Diagnosis

In most cases, the anamnesis (medical history) and description of the accident course are groundbreaking for diagnostics. During palpation of the joint space, a painful feeling of pressure is evident. In some cases, an accompanying knee joint effusion occurs due to the joint inflammation.

There are different meniscus signs, which should be checked if an inner meniscus lesion is suspected. There are different meniscus tests that can trigger a positive meniscus sign. A passive external rotation of the affected knee joint causes pain.

This is called a positive Steinmann I sign (positive meniscus sign). When testing the joint space, the resulting pressure pain moves backwards (dorsally) when the knee joint is bent. This is known as a positive Steinmann II sign.

If the patient sits cross-legged, pain occurs in the joint space.This is caused by the injured inner meniscus, which exerts pressure on the medial joint space and is called the Payr sign. The Apley test can also be used to check the function of the inner meniscus. Here the patient lies on the stomach while a flexion of ninety degrees is performed in the knee joint.

Pressure on the sole of the foot and external rotation causes pain (meniscus sign) in the inner meniscus lesion. The posterior horn is the most common site for a torn meniscus in the inner meniscus. Often, a longitudinal tear occurs here, which is usually caused by long-term stress rather than trauma.

In principle, these longitudinal tears can heal by themselves. The outer edges of the meniscus are not affected by this type of damage. However, there is a risk that the tear will be intensified under further strain and thus spread through the entire meniscus, or that it will widen into a so-called basket handle tear.

This can then cause a part of the meniscus to fold over and thus lead to a complete blockage of knee mobility. Horizontal tears also often start in the posterior horn of the inner meniscus, but these are usually more likely to occur after an accident. In principle, all the surgical procedures described above can be used in this area of the meniscus.

A special therapeutic option, which is mainly used for a small lesion of the posterior horn of the inner meniscus, is the injection of hyaluronan to the affected parts. The hyaluron should help to close the tears and stimulate the formation of new cartilage. However, even with this therapy, further stressing carries the risk of an expansion of the inner meniscus lesion and thus a deterioration of the findings.