilage or to wear and tear (degeneration) of the meniscal cartilage in older people.
In severe injuries, other parts of the knee may also be damaged in addition to a meniscal tear.
The typical symptoms of a meniscal tear are:
- Knee pain – this may be felt either at the front or the back of the knee
- Giving way – this is normally associated with episodes of sudden pain
- Swelling – this may be permanent or may occur after episodes of giving way
- Locking – this is where the knee gets stuck and cannot straighten fully.
- Clicking- Some people notice a clicking or catching feeling when they walk
A patient with a meniscal tear may not necessarily experience all of these symptoms, but can have any combination of the above.
Meniscal pain worsens on twisting/turning on the affected joint and is often painful when squatting or on deep knee bends.
For some people, the symptoms of meniscal injury go away on their own after a few weeks. However, for others the symptoms persist long-term, or flare up from time to time, until the tear is treated
Knee Specialists surgeons are committed to the evidence based treatment of meniscal injuries. Some of our surgeons have been involved in the development of guidelines for the management of meniscal injuries for the British Association of Knee Surgery.
All Knee Specialists surgeons comply with guidelines from the British Association for Surgery of the Knee and European Sports, Knee and Arthroscopy Association.
Small tears may heal by themselves in time within a few months of injury. Some tears which do not heal do not cause long-term symptoms once the initial pain and swelling subside, or cause only intermittent or mild symptoms. In these cases, surgery may not be needed. You may be advised to have physiotherapy to strengthen the supporting structures of the knee, such as the quadriceps and hamstring muscles. Sometimes steroid injections can help to improve symptoms from mild meniscal tears.
If the tear continues to causes persistent symptoms then surgery may be considered. The surgery performed is usually a key hole (arthroscopic) procedure. The types of operations which may be considered include the following:
- Meniscal Repair - The torn meniscus may be able to be repaired and stitched back into place. This is not always possible as the meniscus does not always have the potential to heal. See meniscal repair page.
- Meniscectomy - In some cases where repair is not possible, a small portion of the meniscus may be trimmed or cut out to even up the surface.
- Meniscal transplant - The missing meniscal cartilage is replaced with donor tissue, which is screened and sterilised much in the same way as for other donor tissues. This is not an option for all patients. There are very specific criteria for when this type of surgery may be appropriate
- Meniscal Scaffold - There is an operation in which collagen meniscal implants are inserted. The implants are made from a natural substance and allow your cells to grow into it so that the missing meniscal tissue regrows. This is not an option for all patients. There are very specific criteria for when this type of surgery may be appropriate