Cervical spine hyperextension injury

Introduction to cervical hyperextension injury Cervical hyperextension injury is a cervical spinal cord injury caused by excessive stretching of the cervical vertebrae. Usually there is a slight or hidden bone injury, and there are no abnormal signs on the X-ray. Cervical hyperextension injury can also be called "whiplash injury". In recent years, due to the emergence of highways and the continuous increase of speed, such injuries are increasing day by day. Those with insufficient clinical experience are likely to miss the diagnosis and misdiagnosis. Most of the injured people have residual sequelae, especially the influence of the function of the opponent. The main pathological anatomical changes of cervical hyperextension injury are located in the central canal of the spinal cord, hence the name "central spinal cord syndrome". basic knowledge The proportion of illness: 0.005% Susceptible people: no specific population Mode of infection: non-infectious Complications: spinal cord injury

Causes of cervical hyperextension injury

(1) Causes of the disease

When the vehicle at high speed brakes urgently, the forehead and the face hit the front to block and cause injury.

(two) pathogenesis

Most of the occurrences are caused by sudden braking or crashing of a high-speed vehicle. At this time, due to the inertia, the driver's or passenger's face, jaw, forehead, etc. are subjected to impact from the front (mostly the windshield or the front seat). The backrest) makes the head and neck over-extension (Fig. 1); in an instant, the head and neck are bent forward (Fig. 2), so it is also easy to cause buckling damage. In addition, other violence from the front, the neck is from the neck. The same effect can be achieved if the height falls and the neck is lifted upwards, and the backward violence is pulled.

The above-mentioned violence depends on its focus. In addition to cervical dislocation, Hangman fracture, lower cervical pedicle fracture, odontoid fracture and atlantoaxial dislocation, the most serious consequence is damage to the spinal cord. .

When the cervical vertebra is in normal elevation, the spinal cord and dural sac in the spinal canal are folded (accordion type) compressed and shortened; but if the anterior longitudinal ligament is broken and the intervertebral space is separated, the spinal cord can be stretched. The dural sac has a certain restrictive effect. In this case, if the injured cervical spinal canal is narrow, it is easy to cause the spinal cord to be clamped to the sudden lordosis, the invaginated ligamentum flavum and the anterior bony wall. Among them, especially in the case of nucleus pulposus or spur formation in front of the spinal canal, this hemostatic pressure is finally concentrated in the central canal of the spinal cord, causing congestion, edema or hemorrhage around the site, such as the central canal. If the degree of damage around is light, most pathological processes may completely reverse the healing; however, if the spinal cord parenchymal damage is large and the injury is heavy, it is generally difficult to completely recover, and it is easy to residual sequelae.

In addition, this injury is also common in patients with rheumatoid spondylitis, ankylosing spondylitis, diffuse idiopathic bone hypertrophy (DISH) syndrome or Marie-Striimpell syndrome, mainly because such patients are sick Residual and limited range of cervical vertebrae movement, cervical spinal injury is easy to occur, especially after drinking, or due to poor eyesight or transient ischemic attack, when the patient's face is falling forward, it can cause cervical extension Injury is more common in the neck 6 and neck 7 level, so that the anterior longitudinal ligament, the annulus fibrosus and intervertebral disc are broken; the posterior longitudinal ligament also tears; occasionally the joint capsule of the facet joint is separated, and may also be accompanied by different degrees of nerve damage.

Such damage can have the following three outcomes:

1. No nerve damage: Due to the extension of the injury, the spinal cord is rarely squeezed, especially when the spinal canal is wide.

2. Impaired anterior spinal artery: Causes arterial thrombosis and limb paralysis.

3. Incomplete spinal cord injury: direct injury of the anterior pulp, or central spinal cord injury due to compression, the stiffer the spine, the more severe the damage and instability, most of which require surgery.

Cervical hyperextension injury prevention

The disease is a traumatic disease, pay attention to safety, drive carefully, keep the home environment bright, walk carefully, watch children and avoid trauma.

Complications of cervical hyperextension injury Complications spinal cord injury

Cervical spine overextension is often accompanied by spinal cord injury. Many authors believe that during hyperextension, the spinal cord may be crushed by the ligamentum flavum at the posterior portion of the spinal canal and the posterior edge of the anterior vertebral body, resulting in a central cervical spinal cord tube. Or the injury to the front of the spinal cord, the corresponding clinical manifestations are central syndrome of the spinal cord injury and anterior spinal cord syndrome.

Cervical hyperextension injury symptoms Common symptoms Neck pain Head and neck activity restricted feeling separation eye-head reflex disappears

1. Neck symptoms|: In addition to the pain in the back of the neck, due to the involvement of the anterior longitudinal ligament, it is often accompanied by pain in the front of the neck; neck activity is significantly limited, especially the stretching action (do not repeat the examination); neck There is obvious tenderness around the department.

2. Symptoms of spinal cord injury: pathological changes are located around the central canal. The closer the lesion is to the central canal, the more severe the lesion is. Therefore, the deep part of the pyramidal tract is the first to be affected. The clinical manifestation is that the upper extremity is more severe than the lower limb, and the hand dysfunction is heavier than the shoulder and elbow. Department, the patient feels functional involvement, clinical manifestations of temperature and pain disappeared, and position and deep feeling exist, this phenomenon is called sensory separation, severe cases may be associated with fecal incontinence and urinary retention.

Examination of cervical hyperextension injury

X-ray film

Early X-ray lateral radiographs have the greatest significance for clinical diagnosis. It is necessary to obtain a clear plain film. Typical cases are mainly shown on X-ray films:

(1) Widening of the anterior vertebral shadow: When the injury plane is high, the main manifestation is that the soft tissue shadow of the posterior pharynx is widened (normally within 4 mm), and when the lesion plane is below the cervical vertebrae 4 to 5, the shadow behind the larynx is obvious. Widening (normally no more than 13mm).

(2) widening of the intervertebral space: the height of the leading edge of the damaged intervertebral space is more than that of other vertebrae, and there may be small bone tears on the upper edge of the damaged vertebra (about 15% to 20%) .

(3) Other characteristics: Most cases show that the sagittal diameter of the spinal canal is smaller than the normal value, and about half of the cases may be accompanied by the formation of the posterior margin of the vertebral body.

2. MRI examination

The determination of the degree of disc herniation and spinal cord involvement is significant, and each case should be considered routine.

3. Other

CT examination has a certain effect on the determination of bone injury and nucleus pulposus detachment. It can be used as appropriate; and attention should be paid to the presence or absence of laminar or other fractures. Myelography should not be used in the acute phase.

Diagnosis and differentiation of cervical hyperextension injury

diagnosis

The diagnosis of cervical hyperextension injury is mainly based on the following three points:

1. The history of trauma is as described above. It is mostly from the direction of the face and jaw. If the patient can't remember the situation at the time of the accident, it can be judged according to whether there is epidermis and subcutaneous damage in the face and jaw of the patient.

2. The clinical manifestations are mainly quadriplegia with upper limbs heavier than lower limbs, sensory separation and neck symptoms.

3. X-ray film, MRI and CT examination can confirm the diagnosis.

Differential diagnosis

1. Spinal artery anterior central artery syndrome: Because both can occur in completely similar trauma situations (such as during sudden braking), sputum is also present, which is confusing.

2. Syringomyelia: pathological anatomical changes are similar, the symptoms are similar, so it is easy to be confused, but the disease generally has no history of trauma, and there is no broadening of the anterior shadow of the vertebral body on the X-ray film, and the spinal cord is displayed on the MRI There is a hollow in the center.

3. Acute disc herniation: sudden onset of acute disc herniation, seen after trauma, and with spinal cord symptoms, it needs to be identified, the nucleus pulposus is not necessarily serious when the nucleus is removed, even the general cough can cause; spinal cord involvement The pyramidal tract is the main one, and there is little sensation separation. MRI examination has the significance of diagnosis.

4. Others: In addition to the above diseases, attention should also be paid to the identification of cervical spinal canal stenosis, cervical spondylotic myelopathy and other injuries.

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