The meniscus is a structure of elastic consistency that lies between the femur and tibia, acting as a shock absorber. It has a special crescent shape so that the femur fits perfectly with the tibia. We have two menisci in each knee: an external and an internal one.
The most frequent mechanism of injury is by a twist of the knee. Isolated injuries of the meniscus can be found or associated with rupture of ligaments (anterior cruciate, internal lateral…) and/or of the articular cartilage.
Types of injury
The most frequently affected meniscus is the posterior part of the internal meniscus, but any part can be injured, depending on the movement performed. Due to the special form of blood supply of the meniscus, there are two types of tears: the more central localized ones (where no blood reaches and the lesion must be resected, since it does not heal) and the more peripheral localized ones (where blood supply does reach and it is possible to suture and preserve them).
When the ‘entire meniscus’ is torn and has to be resected, the pressure between the femur and tibia increases by up to 300%, with the consequent wear and tear of the cartilage in the medium term and early osteoarthritis. This is why, whenever possible, the meniscus should be preserved and sutured. Nowadays, the meniscus can be sutured by arthroscopy without any problems, thus preserving the natural ‘shock absorber’ of the knee.
Consequences of removal
It all depends on the amount and the area of torn and resected meniscus, the more meniscus resected, the greater the possibility of sequelae in the medium term. If over the years there is pain and limitations due to cartilage wear, there are other treatment options: from meniscal replacement with artificial collagen implants or meniscus transplantation with donor grafts. There are also novel treatments for focal cartilage lesions, such as that used with bone-derived stem cells and BST-Cargel.