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 is perfectly coupled with the tibia. We have 2 menisci in each knee, one external and one internal.
Meniscus Injury
The most frequent mechanism of injury is by a twist of the knee. Isolated lesions of the meniscus or associated with rupture of ligaments (anterior cruciate, internal lateral…) and/or articular cartilage can be found.
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 2 types of tears:
1. The more central localized ones (where blood does not reach and the lesion must be resected, since it does not heal).
2. The more peripheral localized ones (where blood supply does arrive and it is possible to suture and preserve them).
Fig. 1: torn meniscus. Fig. 2: normal meniscus
How to treat it
When the “whole meniscus” is torn and has to be resected, the pressure between the femur and tibia increases by up to 300%, with consequent wear of the cartilage in the medium term and early osteoarthritis. This is why, whenever possible, the meniscus should be preserved and sutured. Today, the meniscus can be sutured arthroscopically without any problems, thus preserving the natural “shock absorber” of the knee.
Fig. 3: Condition after partial resection of the torn meniscus
The more meniscus resected, the greater the possibility of medium-term sequelae. 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 the bone’s own stem cells and BST-Cargel, a product that is applied during cartilage repair procedures.