General
The knee is a very complex joint with a supporting function for the body. It can mainly perform bending and stretching movements, but to a lesser extent rotary movements in the knee joint are also possible. In order to provide a high degree of stability, the knee is fixed by many structures.
In addition to the two cruciate ligaments, these include the ligaments that run along the side of the knee (collateral ligaments) and the menisci, which are located inside the knee joint. The two cruciate ligaments are very strong ligament structures that run inside the knee joint and connect the thigh bone with the shin bone. Since they cross relatively in the middle, they are called cruciate ligaments.
They can rupture under the influence of strong forces, whereby the front cruciate ligament ruptures about 10 times more frequently than the rear one. In most cases, this is caused by injuries during sports, such as overstretching, sudden braking, or other violent impact. During a magnetic resonance tomography, sectional images of the body are taken.
This method is based on applying a strong magnetic field and radio waves. There is no radiation exposure for the patient. During an MRI examination, especially the soft tissues of a joint can be displayed very precisely.
This also includes the cruciate ligaments. Therefore, an MRI is very well suited to detect a torn cruciate ligament. In some cases, however, a cruciate ligament rupture is present although it is not visible on the MRI images and vice versa.
In these cases, the MRI must be considered incorrect. The number of incorrect MRIs ́s depends on the quality of the MRI images and the diagnostician (radiologist-orthopedist). General information on cruciate ligament injuries can be found at
- Anterior cruciate ligament rupture
- Rupture of the posterior cruciate ligament
Before the examination can be performed, the patient must remove all metal objects from his body.
This includes jewelry, piercings, but also keys and wallets. All items of clothing with metal must be removed. Furthermore, no electronic devices may be taken into the examination room.
The patient lies down on a couch which is moved into the MRI tube. This can be done either with the head or with the feet first. The admission time is then about 15 to 20 minutes.
During this time, the patient has sound-proof headphones or headphones with music on the ears to drown out the knocking sounds of the MRI machine. It may be necessary to inject a contrast medium through the vein after the first recording sequence. This will allow a more precise representation of the structures in the joint. After the examination, a final consultation with a radiologist is held to evaluate the MRI images.
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