Knee joint and patellar dislocation

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Knee joint and patellar dislocation

In the knee there are three types of dislocations or subluxations: tibia, meniscus and patella. Dislocations complete tibia (front, back and side) - are extremely rare. Bending only anteroposterior (sagittal) direction, the knee is held by anterior-posterior displacement of powerful intra cruciate ligaments: anterior cruciate ligament (lig. Cruciatum anterius), which goes from the outer condyle anterior to the intercondylar fossa of the tibia (fossa intercondyloidea anterior tibiae) and strains with strong bending, and posterior cruciate ligament (lig. cruc. posterius), which goes from the inner condyle to the rear-top edge of the tibia and prevents hyperextension of the knee.

The force acting on the back or the shin in the sense of enhanced bending tearing the anterior cruciate ligament only. The posterior cruciate ligament while relaxing. Together with long lateral ligament it holds joint ends of the total dislocation, giving a subluxation forward. If, with continued effort, behind the front is broken and the posterior cruciate ligament, it turns a full dislocation forward.

Side view of the patella (kneecap) and the meniscus of the knee.

Under the action of forces on the front of the shin, or in the sense of hyperextension of the knee is strained and torn posterior cruciate ligament. This shift tibia posteriorly anterior cruciate ligament and relaxes while remaining intact, along with the long lateral ligament keeps the shin of the total dislocation, forming a posterior subluxation. The gap is continuing efforts of the anterior ligament gives complete dislocation posteriorly.

Complete dislocation of the tibia forward or backward requires very large, long effort, which should break both cruciate ligaments.

Lateral dislocation of the tibia requires not only the gap of both cruciate ligaments, but also both long lateral ligaments, and there is even rarer.

Rear view of the cruciate, lateral ligament and meniscus of the knee.

Clinical presentation a dislocation of the knee is so common that there is diagnostic difficulty. However, hemarthrosis at break internal ligaments can greatly hinder a correct diagnosis of dislocation. Profuse bleeding above and below the knee may be evidence of rupture of large vessels than is often complicated by the complete dislocation of the knee joint.

Reduction of dislocation of the knee joint performed pretty easily - by stretching the length of the lower leg with back pressure on the protruding ends. Fixation bandage fixed in position extensions for 4-6 weeks and then massage with careful active and passive movements.

X-ray of the knee joint during the motion control allows properly conducted reposition when dislocation.

Knee joint subluxation

More often dislocation of the knee joint seen front and rear subluxations. Subluxations are based on only one gap cruciate ligament, anterior or posterior, and learn of the history and hemarthrosis, with detachment of the anterior cruciate ligament palpation gives a sharp pain under the patellar ligament (lig. Patellae) - on the site of its attachment to the upper epiphysis of the tibia, and the posterior cruciate ligament tear - in the popliteal fossa, the site of attachment to the rear surface of the tibia.

There are a symptom of the tibia subluxation back and forth, which is called the syndrome "drawer" - a slight displacement of the tibia on the ends of the thigh. At rupture of the anterior cruciate ligament of the knee, hip and with fixed foot, slightly curved shank with two hands pushed somewhat to the femoral condyles forward and to break the rear cruciate ligament shin pushed posteriorly with the femoral condyles. Patients learn themselves did this extend and shin "drawer" retraction: fixing the foot end of the bed or on the other foot, straining slightly bent at the knee muscles, they produce a movement of the tibia condyles forward or backward.

Magnetic resonance imaging (MRI) of the cruciate and lateral ligaments and meniscus of the knee joint.

Fresh subluxations are treated the same way and dislocations - all the normal installation with a knee bandage, fixing the limb in position extensions for 3-4 weeks, followed by a massage and passive and active exercises.

In connection with the development of skiing, soccer, inline skates and snowboards subluxations knee began to meet more often. Chronic subluxations, repetitive and interfere with walking, sometimes these patients have to operate. For the restoration of torn cruciate ligaments proposed a number of plastic surgery, including arthroscopic surgery with minimally invasive endoscopic technique through.

Among the diagnosis methods of the knee joint dislocation doctor can be assigned:

  • CT scan of the knee joint (computed tomography)
  • MRI of the knee joint (magnetic resonance imaging)
  • X-ray of of the knee joint (arthrography)


Meniscus dislocation

Meniscus dislocation, mainly the medial were considered before it's too frequent. Currently, with widespread use of MRI of the knee found that more often than dislocation, there is a break (fracture) meniscus. Crescent-shaped menisci associated wide outside of the capsule, and rounded ends, with the cruciate ligament, prevent loosening side of the knee. Dislocation of the meniscus as tears occur most often during the rotation (rotation) of the body at a fixed stop. Net dislocated meniscus difficult differentiated from its rupture or fracture without the use of an MRI of the knee.

Leg in a special knee joint ligaments retainer.


Patellar (kneecap) dislocation

Dislocation of the kneecap (patella) occurs mainly in the outer side of the lower limb. In the mechanism of the side (lateral) dislocation of the kneecap (patella), the main factors are many: valgus position of the lower limbs, reduction of the intercondylar fossa, reducing external femoral condyle and the flattening of the patella, and the elasticity of the capsule laxity (instability) of the joint capsule after prolonged infection. The presence of these factors creates a very common after the first dislocation of the kneecap (patella) habitual dislocation.

The procedure for reduction of dislocation of the knee chaschechki done under anesthesia with nitrous oxide.

Availability kneecap (patella) to direct the feeling allows easy recognition of its bias. Even the primary dislocation of the kneecap (patella) are too rare to see and reduce a, t. To. Often the patient standing on his feet and bending the knee, thigh muscle relaxes square (quadriceps) and, at the same time rubbing his knee, reduce a kneecap (patella ). Especially do not have to see the surgeon secondary dislocations, as patients themselves are easy to learn to reduce a specified way - natural bending (flexion) in the pelvis at the hip unbent knee, with lateral pressure on the kneecap.

The procedure for reduction of dislocation in the knee joint is performed under intravenous anesthesia.

Often repeating habitual dislocation of the patella (patella) outwards have to operate. There are up to 55 different versions of fixing kneecap (patella) with habitual dislocation: using - extirpation of her, deepening the intercondylar fossa bone kondiloplastiki excised pieces of the capsule or her patella suturing, direct thigh muscles on the outside to the inside, and so on. N.

Depending on the degree and type of joint damage during ankylosis, the following conservative therapeutic action:

  • drug therapy (NSAIDs, analgesics, hormones)
  • therapeutic injection - the introduction of drugs into the joint cavity
  • manual therapy (muscle and joint type)
  • massage
  • physiotherapy (UHF, electrophoresis, SMT)
  • therapeutic exercises
  • surgical treatment

Most of these operations leaves long scars and restore motor function of the knee. There were even trophic changes in the damaged sensory branches n. cruralis and n. sapheni. Therefore it is best to perform the following, simple operation. Otseparovannoy transplant incision is made from the capsules of the lateral half of the patellar tendon, together with the corresponding part of the tibial tuberosity (tuberositatis tibiae). The latter is transferred to the medial surface of the tibia and with a strong tension is attached here under otsloёnnymi periosteal muscles, bones in the nick.