Few people know where the odontoid process is.
Most vertebrae have seven processes: spinous, four articular and two transverse. But in the cervical spine there is a vertebra with a special structure. He has one process more than all the others. This is the second cervical vertebra. Its eighth process points upwards.
Anatomical location
The odontoid is articulated with the first cervical vertebra, called the "atlas" because it holds the base of the skull. Between these vertebrae there is a movable articulation. Its medical name is atlanto-axial. Figuratively speaking, the ring of the first cervical vertebra is put on the odontoid process of its lower neighbor. That is why the human neck is so mobile. Almost 70 percent of the volume of all head turns occurs in this joint. And the odontoid process is the point of rotation of our neck.
What causes the occurrence?
The emergence of the odontoid process is due to evolutionary reasons, becausea person (as well as a number of other vertebrates) needed a quick and complete overview of the space around him to survive. However, the atlanto-axial articulation is very vulnerable. Where there is a high degree of mobility, there is also a risk of pathological displacements, fractures, and hypermobility. This joint is surrounded by a strong ligamentous apparatus, which ensures the strengthening of the odontoid process of the vertebra during physiologically normal movements. But prolonged or sudden pressure, exceeding normal, can lead to a violation of its integrity.
What causes problems with the second cervical vertebra?
In case of fractures of the second cervical vertebra, if the process has not been displaced, the symptoms of this pathology are not obvious, and sometimes they are completely absent. Approximately half of these fractures go unnoticed in the acute period, and almost a third are diagnosed only after two to three months, and sometimes years pass before this fracture is established in the patient. Doctors say that even an X-ray of the upper cervical spine is very problematic, since images of other bone structures are superimposed on the first and second vertebrae.
However, this is a very significant injury, in which the odontoid process and the atlas are often displaced along with the skull towards the spinal canal. And this leads to increasing problems with motor activity, to the formation of a patient's craniospinal syndrome, sometimes with a fatal outcome.
With asymmetry of the odontoid process C2very often patients have headaches that can last for a long time.
Statistics
About 20 percent of odontoid fractures are complicated by damage to the integrity of the spinal cord, and about seven percent lead to the worst outcome - death of the patient. At the same time, about 8-15 percent of all cervical fractures are of this type. Risk groups are children under eight and older people over seventy.
Injuries to the odontoid process are so serious in their consequences that doctors consider all patients with suspected ones as those who already have a fracture. That is, they are immobilized in the cervical region and taken in a neutral position to the vertebrological ambulance center (or other medical institution where there is a neurosurgical or trauma department).
Types of fractures
Thanks to computed tomography, today doctors have the opportunity to accurately determine which of the following types of fracture of the odontoid process of the vertebra can be attributed to:
- First type - in this case, an oblique fracture of the apex of the dental process occurs at the point of attachment of the pterygoid ligament to it. It is considered very rare.
- Second type - when it break line crosses the narrowest part of the "tooth", ie, the junction of the dental process and the vertebra. In this case, the stability of the articulation of the axis and atlas is lost. And comminuted fractures of this type significantly complicate the treatment process.
- Third type. Here is the break lineruns along the vertebra itself, starting from the base of the dental process. The stability of the articulation is also broken here.
Clinical picture of fractures of the second cervical vertebra
With these fractures, the clinical picture is very wide: from slight pain when turning the head and up to instant death. If a fracture has occurred with no or slight displacement, the patient may experience some pain in the upper neck, which increases slightly when the head is turned. This also happens with the asymmetry of the odontoid process.
There may also be pain that disappears quickly when swallowing, neck mobility may be somewhat limited. Pain can also occur with a wide opening of the jaws. In addition, all these sensations can quickly pass, and the patient begins to behave as usual. But doctors warn that the apparent well-being with this fracture is life-threatening. Enough of a careless step, a sudden push, etc. - and there will be a secondary displacement of the broken dental process, displacement of the upper cervical vertebra and compression of the spinal cord. And then the symptoms will be acutely pronounced, up to loss of consciousness.
If there was a significant displacement of the dental process of the second type, then symptoms of a compressed spinal or medulla oblongata, transmitted vertebral arteries are possible. This may be tetraparesis, weakness or numbness of the limbs, a disorder of sensitivity, dysfunction of the pelvic or respiratory organs. They canjoin symptoms such as impaired speech, swallowing disorders, difficulty opening the mouth and taste disturbances. Severe symptoms of spinal cord injury include difficulty breathing or development of cruciate palsy.
What is typical?
For such fractures of the odontoid process (photo below), the so-called late spinal disorders are characteristic, which develop as a result of compression of the spinal cord by the back of the upper cervical vertebra with continued displacement of the odontoid process as a result of its secondary shifts.
With a fracture of the odontoid process without its displacement, the delayed clinical picture (when a timely diagnosis was not followed due to the fact that the patient did not consult a doctor) may consist in aching pains in the back of the head or upper neck. These pains develop with movement and subside at rest. Difficulty moving the neck, dizziness, facial numbness. The patient turns his whole body to look around.
But subluxation of the odontoid process can also manifest itself in this way.
Fracture diagnosis
Diagnosis of all injuries localized in the upper cervical region is carried out according to a strict scheme. If it is not possible to conduct an immediate computed tomography of the cervical spine, the patient is directed to a radiograph of this area in a lateral projection through an open mouth. Also, this study can be carried out in a flexion position orneck extension. Since neck movements in case of a suspected such a fracture are potentially dangerous for the patient, these studies should be carried out under the supervision of a physician and not exceed the limits in which the patient has the ability to bend or straighten the neck.
It is important to conduct an x-ray in a flexed and extended position, especially for chronic fractures, since with a straight neck position, the ratio of the vertebrae in the images is likely to be normal.
If, despite these manipulations, the diagnosis is difficult, doctors resort to frontal and sagittal sonography or axial computed tomography. These are special studies that help improve the accuracy of images needed to diagnose areas of the spine.
Fracture treatment
In the acute period, decentration of the odontoid process in the upper part of the cervical spine often includes immobilization, i.e. immobilization of the patient's neck. The picture of treatment depends on the type of injury. In general, it must be remembered that manipulations that involve tilting the patient's head forward are very dangerous here, as this can lead to spinal cord injury. In general, treatment involves eliminating the displacement of the vertebrae and stabilizing the joint.
Thus, in case of an injury resulting from diving upside down or falling on the head of a heavy object, a plaster bandage is applied, which the patient wears for about six months. The fusion is slow. Also, the patient is prescribed therapy with the device"Halo" for three to four months.
Also for fractures of the odontoid process without displacement, traction on the Glisson loop is used for one or one and a half months, after which a thoracocranial plaster corset is applied, which must be worn from 4 to 6 months.
In traumatic spondylolisthesis of the second cervical vertebra, called a hangman's fracture, skeletal traction is used in an extension position (i.e., traction of the spine) for three weeks, after which the patient is given a thoracocranial plaster cast for three months. It also uses the Halo apparatus for up to four months.
Prevention of neck injuries
To avoid fractures of the upper cervical vertebrae, general recommendations will help, which are generally suitable for preventing neck injuries. First of all, it is the fulfillment of safety requirements and regulations. Also, while relaxing in nature, in no case should you dive headfirst into water bodies, as well as swim while intoxicated.
Often, fractures of the two upper vertebrae occur during an accident, so prevention in this case will be strict observance of the rules of the road, checking the car for technical serviceability, the presence of airbags, etc.
First aid for suspected fracture of the second cervical vertebra
Unfortunately, this type of injury always happens suddenly. As we have already mentioned, such a fracture may go unnoticed, or it may immediately manifest itself in the most serious form. It can be an accident, an accident while relaxing onnature, bruised his head in the fall of an elderly person. Often the victim needs first aid to be in a safe position and wait for the ambulance to arrive.
Types of accidents
In general, all accidents with neck injuries can be divided into injuries, trauma to the intervertebral discs, fractures, dislocations, dislocations, sprains and bruises. But the main point is that all neck injuries are extremely dangerous, therefore, before the doctor arrives, neck movements should not be allowed, since if there are fractures of the vertebrae, the spinal cord can be injured.
Of course, others cannot establish the nature of the victim's injury. Therefore, it is necessary to act according to the strict rules of first aid for these cases. It is urgent to call an ambulance - the patient must be urgently taken to the hospital for diagnosis and treatment.
For any injury to the cervical spine, the first step is to ensure peace by immobilizing the cervical spine. If there is no danger to the victim and he is in a horizontal position, then it is better not to move him and even stop his attempts to get up. If there are open wounds of the cervical region, they should be washed and an aseptic bandage applied, if possible (for example, a first-aid kit in the car).
What else is considered first aid?
Also, first aid for injuries of the odontoid process includes urgent prophylaxis of tetanus and the introduction of drugs that reduce the symptoms of shockthe victim. After the arrival of the ambulance, the medical team examines and transports the patient in a prone position on a flat shield. A special splint will be placed on the cervical region or the ambulance staff will splint from the crown of the head to each of the patient's shoulders. Any movements of the body of the victim in this case are made as carefully as possible in order to prevent possible injury to the spinal cord. Such a patient will be hospitalized and examined as soon as possible.
