Knee dislocation
Introduction
Introduction to knee dislocation Dislocation of joints refers to the loss of a normal correspondence between the articular surfaces of the various bones that make up the joint. Clinically, it can be divided into traumatic dislocation, congenital dislocation and pathological dislocation. After dislocation of the joint, soft tissues such as joint capsule, ligament, articular cartilage and muscle are also damaged. In addition, the joint around the joint is swollen and may have hematoma. If it is not reset in time, the hematoma is mechanized and the joint is stuck, causing the joint to lose function to different degrees. basic knowledge The proportion of illness: 0.001% Susceptible people: no specific population Mode of infection: non-infectious Complications: sciatic nerve injury
Cause
Cause of knee dislocation
Cause (90%):
The upper part of the humerus is subjected to strong direct or indirect violence to rotate the knee and cause injury when stretched. Because there are many structural special ligaments around the knee joint and joints to maintain the stability and function of the joint, and it is tough, the traumatic dislocation of the knee is rare, and when the upper end of the humerus is subjected to strong direct violence, such as Car accidents, competitive sports, etc., can cause severe laceration of certain ligament structures. When the violence exceeds the mechanical strength provided by the stable structure, the knee joint can be dislocated, so it can be considered that the knee dislocation is definitely accompanied by knees. In the case of joint-stable structural trauma, in some cases, violence may also cause ligament structural damage, causing fractures of the humeral condyle and causing fracture-dislocation of the knee joint, but the violent strength of the knee joint stability injury is not enough to cause the knee When the joint is completely dislocated, the femur is abnormally moved on the tibia to cause subluxation before complete dislocation, and the patellofemoral subluxation is easy to be immediately reset without leaving any deformity, so it is often diagnosed as knee instability in the clinic. disease.
Prevention
Knee dislocation prevention
1. Prevention of joint dislocation The main prevention of this disease is to strengthen labor protection and prevent trauma. Before exercise, adequate preparations should be taken to prevent injury. Children should avoid pulling hard.
2. Perform adequate warm-up activities before exercise to improve the excitability, responsiveness and confrontation ability of muscle tissue, and gradually increase the degree of confrontation, which is helpful for reducing joint dislocation.
3, homeopathic tumbling professional athletes in the fall of some self-protection measures, it is also worth learning from ordinary people. For example, when a volleyball player saves a ball or a football player falls after a collision, he will roll over and change his hand directly to the palm of his hand and gradually roll over the elbows and shoulders. Sometimes, athletes roll on the ground for several laps, as if they are stressed, but they can stand up and continue to fight. The reason is that the huge impact when they land is shared by multiple parts of the body during the tumbling, so Will focus on a certain location and cause serious damage.
Complication
Complications of knee dislocation Complications sciatic nerve injury
Knee dislocation often also complicated by vascular nerve injury, the incidence of which can be as high as 50%, vascular injury is more common in anterior dislocation, and the observation of the dorsal artery of the dorsal artery and the observation of distal blood supply can give an impression of vascular injury. Further examination, including angiography or surgical exploration, vascular embolization may lead to limb necrosis, must be vigilant, nerve damage accounted for 16% to 43%, sciatic nerve injury is the most common.
Symptom
Knee dislocation symptoms Common symptoms Knee bruises swelling and painful swelling of the knee joints... Joint swelling Knee joints can not fully straighten knee sprains Knee weakness Weak soft legs Adolescent knee pain Knee bruise
According to the degree of dislocation and whether there is a fracture, the dislocation of the knee is divided into the following three categories:
Knee joint (full) dislocation
According to the position of the relative position of the humerus and the distal femur at the time of dislocation, it was divided into: 1 anterior dislocation of the knee joint; 2 posterior dislocation of the knee joint; 3 lateral dislocation of the knee joint; 4 lateral dislocation of the knee joint; 5 rotational dislocation of the knee joint.
The frequency of joint displacement in the dislocation of the knee is generally arranged in the following order: anterior dislocation, posterior dislocation, lateral dislocation, rotational dislocation and medial dislocation. The incidence of anterior dislocation of the knee is twice that of posterior dislocation, and dislocation to the medial side The case is about 1/8 of the anterior dislocation.
2. Knee joint fracture and dislocation
Usually in the process of dislocation formation, due to the impact of the femoral condyle on the humerus, it can lead to fracture of the humerus and fracture displacement as the external force continues; of course, the muscle contraction at the attachment also plays an important role in clinical Upper avulsion of the bone at the attachment point of the ligament can also be regarded as joint dislocation with a fracture.
3. Knee subluxation
Subluxation of the knee joint is usually caused by the fracture of the corresponding ligament structure of the knee joint, and the tibia is moved forward, backward or rotated. Some authors do not advocate subluxation as a classification of knee dislocation. It is recommended to treat it as a kind of knee instability. .
After knee injury, the pain is severe, the calf may shift forward or backward, the inner and outer sides are distorted, the normal connection is lost, the local tenderness is obvious, the skin has a fluent emptiness, and there are large pieces of congestion, front and rear drawer tests. , internal and external stress test, over-extension stress test are positive, should pay attention to the presence or absence of vascular injury or nerve damage, carefully examine the foot, posterior tibial artery pulsation and distal limb sensation.
Examine
Knee dislocation examination
The diagnosis of dislocation of the joint is not difficult. Generally, the diagnosis can be made according to its medical history and clinical manifestations, as well as simple physical examination. However, the clinical application of the auxiliary examination can more clearly understand the dislocation, including whether the surrounding bone is damaged. .
Imaging examination: standard positive, lateral X-ray film, is helpful for diagnosis and differential diagnosis. If you need to further clarify ligament injury, you can use MRI, CT scan to help determine the fracture.
Diagnosis
Diagnosis and differentiation of knee dislocation
History of trauma
There is a typical history of trauma, and should be asked in detail in order to determine and estimate the injury and the damage of the ligament.
2. Clinical manifestations
Mainly for swelling and pain of the knee joint, if deformed by dislocation, it is easier to diagnose. It should be noted whether neurovascular injury is combined. The internal and external compression test of the knee joint and the front and rear drawer test can help to confirm the diagnosis. Classification and treatment options, etc.
