Meniscus

Der Meniskus

The meniscus is made up of fibrous cartilage (similar to a spinal disc) and absorbs shock as well as stabilizing the knee joint. It is possible to damage the meniscus through acute injury and/or degenerative wear. 

Acute injuries generally occur while doing sports, but can also happen when simply standing up, if the meniscus is pinched and torn by a rotational movement at the same time. 

Bei festgestelltem Meniskusschaden ist oft eine Operation oft erforderlich, das muss aber genau beurteilt werden, denn nicht jeder kaputte Meniskus muss auch operiert werden. Oft führt ein Meniskusriss sehr rasch zu Knorpelschäden, daher ist eine sorgfältige Evaluierung der Vor- und Nachteile einer Operation ausgesprochen wichtig.

MRI assessment is always advisable.

Prolonged athletic restrictions are not necessary after a meniscus operation. It should be kept in mind, however, that there is a correlation between the degree of resected meniscal tissue and the statistical probability of early onset osteoarthritis. 

A return to athletics depends on the surgical method and the extent of damaged tissue.

The medial and lateral menisci carry out the shock absorbing function in the knee jointThey are crescent or sickle-shaped structures that lie between the thigh and lower leg. The meniscus (similarly to the intervertebral discs in the spine) consists of fibrous cartilage, a rubber-like substance, and, in addition to its shock absorbing function, is tasked with guiding movements of the knee joint and stabilising the joint in addition to the ligament structures.

Even with menisci, acute injuries (often this involves sporting injuries such as those sustained during skiing, football etc., however a meniscus injury can also be caused by significant turning when standing up from crouching), can be differentiated from degenerative, i.e. "wear-related" damage . Injuries of the medial meniscus are significantly more common than injuries of the lateral meniscus, as the medial meniscus grows firmly together with the Collateral Ligament . 

In the event that meniscus damage is determined, an operation (arthroscopy of the knee) is favoured very early on, even if there is no or very little pain, because a damaged meniscus causes constant wear on the cartilage. As a result, this can very quickly result in cartilage damage.

This irritation also rarely stops as the meniscus is barely perfused and can rarely heal itself.

There is only a good tendency for healing in the red zone (image 4). Perfusion and therefore the tendency to heal decreases constantly in a medial direction until zone III.

These constant wear movements on the damaged meniscus in untreated meniscus injuries lead to recurring pain on exertion, signs of impingement, swelling of the knee joint and secondary damage to the cartilage surfaces and therefore to early-onset arthrosis.

Cysts occasionally form on the base of the meniscus, this is called a ganglion (or meniscus ganglion). A ganglion is usually filled with a jelly-like fluid. In the majority of cases, a meniscus tear also exists, which must be treated immediately. Removal of the ganglion alone, without rectifying the cause, usually has no merit.

During arthroscopy of the knee joint , only the damaged section of the meniscus is removed and the meniscus is carefully smoothed.

Retention of the meniscus can be attempted in order to minimise the risk of arthrosis that exists following partial removal of the meniscus. Suturing of the meniscus is only carried out in rare cases, primarily in zone I (see image 4).

The advantage of meniscus refixation is that the increased risk of arthrosis, which exists following partial removal of a meniscus, can be minimised. The disadvantage of meniscus refixation is that patients are not permitted to bear weight on the leg that has been operated on for up to six weeks - and even then, there is still a relatively high risk of a repeat tear. The conditions for healing are only ideal if meniscus refixation was possible in zone I (see image 4).

FOLLOW-UP TREATMENT:

Following a meniscus operation (partial removal of the damaged meniscus), weight bearing on the leg is possible immediately, provided that the patient's pain permits this. Crutches are often only required for a few days. Bicycle riding or ergometer training is possible after two weeks, running after four weeks, and ball sports and skiing after six weeks. Following suturing of the meniscus and meniscus refixation, mobilisation on crutches with no weight bearing is required for four weeks, followed by two weeks in which weight bearing is permitted with half the patient's body weight. Immobilisation using a splint is often not indicated, with the exception of the presence of existing concomitant injuries, e.g. of the collateral ligament. Bicycle riding or ergometer training is possible after six weeks, running after twelve weeks, and ball sports and skiing after six weeks.

No restrictions are to be expected after a meniscus operation in terms of sport. Returning to the different types of sport depends on the operation method and the extent of the damaged meniscus tissue. It must be made clear, however, that there is a direct correlation between the extent of the resected meniscus tissue and the statistical likelihood of early-onset arthrosis. The more meniscus tissue that has to be removed, the more likely it is that the patient will suffer from early-onset joint wear (arthrosis).