Hyperextension of the knee - in short summary
Within the knee joint there are four band structures. In a strong overstretching of the band structures in the knee joint, usually due to a sports accident, the bands can not withstand the load and tear or completely rupture. The main symptom is acute acute pain immediately after the event. Accompanying may be a restriction of movement, disability and joint effusion. The doctor examines the knee joint, X-ray and magnetic resonance imaging complement the diagnosis. The therapy depends on the findings, ie which ligaments are affected to what extent and range from restraint and protection (conservative therapy) to surgical treatment.
What is a Hyperextension of the knee ?
The knee joint is stabilized by multiple ligament structures: the outer band, the inner band, the anterior and posterior cruciate ligaments. Especially in sports accidents, these band structures can be overstretched and partially or completely tear (ligament tear, ligament rupture). It can only come to the tearing of a single band (isolated rupture), but often several structures are affected, there is often oneMeniscal injury . Especially sports with a fixed foot such as skiing or playing football with studded shoes pose an increased risk.
Background information - The knee joint
The knee joint can be bent and stretched, as well as easily turned in the bending state. It is exposed to great stress and at the same time has to offer enough mobility. Bones are composed of the knee joint (femur), the tibia (shinbone) and the kneecap (patella). The femur and tibia are covered with cartilaginous tissue, the joint space is only a few millimeters. The knee joint is stabilized by the surrounding capsule as well as several ligaments (lateral collateral ligaments, anterior and posterior cruciate ligament). The anterior cruciate ligament arises at the lower leg in front and pulls through the knee joint to the thigh to the rear. The posterior cruciate ligament pulls from the thigh to the front of the lower leg, so the two bands intersect, hence the term cruciate ligament. The menisci consist of cartilaginous tissue and serve to buffer and rotate and to increase the articular surfaces. There are two menisci (inner meniscus, = meniscus medialis and outer meniscus = meniscus lateralis), the inner meniscus is fused with the inner band and therefore immobile and vulnerable to injury.
Causes of a ligament tear
A ligament tear in the knee can occur when ligaments are stretched beyond their elastic limit. If this limit is exceeded only slightly, it will stretch or strain the tape. In the case of stronger force, the band eventually tears partially (partial rupture, partial rupture) or completely (complete rupture, complete tear of the ligament).
The unhealthy force arises mostly in accidents, mainly sports accidents. Sometimes even several tapes break at the same time. In addition, cartilage, menisci, articular capsule or bone may be injured.
Scientists believe that some people are at higher risk for torn ligaments than others. The causes are not clear. Maybe they are partly already in the genetic material. Women are more at risk of anterior cruciate ligament ruptures (cruciate ligament ruptures) than men. The individual fitness also plays a role. The risk for ligament injuries also increases when the warm-up before the sport is deficient.
A ligament tear in the knee, for example, a cruciate ligament rupture, is often the result of a ski accidentTypical sports accidents: This leads to a torn ligament
Most often, the ligaments in the knee - especially the anterior cruciate ligament - are torn by an indirect trauma. That means: In a sports accident no other athlete is involved.
This happens, for example, in the event of a jump or an abrupt change of direction: The athlete stops out of full speed and suddenly because he wants to change his direction. His foot is firmly attached to the floor, the knee is stretched or only slightly bent, the leg in a slight "X-leg position" - the upper body turns but already with momentum in the new direction. Episode: The knee twists too much. The bands give way. Sports such as football, handball, basketball, tennis or squash offer ample opportunity for such disastrous maneuvers.
Even skiers have an increased risk of injuring their knee joints. Example: A skier ascends in an arc. The valley ski goes its own way and - together with the foot - drives in a different direction down the slope. The result: The knee joint is excessively over-turned outwards, straining the ligaments. Or: In a fall, the bonds do not dissolve in time. The skis fall with their feet in different directions and act like a lever on the knee joint, increasing the twist beyond the injury limit.
Classification of ligament injuries:
- Anterior cruciate ligament rupture: An anterior cruciate ligament tear can be isolated or combined with a multiple injury and is a typical sports injury, especially in fixed-foot sports.
- Posterior cruciate ligament rupture: The overall rare ACL tear (the posterior cruciate ligament rupture) is more often caused by direct trauma, ie external violence: This includes traffic accidents or clashes between players in team sports. In most cases, the knee injury is worse on the whole: in addition to the posterior cruciate ligament, other joint structures are often injured.
- Internal ligament rupture: They are among the most common sports accidents. Accompanying injuries with bony eruption of the ligament, an anterior cruciate ligament tear and / or inner meniscal tear are often found. In violation of all three structures mentioned above (inner ligament, inner meniscus and anterior cruciate ligament) one speaks of the so-called "unhappy triad" (unfortunate triad).
- Outer rupture: Pure lateral ligament ruptures are extremely rare. When the outer ligament is torn, there is usually a more complex lesion of the capsule-ligament apparatus and the cruciate ligaments.
Symptoms of ligament injury:
If there is a ligament rupture in the knee joint , sometimes even the tearing off of the band can be heard aloud. Other symptoms that indicate partial or complete tearing are:
- Pain : A tearing of the ligaments in the knee causes intense pain that begins immediately after the event, and that can subside again in the course of time.
- Swelling : After ligament rupture, swelling often develops in the knee joint. Cause is an articular effusion by increased fluid accumulation or hemorrhage in the joint (hemarthrosis).
- Limitations of movement : Due to the pain, accompanying swelling and instability, the knee joint is significantly less resilient and limited in its mobility.
- Instability : After a complete ligament tear in the knee, the joint may show instability. Depending on which band is affected by a crack, this instability is different. Most of these occur only after weeks or months. In an anterior cruciate ligament rupture, there is a feeling that the joint or lower leg may slip forward. A "giving-way" can also exist. If there is a tear in the outer or inner band, the lateral stability of the knee is impaired.
Low on symptoms: Chronic ligament injuries
If a ligament injury in the knee is ignored, the knee may become permanently unstable. If you hurt your knee, you should go to a doctor. Especially untreated ligament tears harbor an increased risk of premature joint wear ( knee arthrosis ).
Diagnosis of ligament injury
The doctor first inquires about the patient's complaints and triggers (accident mechanism). The medical history of the patient is also of interest.
Examination of the knee:
The symptoms of ligament rupture may be similar to discomfort with ligament stretch. Therefore, the doctor applies certain orthopedic tests (stability studies). They help to make that distinction. These tests examine the knee joint for abnormal mobility, ie increased mobility. An unnaturally large range of motion in the knee strongly indicates that a band is torn. For example, if the joint is "hinged" sideways, so it has more play than usual, this could indicate the injury of a sideband.
Common stability tests are the so-called Lachman test and the drawer test. They are used to diagnose or exclude cruciate ligament tears (cruciate ligament ruptures). In the drawer test, the doctor checks whether the lower leg can be moved more than usual forward or backward relative to the thigh (drawer phenomenon).
Since the range of motion in the knee differed from person to person, physicians take as a comparison value for the normal range of motion, the intact joint. So you check both knee joints in comparison.
Imaging procedures :
X-ray examination: The X-ray image is mainly used to exclude bony accompanying injuries and is made for every knee injury. The bands themselves are not displayed in the X-ray image.
Magnetic Resonance Imaging (MRI): The MRI examination is highly informative, since not only the ligaments can be assessed, but also the extent of the injury, effusion and the smallest cartilage and bone damage. The MRI is used primarily for more complex injuries.
The computed tomography ( CT ) and ultrasound can be used in special cases also.
Arthrocentesis:
If a large effusion has formed in the knee joint, the doctor may remove some of the fluid via a hollow needle in order to relieve the knee (joint puncture). As a result, a pressure relief is possible, which leads to pain relief. At the same time the joint mobility and thus the possibility of a better examination of the knee joint increases. The analysis of the withdrawn fluid can provide indications for the diagnosis: If blood forms in the joint effusion, this makes ligament rupture more likely.
Therapy of ligament injuries:
Immediately after a sports accident, the so-called PECH rule has proven itself. This stands for:
- Rest : Protect the affected lot.
- Ice : so cooling (Caution: do not lay ice directly on the skin, otherwise frostbite is threatening)
- Compression: Apply elastic pressure bandage
- Elevation : high up the affected leg.
For knee injuries, a doctor should be consulted to ensure the accurate diagnosis.
Keyhole surgery on the knee: doctors usually repair torn ligaments as part of a joint mirroring (arthroscopy)Torn ligament: Which therapy is the right one?
A torn ligament can be treated conservatively, ie without surgical intervention or surgically. The choice of which method to use depends, among other things, on the extent of the injury.
Other points that speak more for an operation are:
- The knee joint does not have sufficient stability anymore
- The injury is complicated or extensive, affecting, for example, other joint structures or the bone
- The patient is still young and is likely to survive an intervention very well
- The patient practices a sport or a profession that puts a heavy strain on his knees
If it is an (older) uncomplicated ligament injury in an elderly patient who no longer demands maximum performance from his knees, and the knee still has sufficient stability, conservative treatment can bring quite satisfactory results.
But there is no general age limit for surgery. Anyone who still wants or has to use his knees intensively, despite his advanced age, can definitely opt for an intervention - provided that there is nothing else against it.
Conservative therapy
The conservative therapy, ie non-operative, consists mainly in an immobilization of the affected knee joint. For this purpose, the doctor prescribes, for example, a (movable) splint, a so-called orthosis, or crutches. Mostly the treatment lasts several weeks.
Medications can relieve the symptoms. The doctor recommends analgesic, anti-inflammatory and decongestant medicines.
An important therapy element is the subsequent strengthening of the leg muscles. It gives the joint additional stability. Because not every band grows together again by itself. Its function must then at least partially take over other ligaments and muscles .
Operative therapy
The operation on the knee is usually minimally invasive, in "keyhole technique" via a joint mirroring (arthroscopy). This means that the doctor uses very small incisions, through which thin optical instruments (a camera for imaging) and surgical instruments are inserted into the joint (see graphic above). The procedure can be performed inpatient or outpatient.
As part of such arthroscopy , physicians can accurately inspect the joint. At the same time the therapy can be carried out. For example, in an anterior cruciate ligament rupture, the ligament may be reconstructed by a new one of endogenous or very rarely exogenous material. For this purpose, parts of healthy tendons from the patient's leg muscles or from the patellar tendon (patella tendon) are removed in an open procedure and inserted and anchored as a replacement for the torn ligament.
Likewise, any injuries to bones, joint capsule or menisci can be seen and treated.
Possibly Doctors go in stages before: First, they examine, for example, the injured joint by Gelenkspiegelung, remove it immediately the band stumps of the torn band, sew the torn meniscus again or remove it in part. The patient then receives physiotherapy for a few weeks until the joint is completely swollen. Then - by renewed arthroscopy - the actual repair of the tape. The operation should only take place if the joint is not overheated or reddened and is able to move normally again.
Supports healing: Physiotherapy
Conservative or operative treatment of a ligament tear in the knee is usually followed by physiotherapy. This follow-up treatment is designed to aid and accelerate healing, restoring impaired knee stability as quickly as possible. The most important element are specific exercises for muscle building ( physiotherapy ).
Coordination training is also important. It enables the patient to better absorb adverse movements that could compromise the knee. It also helps to compensate for deficits caused by the loss of a "natural" bond. Because healthy ligaments provide the body with built-in probes at any time feedback on the exact position of the limbs. If this built-in control is lacking, the organism must first adapt to the new situation.
The knee joint is gradually becoming accustomed to growing strain. It can take up to a year until the knee joint has regained full fitness after a torn ligament. When the knee is fully operational again in an individual case, the attending physician knows.
A ligament injury can lead to premature wear of the knee joint - especially if it does not heal properly. In particular, cruciate ligament ruptures (cruciate ligament ruptures) favor a subsequent knee osteoarthritis .