Definition outer meniscus tear
The outer meniscus (meniscus lateralis) is located at the outer edge of the joint space and, together with the inner meniscus, serves to stabilize and enlarge the joint surface of the knee joint. Since the outer meniscus has a higher mobility, injuries are rather rare here. Since meniscal lesions often occur in the context of sports accidents, men are twice as likely to suffer from meniscal lesions than women. Overall, the number of inner meniscus lesions is much higher than that of outer meniscus lesions.
Cause of the outer meniscus lesion
Basically two different causes of meniscal lesion are distinguished: Degenerative changes in the area of the menisci begin approximately from the age of 40. This depends on the strain on the knee. Sportsmen with very knee-straining sports such as: are particularly affected.
But also professions such as tiling put a lot of strain on the knees and can thus lead to spontaneous tears. Traumatic (accident-related) external meniscus lesions mostly affect young people. Often a clumsy movement in combination with an incorrect load is the trigger for a meniscus lesion.
The outer meniscus is affected when the knee is rotated inwards and an axial load (force from above) is applied at the same time. This would be typical, for example, in a foul game in football. Due to its significantly higher mobility, the outer meniscus is generally less frequently affected by injuries than the inner meniscus.
- Discus Throwing
- The degenerative causes (wear) and
- The lesion caused by accidents. There are different forms of meniscal lesion. A rough distinction can be made between a simple bruise (contusion) and a true meniscus tear.
The meniscus tear is subdivided again according to its course. The radial tear moves from the inner edge of the meniscus along the meniscus radius to the outside. If the tear line runs parallel to the inner edge after a bend, this tear is also called flap tear.
In the case of a tear in the handle of a basket, the tear line runs longitudinally through the meniscus and thus parallel to the main direction of the individual fibres. There is no connection to the inner rim and the front and back ends of the fibres are connected to the rest of the meniscus. If the free edge is moved (dislocated) into the joint space, this can lead to discomfort. The horizontal tear describes a tear that is horizontal to the meniscus.
If an outer meniscus lesion occurs acutely, the patient suddenly feels severe pain in the area of the outer joint space. This pain occurs mainly when walking. Sometimes, a snap over the joint space is also possible.
If the meniscus is snapped in the joint gap, the joint is blocked. As a result, bending or stretching of the knee joint is no longer possible. Small spontaneously occurring tears can often be asymptomatic.