Synonyms in a broader sense
- VKB Rupture
- Cruciate ligament lesion
- Anterior knee instabilityanteriors
- Knee instability
- Anterior cruciate ligament insufficiency
- Chronic insufficiency of the anterior cruciate ligament
- Cruciate Ligament Rupture
- Cruciate ligament plastic
- Anterior cruciate ligament injury
Definition
A fresh anterior cruciate ligament rupture is the complete or partial interruption (rupture) of continuity (tear) of the ligament after the overstretch reserve has been exceeded by external force. An old anterior cruciate ligament rupture is a permanent, mostly accident-related ligament injury.
Cause for cruciate ligament ruptures
Causes are often so-called “Flexion-Valgus-Outside Rotation Injuries”. This means that the knee is involuntarily bent, turned into the knock-knee position and turned outwards. Typically when skiing or playing soccer, such injuries occur with a fixed lower leg. An instability of the knee joint due to the loosening of the capsular ligament apparatus can occur. The result is a derailment of the roll-slide mechanism and increasing degenerative (wear-related) cartilage damage and meniscus.
Complaints and symptoms
Patients with a torn cruciate ligament sometimes suffer from severe pain in the knee joint, which usually swells up within the first few hours. The doctor will try to examine the knee with so-called stability tests. This is not too easy to do because of the general painfulness, as the patient uses his or her muscles to counter-tension.
In most cases, the examination can only be determined a few days after the rupture of the anterior cruciate ligament, since only then is the pain caused by the accident reduced to such an extent that the patient can be examined without defensive tension. A normal X-ray provides information about any bony injuries that may be present at the same time. A larger joint effusion should be punctured in order to relieve the cartilage and the remaining soft tissue.
If the effusion is bloody, it is suspected that the cruciate ligament has been torn, although this is not evidence. With the widespread use of magnetic resonance imaging, with which the cruciate ligaments or their remnants are very clearly visible, the diagnosis can be predicted with relative certainty. In the image above, the red arrows indicate the torn cruciate ligament (rupture of the anterior cruciate ligament).
The damage can be verified by means of magnetic resonance imaging. The slice images show the course of the cruciate ligaments and their attachment to the thigh and lower leg bones. In the case of a rupture, the fibre courses are not continuous and the localisation of the rupture becomes possible.
Only a few years ago, all patients would have to undergo surgery due to a lack of diagnostic possibilities. These times are over, because with the magnetic resonance imaging (MRI) examination, the damage that has occurred can be estimated very accurately and possibly necessary operations can be planned. The X-ray image is normally inconspicuous in isolated cruciate ligament ruptures.
However, since similar symptoms can also be caused by a torn meniscus, for example, it is difficult for the layperson to make a diagnosis. Here again all examination methods to diagnose an anterior cruciate ligament injury Clinical diagnostics by the orthopedist:
- Assessment of knee swelling, joint effusion, range of motion and motion pain
- Assessment of gait pattern, leg axes
- Evaluation of the femoropatellar joint (sliding bearing of the patella)
- Assessment of knee stability and meniscus
- Muscular atrophy (weakening of the muscle relief)
- Assessment of adjacent joints
- Assessment of blood circulation, motor skills and sensitivity (feeling on the skin)
Apparative diagnostics (diagnosis by equipment) Necessary apparative examinationsX-ray: knee joint in 2 planes, patella (kneecap) tangential Apparative examination useful in individual cases
- X-ray: Knee joint p. a. in standing position in 45 degree flexion
- Fricke image (tunnel image) to show a bony tear of the anterior cruciate ligament of the femur
- Captured images
- Whole leg images under load
- Functional images and special projections
- Sonography = ultrasound (e.g. for meniscus, Baker’s cyst)
- Computer tomography (in case of a tibial head fracture = tibial head fracture)
- Magnetic resonance tomography (cruciate ligaments, menisci, bone injury)The MRI is the most valuable diagnostic tool in the case of an anterior cruciate ligament rupture, since the MRI can assess partial damage in particular. An MRI for a torn cruciate ligament helps to better assess the prognosis of the knee joint.
In order to document the extent of a cruciate ligament injury (torn anterior cruciate ligament), the anterior drawer test is often performed.
In this test, the knee joint is angled at 90° and the foot is fixed on the base. Now the examiner pulls the lower leg close to the knee joint and assesses whether the lower leg can be pulled out in relation to the thigh. Classification of the anterior drawer sign according to Debrunn Grade I (+): slight displacement 3-5 mm Grade II (++): medium displacement 5-10 mm Grade III (+++): pronounced displacement > 10 mmIn an experienced examiner, the diagnosis of a cruciate ligament rupture is usually possible very quickly and reliably even without imaging.
Nevertheless, MRI has established itself as the standard method. In contrast to X-rays or CT, MRI allows all ligaments and soft tissues of the knee to be displayed and thus existing tears to be detected in principle. However, partial tears are often difficult to visualize on an MRI.
In this respect, the MRI is less reliable for making a diagnosis than a good examination by an experienced examiner. Nevertheless, an MRI examination of the knee after an injury, in which the cruciate ligament may also be affected, is often useful. MRI often enables the physician to assess what treatment is now required and how quickly, if necessary, surgery should be performed.
MRI can also often clearly identify possible injuries to other structures (meniscus, inner and outer ligament) of the knee. This information then also has a significant influence on whether and how quickly surgery is required. If, however, the examination already shows a rupture of the cruciate ligament and the course of the accident does not suggest that other structures are also damaged, an MRI is not necessarily necessary and often does not provide any new information.
If an injury cannot be precisely detected and narrowed down by MRI, a knee examination is usually necessary.
- Quadriceps Tendon
- Thigh bone (femur)
- Torn anterior cruciate ligament (red arrow indicates a tear)
- Shinbone (Tibia)
- Kneecap (patella)
- Hoffa ́scher Fat body
- Patellar tendon (patellar vision)
Surgery is usually the method of choice for cruciate ligament rupture. Only if the posterior cruciate ligament is torn, or if the tear is very slight, surgery may not be necessary.
However, this always involves the risk that the knee is less stable and less resilient in the long term. For this reason, the operation is highly recommended, especially for younger people, especially if they are active in sports. However, the operation is only performed when the inflammation and swelling of the knee has subsided sufficiently.
This is usually the case after about 4-6 weeks. This waiting period is important, as surgery in irritated tissue can lead to much worse results. An operation directly after the injury is only performed in very severe cases involving bone structures.
Meanwhile, the cruciate ligament rupture can be operated on minimally invasively, which reduces complications and accelerates healing. The whole procedure is therefore then performed within the scope of a knee endoscopy (arthroscopy). The surgery itself then consists of completely replacing the destroyed cruciate ligament with other ligament structures.
Repairing the old ligament only leads to insufficient results. For this reason, parts of the ligament from adjacent ligaments are usually removed. The ligament of the patella or of a thigh muscle, for example, is suitable for this purpose.
The ligaments are removed in such a way that they can still fulfill their own function without any problems. The removed piece of ligament is then adjusted as precisely as possible to take over the function of the torn cruciate ligament. However, this method can cause sometimes quite severe pain at the removal site.
This is especially the case when a part of the patella tendon is removed. On the other hand, this type of implant usually grows in somewhat faster. Ligament sections obtained as part of organ donation can also be used, but these have the disadvantage that they can lead to rejection of the foreign material.In return, the pain at the removal points of the autologous tendons is avoided.
Various systems are used to attach the ligament to the knee: On the one hand, simple metal screws or fixation buttons, but also absorbable materials can be used. The result of the operation is then of course also determined by good rehabilitation. Besides the general complications of an operation, such as: there are special risks for a cruciate ligament operation.
So-called operation-specific complications include :
- Infection
- Bleeding
- DeafnessParalysis
- Arthrofibrosis – a particularly dreaded complication. This is a partial stiffening of the knee joint after cruciate ligament plastic surgery through scarring. The risk of arthrofibrosis is particularly high if surgery is performed shortly after the accident.
- Cyclops syndrome – due to scarring of the cruciate ligament, which results in a stretching deficit
- Cruciate ligament plastic impingement – the cruciate ligament graft becomes trapped between the femoral rolls during stretching, which prevents complete stretching of the knee joint.
