Simple atlantoaxial dislocation

Introduction to simple atlantoaxial dislocation Simple atlantoaxial dislocation is a rotational subluxation and has been described by Coutts (1908, 1934) and Fielding (1977). The essence is that the lateral mass of the first cervical vertebra is displaced above the second cervical vertebra side block; from the dynamic observation, the first cervical vertebra is separated from the dentate of the second cervical vertebra by a rotational subluxation. Simple atlantoaxial dislocation is clinically free of obvious symptoms and is therefore easily overlooked and missed. basic knowledge The proportion of sickness: 0.01% Susceptible people: no specific people Mode of infection: non-infectious Complications:

Causes of simple atlantoaxial dislocation

(1) Causes of the disease

When the external force causes the transverse ligament of the atlas to break, it is easy to cause the atlas to slide forward and dislocation.

(two) pathogenesis

1. Trauma type: Any external force acting on the back of the head and neck may cause the anterior dislocation of the atlantoaxial sacral ligament due to the fracture of the transverse ligament of the atlas, including excessive force during heavy manipulation, in which the flexion type is more See, if the degree of displacement exceeds the effective gap of the spinal canal, it can cause high cervical spinal cord injury. In severe cases, it will die on the scene or in transit. In general, the cervical spinal cord injury caused by the fracture of the atlas caused by the transverse ligament rupture, Compared with odontoid fractures, the mortality rate is high.

2. Pathological: It is not uncommon, especially in children, mainly due to chronic inflammation of the posterior pharynx causing local muscle, ligament and joint capsule edema, relaxation and local bone decalcification caused by loosening of the transverse ligament, avulsion, and gradually caused The axillary dislocation is dislocated forward, because the process is slow, and the neurological symptoms are generally mild. However, if additional traumatic factors are involved, it is easy to cause accidents. In addition, about 20% of patients with rheumatoid arthritis invading the neck may appear. This kind of consequence, due to odontoid deformity, is also likely to cause dislocation of the atlantoaxial joint. Common malformations are seen. In the case of the same trauma, it is more likely to cause dislocation.

Simple atlantoaxial dislocation prevention

The disease is caused by trauma directly affecting the cervical vertebrae, such as kicking, falling, blunt instrument hitting the cervical vertebra directly. Therefore, pay attention to maintaining living habits. For high-risk workers, such as construction workers and mining workers, it is easy to cause damage. In the course of work, you should pay attention to protecting yourself. Pay attention to calmness and avoid emotional conflicts leading to the disease. Secondly, early detection, early diagnosis and early treatment are also important for indirect prevention of this disease.

Complications of simple atlantoaxial dislocation Complications

Can be completely concurrent.

Simple atlantoaxial dislocation symptoms Common symptoms Neck instability, difficulty swallowing, difficulty in opening mouth, limited head and neck activity

Depending on the degree of displacement and the mechanism of injury, the clinical symptoms are very different. The lighter ones have no abnormal complaints, and the severe ones can cause complete paralysis. The clinical features should be observed and identified.

1. High mortality rate: traumatic, such as strong violence, rapid effect, easy to die due to high cervical spinal cord injury on the scene or in transit, even if the incomplete spinal cord injury, it is easy to die of various complications, should pay attention to Early prevention.

2. Neck instability: that is, the patient feels that the head and neck are divided into two, such as the instability of the break, so that they do not dare to sit up or stand up (spontaneous is lighter), like to hold with both hands head.

3. Neck pain and muscle cramps: traumatic people are more severe, especially within a few days after the injury.

4. Restricted activities: Regardless of traumatic or pathological, there are generally varying degrees of head and neck activity, and severe cases are difficult to open.

5. Forced position: If the bilateral joints are dislocated, the head and neck are in a forward tilt position; if one side joint is dislocated, the head rotates to the healthy side and tilts to the affected side. This position aggravates the activity limitation. The degree, including the difficulty of opening the mouth.

6. Others: such as post-occipital tenderness, dysphagia and abnormal pronunciation with nasal sounds, when the spinal cord nerve is involved, the corresponding symptoms and signs appear.

Simple atlantoaxial dislocation

1. X-ray film: In addition to the positive side of the neck 1, 2, the open position should be taken (the film allows the patient to continue to open and close the jaw, so that you can get a clearer Open the position) to observe whether the anterior shadow of the cervical vertebral body is widened, and the degree and direction of joint dislocation, and measure it while reading the film, so as to facilitate diagnosis and future contrast observation. Under normal circumstances, the molar joint space For 2 ~ 3mm (children are similar), more than 4mm is suspected to be a transverse ligament rupture of the atlas, more than 7mm may be accompanied by pterygoid ligament, ligament and collateral ligament rupture, if necessary, can be added left and right 15 ° The oblique position of the opening piece was observed and compared.

2. CT and MRI examination: ordinary CT, CT three-dimensional reconstruction and sagittal MRI examination will help to diagnose the damage and determine the spinal cord involvement.

Diagnosis and diagnosis of simple atlantoaxial dislocation

Diagnostic criteria

1. History of trauma and history: As mentioned above, in addition to head and neck trauma, children should be aware of the history of chronic inflammation in the throat.

2. Clinical manifestations: as mentioned above.

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