The meniscus tear is one of the most common knee injuries and usually occurs when the femur and tibia in the knee joint twist violently against each other under high pressure (knee torsion). This severely overloads the inner meniscus and can cause it to tear. Meniscus tears are common in younger people who do a lot of sports.
A typical symptom of a meniscus tear is very severe pain when twisting or bending. Those affected often report a popping or whipping noise, along with swelling in the knee.
How a meniscus tear manifests also depends on the severity of the injury. If there is a major injury to the meniscus, movement of the knee is severely restricted and swelling of the knee occurs.
Less severe meniscal injuries often go unnoticed for some time. It can be the case that pain only arises after several hours or days. In some cases, it may be several weeks before the patient notices the meniscus damage.
In order to confirm the meniscus tear, the doctor will carry out various examinations, as well as asking how the injury occurred.
During the initial examination, the doctor feels the knee to find out where the pain is or if there is swelling in any parts of the meniscus. The knee is then bent and rotated in various positions. This creates pressure on different areas of the menisci, which triggers the pain. An MRI is taken to rule out the possibility of injuries to other parts of the knee.
The meniscus can tear when the knee is twisted. The greatest risk of a meniscus tear occurs when the leg is twisted with the foot flat on the floor and the knee bent.
Risk factors include sports with rapid changes of direction and frequent start-stop movements, such as football, tennis and handball. Individuals with previous conditions or a history of cruciate ligament surgery also have an increased risk, as these affect the stability of the knee.
Meniscus damage can also occur in old age or by certain jobs that require frequent squatting or crouching.
Meniscus tears can be treated conservatively or surgically. The method of treatment depends on the age of the patient, the diagnosis and whether there are other knee injuries.
It is possible to live with a meniscus tear if you lead a less active lifestyle or if you can avoid all twisting and flexing of the knee joint in day-to-day life.
The main conservative treatment for a meniscus tear is physiotherapy. The aim of this is to strengthen the muscles and improve stability and mobility.
The meniscus will not grow back together by itself. There is a risk that the tear will get bigger with every turning movement, in which case the patient will experience new, stabbing pains in the knee. In the worst case scenario, the knee joint may become locked.
Surgery is usually recommended in the following cases:
There are different meniscus operations that can be carried out, such as:
The interventions are all minimally invasive with the help of joint endoscopy (arthroscopy). Small incisions of about one centimetre are made to the right and left of the kneecap tendon, through which a video camera and the appropriate instruments are inserted.
With the aid of meniscus suture, the torn meniscus tissue is connected to the healthy part of the meniscus and the joint capsule to reinstate the blood flow to the torn meniscus tissue, allowing the healing process to begin.
Not all meniscus tears can be sutured. The decision to go down the meniscus suture route depends on the age of the patient and the location of the tear.
Whether or not a meniscus suture is possible can only be determined during the arthroscopy. In 20% of patients who have undergone this treatment, the suture does not heal and further tearing occurs. If this happens, the operation has to be repeated.
The most common procedure for a meniscus tear is removal of the meniscus. This is carried out when the meniscus has torn several times or has deteriorated so much over time that it can no longer be sutured.
The part of the meniscus that is no longer functioning is removed, the aim being to remove “as little as possible, but as much as necessary.” This procedure is called a partial meniscus resection because only the torn pieces of the meniscus are removed. A meniscus resection is where the entire meniscus has to be removed. With these procedures, the problematic mechanical complaints are eliminated and the symptoms disappear very quickly.
However, this operation reduces the weight-bearing surface of the joint, which increases the risk of another tear if the knee is overloaded or twisted. It also increases the risk of osteoarthritis in the knee. Therefore, the first step is always the meniscus suture.
In very rare cases, the meniscus needs to be replaced.
Meniscus replacement is mostly used in younger patients with little or no cartilage damage. A meniscus transplant is performed using a donor meniscus. The replacement meniscus is made from polyurethane, which is gradually replaced by the body’s own tissue. It is also possible to fill the gap with biological tissue replacement.
Aftercare depends on the type of surgery. During the aftercare period, physiotherapy is used to support movement and build muscle. This can take up to three months.
The operation lasts between 30 and 60 minutes.
Depending on the type of activity involved, the patient may be off work for up to eight weeks.