What are the menisci?
The menisci are two fibrocartilage structures that are located inside the knee. They improve joint function by being cushions that absorb body weight and pressure. In this way they provide the knee joint with a lot of stability and play a key role in proper joint function. The knees are the most vulnerable joints and can suffer greater injuries, since they support great pressures and assume any excessive force, making an effort of cushioning and dissipation of forces, where the menisci play a fundamental role.
In humans, in addition to the menisci of the knee, they are also found in the temporomandibular joint, in the acromioclavicular joint, in the wrist and in the ribs, at the junction with vertebral transverse joints. Complete menisci are in the sternoclavicular joint and wrist. Partial discs are at the knee and acromioclavicular. Partial or complete discs may be in the temporomandibular joint.
The menisci act as cushions that cushion the body weight and pressures.
Function of the menisci
The menisci can perform different functions:
- Absorb shock waves that occur during walking. The meniscus can absorb almost 20% of these waves.
- Load transmission. The fibers that make up the meniscus can transmit compression forces up to 50% when the knee is extended and up to 90% of the compression forces when the knee is flexed.
- Joint stability. If the knee fails, it may be due to laxity or rupture of the anterior cruciate ligament. Knee stability is influenced by the menisci, quadriceps and hamstrings.
- Proprioceptive sensitivity. The menisci help in the perception of proprioceptive sensitivity.
- Joint gliding. They contribute to joint lubrication, due to their high water content and shape.
Pathologies that can suffer the meniscus
Certain movements of the knee can produce lesions in the menisci, when they do not follow the displacements of the condyles on the glenoid. This happens when, for example, there is a sudden movement of extension of the knee, something very common in soccer players. In this case there is no time for the meniscus to move forward, remaining wedged between the condyle and the glenoid.
Another type of injury is the mechanism of knee distortion, associating external rotation and external laterality, which causes the meniscus to shift under the convexity of the internal condyle, resulting in a longitudinal meniscal tear. In addition, rupture of an internal ligament can also lead to meniscal tear. Meniscal tears are one of the most common injuries. Although it is typical in athletes, anyone can suffer this injury.
Tears can be different, depending on what they look like and where they occur. The most common are longitudinal, parrot beak, flap, bucket-handle and mixed/complex. In case of sports injuries they are usually accompanied by ligament injuries: anterior cruciate ligament and/or posterior cruciate ligament.
Treatments for meniscus pathologies
The main thing in this type of injury will be conservative treatment, which is sometimes sufficient for the meniscus tear, giving the knee time for the injury to heal on its own. This procedure is called RICE. Thus, R (Rest), I (Ice), C (Compression) and E (Elevation). This may be supplemented with anti-inflammatory medications to reduce pain and inflammation.
However, in other cases surgery may be necessary if the symptoms do not cease. In such a case the specialist in Traumatology will recommend, in most cases, an arthroscopy of the knee. During the arthroscopy a mini camera with a small incision is introduced in the knee, to be able to observe the interior of the joint. The specialist will make other small incisions (2 or 3), to be able to access the knee and repair the injury.
After surgery, the specialist will immobilize the knee and, when the wounds heal slightly, the patient should begin to perform rehabilitation exercises. In this way the mobility and strength of the joint will be restored.
Specialist who treats meniscus pathologies
The specialist who treats the pathologies of the meniscus is the traumatologist. Specifically, they are usually traumatologists who have specialized in the knee and in the approach to any pathology that this joint may suffer.