Recurrent patellar dislocation

Introduction to recurrent patella dislocation During flexion and extension of the knee, the tibia moves up and down in the front of the lower femur. Due to the anatomical structure of the tibia, the quadriceps and joint capsules act to maintain stability during exercise. The center of the tibial articular surface is a longitudinal ridge-like protrusion that coincides with the corresponding articular surface at the lower end of the femur to prevent the humerus from sliding left and right. The quadriceps contraction is mainly caused by the quadriceps traction, which prevents the tibia from dislocating outward. The tension of the joint capsule also stabilizes the tibia during muscle contraction, but it can cause recurrence due to trauma and pathological factors of the knee joint congenital or acquired. Dislocation of the humerus. basic knowledge The proportion of illness: 0.008% Susceptible people: no special people Mode of infection: non-infectious Complications: osteoarthritis

Cause of recurrent patella dislocation

(1) Causes of the disease

After the acute dislocation of the humerus, the medial support of the tibia was lax and weak; the lateral support of the humerus was contracted; the knee valgus deformity and knee flexion deformity.

(two) pathogenesis

Recurrent dislocation of the tibia is often caused by one or several factors after acute dislocation, including: sagging or weakness of the medial support of the humerus; contracture of the lateral humerus; knee valgus deformity; knee flexion deformity; femoral neck anteversion Increase or internal rotation of the femur; external rotation of the humerus; external insertion of the iliac crest in the humerus; and pterygium or high-riding patella, additional factors including atrophy of the medial femoral muscle, and total joint relaxation.

Recurrent patella dislocation prevention

In some habitual dislocations caused by congenital causes, there is no effective preventive measure for this disease. Therefore, the prevention of this disease is mainly aimed at dislocation caused by traumatic causes, and avoiding trauma is the key to prevention and treatment of this disease. In addition, it should 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.

Recurrent patellofemoral complications Complications osteoarthritis

Recurrent patellofemoral dislocation, advanced osteoarthritis.

Recurrent patellofemoral dislocation symptoms Common symptoms Tibial strain, post-surgical pain, swing, gait, knee joint swelling, blood

1. Knee Symptoms Clinically, patients often have symptoms of knee instability, and occasionally knee joints can appear swaying gait.

2. Physical examination positive clinical examination can have the following phenomena: posterior medial pain, frictional sound of the tibia and swelling of the knee joint.

3. Inducing dislocation during exercise It is easy to find that the humerus has a subluxation phenomenon during exercise, and it can touch the feeling of effusion and friction in the knee joint, and the symptoms of other injuries in the knee joint can also be found.

4. Measurement of quadriceps angle (Q angle) is important for the evaluation of recurrent patellofemoral dislocation.

In theory, it is the angle between the axis of the quadriceps and the center of the tibia to the midline of the iliac crest. This angle is clinically measured from the angle between the anterior superior iliac spine and the tibial tuberosity and the tibia- midline.

Examination of recurrent patella dislocation

The positive and lateral slices of the knee joint and the 30-degree axial radiograph of the tibia are beneficial for revealing the tendency of subluxation between the tibia and the femur.

Diagnosis and diagnosis of recurrent patella dislocation

Under normal circumstances, the male Q angle standard value is 8 ° ~ 10 °, female 15 ° ± 5 °, Insall et al believe that more than 20 ° is abnormal, the tibial tuberosity can shift the Q angle, so the use of shift The tibial tuberosity is used to adjust the size of the Q angle.

1. Patients with history of trauma have a history of trauma, after which the tibia can be dislocated several times due to general trauma.

2. Easy to reset the patella after dislocation is easy to repay, and can be found in the medial and lateral humerus often tenderness.

3. Q angle>20° On the X-ray film, the Q angle of the tibia is more than 20°.

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