Meniscal Problems

Choose a Procedure

Meniscal Problems

About the meniscus

The meniscus is a C-shaped piece of cartilage that sits between the femur (thigh bone) and the tibia (shin bone) and is attached to the lining of the knee joint. There are two menisci in a normal knee; the one on the inner side of the knee is called the medial meniscus and the one on the outer side of the knee is called the lateral meniscus. The menisci act as shock absorbers within the knee joint, protecting the articular cartilage (gristle) that lines the surface of the bone from impact. They also have a stabilising role and cup the femur preventing excessive movement of the femur on the tibia.

Menisci are a commonly damaged knee structure. The injury may occur in any age group, however in younger people where the meniscus is tough and rubbery it may take a forceful twisting injury to do so (figure 1). In older people, where the meniscus is often degenerate and weak, it may only require a trivial mechanism to tear (such as squatting).

Types of meniscal tear

There are two different mechanisms for tearing a meniscus.

Traumatic tears result from a sudden load being applied to the meniscus that is severe enough to cause the meniscal cartilage to fail and separate. These usually occur from a twisting injury or a blow to the side of the knee that causes the meniscus to be pushed against and compressed.

Degenerative meniscal tears are best thought of as a failure of the meniscus over time. The meniscus becomes less elastic and complaint, and as a result may fail with only minimal trauma. It may be that there was no injury leading to the tear at all.

Symptoms and signs

When you tear the meniscus, you may feel a "popping" sensation. This may or may not prevent you from continuing the activity you were doing. As the inflammation sets in, a number of symptoms and signs may present:

• Pain along the joint line (where the meniscus sits)
• Stiffness
• Joint swelling ("fluid on the knee")

The pain often improves with rest following the initial injury however the pain commonly recurs with twisting, squatting or aggressive activity. Joint swelling may occur although meniscal tears by themselves don't usually cause a tensely swollen knee. It may become difficult to fully straighten the knee (locking). This happens when a torn piece of meniscus displaces and becomes lodged in the hinge mechanism of the knee. If you think you have a torn meniscus, you should contact your local doctor as soon as possible.

Diagnosis

You will be asked a detailed series of questions by your surgeon particularly how the problem started and what issues it is causing now. An examination will then be performed. Generally you will require an X-ray of the knee to look for any arthritis (wear and tear) which might also be causing your symptoms. Quite often you will be sent for an MRI scan to have a more detailed look at the knee.

Treatment

Initial treatment for a torn meniscus is usually aimed at reducing the pain and swelling in the knee. You may be referred for physiotherapy to work on improving the range of movement and alleviate the pain and swelling. If you have a “locked knee” which cannot be straightened, surgery may be recommended as a matter of urgency to remove the torn piece of cartilage that is trapped in the joint. If your meniscal tear fails to heal on its own and your knee continues to be stiff and sore, surgery will be required to either remove the torn portion of the meniscus (partial meniscectomy) or to repair the tear (meniscal repair).

Meniscal Repair

Meniscal surgery is performed using an arthroscope (camera). A small incision is made in the knee to allow the insertion of the arthroscope into the joint. Through another small incision, special instruments are used to repair the meniscus while the arthroscope is used to see what is happening. Stitches are inserted into the torn meniscus until the tear is repaired (see fig 2). The success of the repair depends on a number of factors including the type of tear, the time from injury, your age and whether you have also injured your ACL.

Partial Meniscectomy

If the meniscus is not repairable, the torn edges will be trimmed off (see fig 3). This is commonly the case with degenerate tears seen in older people.

Before the operation

• Healthy patients are admitted on the day of surgery. You should inform your surgeon and anaesthetist of any medical conditions or previous medical treatment as this may affect your operation.
• It is extremely important that there are no cuts, grazes or spots on your leg as this significantly increases the risk of infection. Your operation will be postponed until these have healed. You should avoid shaving or waxing your legs for one week prior to the operation.

After the operation

• You should be able to go home later the same day. Overnight stay may be required due to the affects of the anaesthetic or an inability to manage crutches.
• If you have had a meniscal repair your knee will be immobilised in a brace for up to 6 weeks.
• Physiotherapy is commenced immediately following surgery. A physiotherapist will supervise muscle contractions, walking and weight bearing.
• Sedentary and office workers may return to work approximately 2-3 days following surgery
• Return to sports / physical activity is governed by the type of surgery performed. If you have had a meniscal repair you will need a longer time to rehabilitate the knee.

Potential complications related to surgery

As with any operation, if something seems amiss it is better to get in touch rather than wait and worry.

Deep vein thrombosis and pulmonary embolus:

These are very rare complications, however, the combination of knee injury, immobilisation of the limb, smoking and the oral contraceptive pill or hormonal replacement therapy (HRT) all multiply to make the risk greater. You should inform the surgeon if you have any history of thrombosis. Smoking should be stopped a minimum of one week prior to surgery.

Excessive bleeding:

This is more common in patients taking aspirin or nonsteroidal anti-inflammatory drugs NSAIDs) - such as naproxyn, voltarol and ibuprofen. These should be stopped at least one week prior to surgery.

Infection (1 in 300 patients):

Surgery is undertaken in an operating theatre in an ultra clean environment. Despite these measures, infection can still occur. This may present with a feeling of warmth and redness around the knee. It is imperative that this is not treated with antibiotics until you have seen your surgeon. Prolonged courses of antibiotics and / or further operations may be required and the recovery period will be delayed.

Skin Numbness:

It is very common to develop a patch of numbness around your wounds. This is nothing to worry about and tends to shrink in size over time.

Portal Pain:

It is very common to experience pain around the scars. This may take up to a year to settle down.

Commonly asked questions