Habitual patellar dislocation
Introduction
Introduction to habitual patella dislocation The disease is more common in children, more women than men. Traumatic patellofemoral dislocation combined with femoral condyle fractures, mostly caused by improper treatment, most of the patients with knee joint local structural abnormalities, caused by minor trauma. Local structural dysplasia, knee soft tissue contracture; lateral patellofemoral attachment point; abnormal lateral femoral muscle; small and flat tibia development; femoral condyle shallow stenosis; knee valgus deformity. basic knowledge The proportion of illness: 0.001% Susceptible people: no specific population Mode of infection: non-infectious Complications: osteoarthritis
Cause
Causes of habitual patella dislocation
The etiology of habitual dislocation of the patella is complicated, and some may be related to trauma. It is associated with high humerus, dysplasia of the femoral condyle, knee valgus, dysplasia of the medial femoral muscle, hypertrophy of the lateral femoral muscle, relaxation of the soft tissue inside the knee joint, and contraction of the lateral soft tissue. Knee joint bone and surrounding soft tissue dysplasia is an innate factor in the occurrence of habitual patellofemoral dislocation, suggesting that habitual patella dislocation may be related to genetic factors.
Prevention
Habitual patella dislocation prevention
If there are some habitual dislocations caused by congenital causes, there is no effective preventive measure for this disease. Therefore, the prevention of this disease is mainly for the habitual dislocation caused by traumatic causes, and avoiding trauma is the key to prevention and treatment of this disease. It should also be noted that the orthopedics should be effective in correcting dislocation, and maintaining the normal patellofemoral joint structure as much as possible, keeping the patellofemoral joints in a normal relationship, leaving no knee pain and patellofemoral arthritis, and the function recovery is fast.
Complication
Habitual patella dislocation complications Complications osteoarthritis
There is no obvious trauma in the knee joint, or the quadriceps muscle contracted strongly, which can cause dislocation. Most patients often dislocated. When the knee flexes, the hip bone is off the lateral side of the femoral condyle. When the knee is stretched, it is naturally reset, and the quadriceps atrophy and extension. The knee is weak and easy to wrestle, but there is no obvious pain.
The disease is also prone to some postoperative complications, including dislocation, knee flexion, flexion limitation, osteoarthritis, etc. After surgery, if the patellofemoral joints are poor, it can cause patellofemoral arthritis and residual ankle pain. Oral correction should not only effectively correct dislocation, but also maintain the normal patellofemoral joint structure as much as possible, maintain the normal relationship of patellofemoral joints, leave knee pain and patellofemoral arthritis after operation, and restore function quickly.
Symptom
Habitual patella dislocation symptoms Common symptoms Knee joint pain, tibia pain, knee joint swelling, anterior emptiness, knee joint, can not fully extend, underarm pain, push and resist pain
The main symptom of this disease is that when the patient bends the knee, the humerus leaves the center of the femoral condyle and slides to the front of the femoral condyle, which is outside the knee joint, which affects the appearance of the knee and greatly weakens the knee joint strength. Normal function, for a long time, can induce osteoarthritis of the knee joint, obvious swelling of the wound, tenderness of the tibia, limited activity, feeling soft knees, difficulty walking, knee extension and hand push can be reset, arthroscopy and X Line examination showed dislocation of the humerus.
Examine
Examination of habitual patella dislocation
The examination method of this disease is mainly sacral X-ray examination and arthroscopy
(1) X-ray examination of the tibia
The tibia up dislocation can be seen on the anterior slice of the humerus. The tibia is displaced from the femoral condyle. The lateral humerus shows the length of the humerus and the length of the patellofemoral ligament. Under normal circumstances, the tibial nodule is the distance from the lower edge of the humerus. (ie the length of the patellar ligament) is consistent with the length of the tibia. If the distance is significantly larger than the length of the tibia, it indicates that the humerus is dislocated upward. The lateral dislocation of the humerus is difficult to detect by conventional X-ray examination. It is suitable for bending at a position of 20-30 degrees. The humeral axial slice can be found with or without the dislocation of the humerus. On the axial slice, the AA' line is used to connect the two parts of the femur. The second BB' line is the connecting line of the lateral articular surface of the humerus. The two jumpers intersect. The tibia femoral angle is formed. Under normal circumstances, the patellofemoral angle is open to the outside, and the humerus is dislocated outward. The two body lines are parallel or the patellofemoral angle is open to the inner side. This oblique expression indicates that there is a backward direction on the lateral side of the tibia. The force of pulling, the other manifestation is that the humerus has left the normal central position at the femoral notch and displaced to the outside, becoming a subluxation, and sometimes both cases exist simultaneously, which increases the dislocation of the patella. Complexity.
(2) Arthroscopy
Arthroscopy is mainly to evaluate the degree of articular cartilage surface damage. According to the degree of degeneration of the tibial cartilage surface, which surgery can be selected, it can be divided into four grades: grade 1, only the cartilage becomes soft, grade 2, and has a fiber diameter of less than 1.3cm. Chemotherapy, grade 3, fibrotic lesions larger than 1.3 cm in diameter, grade 4, subchondral cortical bone has been exposed.
Diagnosis
Diagnosis and differentiation of habitual dislocation of the humerus
The disease should be differentiated from the dislocation of the tibia caused by trauma. The disease has a history of recurrent episodes, and the latter has a history of trauma.
Some scholars believe that congenital dislocation of the patella and habitual dislocation of the tibia do not belong to the same disease, so the two should be identified, congenital dislocation of the tibia has the following characteristics:
1 There is a dislocation of the tibia at birth;
2 Dislocation is permanent, and the closing technique cannot be reset;
3 flexion and extension knee joint tibia fixed in the lateral femoral condyle;
4 knee flexion contracture and often accompanied by ankle deformity.
