Synonyms
Meniscus lesion, meniscus tear, meniscus tear, meniscus rupture, meniscus damage
Arthroscopy and open surgery
A proper meniscus tear is such a serious injury that it carries a high risk of consequential damage. Therefore, except in a few exceptional cases, where conservative therapy through physiotherapy and the administration of medication is sufficient, surgery can hardly be avoided. Especially younger patients and people who are active in sports are strongly advised to undergo surgical treatment of the torn meniscus.
Nowadays, most operations can be carried out with the help of a knee joint endoscopy (arthroscopy), which serves both for diagnosis and then for definitive therapy. Such an arthroscopy can be performed either under general or partial anesthesia. It is often possible that the operation is performed on an outpatient basis, i.e. the patient does not need to be admitted to hospital.
If this should be necessary, the stay will only be more than one week in exceptional cases. Open surgery is still the preferred option even today if there are other injuries to the knee joint in addition to the torn meniscus, such as damage to the surrounding ligaments or bones. In principle, there are different possibilities to surgically treat a torn meniscus.
Either the damage is repaired (meniscal fixation or meniscal suture) or the damaged part of the meniscus is removed (meniscal (partial) resection), which may then be replaced by an implant. A restoration of the meniscus is only possible if the tear or other injury is not too large. For this variant, the tear should also be located near the edge.
This is due to the fact that this part of the cartilage disc is still supplied with blood vessels and can therefore usually heal well after an operation. The repair is carried out either with the help of screws, special pins or arrows, sometimes the area can be simply sutured. In such a meniscus suture, the edges are first smoothed and then the meniscus is returned to its original position and shape.
This option should always be aimed at first. However, if this is not possible, a larger operation must be performed. If a part of the meniscus is actually torn off, it must be removed.
Depending on the type of damage, a small piece may be partially removed, in severe cases the entire meniscus may have to be removed. Depending on the size of the removed piece and how the functionality of the knee joint remaining after the surgical procedure is assessed, it may be necessary to insert an implant. This implant is typically made of collagen, but sometimes also of synthetic materials such as polyurethane.
The collagen ensures that the missing piece of meniscus does not cause bone to rub against bone, which would massively increase the risk of osteoarthritis of the knee joint. In extreme cases, there is also the option of a meniscus transplant, which is particularly suitable for younger patients. In this case, a donor meniscus from a deceased person is transplanted into the patient.
However, the benefit of this is not yet completely clarified. Some still doubt a long-term improvement of the condition with regard to the wear and tear of the cartilage. A knee arthroscopy can be performed either under regional anesthesia close to the spinal cord (epidural anesthesia) or under general anesthesia (general anesthesia).
Epidural anesthesia only anesthetizes the lower half of the body, the patient remains conscious. Usually with a curved back in a sitting or lateral position, a local anaesthetic is applied to the skin above the spine after disinfection of the injection site. This is followed by anesthesia near the spinal cord, which inhibits pain, sensations and active mobility in the lower half of the body for the duration of the procedure.
Complications of this type of anesthesia are, for example, a drop in blood pressure, which can usually be avoided by fluid intake. In some cases, headaches can occur after the operation due to the anaesthesia close to the spinal cord. In rare cases, if the epidural anaesthesia is complicated, a deeper anaesthesia than desired can be given (so-called total spinal anaesthesia), resulting in a drop in blood pressure, respiratory paralysis and a slowing of the heartbeat.
In this situation it may be necessary to switch to general anesthesia with artificial respiration. An extremely rare complication is injury to the spinal cord, with the risk of permanent paraplegia.Systemic side effects of the local anaesthetic may also occur, for example as an allergic reaction. With general anesthesia, on the other hand, the consciousness is switched off together with the sensation of pain, the patient cannot be awakened.
Artificial respiration and airway protection is necessary. After general anesthesia, nausea and vomiting, coughing, hoarseness and difficulty swallowing often occur as side effects. Sometimes there may be muscle tremors or sensation of cold.
In very rare cases, general anesthesia can lead to complications such as damage to the teeth, vocal chords or pneumonia. After the anaesthetic has been administered, in arthroscopic meniscus surgery a blood pressure cuff is attached to the thigh and inflated, thus achieving a so-called tourniquet. As a result, there is hardly any blood loss during arthroscopy.
As a rule, an outpatient arthroscopic operation is performed in case of a torn meniscus. This means that the operated patient can leave the recovery room a few hours after the operation in company and be discharged home. It is not advisable to drive a car during this procedure.
For some time after the operation, the knee should be relieved with the help of forearm crutches, but it is possible to load the operated leg with part of its body weight (approx. 20-30 kg) already on the first day after the operation. Thromboembolism prophylaxis (so-called “abdominal injections”) is necessary for the time when the crutches are needed.
The treating physician also frequently prescribes anti-inflammatory and painkilling medication, which should be taken regularly. The small puncture marks can be somewhat sensitive for a while. Some people experience a feeling of “splashing” of fluid in the knee joint after the operation; this can certainly occur and is caused by residual fluid from the arthroscopy.
The sutures should be covered with waterproof plasters to protect the wound until the stitches are removed (after about one to two weeks). Careful showering is thus usually possible, bathing and swimming should be avoided for about two weeks. If a drainage was inserted into the knee joint during the operation to allow wound secretion to drain away, it is usually removed after one or two days.
In order to minimize knee swelling, the knee should be protected, elevated and cooled with ice for the first few days. Going to the sauna or sunbathing increases the risk of severe knee swelling, so these things should be avoided for a few weeks. It is important to take care of the affected leg after the operation, but this will quickly lead to the loss of thigh muscles.
In consultation with the treating physician, muscle training and physiotherapy should therefore be started as soon as possible. During the first six weeks after the meniscus operation, the knee should not be bent over 90 degrees under load, so you should not squat. There can be individual differences, so all loads should be increased slowly, even if the knee no longer hurts, because the tissue that is being built up is still in the process of maturing. It is important that the knee is not exposed to any shock loads in the first weeks after the meniscus operation (e.g. by hard shoe heels). This can lead to so-called fatigue fractures in the tibial plateau, especially in older people.